DEVELOPMENT OF A SURGE PROTECTOR SUITABLE FOR EQUATORIAL BELT COUNTRIES N.A.A.N.Dilrukshi (149351J) Degree of Master of Science in Industrial Automation Department of Electrical Engineering University of Moratuwa Sri Lanka July 2017 DEVELOPMENT OF A SURGE PROTECTOR SUITABLE FOR EQUATORIAL BELT COUNTRIES Nissanka Arachchi Appuhamilage Nadeesha Dilrukshi (149351J) Dissertation submitted in partial fulfilment of the requirements for the Degree Master of Science in Industrial Automation Department of Electrical Engineering University of Moratuwa Sri Lanka July 2017 i DECLARATION OF THE CANDIDATE & SUPERVISOR I declare that this is my own work and this dissertation does not incorporate without acknowledgement any material previously submitted for a Degree or Diploma in any other University or institute of higher learning and to the best of my knowledge and belief it does not contain any material previously published or written by another person except where the acknowledgement is made in the text. Also, I hereby grant to University of Moratuwa the non-exclusive right to reproduce and distribute my dissertation, in whole or in part in print, electronic or other medium. I retain the right to use this content in whole or part in future works (such as articles or books). Signature: Date: The above candidate has carried out research for the Masters Dissertation under our supervision. Signature of the supervisor: ………………. Date : Prof. J.R. Lucas Signature of the supervisor: …………………. Date : Dr. D.P. Chandima ii DEDICATION I dedicate this thesis to Mr. Buddhika Ranatunga, my husband for his endless encouragement and patience and to Mr. Nissanka & Mrs.Ramyalatha, my parents for earning an honest living for us and for supporting and encouraging me, to believe in myself and for nursing me with affections and love and their dedicated partnership for success in my life. iii ACKNOWLEDGEMENTS Firstly, I would like to express my sincere gratitude to my advisors Prof. J.R. Lucas and Dr. D.P. Chandima for the continuous support of my MSc study and related research, for his patience, motivation, and immense knowledge. Their guidance helped me in all the time of research and writing of this thesis. Besides my advisors, I would like to thank Mrs. Janaki Athuraliya and Mr. Nihal Kularathne, for their insightful comments and encouragement, but also for the hard questions which encouraged me to widen my research from various perspectives. My sincere thanks also goes to my colleagues at the Electronic Division of Arthur C Clarke Institute for Modern Technologies who provided me an opportunity to join their team as Research Engineer, and who gave access to the laboratory and research facilities. Without their precious support it would not be possible to conduct this research. Lastly, I should thank many individuals, friends and colleagues who have not been mentioned here personally in making this educational process a success. I could not have made it without your support. iv ABSTRACT In most tropical countries like Sri Lanka, lightning activity is high and can cause severe damage to equipment within buildings. Thus lightning surges should be prevented from entering sensitive equipment by installing high quality surge protection devices. Traditionally, surge protection circuits use non-linear devices to clamp the overvoltage. However, typical non-linear devices have low relatively short duration energy absorption ratings and cause the life of the surge protection device to decrease. As it is known that supercapacitors have large continuous energy storage capabilities, a supercapacitor based surge energy absorption technique has been developed by combining a multi-winding magnetic component with a typical non-linear device in a novel configuration. This research presents an overview of new supercapacitor technique and the basis for selecting the magnetic core required so that the supercapacitor sub-circuit works effectively. Selection of the magnetic core is critical for the success of the technique, since the combination of the leakage and magnetizing components of the multi-winding magnetic core plays a dominant role. Experimental results generated using a lightning surge simulator with surge capability up to 6 kV/3 kA are used to validate the results. Overall performance of this technique with optimized magnetics is compared with a typical commercially available surge protector, which is practically used to safeguard electronic systems against transient over-voltage related power quality issues. This technique utilizes a multi-winding transformer, common surge protector devices such as metal oxide varistors combined with a supercapacitor sub-circuit to absorb part of the surge energy usually expected to dissipate within the metal oxide varistor and improve the life of the surge protective device. Also the output clamping voltage is controlled to a lower value to give better protection for the equipment. Test results clearly indicate, the supercapacitor assisted surge protective device has a much higher energy absorption capacity than tested commercial products and can be v used in commercial surge protectors with better performance than traditional surge protectors with higher component counts. Keywords: Lightning Protection, Supercapacitor, Metal Oxide Varistor, Non Linear Device vi TABLE OF CONTENTS DECLARATION OF THE CANDIDATE & SUPERVISOR ..................................... i DEDICATION ............................................................................................................. ii ACKNOWLEDGEMENTS ........................................................................................ iii ABSTRACT ................................................................................................................ iv TABLE OF CONTENTS ............................................................................................ vi LIST OF FIGURES .................................................................................................. viii LIST OF TABLES ....................................................................................................... x LIST OF ABBREVIATIONS ...................................................................................... x LIST OF APPENDICES .............................................................................................. x 1 INTRODUCTION ................................................................................................ 1 1.1 Background ................................................................................................... 1 1.2 Problem Statement ........................................................................................ 4 1.2.1 Typical Surge protector circuit .............................................................. 4 1.2.2 Associated Problems .............................................................................. 4 1.2.3 Problem statement .................................................................................. 5 1.3 Typical designs of SPDs ............................................................................... 6 1.4 Objectives ...................................................................................................... 7 2 LITERATURE REVIEW ..................................................................................... 8 3 METHODOLOGY ............................................................................................. 20 3.1 Background ................................................................................................. 20 3.2 Design Approach ......................................................................................... 20 3.3 Selection of components ............................................................................. 22 3.3.1 Characteristics of MOVs ...................................................................... 22 3.3.2 Voltage build up across MOVs ............................................................ 22 3.3.3 Voltage buildup across super capacitors .............................................. 24 4 SYSTEM DEVELOPMENT .............................................................................. 28 4.1 Design Overview ......................................................................................... 28 4.2 Complete Design Circuit & Its Operation ................................................... 28 4.3 Impact of The Supercapacitor Subcircuit and The Magnetic Component .. 30 5 RESULTS AND ANALYSIS ............................................................................ 32 vii 5.1 General Mathlab simulation results ............................................................. 32 5.2 Matlab simulation results for the complete circuit ...................................... 39 5.3 Energy Calculation ...................................................................................... 45 5.3.1 By using powdered core as a transformer ............................................ 45 5.3.2 By using ferrite core as a transformer .................................................. 48 5.4 Energy Comparison of Two Different Cores .............................................. 49 5.5 Prototype implementation of the prosed system ......................................... 50 5.5.1 Differential Mode ................................................................................. 50 5.5.2 Common Mode .................................................................................... 51 6 CONCLUSION .................................................................................................. 52 REFERENCES .......................................................................................................... 54 Appendix A ................................................................................................................ 55 Appendix B ................................................................................................................ 56 Appendix C ................................................................................................................ 69 Appendix D ................................................................................................................ 71 Appendix E ................................................................................................................ 72 Appendix F ................................................................................................................. 80 viii LIST OF FIGURES Page Figure 1.1 Propagation of lightning channel 1 Figure 1.2 Lightning distribution in the world 2 Figure 1.3 Percentage increase in storm surge zone, SAR Region 2 Figure 1.4 Typical Surge Protective Device 4 Figure 1.5 Typical designs of SPDs 6 Figure 2.1 Histograms of Annual Damage by lightning strike 9 Figure 2.2 TT wiring system 10 Figure 2.3 Two types of SPD connections in a TT wiring system 10 Figure 2.4 Concept of zonal protection 10 Figure 2.5 Two current test waveforms 11 Figure 2.6 Multiple MOV based SPD 14 Figure 2.7 Exploded multiple MOV based SPD module 15 Figure 2.8 SPD internal fire 15 Figure 2.9 Structural comparison of capacitors 16 Figure 2.10 Ferrite Core Characteristic 18 Figure 3.1 Flow chart of testing of the voltage protection level 21 Figure 3.2 MOV - Epcos – S20 characteristic for 6 kV 23 Figure 3.3 MOV - B722 PANASONIC characteristic for 6 kV 23 Figure 3.4 Terminal voltage development versus number of surges 24 Figure 3.5 Terminal voltage development versus number of surges 25 Figure 3.6 Terminal voltage development versus number of surges 26 Figure 3.7 Terminal voltage development versus number of surges 26 Figure 4.1 Circuit Diagram – Differential Mode 28 Figure 4.2 Differential and common mode surges 29 Figure 4.3 Mathematical relationship 29 Figure 4.4 Possible Sub Circuits 30 Figure 4.5 TT wiring system 31 Figure 4.6 Design Circuit – Common Mode 31 Figure 5.1 Capacitor charging curves 33 ix Figure 5.2 1.2/50us - Normalized open circuit voltage 34 Figure 5.3 1.2/50us – Fourier transform of open circuit voltage 34 Figure 5.4 8/20us - Normalized short circuit current 35 Figure 5.5 8/20us – Fourier transform of short circuit current 35 Figure 5.6 Impact on an RC circuit 36 Figure 5.7 MOV V-I observation curve 37 Figure 5.8 MOV Log scale V-I curve 37 Figure 5.9 Current and voltage variation of MOV 38 Figure 5.10 Power variation for different supercapacitors 38 Figure 5.11 Energy variation for different supercapacitors 39 Figure 5.12 Primary and secondary winding current variation 40 Figure 5.13 Primary voltage variation 40 Figure 5.14 Sub-circuit voltage variation 41 Figure 5.15 Secondary voltage variation 41 Figure 5.16 Open circuit voltage (No-load) 42 Figure 5.17 Sub-circuit voltage variation for different capacitors 42 Figure 5.18 Sub-circuit voltage variation for different resistors 43 Figure 5.19 Sub-circuit voltage variation for different combinations 43 Figure 5.20 Power distribution across NLD and sub circuit 44 Figure 5.21 Power-Total, across NLD and sub circuit with magnetic Core 44 Figure 5.22 Current, voltage & power waveforms across MOV 45 Figure 5.23 Total current, voltage & power waveforms across MOV 45 Figure 5.24 Power across MOV 46 Figure 5.25 Total power at the input 46 Figure 5.26 Power across MOV 47 Figure 5.27 Total power at the input 47 Figure 5.28 Total power at the input and across MOV 48 Figure 5.29 Total power at the input and across MOV 49 Figure 5.30 Proposed design of SPD (Differential Mode) 50 Figure 5.31 Proposed design of SPD (Common Mode) 51 x LIST OF TABLES Page Table 1.1 Comparison of TVS devices 5 Table 2.1 Impulse current waveforms 11 Table 2.2 The current handling capacity of SPDs 11 Table 3.1 Comparison of two types of MOVs 22 Table 3.2 Comparison of clamping voltage 22 Table 3.3 Voltage build up across 1F-2.5 V SC 24 Table 3.4 Voltage build up across 5F-2.7 V SC (Maxwell) 25 Table 3.5 Voltage build up across 5F-2.7 V SC(DCN) 25 Table 3.6 Voltage build up across 150F-2.7 V SC 26 Table 5.1 Energy levels of powdered/ferrite cores 49 Table 5.2 Output voltage at load end (Differential mode) 50 Table 5.3 Output voltage at load end (Common mode) 51 LIST OF ABBREVIATIONS Abbreviation Description BBD Bidirectional Break-Over Diode HV High Voltage MOV Metal Oxide Varistor NLD Nonlinear Device SC Supercapacitor LIST OF APPENDICES Appendix Description Page Appendix - A Cost of implemented units 55 Appendix - B Data sheet (MOVs) 56 Appendix - C Data sheet (Supercapacitors) 69 Appendix - D Data sheet (Powdered core) 71 Appendix - E Energy calculation data (Powdered core) 72 Appendix - F Energy calculation data (Ferrite core) 80 1 1 INTRODUCTION 1.1 Background Lightning is a huge discharge originating in cumulonimbus clouds. As is seen in figure 1, they can occur within a cloud, between clouds, down to earth or just expend their charge in air. Fortunately in the tropics, only about 10 % of the discharges terminate on the earth or earth bound object. However, even this 10% can cause a disaster, and these disasters have occurred in a cyclical pattern in the world. Figure 1.1: Propagation of lightning channel Lightning causes damage to buildings, electronic and other equipment as well as causing injury and even death to people and livestock. This may be compared to typical temperate climates where the thunder days may be low, around 25 or 30 per year. Since the majority of high technology specialized military, communications, navigational and switching equipment is designed and generally manufactured in these temperate countries, scant regard is often paid to the need to protect this equipment from the devastating effects of lightning strikes whether they be direct or indirect. For this reason lighting protection against both direct and indirect lighting strikes at critical communications and navigational aid sites in tropical regions of the world should perhaps be mandatory. 2 In most tropical countries, lighting and storm activity is high, compared to the more temperate regions of the world. For example in the equatorial belt, ten degrees north and south of the equator, thunder day statistics may vary from 150 to 200 days per year. Figure 1.2: Lightning distribution in the world Source : EDN Magazine, Aprl14, 2005 Figure 1.3: Percentage increase in storm surge zone, SAR Region Source : Sea-Level Rise and Storm Surges: A Comparative Analysis Of Impacts in Developing Countries When lightning strikes, a human being may be killed, badly injured or spared with some skin burns. When lightning strikes a building, it may explode, catch fire or left with few cracks on the walls. However, most often when a building is lightning struck, many of the electrical and electronic appliances housed in the building will be destroyed. Equipment may also be damaged by large current pulses that may come through service lines such as electricity and telephone. 3 In order to protect buildings against lightning, a structural protection system should be installed at the building. These do not protect domestic appliances which can usually be protected from lightning currents by unplugging them from service lines during thunderstorm periods. However, such an act is not realistic in most of the industrial and service sectors as even a short period of out-of-operation could cost the company a few million rupees. Therefore in such cases, lightning surges should be prevented from entering the building, or in particular sensitive equipment. This is done by installing surge protection devices (SPDs) to the power and communication lines. In the case of surge protection, both the quality of the product and the engineering of installation are equally important. It should be remembered that the provision of lighting protection both against direct strikes and indirect effects will only improve lighting immunity. It is unlikely that 100% protection can ever be achieved even by proper design at an early stage before equipment installation. It can both reduce later costs and substantially improve protection in the longer term. Most common surge protectors consist of non-linear devices in the market do not work well during monsoon lightning times in equatorial belt countries like Sri Lanka and many other parts of the world due to their failure of components, such as capacitors. The use of high value capacitors (supercapacitors) could probably overcome some of these problems as they reduce the spikes. A supercapacitor (SC) is a high-capacity electrochemical capacitor, with capacitance values much higher than other capacitors, but in lower voltage limits. It has the ability to absorb high-voltage (HV) transient surges with a short-duration occurrence. Early researchers [3] have shown that a supercapacitor is not destroyed by the repeated application of HV transients and the gradual voltage rise across terminals after each hit is in the order of millivolt This also indicates that the device still retains its capacitive behaviour and not adversely affected by the transient HV at the terminals. Therefore a supercapacitor can be used to absorb part of the surge energy in the SPD during a transient traveling through the incoming mains or the telecom/data circuits. 4 1.2 Problem Statement 1.2.1 Typical Surge protector circuit Figure 1.4 shows a typical surge protector circuit with nonlinear devices (NLDs) such as metal oxide varistors (MOVs) and bidirectional break-over diodes (BBDs), coupled with LC-type filter stages. Depending on the level of protection required, different sizes of NLDs are used in varied versions of this general configuration. (a) (b) Figure 1.4: Typical Surge Protective Device Figure 1.4 (a) is a circuit which is designed to protect against both common and differential mode transients. M1 to M3 are MOVs that will enter their firing or conduction mode when the transient exceeds the threshold voltage limit. Inductors L1 and L2 acts high impedances for the transient signal. Similarly, the capacitors Cnx and Cny act as low impedance paths to the transient signal. The overall effect of these circuitry is to minimize the transfer of the transient voltage toward the critical load side. Figure 1.4 (b) represents its PCB arrangement and the component arrangement of the typical surge protective device. 1.2.2 Associated Problems Power surges can cause failure, permanent degradation, or temporary malfunction of electronic devices and systems. The development of an effective surge protective device is of paramount importance to manufacturers and users of industrial electronic equipment. 5 When a HV surge such as a lightning gets induced on the wire pairs (differential form on the live-neutral pair, common mode on neutral-earth or live-earth pairs), if the peak voltage of the induced voltage exceeds the firing voltage of the corresponding MOV. It fires and starts conducting a high instantaneous current. A maximum voltage termed as clamping voltage develops across the terminals of the MOV and the MOV starts absorbing the surge energy based on the voltage current product over the period of the surge. Table 1 shows the comparison of common TVS (Transient Voltage Suppression) devices. Suppression Element Features Expected Life GDT (Gas Discharge Tube) Very high current handling capability Low capacitance High insulation resistance Slow response time Limited MOV (Metal Oxide Varistor) High current handling capability Broad current & voltage spectrum High clamping voltage Gradual degradation Degrades TVS diodes Low clamping voltage Extremely fast response Does not degrade Limited surge current rating Long limited Spark Gaps Slow to conduct Require high initiating voltage to form the arc Degrades Fuse Less reliability Suffer aging from mechanical shock Age over a period of a few years Table 1.1 : Comparison of TVS devices 1.2.3 Problem statement Overall, a surge protector that absorbs the energy of the HV transient is designed on the basis of transient energy absorption capability of the NLDs used. In general, these NLDs are characterized by their transient energy absorption rating given for a short duration such as few milliseconds, which is typically related to transients lasting less than about 100–200 microseconds. During this time, the NLD heats up 6 due to the absorbed transient energy, while maintaining the clamping voltage across the device. However, if repeated high-energy transients keep firing the NLD, device’s transient energy absorption rating (Joule rating) will be exceeded and device ends up in a failure. In most general cases of MOVs, every time a transient is absorbed by the device, it deteriorates gradually, and after a limited period of time, its surge absorption capability could be totally lost. 1.3 Typical designs of SPDs Some typical designs of SPDs are shown in figure 1.5. MOV+GDT Output clamping voltage = 690 V MOV + Spark Gaps Output clamping voltage = 890 V MOV + 15A Fuse Output clamping voltage = 950 V Figure 1.5: Typical designs of SPDs 7 In those typical designs, there is no other way to absorb part of the surge energy apart from the available non-linear devices such as MOV, GDT and spark gaps. Therefore, their life time is much more less than the proposed design of this research. In this thesis, a supercapacitor-based SPD includes NLDs is proposed for the class III type protection level which overcomes the identified problem. 1.4 Objectives The main objective of this research is to develop and implement a super-capacitor assisted surge absorber to improve the performance of a surge protective device by diverting the surge energy from the non-linear device in the SPD to improve its life time and to minimize the clamping voltage across the critical load to be protected. 8 2 LITERATURE REVIEW Surge voltages occurring in low-voltage ac power circuits have two origins; external surges, produced by power system switching operation or by lightning, and internal surges produced by switching of loads within the local system. Typical voltage levels of these surges are sufficient to cause the failure of sensitive electronic appliances or devices, and high surges can cause the failure of rugged electromechanical devices such as clocks, motors, and heaters. However, lightning and other external sourced power disturbances rank high on the list of uncontrollable events that have shut down facilities in recent years. Equipment damage cause by lightning strike was been a hot topic for a quite long ago especially in tropical region. Due to certain component sensitivity level was decreased, so that components easily failed. The research paper [1] based on “Satellite Communication Equipments Reliability And Lightning Surge Measurement Results”, provides that the system facing a wear out zone where the hazard rate is increasing by using satellite equipments reliability calculation. So the appropriate protection level for these equipments to survive during lightning strike would be a challenge. However in this tropical country the study on statistical data for lightning occurrence probability and standardization is fewer even though they experiences on high lightning coupling methods promoting more than activities of 200-240 thunderstorm days / year. Annual equipment’s damage statistical is recorded and illustrated in Fig 2.1 for the year 2003. This damages was been quantified as the damaging due to lightning strike. The damages counted on higher number for May and August. The damaging equipment can be correlated with the raining monsoon lightning activities which is the evening raining season would be a good reason for the damaging. 9 Figure 2.1: Histograms of Annual Damage by lightning strike for a year 2003 There are several SPDs available, utilizing different overvoltage-protection technologies and topologies. The commercially available SPDs significantly differ in terms of their surge handling capabilities and the level of protection they provide. Field experience has revealed serious safety issues related to the SPD operation, particularly during its end of life situation. The research paper [5] based on “A Tutorial On The Selection And Installation Of Surge Protection Devices In A TT Wiring System ”, provides an easy-to- understand guidance for the selection and installation of transient protection devices & several fringe issues with respect to surge protection. The information presented can be used as educational material that guides electrical engineers in addressing lightning protection issues of Low Voltage power systems. The low voltage power line SPDs are most often connected in shunt. In a TT wiring system shown in figure 2.2 which is the most practiced in the South Asian region, SPDs are recommended to be connected in one of the two arrangements as shown in Figure 2.3. Out of the two arrangements, the connection type two has a wider usage among many engineers in the region. 10 Figure 2.2: TT wiring system Figure 2.3 : Two types of SPD connections in a TT wiring system Due to several reasons, SPDs are needed to be connected to the LV system at several stages in a given building. This scenario of connecting SPDs in several stages is known as the “Zonal Concept” as shown in figure 2.4. Figure 2.3: The concept of zonal protection Figure 2.4: Concept of zonal protection The most exposed zone, closer to the power entry point (usually the main power panel) and power outreaching points is termed Zone-1. The Zone-2 is usually the sub panels to which only partial lightning currents or reduced voltage impulses reach and Zone-3 is the power socket level which experiences even lower lightning energy. The surge protective devices are usually referred by their impulse current handling capacity. The more logical way is to refer them by the zone at which they should be connected. The IEC 62305 (2006) Standards specify two current impulse waveforms (figure 2.5) for the testing of surge protective devices (Table 2.1). 11 Zone / Class Current waveform Zone-1 / Class I tested for 10 / 350 μs current impulse Zone-2 / Class II tested for the 8 / 20 μs current impulse Zone-3 / Class III Table 2.1: Impulse current waveforms (a) 10 / 350 μs impulse (b) 8 / 20 μs impulse Figure 2.5 : Two current test waveforms With over 10 years’ experience in the South Asian region in recommending SPDs for various types of buildings, they have developed the following table of specifications for the current handling capacity of SPDs which provides reasonably good outcome (Table 2.2). The specifications have been refined by taking into account the performance of SPDs over 200 installations in the region. Location High lightning density areas (Current in kA/Phase) Low lightning density areas (Current in kA/Phase) Main panel * (Zone-1) 40 (Low risk) 60 (High risk) 30 (Low risk) 40 (High risk) Sub-panels ** (Zone-1) 30 (Low risk) 40 (High risk) 15 (Low risk) 20 (High risk) power feeder level ** (Zone-3) 07 (Low risk) 15 (High risk) 03 (Low risk) 07 (High risk) Table 2.2: The current handling capacity of SPDs. Low Risk: domestic, offices, factories, non-essential service providers etc. High Risk: hospitals, power generation and distribution, communication, broadcasting and other essential service providers 12 High lightning density areas: Areas where isokeraunic (lightning activity in an area based upon the audible detection of thunder) level is greater than 80 thunder days/year Low lightning density areas: Areas where isokeraunic level is less than 80 thunder days/year * For 10 / 350 μs current impulse ** For 8 / 20 μs current impulse Another important factor that should be considered in selecting SPDs is the “Voltage Protection Level” or simply the “Protection Level”. This is the maximum let-through voltage that will appear across the line and neutral (differential mode voltage) and that between the neutral/line and the earth (common mode voltage). Any given electronic equipment has a certain impulse withstanding voltage beyond which the equipment will undergo permanent damage or temporary malfunctioning. This tolerable level should significantly be higher than the voltage protection level of the SPDs that one selects to protect the equipment. Therefore, SPDs with lower value of voltage protection level is better than that with a higher value. The manufacturer should specify the voltage protection level of an SPD at Zone-1 and Zone-2 (Class I and class II SPDs) by applying the maximum current waveform (8 μs / 20 μs) that it is rated for. The SPDs at Zone-3 (class III) should be tested by applying the so called combinational waveform which produces 8 / 20 μs short circuit current waveform and 1.2 / 50 μs open circuit voltage waveform from an impulse generator. The class III SPD should be subjected to such a waveform with peak values 3 kA and 6 kV respectively and the output should be less than 0.6 kV as per the IEC 62305-4 (2006). As in Figure 2.4, it is the output voltage of the Class III SPD (at Zone-3), that will appear across the equipment to be protected. Hence in a properly coordinated surge protection network, the voltage protection level of Class III SPD plays the most vital role in safeguarding the protected equipment. 13 Lightning impulses may have rise times that are in the order of sub-microseconds. Therefore the SPD should have appreciable speed in switching from high impedance to low impedance mode. The response time of a SPD depends basically on its constituent components. SPDs are primarily made by one or more of the following components • Spark gaps or gas discharge tubes (GDT) • Metal Oxide Varistors (MOV) • Zener Diodes or Silicon Avalanche Diodes (SAD) In addition some other linear and non-linear devices such as, capacitors, inductors and positive temperature coefficient resistors (PTCR) etc are also included in the circuits to improve the performance. The three basic components have their own advantages and drawbacks. The current handling capacity and the response time increase in the order of SAD, MOV and GDT. The increment of the former characteristic is an advantage while that of the latter is a disadvantage. Hence, in most of the products the components are combined to improve the overall performance. Thus, the end-product response time may be different from the response time of any of the individual components. Under no-impulse conditions, the SPD remains almost open circuited. However, if the operating voltage (e.g. 230 V rms) is increased to a higher value for few cycles (due to some fault) there is a chance that the SPD may switch into low impedance mode. The SPD goes through this transition at few kilovolts under impulse conditions but at much lower voltage at 50 Hz. If such transition takes place, a large current under nearly operating voltage will flow through the SPD which is not made to withstand such high energy. As a result the SPD may be totally damaged. The maximum of such operating voltage, only under which the SPD is safe, is termed the maximum continuous operating voltage (MCOV). As per the standards IEC 62305-4 (2006), the MCOV should be above 110% of the operating voltage. In most of the European countries an MCOV of 270 V is recommended for MOV based SPDs. However, in countries where the power quality is not very reliable (significantly fluctuating voltage) a value of 300 V or 320 V is more appropriate. It 14 can be shown that the larger the value of MCOV, the greater the let-through voltage of the SPD. Therefore, it is always advisable to select an SPD with the least MCOV that can withstand a power quality of a given region. The research paper [2] based on, “Electrical Surge-Protection Devices for Industrial Facilities”, provides an overview of the critical issue of overvoltage protection for industrial electronic applications and the commercially available surge-protection technologies designed for industrial applications. It is a common practice in the surge protection industry to install protection devices in parallel to achieve a higher rating than just one device. A typical example of a parallel MOV technology is shown in figure 2.6. It is also commonly assumed that the surge performance of a number of devices is a simple multiplication of the performance of an individual device. Figure 2.6 : Multiple MOV based SPD Differences in mechanical design can lead to one individual MOV always having to handle more current than its neighbours. As a Lorentz forces rule, an electrical transient takes the shortest most conductive path, and when it goes around the corners, it exerts forces on the current carrying conductors. The net result is that for large transient currents ad SPDs often explode as a result of these forces as shown in figure 2.7 . 15 Figure 2.7 : Exploded multiple MOV based SPD module Also, the thermal fuses used in SPDs are known to have reliability issues and age over a period of few years usually accentuated by thermal cycling. Conventional and thermal fuses also suffer aging from mechanical shock which can be delivered during operation of the SPD by the transients. Fuses are progressively weakened by transient currents. Obviously, when a fuse opens, the protector is rendered totally ineffective, leaving the equipment unprotected to subsequent surges. Figure 2.8 shows the internal fire due to its failure in fuses. Figure 2.8 : SPD internal fire The research paper [3] based on, “Surge Capability Testing of Supercapacitor Families Using a Lightning Surge Simulator” provides some valuable insight in estimating the capabilities of supercapacitor families to withstand surges and transients. 16 The supercapacitor, also known as ultracapacitor or double-layer capacitor, differs from a regular capacitor in that it has very high capacitance,but lower voltage limits (Ex; 1F 2.5V). A capacitor stores energy by means of a static charge as opposed to an electrochemical reaction. Applying a voltage differential on the positive and negative plates charges the capacitor. Supercapacitors typically store 10 to 100 times more energy per unit volume or mass than electrolytic capacitors. They can accept and deliver charge much faster than batteries, and tolerate many more charge and discharge cycles than rechargeable batteries. Figure 2.9 : Structural comparison of capacitors All the tests conducted by the authors are using a Lighting Surge Simulator (LSS) with voltage variation capability of 6.6 kV, and with a maximum short circuit current capability of 3.3kA. In a simple preliminary test conducted by the authors where several supercapacitors were subjected to a single-shot high voltage surge as well as multiple surges of identical shape from a lightning surge simulator. The waveforms used were as prescribed in standards such as IEEE C62-41 and IEC 61400-4-5.The terminal voltage develop across the supercapacitors are in order of millivolts and do not develop adequate DC terminal voltage even after 20 pulses that would exceed the rated DC voltage. The results demonstrate the fact that a limited number of high voltage transients, up to100 microsecond duration, do not destroy most commercial supercapacitor 17 families. This useful observation, confirms that a limited number of repeated high voltage surges can be safely tolerated by the current commercial supercapacitors and, it leads us to consider more statistical type tests to develop more detailed surge endurance test data for these devices. These information provides that the supercapacitor topology could be used as a base technique to develop full-scale common and differential mode surge protective devices with better performance than traditional surge protectors available in the market. The research paper [6] based on, "An Electrical Circuit Model for Magnetic Cores. " Unitrode Seminar Manual SEMIOOO, 1995, provides the magnetic basics and the process of magnetization in ferromagnetic materials. The fundamental purpose of any magnetic core is to provide an easy path for flux in order to facilitate flux linkage, or coupling, between two or more magnetic elements. In an inductor, the core provides the flux linkage path between the circuit winding and a non-magnetic gap, physically in series with the core. Virtually all of the energy is stored in the gap. High permeability ferrites, or magnetic metal alloys such as Permalloy are incapable of storing significant energy. These cores approach the ideal magnetic material characteristic – square loop with extremely high permeability (60,000), high saturation flux density (0.9 Tesla = 9000 Gauss) and insignificant energy storage. Unfortunately, resistivity of these metal alloys is quite low. To minimize losses due to induced eddy currents, these cores are built up with very thin tape wound laminations. Tape-wound cores are used primarily at 50, 60, and 400 Hz line frequencies. They are generally unsuitable for transformer applications in Switch Mode Power Supplies. Tape-wound cores using the newer, lower loss amorphous metal alloys are used in SMPS applications up to l00 -200kHz, especially as magnetic amplifiers. Ferrites are the most popular core materials used in SMPS applications. Ferrites are ceramic materials made by sintering a mixture of iron oxide with oxides or 18 carbonates of either manganese and zinc or nickel and zinc. MnZn ferrites are used in applications up to l or 2 MHz and include the power ferrite materials used in switching power supplies. The permeability of power ferrite materials is in the range of 1500 to 3000 (relative). As shown in the low frequency characteristic of Fig. 2.10, a ferrite core will store a small amount of energy, as shown by the areas between the hysteresis loop and the vertical axis. This undesired magnetizing energy must be subsequently dealt with in a snubber or clamp. Sometimes it can be put to good use in Zero Voltage Transition circuitry. The permeability is high enough to keep the magnetizing current at a generally acceptable level in transformer applications. Figure 2.10 : Ferrite Core Characteristic Composite powdered-metal cores, such as powdered iron, Kool Mµ, and Permalloy powder cores do store considerable energy, and are therefore used in inductor and flyback transformer applications. However, energy is not stored in the very high permeability magnetic metal portions of the composite, but in the non-magnetic regions between the magnetic particles in the binder that holds the cores together. 19 Essentially, these composite cores store their energy in a non-magnetic gap that is distributed throughout the entire core. These cores are manufactured and categorized by their effective permeability. Different effective permeabilities in the range of 15 to 200 (relative) are achieved by varying particle size and the amount of magnetically inert material in the composite mix. Composite powdered metal cores are not normally used in true transformer applications because their relatively low permeability results in high magnetizing current and energy storage undesired in a transformer. The much greater saturation flux density BSAT of the powdered metal cores compared to ferrite (0.8T vs. 0.3T) would permit a much smaller inductor as a gapped ferrite for the same application. But at 100 kHz and above, this promise is seldom fulfilled because of the restrictions imposed by losses and rounding. 20 3 METHODOLOGY 3.1 Background Researchers have shown [3] that supercapacitors could have continuous energy storage capabilities in the range of energy carried in a transient surge into an electrical circuit. They are comparable with the transient energy absorption capabilities of non linear devices used in typical surge protectors such as metal oxide varistors (MOVs) and bidirectional break-over diodes (BBDs) , coupled with LC- type filter stages. However, at present commercially available supercapacitors have very low DC voltage ratings, such as less than 4 V for single-cell devices. (Ex: 2.5V 1 F, 2.7V 5F). This voltage is far below the instantaneous voltages occurring on the AC mains. Given this problem, a surge protector cannot just substitute a supercapacitor for a MOV or any other non linear devices. Thus the necessity of testing is very important with the instantaneous voltage developed across the supercapacitor sub circuit for the entire design. 3.2 Design Approach Tests were carried out as per the IEC 61643-11 with the 1.2/50 voltage - 8/20 current combination wave generator (EM TEST/UCS 500-M) which has a maximum transient voltage up to 6 kV and the maximum current up to 3 kA. Testing flow chart of the voltage protection level of the class III type SPDs is shown in figure 3.1. 21 Figure 3.1 : Flow chart of testing of the voltage protection level Source : IEC 61643-11 – Low voltage surge protective devices 22 3.3 Selection of components 3.3.1 Characteristics of MOVs Two types of MOVs which has following characteristics were tested using the lighting surge simulator (UCS 500-M). As per the IEC 61643-11, class III type SPDs have the output clamping voltage of 600V. Therefore two MOVs which has the voltage rating of 230 V and the clamping voltage about 595 V, were selected for this design. Details description of these two components are shown in Appendix B. Parameter Type of MOV Epcos – S20 B722 PANASONIC Voltage Rating V AC 230 V 230 V Voltage Rating V DC 300V 300V Clamping Voltage Vc 595V 595V Peak Surge Current @ 8/20µs 8kA 10kA Operating Temperature Min -40°C -40°C Operating Temperature Max 85°C 85°C Peak Energy (10/1000uS) 130J 255J Table 3.1 : Comparison of two types of MOVs 3.3.2 Voltage build up across MOVs By applying 1 kV to 6 kV surges from the lighting surge simulator, different clamping output voltages could be observed. Applied Surge Voltage (V) Output Clamping Voltage (V) Epcos – S20 B722 PANASONIC 1000 510 570 4000 630 710 6000 690 760 Table 3.2 : Comparison of clamping voltage 23 Figure 3.2 : MOV - Epcos – S20 characteristic for 6 kV Figure 3.3 : MOV - B722 PANASONIC characteristic for 6 kV Therefore, Epcos – S20 MOV which has the clamping voltage nearly 600 V, was selected for this design topology. 24 3.3.3 Voltage buildup across super capacitors Four types of supercapacitors were tested by applying different levels of transient voltages. Terminal voltage developed across supecapacitor after several strikes were measured using a multimeter. The test data set provides some valuable insight in estimating the capabilities of these new supercapacitors to withstand surges and transients, which in turn could lead to non-traditional applications. Details description of these supercapacitors are shown in Appendix C. (a) 1F – 2.5V SC (B Series)– Initial voltage 0.20mV No. of strikes mV (for 1.5 kV) mV (for 4.5 kV) mV (for 6.0 kV) 5 22.5 58.3 76.43 10 43.7 78.2 145.3 15 64.1 90.6 209.3 20 83.5 110.2 269.2 Table 3.3: Voltage build up across 1F-2.5 V SC Figure 3.4 : Terminal voltage development versus number of surges 25 (b) 5F - 2.7V SC (Maxwell)– SC – Initial voltage 0.26 mV No. of strikes mV (for 1.5 kV) mV (for 4.5 kV) mV (for 6.0 kV) 5 3.7 10 22.8 10 4.1 15 44.9 15 4.3 20 66 20 4.5 24 88 Table 3.4 : Voltage build up across 5F-2.7 V SC Figure 3.5 : Terminal voltage development versus number of surges (c) 5F – 2.7 V (DCN) – Initial voltage 16.6 mV Table 3.5 : Voltage build up across 5F-2.7 V SC No. of strikes mV (for 1.5 kV) mV (for 4.5 kV) mV (for 6.0 kV) 5 16.6 35.9 121 10 21.2 53.68 154 15 25.1 71.82 185 20 29.1 89.6 215 26 Figure 3.6 : Terminal voltage development versus number of surges (d) 150F - 2.7V SC (Maxwell) – Initial voltage 17 mV No. of strikes mV (for 1.5 kV) mV (for 4.5 kV) mV (for 6.0 kV) 5 42 56 72 10 45 60 77 15 48 64 80 20 50 67 83 Table 3.6 : Voltage build up across 150F-2.7 V SC Figure 3.7 : Terminal voltage development versus number of surges 27 These results indicated that the supercapacitor is not destroyed by the repeated application of HV transients and the gradual voltage rise after each hit is in the order of millivolt. Also they still retain its capacitive behaviour and not adversely affected by the transient HV at the terminals. Therefore , 1F-2.5 V supercapacitor which has the highest voltage rise with 1 ohm resistor was selected as a supercapacitor sub circuit for this design. 28 4 SYSTEM DEVELOPMENT 4.1 Design Overview The implemented supercapacitor assisted surge absorber device was developed by using 2.5V/1F SC, 1Ω resistor, transformer and a non-linear device(MOV). SC’s continuous surge energy absorption capability given by 1⁄2 CV^2 could be effectively used with several other components such as MOVs, LC filters and a multi-winding magnetic components. This magnetic part works as a transformer when a surge travels through the power line and fires a nonlinear device such as a MOV or a semiconductor device such as bidirectional break-over device . 4.2 Complete Design Circuit & Its Operation Designed circuit of the surge protective device for the differential mode based on the supercapacitor concept is shown in Figure 4.1. Figure 4.1: Circuit Diagram – Differential Mode In this circuit, typical NLDs such as a MOV is combined with a magnetic component and an SC-based sub circuit. However, compared to a typical surge arrestor without supercapacitors, where NLDs are placed directly across the pairs of wires such as the neutral and the live (differential mode) or neutral or live and earth(common mode) as shown in figure 4.2 2.5 V/1F 1 Ω /1W MOV 29 Figure 4.2: Differential and common mode surges The NLD is placed in between the load side end of a primary coil of a transformer and the return wire as in Figure 4.1. Given this configuration, when a surge occurs at the AC input, and when the instantaneous voltage due to surge exceeds the firing voltage of the NLD, high instantaneous current flows through the primary coil, developing a voltage across the primary turns. This in turn develops an induced voltage across the secondary coil, and by winding the secondary coil in the opposite direction, secondary induced voltage can be generated to oppose the surge voltage. Result is to create a voltage across the critical load to be protected, which could be less than the instantaneous surge voltage. By adjusting the turns ratio, we can adjust secondary voltage in such a way that the instantaneous voltage across the supercapacitor-based sub circuit can be varied. Mathematical relationship for this design can be shown as follows. Figure 4.3: Mathematical relationship Vsurge = Vp + VNLD Vp = Lp dip/dt + M dis/dt Vs = Ls dis/dt + M dip/dt Isub = (Vs -Vp)/Zsub Vload = VNLD – isub*Zsub Vload = Vsurge - Vs Load Active Neutral Ground Differential mode Common mode 30 Once a superimposed HV transient travels along the mains input, NLD fires and enters into conduction stage, developing a transient voltage across the connected winding (Vp). When the HV transient exceeds the firing voltage of the NLD, it conducts heavily creating a surge current through the primary coil. Due to induction, secondary coil also develops a voltage (Vs) and the two windings are configured to create this induced secondary voltage higher than that of the primary winding and to oppose the transient so that the critical load end sees the difference between these two voltages. 4.3 Impact of The Supercapacitor Subcircuit and The Magnetic Component As indicated in Figure 4.4, a supercapacitor-based subcircuit configuration could have a few possible variations as shown in figure 4.4. Figure 4.4: Possible Sub Circuits SC-based sub circuit receives the voltage difference between the two coils to create a circulating current through the sub circuit, absorbing part of the surge energy into the supercapacitor. With the ability of the supercapacitor to absorb part of the surge energy, which will be dissipated in the closed loops formed, transient surge energy burden on the NLD is significantly reduced. In addition, supercapacitor sub circuit will perform a useful filter function to reduce the ringing waveform created by the surge. In the SCASA technique, overall performance is mainly governed by the capability of the magnetic component, where its leakage inductance combined with the transformer action assists creating a lower effective clamping voltage across the critical load. Depending on the permeability of the selected core material, overall performance varies, since the secondary winding voltage due to the superimposed 31 surge depends on the core’s saturation behavior. Therefore, powdered core transformer with primary to secondary turns ratio (np/ns) of 6:30 with relative permeability (µr) of 60 is used for this design. Detailed description of the powdered core is attached under Appendix D. The most practiced power distribution in the South Asian region is the TT wiring system as shown in figure 4.5. The low voltage power line SPDs are most often connected in shunt. Therefore it is essential to have SPDs which are designed for the common mode as well. Figure 4.5: TT wiring system Figure 4.6 shows the conceptual design for the common mode as well. Figure 4.6: Design Circuit – Common Mode 2.5 V/1F 2.5 V/1F 1 Ω /1W MOV MOV 1 Ω /1W 32 5 RESULTS AND ANALYSIS In general practical circuit developments for low voltage surge protector for equipment are based on designing the protective circuit as an add-on block to the input wiring of the equipment. This block is used to attenuate the incoming transient using passive series impedances or bypassing the surge currents and absorbing the transient energy which is done using non-linear devices such as GDTs, MOVs, TVS, spark gaps, fuses, etc. In the usual surge protector devices, the high transient energy can cause these non- linear devices to deteriorate and eventually fail. If this energy can be taken out from the non-linear devices their life time will be greatly enhanced. This chapter presents the results of the use of supercapacitor based together with non-linear devices to not only absorb the transient energy, but also to control the output clamping voltage to a lower value to give better protection for the equipment. In particular a math lab simulation has been carried out to determine the best sub- circuit combinations as describe in chapter 4 (4.3). The implementation of the supercapacitor concept in the final prototype was analysed with different input voltages to determine the clamping voltage at the load end. Since the protection circuit is for class III SPD, the equipment should be subjected to a 6 kV. Thus testing has been carried out at both 4 kV and 6 kV in the comparison. 5.1 General Math lab simulation results If we consider a supercapacitor as an ideal device, the device will have an energy storage capacity of 1/2CVc 2 , where C is the device capacitance and Vc is the rated DC voltage of the device. Now if this capacitor is used in a simple circuit where an ideal DC voltage source of value Vs and a resistor of value R are used, the overall RC circuit will have a time constant of Ʈ=RC. The capacitor voltage is given by the following equation. 33 Based on the general validity of above equation, if we can control the duration of occurrence of a HV source to a “short-enough” period, final voltage across the terminals of the capacitor will be kept within the limit of Vc. This discussion indicates us that a very large value capacitor, such as a supercapacitor in a circuit loop of finite series resistance, can be used to safely absorb energy from a HV (transient) source with a short-duration occurrence. The charging curve for the supercapacitor and the normal electrolytic capacitor is shown in figure 5.1. Figure 5.1 : Capacitor charging curves Open circuit surge voltage waveform which we have used (1.2/50us) can be mathematically represented as, 34 By suitable mathematical manipulations and approximations we can get the following relationship to approximate the normalized open circuit voltage waveform and the short circuit current as a function of time in microseconds. Figure 5.2 : 1.2/50us - Normalized open circuit voltage Figure 5.3 : 1.2/50us – Fourier transform of open circuit voltage 35 Figure 5.4 : 8/20us - Normalized short circuit current Figure 5.5 : 8/20us – Fourier transform of short circuit current 36 Figure 5.6 indicates the MATLAB generated waveform, which closely matches the shape of the normalized open circuit voltage waveform together with its impact on an RC circuit comprising of 220μF and 1F capacitors in series with a 1 Ω resistor. Figure 5.6 : Impact on an RC circuit Figure 5.6 clearly indicates that due to very large time constants in supercapacitors, such a high voltage waveform which has a total duration of about 200μs will not develop an adequate voltage across the capacitor. For example, if the peak of the surge waveform is 6 kV, a 220 μF capacitor in series with a 1Ω resistor could develop an approximate peak voltage of 600V, while a 1F capacitor will develop only an extremely minimal voltage. Non-linear equation for the metal oxide varistor is, The observation values for the voltage and current of the MOV is shown in figure 5.7. Normalized open circuit voltage of 1.2 μs/50 μs duration Impact of normalized open circuit waveform on a 220 μF supercapacitor in with a 1 Ω resistor Impact of the same waveform on a 1 F supercapacitor in series with a 1Ω resistor 37 Figure 5.7 : MOV V-I observation curve Figure 5.7 : MOV V-I observation curve By plotting ln(V) vs ln(I), we can calculate the coefficients of K and n. Figure 5.8 : MOV Log scale V-I curve K= 330.3 n = 0.105 38 Therefore the characteristics equation for the MOV is, Current and voltage variation of MOV is shown in figure 5.9. Figure 5.9 : V-I curve of MOV Power and Energy absorption capability of supercapacitors P0.1F > P1F > P5F Figure 5.10 : Power variation for different supercapacitors 39 E0.1F > E1F > E5F Figure 5.11 : Energy variation for different supercapacitors 5.2 MATLAB simulation results for the complete circuit By applying surge input of 6 kV, the primary and secondary current variation of the magnetic core is shown as in figure 5.12. 40 Ip(max) = 2523 A Is(max) = 87A Figure 5.12 : Primary and secondary winding current variation Vp = Vsurge - VNLD Vp(max) = 734 V Figure 5.13 : Primary voltage variation Primary voltage 41 Vsub = Isub*Zsub Vsub(max) = 87 V Figure 5.14 : Sub-circuit voltage variation Vs = Vp+Vsub Vs(max) = 821 Figure 5.15 : Secondary voltage variation 42 Voc = Vsurge-Vs Voc(max) = 667 V Figure 5.16 : Open circuit voltage (No-load) Sub-circuit voltage variation for different capacitors Figure 5.17 : Sub-circuit voltage variation for different capacitors When capacitor value increased, voltage across sub circuit was decreased. 43 Sub-circuit voltage variation for different resistors (R+1F sc) Figure 5.18 : Sub-circuit voltage variation for different resistors When resistor value increased, voltage across sub circuit was increased. Sub-circuit voltage variation for different combinations (R+C, C+L, R+C+L) Figure 5.19 : Sub-circuit voltage variation for different combinations Vsub (R+C) < Vsub (C+L) < Vsub (R+C+L) 44 Power distribution across NLD and sub circuit Figure 5.20 : Power distribution across NLD and sub circuit Total power , across NLD and sub circuit with magnetic core Figure 5.21 : Power distribution – Total, across NLD and sub circuit with magnetic Core 45 5.3 Energy Calculation 5.3.1 By using powdered core as a transformer By applying 4 kV and 6 kV, total energy at the input and the energy absorbed by the MOV is calculated using the CSV values from the oscilloscope trace. Tabulated values are shown in Appendix E. 5.3.1.1 For 4 kV Surge Figure 5.22: Current, voltage & power waveforms across MOV Figure 5.23: Total current, voltage & power waveforms at the input Power Voltage Current Current Voltage Power 46 -2.00E+05 0.00E+00 2.00E+05 4.00E+05 6.00E+05 8.00E+05 1.00E+06 1.20E+06 0 .0 0 E+ 0 0 1 .0 0 E- 0 6 2 .0 0 E- 0 6 3 .0 0 E- 0 6 4 .0 0 E- 0 6 5 .0 0 E- 0 6 6 .0 0 E- 0 6 7 .0 0 E- 0 6 8 .0 0 E- 0 6 9 .0 0 E- 0 6 1 .0 0 E- 0 5 1 .1 0 E- 0 5 1 .2 0 E- 0 5 1 .3 0 E- 0 5 1 .4 0 E- 0 5 1 .5 0 E- 0 5 1 .6 0 E- 0 5 1 .7 0 E- 0 5 1 .8 0 E- 0 5 1 .9 0 E- 0 5 2 .0 0 E- 0 5 P o w e r (w a tt ) Time (s) Power Across MOV - 4 kV Figure 5.24: Power across MOV Figure 5.25: Total power at the input Output clamping voltage = 660 V Total Energy = 17.2 J Energy across MOV = 14.6 J Energy absorbed by the supercapacitor subcircuit = (17.2-14.6) J = 2.6 J 47 5.3.1.2 For 6 kV Surge Figure 5.26: Power across MOV Figure 5.27: Total power at the input Total Energy = 30.8 J Output clamping voltage = 720 V Energy across MOV = 25.2 J Energy absorbed by the supercapacitor subcircuit = (30.8-25.2) J = 5.6 J Hence, supercapacitor subcircuit plays the role of absorbing part of the surge energy superimposed on the incoming pair of wires and increase the overall life time of the SPD device. 48 5.3.2 By using ferrite core as a transformer By applying 4 kV and 6 kV, total energy at the input and the energy absorbed by the MOV is calculated using the CSV values as earlier. 5.3.2.1 For 4 kV Surge Figure 5.28: Total power at the input and across MOV Total Energy = 15.7 J Output clamping voltage = 720 V Energy across MOV = 14.3 J Energy absorbed by the supercapacitor subcircuit = (15.7-14.3) J = 1.4 J 49 5.3.2.2 For 6 kV Surge Figure 5.29: Total power at the input and across MOV Total Energy = 29.1 J Output clamping voltage = 760 V Energy across MOV = 24 J Energy absorbed by the supercapacitor subcircuit = (29.1-24) J = 5.1 J 5.4 Energy Comparison of Two Different Cores Table 5.1 : Energy levels of powdered/ferrite cores Surge Voltage (V) Energy Absorbed by SC Sub-Circuit (J) Powdered Core Ferrite Core 4000 2.6 1.4 6000 5.6 5.1 50 Ferrite core stores less energy from the source which will be absorbed and dissipated by the SC sub-circuit. Hence, powdered core has more capability of absorbing surge energy than the ferrite cores. 5.5 Prototype implementation of the prosed system 5.5.1 Differential Mode Final prototype implementation of the supercapacitor concept in a differential-mode surge protector circuit is shown in figure 5.30. The SC sub- circuit is formed by a 1 Ω resistor and a 1 F/2.5 V SC in series. The Epcos S-20 MOV with a maximum clamping voltage 595 V together with SC sub- circuit-created input/output waveforms as per Fig 3.2 and 5.22. Figure 5.30: Proposed design of SPD (Differential Mode) The output clamping voltage for the different voltages are tabulated as follows. Applied Surge Voltage (V) Output Voltage At Load End L-N (V) 2000 600 4000 675 6000 690 Table 5.2 : Output voltage at load end 51 5.5.2 Common Mode Conceptual design of the SPD for common mode which consists of 2.5V /1F SCs, 1Ω resistors, Epcos S-20 MOVs and the powdered core transformers (turns ratio - 6:30) is shown in figure 5.31. Figure 5.31: Proposed design of SPD (Common Mode) The output clamping voltage for the different voltages are tabulated as follows. Table 5.3 : Output voltage at load end Applied Surge Voltage (V) Output Voltage At Load End (V) L-N L-E N-E 2000 600 535 535 4000 675 545 583 6000 690 623 607 52 6 CONCLUSION The research study has been carried out to determine the best configuration of a supercapacitor (SC) to absorb excess energy during a transient. The study has shown that the large value supercapacitors are able to not only handle large amounts of energy but also their large time constants permit this stored energy to be released at a slow rate permitting a longer life to the surge protective device. Compared to typical non-linear devices used in suge protective device (SPD) circuits, supercapacitors are capable of storing a large amount of energy despite their very low DC voltage rating.In the usual surge protector devices, the high transient energy can cause these non-linear devices to deteriorate and eventually fail. If this energy can be taken out from the non-linear devices their life time will be greatly enhanced. In this development of SPD, typical non-linear devices (NLDs) such as MOV is combined with a magnetic component and an SC-based sub circuit. However, compared to a typical surge arrestor without supercapacitors, where NLDs are placed directly across the pairs of wires such as the neutral and the live (differential mode) or neutral or live and earth(common mode), the NLD is placed in between the load side end of a primary coil of a transformer and the return wire. Given this configuration, when a surge occurs at the AC input, and when the instantaneous voltage due to surge exceeds the firing voltage of the NLD, high instantaneous current flows through the primary coil, developing a voltage across the primary turns. This in turn develops an induced voltage across the secondary coil, and by winding the secondary coil in the opposite direction, secondary induced voltage has been generated to oppose the surge voltage. This has created a voltage across the critical load to be protected, which is generally less than the instantaneous surge voltage. The test results indicate that the supercapacitor is not destroyed by the repeated application of high voltage transients and the gradual voltage rise after each hit is in the order of millivolt. Also it still retain its capacitive behavior and is not adversely affected by the transient high voltage at the terminals. Therefore , 1F-2.5 V 53 supercapacitor which has the highest voltage rise with 1 ohm resistor was selected as a supercapacitor sub circuit for this design. When applied input surge voltage of 6 kV, energy absorbed by the supercapacitor subcircuit with magnetic core is nearly 40% of total energy . Hence, supercapacitor subcircuit plays the role of absorbing part of the surge energy superimposed on the incoming pair of wires and increase the overall life time of the SPD device. Although the clamping voltage of SPD without supercapacitor is nearly 890 V, the supercapacitor assisted surge protective device has a 690 V at its output. As the test results clearly indicate that the supercapacitor assisted surge protective device forms the basis of an entirely new on non-traditional applications that will yield not only longer life, but also a lower clamping voltage across a critical load to be protected. This proves that the new topology could be used as a base technique to develop full-scale common and differential mode surge capable, fully versatile, commercial surge protectors with better performance than traditional surge protectors with higher component counts. Overall performance of the supercapacitor technique with optimized magnetics is practically used to safeguard electronic systems against transient over-voltage related power quality issues. Further, this research can be developed to analyse the overall circuit, in order to predict its theoretical performance in detail. This useful ability of supercapacitors can be extended to other major areas such as uninterruptible power supplies and DC-DC converters. 54 REFERENCES [1] Md Hisam Hanapei and Mohd Rezadzudin Hassan, “Satellite Communication Equipments Reliability And Lightning Surge Measurement Results”, Lightning Protection And EMC Unit, CEEM'2006/Dalian 3A1-05. [2] Kostas Samaras, Chet Sandberg, Chris J.Salmas and Andreas Koulaxouzidis, “Electrical Surge-Protection Devices for Industrial Facilities”, IEEE Transactions on Industrial Applications ,vol.43,No.1,January/February 2007. [3] N. Kularatna, J. Fernando, S. James, A. Pandey, “Surge capability testing of supercapacitor families using a lightning surge simulator”, IEEE transactions on Industrial Electronics, 2011,58, 10 ,pp.. 4942 – 4949. [4] Nihal Kularatna, “Energy Storage Devices For Electronic Systems-Rechargeable Batteries and Supercapacitors” , School of Engineering, The University of Waikato Hamilton, New Zealand, 8th September 2014. [5] Chandima Gomes, “On the selection and installation of surge protection devices in a TT wiring system for equipment and human safety” , 4th February 2011, Elsevier Journal. [6] Texas Instrument, reference with “Magnetic Core Properties," originally titled "An Electrical Circuit Model for Magnetic Cores. " Unitrode Seminar Manual SEMIOOO, 1995. [7] Alin Grama, Dorin Petrcus, Paul Borza, and Lacrimioara Gramal,” Experimental Determination of Equivalent Series Resistance of a Supercapacitor”, Applied Electronics Department, Technical University, Cluj-Napoca, Romania & Department of Electronics and Computers, Transilvania University, Brasov,Romania. [8] http://news.nationalgeographic.com/news/2013/11/131102-lightning-deaths- developing-countries-storms/ [9] http://batteryuniversity.com/learn/article/whats_the_role_of_the_supercapacitor [10] http://www.capacitorguide.com/supercapacitor/ [11] https://www.mag-inc.com/Products/Powder-Cores/Learn-More-about-Powder- Cores.aspx 55 Appendix A Cost of implemented unit. Type Part No. Quantity Price Resistors 1Ω / 1 W 3 30.00 Supercapacitors 1F / 2.5 V 2148494 3 1440.00 Transformer Powdered core 0077071A7 3 1080.00 MOV Epcos S-20 1004287 4 600.00 Miscellaneous 350.00 Total (Rs): 3500.00 56 Appendix B 57 58 59 60 61 62 63 64 65 66 67 68 69 Appendix C 70 71 Appendix D 72 Appendix E 4 kV Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 1.79E+02 -2.90E+01 6.62E+03 -1.66E-03 2.50E-07 5.23E+02 9.99E+00 3.91E+03 9.77E-04 5.00E-07 5.52E+02 9.04E+01 4.78E+04 1.19E-02 7.50E-07 5.68E+02 1.42E+02 7.87E+04 1.97E-02 1.00E-06 5.84E+02 2.50E+02 1.44E+05 3.60E-02 1.25E-06 6.03E+02 3.32E+02 1.98E+05 4.96E-02 1.50E-06 6.03E+02 3.72E+02 2.23E+05 5.57E-02 1.75E-06 6.03E+02 4.81E+02 2.88E+05 7.20E-02 2.00E-06 6.04E+02 5.33E+02 3.20E+05 7.99E-02 2.25E-06 6.03E+02 6.13E+02 3.68E+05 9.20E-02 2.50E-06 6.23E+02 6.72E+02 4.17E+05 1.04E-01 2.75E-06 6.23E+02 7.74E+02 4.80E+05 1.20E-01 3.00E-06 6.23E+02 8.14E+02 5.05E+05 1.26E-01 3.25E-06 6.28E+02 8.63E+02 5.40E+05 1.35E-01 3.75E-06 6.38E+02 9.75E+02 6.20E+05 1.55E-01 4.00E-06 6.43E+02 1.02E+03 6.51E+05 1.63E-01 4.25E-06 6.39E+02 1.06E+03 6.78E+05 1.69E-01 4.50E-06 6.33E+02 1.14E+03 7.17E+05 1.79E-01 4.75E-06 6.29E+02 1.18E+03 7.37E+05 1.84E-01 5.00E-06 6.43E+02 1.22E+03 7.81E+05 1.95E-01 5.25E-06 6.28E+02 1.27E+03 7.92E+05 1.98E-01 5.50E-06 6.34E+02 1.30E+03 8.20E+05 2.05E-01 5.75E-06 6.29E+02 1.34E+03 8.38E+05 2.10E-01 6.00E-06 6.43E+02 1.38E+03 8.82E+05 2.21E-01 6.50E-06 6.33E+02 1.42E+03 8.94E+05 2.24E-01 6.75E-06 6.23E+02 1.46E+03 9.06E+05 2.27E-01 7.00E-06 6.43E+02 1.46E+03 9.36E+05 2.34E-01 7.25E-06 6.28E+02 1.47E+03 9.18E+05 2.30E-01 7.50E-06 6.34E+02 1.52E+03 9.59E+05 2.40E-01 7.75E-06 6.43E+02 1.54E+03 9.87E+05 2.47E-01 8.00E-06 6.23E+02 1.54E+03 9.57E+05 2.39E-01 8.25E-06 6.23E+02 1.54E+03 9.56E+05 2.39E-01 8.50E-06 6.34E+02 1.56E+03 9.85E+05 2.46E-01 8.75E-06 6.38E+02 1.58E+03 1.00E+06 2.51E-01 9.00E-06 6.43E+02 1.62E+03 1.04E+06 2.59E-01 9.25E-06 6.28E+02 1.59E+03 9.94E+05 2.49E-01 9.50E-06 6.23E+02 1.62E+03 1.01E+06 2.51E-01 9.75E-06 6.43E+02 1.62E+03 1.04E+06 2.60E-01 73 Time(S) Volt(V) Current(A) Power(W) Energy(J) 1.00E-05 6.23E+02 1.58E+03 9.82E+05 2.46E-01 1.03E-05 6.39E+02 1.62E+03 1.03E+06 2.58E-01 1.05E-05 6.23E+02 1.62E+03 1.01E+06 2.52E-01 1.08E-05 6.23E+02 1.61E+03 9.99E+05 2.50E-01 1.10E-05 6.23E+02 1.58E+03 9.81E+05 2.45E-01 1.13E-05 6.23E+02 1.61E+03 1.00E+06 2.50E-01 1.15E-05 6.23E+02 1.58E+03 9.81E+05 2.45E-01 1.20E-05 6.23E+02 1.58E+03 9.81E+05 2.45E-01 1.23E-05 6.19E+02 1.57E+03 9.69E+05 2.42E-01 1.25E-05 6.23E+02 1.54E+03 9.56E+05 2.39E-01 1.28E-05 6.09E+02 1.54E+03 9.34E+05 2.33E-01 1.30E-05 6.22E+02 1.54E+03 9.54E+05 2.39E-01 1.33E-05 6.03E+02 1.50E+03 9.01E+05 2.25E-01 1.35E-05 6.03E+02 1.48E+03 8.90E+05 2.22E-01 1.38E-05 6.03E+02 1.46E+03 8.77E+05 2.19E-01 1.40E-05 6.03E+02 1.46E+03 8.77E+05 2.19E-01 1.43E-05 6.03E+02 1.42E+03 8.53E+05 2.13E-01 1.45E-05 6.03E+02 1.42E+03 8.53E+05 2.13E-01 1.48E-05 5.83E+02 1.42E+03 8.24E+05 2.06E-01 1.50E-05 5.83E+02 1.38E+03 8.00E+05 2.00E-01 1.53E-05 5.83E+02 1.35E+03 7.82E+05 1.96E-01 1.55E-05 5.83E+02 1.32E+03 7.66E+05 1.92E-01 1.58E-05 5.89E+02 1.33E+03 7.78E+05 1.95E-01 1.60E-05 5.83E+02 1.30E+03 7.54E+05 1.88E-01 1.63E-05 5.83E+02 1.26E+03 7.30E+05 1.83E-01 1.65E-05 5.83E+02 1.22E+03 7.07E+05 1.77E-01 1.68E-05 5.83E+02 1.23E+03 7.14E+05 1.78E-01 1.70E-05 5.82E+02 1.21E+03 7.06E+05 1.76E-01 1.73E-05 5.67E+02 1.14E+03 6.48E+05 1.62E-01 1.75E-05 5.63E+02 1.14E+03 6.38E+05 1.59E-01 1.78E-05 5.68E+02 1.10E+03 6.21E+05 1.55E-01 1.80E-05 5.63E+02 1.10E+03 6.14E+05 1.54E-01 1.83E-05 5.63E+02 1.06E+03 5.92E+05 1.48E-01 1.85E-05 5.63E+02 1.03E+03 5.80E+05 1.45E-01 1.88E-05 5.63E+02 9.86E+02 5.53E+05 1.38E-01 1.90E-05 5.63E+02 9.75E+02 5.47E+05 1.37E-01 1.93E-05 5.63E+02 9.75E+02 5.47E+05 1.37E-01 1.95E-05 5.52E+02 8.94E+02 4.92E+05 1.23E-01 1.98E-05 5.43E+02 8.83E+02 4.77E+05 1.19E-01 2.00E-05 5.43E+02 8.54E+02 4.62E+05 1.15E-01 Total 1.46E+01 74 Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 1.78E+02 -7.29E+00 -1.95E+03 -4.88E-04 2.50E-07 9.11E+02 1.51E+00 1.28E+03 3.20E-04 5.00E-07 1.00E+03 3.29E+01 3.22E+04 8.06E-03 7.50E-07 9.88E+02 7.31E+01 7.16E+04 1.79E-02 1.25E-06 9.02E+02 2.34E+02 2.10E+05 5.25E-02 1.50E-06 9.02E+02 2.93E+02 2.63E+05 6.59E-02 1.75E-06 9.02E+02 3.95E+02 3.55E+05 8.89E-02 2.00E-06 9.02E+02 4.75E+02 4.28E+05 1.07E-01 2.25E-06 9.02E+02 5.56E+02 5.00E+05 1.25E-01 2.50E-06 8.92E+02 6.36E+02 5.66E+05 1.42E-01 2.75E-06 9.02E+02 7.16E+02 6.46E+05 1.61E-01 3.00E-06 8.83E+02 7.95E+02 7.02E+05 1.75E-01 3.25E-06 8.82E+02 8.37E+02 7.37E+05 1.84E-01 3.50E-06 8.93E+02 9.17E+02 8.18E+05 2.05E-01 3.75E-06 8.68E+02 9.69E+02 8.40E+05 2.10E-01 4.00E-06 8.82E+02 1.04E+03 9.13E+05 2.28E-01 4.25E-06 8.67E+02 1.08E+03 9.33E+05 2.33E-01 4.50E-06 8.62E+02 1.12E+03 9.63E+05 2.41E-01 4.75E-06 8.62E+02 1.19E+03 1.02E+06 2.56E-01 5.00E-06 8.62E+02 1.20E+03 1.03E+06 2.58E-01 5.25E-06 8.62E+02 1.28E+03 1.10E+06 2.75E-01 5.50E-06 8.33E+02 1.30E+03 1.08E+06 2.70E-01 5.75E-06 8.48E+02 1.32E+03 1.12E+06 2.79E-01 6.00E-06 8.41E+02 1.40E+03 1.18E+06 2.94E-01 6.25E-06 8.38E+02 1.43E+03 1.20E+06 2.99E-01 6.50E-06 8.22E+02 1.44E+03 1.18E+06 2.96E-01 6.75E-06 8.08E+02 1.44E+03 1.16E+06 2.90E-01 7.00E-06 8.02E+02 1.48E+03 1.19E+06 2.97E-01 7.25E-06 8.22E+02 1.52E+03 1.25E+06 3.12E-01 7.50E-06 8.02E+02 1.50E+03 1.20E+06 3.01E-01 8.00E-06 7.82E+02 1.56E+03 1.22E+06 3.05E-01 8.25E-06 7.82E+02 1.56E+03 1.22E+06 3.05E-01 8.50E-06 7.72E+02 1.60E+03 1.23E+06 3.09E-01 8.75E-06 7.62E+02 1.60E+03 1.22E+06 3.04E-01 9.00E-06 7.62E+02 1.60E+03 1.22E+06 3.04E-01 9.50E-06 7.52E+02 1.62E+03 1.22E+06 3.05E-01 9.75E-06 7.42E+02 1.64E+03 1.22E+06 3.04E-01 1.00E-05 7.42E+02 1.60E+03 1.19E+06 2.97E-01 75 Time(S) Volt(V) Current(A) Power(W) Energy(J) 1.03E-05 7.21E+02 1.64E+03 1.18E+06 2.96E-01 1.05E-05 7.21E+02 1.62E+03 1.17E+06 2.92E-01 1.08E-05 7.21E+02 1.64E+03 1.18E+06 2.96E-01 1.13E-05 7.01E+02 1.60E+03 1.12E+06 2.80E-01 1.15E-05 6.92E+02 1.62E+03 1.12E+06 2.80E-01 1.18E-05 6.96E+02 1.57E+03 1.09E+06 2.73E-01 1.20E-05 7.01E+02 1.60E+03 1.12E+06 2.80E-01 1.23E-05 6.81E+02 1.60E+03 1.09E+06 2.72E-01 1.25E-05 6.72E+02 1.54E+03 1.03E+06 2.58E-01 1.28E-05 6.61E+02 1.54E+03 1.02E+06 2.55E-01 1.30E-05 6.61E+02 1.56E+03 1.03E+06 2.57E-01 1.33E-05 6.61E+02 1.56E+03 1.03E+06 2.58E-01 1.35E-05 6.41E+02 1.52E+03 9.74E+05 2.43E-01 1.38E-05 6.41E+02 1.52E+03 9.74E+05 2.43E-01 1.40E-05 6.41E+02 1.48E+03 9.47E+05 2.37E-01 1.45E-05 6.32E+02 1.44E+03 9.08E+05 2.27E-01 1.48E-05 6.07E+02 1.44E+03 8.72E+05 2.18E-01 1.50E-05 6.21E+02 1.40E+03 8.68E+05 2.17E-01 1.53E-05 6.05E+02 1.39E+03 8.40E+05 2.10E-01 1.55E-05 5.91E+02 1.36E+03 8.03E+05 2.01E-01 1.58E-05 5.86E+02 1.35E+03 7.89E+05 1.97E-01 1.60E-05 5.81E+02 1.32E+03 7.65E+05 1.91E-01 1.63E-05 5.65E+02 1.31E+03 7.39E+05 1.85E-01 1.65E-05 5.81E+02 1.28E+03 7.42E+05 1.86E-01 1.68E-05 5.81E+02 1.24E+03 7.19E+05 1.80E-01 1.70E-05 5.80E+02 1.20E+03 6.95E+05 1.74E-01 1.73E-05 5.65E+02 1.19E+03 6.71E+05 1.68E-01 1.75E-05 5.50E+02 1.18E+03 6.47E+05 1.62E-01 1.78E-05 5.46E+02 1.13E+03 6.16E+05 1.54E-01 1.80E-05 5.61E+02 1.12E+03 6.26E+05 1.56E-01 1.83E-05 5.56E+02 1.11E+03 6.16E+05 1.54E-01 1.85E-05 5.51E+02 1.06E+03 5.82E+05 1.45E-01 1.88E-05 5.41E+02 1.04E+03 5.61E+05 1.40E-01 1.90E-05 5.41E+02 1.04E+03 5.61E+05 1.40E-01 1.93E-05 5.25E+02 9.98E+02 5.23E+05 1.31E-01 1.95E-05 5.20E+02 9.58E+02 4.97E+05 1.24E-01 1.98E-05 5.20E+02 9.17E+02 4.77E+05 1.19E-01 2.00E-05 5.20E+02 8.77E+02 4.56E+05 1.14E-01 Total 1.72E+01 76 6 kV Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 1.34E+02 -3.44E+01 -5.68E+03 -1.42E-03 2.50E-07 5.21E+02 4.47E+01 2.17E+04 5.42E-03 5.00E-07 5.97E+02 1.25E+02 7.32E+04 1.83E-02 7.50E-07 6.08E+02 2.86E+02 1.72E+05 4.31E-02 1.00E-06 6.37E+02 3.66E+02 2.31E+05 5.78E-02 1.25E-06 6.53E+02 4.87E+02 3.16E+05 7.91E-02 1.50E-06 6.47E+02 6.26E+02 4.03E+05 1.01E-01 1.75E-06 6.57E+02 7.57E+02 4.96E+05 1.24E-01 2.00E-06 6.57E+02 8.88E+02 5.81E+05 1.45E-01 2.25E-06 6.57E+02 9.69E+02 6.35E+05 1.59E-01 2.50E-06 6.57E+02 1.09E+03 7.14E+05 1.78E-01 2.75E-06 6.77E+02 1.20E+03 8.10E+05 2.02E-01 3.00E-06 6.77E+02 1.33E+03 8.99E+05 2.25E-01 3.25E-06 6.77E+02 1.41E+03 9.54E+05 2.39E-01 3.50E-06 6.67E+02 1.47E+03 9.79E+05 2.45E-01 3.75E-06 6.77E+02 1.57E+03 1.06E+06 2.66E-01 4.00E-06 6.77E+02 1.65E+03 1.12E+06 2.79E-01 4.25E-06 6.82E+02 1.73E+03 1.18E+06 2.95E-01 4.50E-06 6.77E+02 1.79E+03 1.21E+06 3.03E-01 4.75E-06 6.92E+02 1.89E+03 1.31E+06 3.27E-01 5.00E-06 6.97E+02 1.93E+03 1.35E+06 3.36E-01 5.25E-06 6.82E+02 1.98E+03 1.35E+06 3.37E-01 5.50E-06 6.77E+02 2.08E+03 1.40E+06 3.51E-01 5.75E-06 6.92E+02 2.14E+03 1.48E+06 3.69E-01 6.00E-06 6.97E+02 2.17E+03 1.51E+06 3.78E-01 6.25E-06 6.77E+02 2.22E+03 1.50E+06 3.75E-01 6.50E-06 6.88E+02 2.27E+03 1.56E+06 3.91E-01 6.75E-06 6.83E+02 2.30E+03 1.57E+06 3.91E-01 7.00E-06 6.78E+02 2.30E+03 1.56E+06 3.89E-01 7.25E-06 6.93E+02 2.38E+03 1.64E+06 4.11E-01 7.50E-06 6.97E+02 2.40E+03 1.67E+06 4.17E-01 7.75E-06 6.77E+02 2.46E+03 1.66E+06 4.16E-01 8.00E-06 6.77E+02 2.42E+03 1.64E+06 4.09E-01 8.25E-06 6.77E+02 2.46E+03 1.66E+06 4.16E-01 8.50E-06 6.77E+02 2.50E+03 1.69E+06 4.22E-01 8.75E-06 6.83E+02 2.50E+03 1.70E+06 4.26E-01 9.00E-06 6.77E+02 2.50E+03 1.69E+06 4.22E-01 9.25E-06 6.77E+02 2.53E+03 1.71E+06 4.27E-01 9.50E-06 6.77E+02 2.54E+03 1.72E+06 4.29E-01 77 Time(S) Volt(V) Current(A) Power(W) Energy(J) 9.75E-06 6.77E+02 2.57E+03 1.74E+06 4.34E-01 1.00E-05 6.77E+02 2.54E+03 1.72E+06 4.29E-01 1.03E-05 6.62E+02 2.54E+03 1.68E+06 4.19E-01 1.05E-05 6.77E+02 2.54E+03 1.72E+06 4.29E-01 1.08E-05 6.72E+02 2.54E+03 1.70E+06 4.25E-01 1.10E-05 6.77E+02 2.54E+03 1.71E+06 4.29E-01 1.13E-05 6.73E+02 2.51E+03 1.68E+06 4.21E-01 1.15E-05 6.57E+02 2.54E+03 1.67E+06 4.16E-01 1.18E-05 6.72E+02 2.50E+03 1.67E+06 4.19E-01 1.20E-05 6.57E+02 2.46E+03 1.61E+06 4.03E-01 1.23E-05 6.53E+02 2.46E+03 1.60E+06 4.00E-01 1.25E-05 6.47E+02 2.46E+03 1.59E+06 3.97E-01 1.28E-05 6.43E+02 2.43E+03 1.56E+06 3.90E-01 1.30E-05 6.57E+02 2.42E+03 1.58E+06 3.96E-01 1.33E-05 6.53E+02 2.38E+03 1.55E+06 3.87E-01 1.35E-05 6.47E+02 2.34E+03 1.51E+06 3.77E-01 1.38E-05 6.43E+02 2.34E+03 1.50E+06 3.75E-01 1.40E-05 6.57E+02 2.30E+03 1.51E+06 3.76E-01 1.43E-05 6.57E+02 2.26E+03 1.49E+06 3.72E-01 1.45E-05 6.37E+02 2.22E+03 1.41E+06 3.52E-01 1.48E-05 6.37E+02 2.22E+03 1.41E+06 3.52E-01 1.50E-05 6.37E+02 2.21E+03 1.41E+06 3.52E-01 1.53E-05 6.37E+02 2.14E+03 1.36E+06 3.41E-01 1.55E-05 6.28E+02 2.12E+03 1.33E+06 3.32E-01 1.58E-05 6.23E+02 2.09E+03 1.30E+06 3.26E-01 1.60E-05 6.17E+02 2.05E+03 1.27E+06 3.16E-01 1.63E-05 6.17E+02 2.01E+03 1.24E+06 3.10E-01 1.68E-05 6.11E+02 1.93E+03 1.18E+06 2.95E-01 1.73E-05 6.17E+02 1.89E+03 1.17E+06 2.92E-01 1.75E-05 6.06E+02 1.85E+03 1.12E+06 2.80E-01 1.78E-05 6.03E+02 1.84E+03 1.11E+06 2.77E-01 1.80E-05 6.17E+02 1.77E+03 1.09E+06 2.73E-01 1.83E-05 6.01E+02 1.73E+03 1.04E+06 2.60E-01 1.85E-05 5.97E+02 1.73E+03 1.03E+06 2.58E-01 1.88E-05 5.97E+02 1.66E+03 9.91E+05 2.48E-01 1.90E-05 5.98E+02 1.65E+03 9.85E+05 2.46E-01 1.93E-05 5.97E+02 1.61E+03 9.61E+05 2.40E-01 1.95E-05 6.08E+02 1.57E+03 9.53E+05 2.38E-01 1.98E-05 5.97E+02 1.53E+03 9.13E+05 2.28E-01 2.00E-05 5.97E+02 1.53E+03 9.13E+05 2.28E-01 Total 2.52E+01 78 Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 1.18E+02 -7.29E+00 -1.95E+03 -4.88E-04 2.50E-07 9.98E+02 2.41E+01 2.27E+04 5.68E-03 5.00E-07 1.00E+03 5.18E+01 5.05E+04 1.26E-02 7.50E-07 1.00E+03 1.13E+02 1.13E+05 2.83E-02 1.00E-06 1.00E+03 2.74E+02 2.73E+05 6.84E-02 1.25E-06 9.87E+02 3.95E+02 3.88E+05 9.71E-02 1.50E-06 9.93E+02 5.34E+02 5.29E+05 1.32E-01 1.75E-06 1.00E+03 6.65E+02 6.65E+05 1.66E-01 2.00E-06 1.00E+03 7.97E+02 7.97E+05 1.99E-01 2.25E-06 1.02E+03 9.26E+02 9.46E+05 2.37E-01 2.50E-06 1.02E+03 1.02E+03 1.04E+06 2.60E-01 2.75E-06 1.00E+03 1.16E+03 1.16E+06 2.90E-01 3.00E-06 1.00E+03 1.24E+03 1.24E+06 3.10E-01 3.25E-06 1.02E+03 1.32E+03 1.34E+06 3.36E-01 3.50E-06 1.00E+03 1.44E+03 1.44E+06 3.60E-01 3.75E-06 1.01E+03 1.52E+03 1.53E+06 3.83E-01 4.00E-06 1.00E+03 1.60E+03 1.60E+06 4.01E-01 4.25E-06 1.00E+03 1.72E+03 1.72E+06 4.31E-01 4.50E-06 1.00E+03 1.78E+03 1.78E+06 4.46E-01 4.75E-06 9.83E+02 1.84E+03 1.81E+06 4.52E-01 5.00E-06 9.83E+02 1.92E+03 1.89E+06 4.72E-01 5.25E-06 9.83E+02 1.97E+03 1.94E+06 4.84E-01 5.50E-06 9.72E+02 2.06E+03 2.00E+06 5.01E-01 5.75E-06 9.63E+02 2.08E+03 2.00E+06 5.01E-01 6.00E-06 9.63E+02 2.16E+03 2.08E+06 5.20E-01 6.25E-06 9.63E+02 2.24E+03 2.15E+06 5.37E-01 6.50E-06 9.52E+02 2.27E+03 2.15E+06 5.39E-01 6.75E-06 9.43E+02 2.30E+03 2.16E+06 5.40E-01 7.00E-06 9.43E+02 2.33E+03 2.19E+06 5.48E-01 7.25E-06 9.22E+02 2.36E+03 2.18E+06 5.45E-01 7.50E-06 9.22E+02 2.38E+03 2.20E+06 5.49E-01 7.75E-06 9.22E+02 2.44E+03 2.25E+06 5.63E-01 8.00E-06 9.22E+02 2.44E+03 2.25E+06 5.63E-01 8.25E-06 9.02E+02 2.52E+03 2.27E+06 5.67E-01 8.50E-06 8.92E+02 2.53E+03 2.25E+06 5.63E-01 8.75E-06 8.82E+02 2.53E+03 2.23E+06 5.57E-01 9.00E-06 8.82E+02 2.53E+03 2.23E+06 5.57E-01 9.25E-06 8.46E+02 2.53E+03 2.14E+06 5.34E-01 9.50E-06 8.51E+02 2.57E+03 2.18E+06 5.46E-01 9.75E-06 8.57E+02 2.57E+03 2.19E+06 5.49E-01 1.00E-05 8.41E+02 2.56E+03 2.16E+06 5.39E-01 79 Time(S) Volt(V) Current(A) Power(W) Energy(J) 1.03E-05 8.22E+02 2.60E+03 2.13E+06 5.33E-01 1.05E-05 8.02E+02 2.57E+03 2.05E+06 5.14E-01 1.08E-05 8.02E+02 2.57E+03 2.05E+06 5.14E-01 1.10E-05 8.02E+02 2.57E+03 2.05E+06 5.14E-01 1.13E-05 7.86E+02 2.57E+03 2.02E+06 5.04E-01 1.15E-05 7.82E+02 2.53E+03 1.97E+06 4.93E-01 1.18E-05 7.67E+02 2.53E+03 1.94E+06 4.84E-01 1.20E-05 7.62E+02 2.49E+03 1.89E+06 4.73E-01 1.23E-05 7.62E+02 2.48E+03 1.88E+06 4.71E-01 1.25E-05 7.31E+02 2.49E+03 1.81E+06 4.54E-01 1.28E-05 7.42E+02 2.49E+03 1.84E+06 4.60E-01 1.30E-05 7.41E+02 2.44E+03 1.81E+06 4.52E-01 1.33E-05 7.06E+02 2.40E+03 1.70E+06 4.24E-01 1.35E-05 7.01E+02 2.40E+03 1.69E+06 4.21E-01 1.38E-05 7.01E+02 2.38E+03 1.66E+06 4.16E-01 1.40E-05 7.01E+02 2.32E+03 1.63E+06 4.07E-01 1.43E-05 6.86E+02 2.32E+03 1.59E+06 3.98E-01 1.45E-05 7.01E+02 2.28E+03 1.60E+06 4.00E-01 1.48E-05 6.67E+02 2.26E+03 1.50E+06 3.76E-01 1.50E-05 6.61E+02 2.24E+03 1.48E+06 3.71E-01 1.53E-05 6.61E+02 2.20E+03 1.46E+06 3.64E-01 1.55E-05 6.50E+02 2.16E+03 1.40E+06 3.51E-01 1.58E-05 6.55E+02 2.12E+03 1.39E+06 3.48E-01 1.60E-05 6.41E+02 2.12E+03 1.36E+06 3.40E-01 1.63E-05 6.61E+02 2.04E+03 1.35E+06 3.37E-01 1.65E-05 6.30E+02 2.04E+03 1.29E+06 3.22E-01 1.68E-05 6.35E+02 2.00E+03 1.27E+06 3.18E-01 1.70E-05 6.21E+02 1.96E+03 1.22E+06 3.04E-01 1.73E-05 6.21E+02 1.92E+03 1.19E+06 2.98E-01 1.75E-05 6.32E+02 1.88E+03 1.19E+06 2.97E-01 1.78E-05 6.15E+02 1.87E+03 1.15E+06 2.87E-01 1.80E-05 6.01E+02 1.84E+03 1.11E+06 2.77E-01 1.83E-05 6.17E+02 1.76E+03 1.08E+06 2.71E-01 1.85E-05 6.01E+02 1.76E+03 1.06E+06 2.64E-01 1.88E-05 6.01E+02 1.72E+03 1.03E+06 2.58E-01 1.90E-05 6.01E+02 1.64E+03 9.85E+05 2.46E-01 1.93E-05 5.96E+02 1.64E+03 9.77E+05 2.44E-01 1.95E-05 5.91E+02 1.60E+03 9.45E+05 2.36E-01 1.98E-05 5.81E+02 1.60E+03 9.28E+05 2.32E-01 2.00E-05 5.81E+02 1.56E+03 9.04E+05 2.26E-01 Total 3.08E+01 80 Appendix F 4 kV Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 2.81E+02 7.54E-01 0.00E+00 0.00E+00 2.50E-07 5.53E+02 4.10E+01 2.29E+04 5.74E-03 5.00E-07 5.63E+02 4.10E+01 2.25E+04 5.62E-03 7.50E-07 6.03E+02 8.12E+01 4.69E+04 1.17E-02 1.00E-06 6.03E+02 1.62E+02 9.57E+04 2.39E-02 1.25E-06 6.33E+02 2.22E+02 1.40E+05 3.49E-02 1.50E-06 6.43E+02 3.22E+02 2.05E+05 5.13E-02 1.75E-06 6.43E+02 4.03E+02 2.58E+05 6.45E-02 2.00E-06 6.43E+02 4.83E+02 3.09E+05 7.71E-02 2.25E-06 6.73E+02 4.83E+02 3.23E+05 8.08E-02 2.50E-06 6.43E+02 5.23E+02 3.35E+05 8.37E-02 2.75E-06 6.43E+02 7.04E+02 4.52E+05 1.13E-01 3.00E-06 6.43E+02 7.24E+02 4.65E+05 1.16E-01 3.25E-06 6.43E+02 7.44E+02 4.78E+05 1.19E-01 3.50E-06 6.43E+02 8.85E+02 5.68E+05 1.42E-01 3.75E-06 6.73E+02 8.85E+02 5.95E+05 1.49E-01 4.00E-06 6.03E+02 9.66E+02 5.80E+05 1.45E-01 4.25E-06 6.43E+02 1.05E+03 6.72E+05 1.68E-01 4.50E-06 6.43E+02 1.09E+03 6.97E+05 1.74E-01 4.75E-06 6.43E+02 1.05E+03 6.72E+05 1.68E-01 5.00E-06 6.43E+02 1.13E+03 7.23E+05 1.81E-01 5.25E-06 6.53E+02 1.21E+03 7.88E+05 1.97E-01 5.50E-06 6.43E+02 1.29E+03 8.26E+05 2.07E-01 5.75E-06 6.43E+02 1.23E+03 7.88E+05 1.97E-01 6.00E-06 6.43E+02 1.29E+03 8.26E+05 2.07E-01 6.25E-06 6.83E+02 1.35E+03 9.20E+05 2.30E-01 6.50E-06 6.43E+02 1.29E+03 8.26E+05 2.07E-01 6.75E-06 6.73E+02 1.37E+03 9.20E+05 2.30E-01 7.00E-06 6.83E+02 1.37E+03 9.34E+05 2.33E-01 7.25E-06 6.43E+02 1.45E+03 9.30E+05 2.32E-01 7.50E-06 6.43E+02 1.45E+03 9.30E+05 2.32E-01 7.75E-06 6.43E+02 1.45E+03 9.30E+05 2.32E-01 8.00E-06 6.43E+02 1.45E+03 9.30E+05 2.32E-01 8.25E-06 6.73E+02 1.47E+03 9.87E+05 2.47E-01 8.50E-06 6.43E+02 1.53E+03 9.82E+05 2.46E-01 8.75E-06 6.03E+02 1.47E+03 8.83E+05 2.21E-01 81 Time(S) Volt(V) Current(A) Power(W) Energy(J) 9.00E-06 6.43E+02 1.53E+03 9.82E+05 2.46E-01 9.25E-06 6.43E+02 1.53E+03 9.82E+05 2.46E-01 9.50E-06 6.23E+02 1.61E+03 1.00E+06 2.50E-01 9.75E-06 6.53E+02 1.59E+03 1.04E+06 2.59E-01 1.00E-05 6.43E+02 1.61E+03 1.03E+06 2.58E-01 1.03E-05 6.33E+02 1.55E+03 9.79E+05 2.45E-01 1.05E-05 6.23E+02 1.61E+03 1.00E+06 2.50E-01 1.08E-05 6.13E+02 1.55E+03 9.48E+05 2.37E-01 1.10E-05 6.43E+02 1.61E+03 1.03E+06 2.58E-01 1.13E-05 6.03E+02 1.53E+03 9.20E+05 2.30E-01 1.15E-05 6.03E+02 1.57E+03 9.44E+05 2.36E-01 1.18E-05 6.13E+02 1.61E+03 9.85E+05 2.46E-01 1.20E-05 6.03E+02 1.53E+03 9.20E+05 2.30E-01 1.23E-05 6.03E+02 1.55E+03 9.32E+05 2.33E-01 1.25E-05 6.03E+02 1.53E+03 9.20E+05 2.30E-01 1.28E-05 6.03E+02 1.53E+03 9.20E+05 2.30E-01 1.30E-05 6.43E+02 1.45E+03 9.30E+05 2.32E-01 1.33E-05 6.03E+02 1.47E+03 8.83E+05 2.21E-01 1.35E-05 6.03E+02 1.45E+03 8.71E+05 2.18E-01 1.38E-05 6.03E+02 1.45E+03 8.71E+05 2.18E-01 1.40E-05 6.03E+02 1.45E+03 8.71E+05 2.18E-01 1.43E-05 6.13E+02 1.43E+03 8.73E+05 2.18E-01 1.45E-05 6.03E+02 1.45E+03 8.71E+05 2.18E-01 1.48E-05 6.03E+02 1.43E+03 8.59E+05 2.15E-01 1.50E-05 5.63E+02 1.45E+03 8.14E+05 2.04E-01 1.53E-05 6.03E+02 1.37E+03 8.24E+05 2.06E-01 1.55E-05 5.83E+02 1.29E+03 7.49E+05 1.87E-01 1.58E-05 6.03E+02 1.31E+03 7.88E+05 1.97E-01 1.60E-05 6.03E+02 1.29E+03 7.75E+05 1.94E-01 1.63E-05 5.63E+02 1.29E+03 7.23E+05 1.81E-01 1.65E-05 5.83E+02 1.21E+03 7.02E+05 1.76E-01 1.68E-05 5.53E+02 1.27E+03 6.99E+05 1.75E-01 1.70E-05 5.63E+02 1.21E+03 6.78E+05 1.69E-01 1.73E-05 5.63E+02 1.19E+03 6.67E+05 1.67E-01 1.75E-05 5.63E+02 1.13E+03 6.33E+05 1.58E-01 1.78E-05 5.93E+02 1.13E+03 6.67E+05 1.67E-01 1.80E-05 5.63E+02 1.05E+03 5.88E+05 1.47E-01 1.83E-05 5.63E+02 1.05E+03 5.88E+05 1.47E-01 1.85E-05 5.63E+02 1.01E+03 5.65E+05 1.41E-01 82 Time(S) Volt(V) Current(A) Power(W) Energy(J) 1.88E-05 5.63E+02 9.86E+02 5.54E+05 1.39E-01 1.90E-05 5.63E+02 1.05E+03 5.88E+05 1.47E-01 1.93E-05 5.63E+02 9.66E+02 5.43E+05 1.36E-01 1.95E-05 5.63E+02 8.85E+02 4.96E+05 1.24E-01 1.98E-05 5.23E+02 8.85E+02 4.61E+05 1.15E-01 2.00E-05 5.63E+02 8.05E+02 4.51E+05 1.13E-01 Total 1.43E+01 Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 2.81E+02 -7.96E+01 -2.34E+04 -5.86E-03 2.50E-07 1.14E+03 -1.93E+01 -2.34E+04 -5.86E-03 5.00E-07 1.45E+03 7.54E-01 0.00E+00 0.00E+00 7.50E-07 1.53E+03 6.11E+01 9.08E+04 2.27E-02 1.00E-06 1.45E+03 1.62E+02 2.32E+05 5.81E-02 1.25E-06 1.24E+03 1.82E+02 2.22E+05 5.54E-02 1.50E-06 1.07E+03 3.63E+02 3.84E+05 9.59E-02 1.75E-06 1.01E+03 3.42E+02 3.42E+05 8.56E-02 2.00E-06 9.65E+02 4.03E+02 3.87E+05 9.67E-02 2.25E-06 9.55E+02 5.23E+02 5.00E+05 1.25E-01 2.50E-06 9.05E+02 6.04E+02 5.45E+05 1.36E-01 2.75E-06 9.25E+02 7.04E+02 6.49E+05 1.62E-01 3.00E-06 9.25E+02 7.24E+02 6.68E+05 1.67E-01 3.25E-06 9.25E+02 8.05E+02 7.42E+05 1.86E-01 3.50E-06 9.05E+02 8.05E+02 7.27E+05 1.82E-01 3.75E-06 8.84E+02 8.65E+02 7.64E+05 1.91E-01 4.00E-06 8.84E+02 8.85E+02 7.81E+05 1.95E-01 4.25E-06 8.84E+02 9.66E+02 8.52E+05 2.13E-01 4.50E-06 8.84E+02 1.05E+03 9.24E+05 2.31E-01 4.75E-06 8.54E+02 1.05E+03 8.92E+05 2.23E-01 5.00E-06 8.84E+02 1.13E+03 9.94E+05 2.49E-01 5.25E-06 8.44E+02 1.19E+03 1.00E+06 2.50E-01 5.50E-06 8.44E+02 1.17E+03 9.83E+05 2.46E-01 5.75E-06 8.34E+02 1.21E+03 1.01E+06 2.51E-01 6.00E-06 8.44E+02 1.21E+03 1.02E+06 2.54E-01 6.25E-06 8.34E+02 1.35E+03 1.12E+06 2.81E-01 6.50E-06 8.24E+02 1.33E+03 1.09E+06 2.73E-01 6.75E-06 8.04E+02 1.37E+03 1.10E+06 2.74E-01 83 Time(S) Volt(V) Current(A) Power(W) Energy(J) 7.00E-06 8.04E+02 1.37E+03 1.10E+06 2.74E-01 7.25E-06 7.74E+02 1.37E+03 1.06E+06 2.64E-01 7.50E-06 7.64E+02 1.45E+03 1.10E+06 2.76E-01 7.75E-06 7.64E+02 1.47E+03 1.12E+06 2.80E-01 8.00E-06 7.64E+02 1.53E+03 1.17E+06 2.92E-01 8.25E-06 7.64E+02 1.47E+03 1.12E+06 2.80E-01 8.50E-06 7.64E+02 1.49E+03 1.13E+06 2.84E-01 8.75E-06 7.34E+02 1.59E+03 1.16E+06 2.91E-01 9.00E-06 7.24E+02 1.53E+03 1.10E+06 2.76E-01 9.25E-06 7.24E+02 1.59E+03 1.15E+06 2.87E-01 9.50E-06 7.24E+02 1.49E+03 1.08E+06 2.69E-01 9.75E-06 6.93E+02 1.53E+03 1.06E+06 2.65E-01 1.00E-05 7.24E+02 1.61E+03 1.16E+06 2.91E-01 1.03E-05 7.24E+02 1.53E+03 1.10E+06 2.76E-01 1.05E-05 7.04E+02 1.53E+03 1.07E+06 2.68E-01 1.08E-05 7.14E+02 1.53E+03 1.09E+06 2.72E-01 1.10E-05 6.83E+02 1.53E+03 1.04E+06 2.61E-01 1.13E-05 6.83E+02 1.59E+03 1.08E+06 2.71E-01 1.15E-05 6.63E+02 1.53E+03 1.01E+06 2.53E-01 1.18E-05 6.43E+02 1.53E+03 9.82E+05 2.46E-01 1.20E-05 6.83E+02 1.61E+03 1.10E+06 2.74E-01 1.23E-05 6.43E+02 1.51E+03 9.69E+05 2.42E-01 1.25E-05 6.23E+02 1.53E+03 9.51E+05 2.38E-01 1.28E-05 6.13E+02 1.47E+03 8.99E+05 2.25E-01 1.30E-05 6.43E+02 1.45E+03 9.30E+05 2.32E-01 1.33E-05 6.43E+02 1.45E+03 9.30E+05 2.32E-01 1.35E-05 6.03E+02 1.41E+03 8.48E+05 2.12E-01 1.38E-05 6.03E+02 1.51E+03 9.08E+05 2.27E-01 1.40E-05 6.03E+02 1.45E+03 8.71E+05 2.18E-01 1.43E-05 6.03E+02 1.37E+03 8.24E+05 2.06E-01 1.45E-05 5.83E+02 1.41E+03 8.19E+05 2.05E-01 1.48E-05 5.73E+02 1.43E+03 8.17E+05 2.04E-01 1.50E-05 6.03E+02 1.37E+03 8.24E+05 2.06E-01 1.53E-05 5.63E+02 1.29E+03 7.23E+05 1.81E-01 1.55E-05 5.63E+02 1.33E+03 7.45E+05 1.86E-01 1.58E-05 5.33E+02 1.31E+03 6.96E+05 1.74E-01 1.60E-05 5.63E+02 1.29E+03 7.23E+05 1.81E-01 1.63E-05 5.23E+02 1.23E+03 6.40E+05 1.60E-01 1.65E-05 5.23E+02 1.25E+03 6.50E+05 1.63E-01 84 Time(S) Volt(V) Current(A) Power(W) Energy(J) 1.68E-05 5.23E+02 1.23E+03 6.40E+05 1.60E-01 1.70E-05 5.23E+02 1.21E+03 6.29E+05 1.57E-01 1.73E-05 5.23E+02 1.15E+03 5.98E+05 1.50E-01 1.75E-05 5.23E+02 1.13E+03 5.88E+05 1.47E-01 1.78E-05 5.23E+02 1.09E+03 5.66E+05 1.41E-01 1.80E-05 4.82E+02 1.13E+03 5.43E+05 1.36E-01 1.83E-05 5.23E+02 1.05E+03 5.45E+05 1.36E-01 1.85E-05 4.82E+02 9.66E+02 4.65E+05 1.16E-01 1.88E-05 4.82E+02 9.66E+02 4.65E+05 1.16E-01 1.90E-05 4.82E+02 9.66E+02 4.65E+05 1.16E-01 1.93E-05 4.82E+02 9.45E+02 4.55E+05 1.14E-01 1.95E-05 4.82E+02 9.66E+02 4.65E+05 1.16E-01 1.98E-05 4.72E+02 8.85E+02 4.17E+05 1.04E-01 2.00E-05 4.82E+02 8.85E+02 4.26E+05 1.06E-01 Total 1.57E+01 6 kV Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 2.81E+02 8.12E+01 2.15E+04 5.37E-03 2.50E-07 5.53E+02 8.12E+01 4.39E+04 1.10E-02 5.00E-07 6.03E+02 1.21E+02 7.13E+04 1.78E-02 7.50E-07 6.33E+02 1.82E+02 1.12E+05 2.81E-02 1.00E-06 6.83E+02 3.22E+02 2.19E+05 5.47E-02 1.25E-06 6.83E+02 4.03E+02 2.73E+05 6.84E-02 1.50E-06 6.83E+02 5.64E+02 3.83E+05 9.57E-02 1.75E-06 6.83E+02 6.64E+02 4.53E+05 1.13E-01 2.00E-06 6.83E+02 7.24E+02 4.94E+05 1.24E-01 2.25E-06 6.93E+02 8.85E+02 6.12E+05 1.53E-01 2.50E-06 6.83E+02 1.05E+03 7.13E+05 1.78E-01 2.75E-06 7.14E+02 1.13E+03 8.03E+05 2.01E-01 3.00E-06 6.83E+02 1.21E+03 8.24E+05 2.06E-01 3.25E-06 7.14E+02 1.29E+03 9.17E+05 2.29E-01 3.50E-06 7.04E+02 1.37E+03 9.59E+05 2.40E-01 3.75E-06 6.83E+02 1.45E+03 9.88E+05 2.47E-01 4.00E-06 6.83E+02 1.53E+03 1.04E+06 2.61E-01 4.25E-06 6.83E+02 1.59E+03 1.08E+06 2.71E-01 4.50E-06 7.04E+02 1.73E+03 1.21E+06 3.03E-01 4.75E-06 7.24E+02 1.85E+03 1.34E+06 3.34E-01 5.00E-06 7.24E+02 1.77E+03 1.28E+06 3.20E-01 85 Time(S) Volt(V) Current(A) Power(W) Energy(J) 5.25E-06 6.83E+02 1.85E+03 1.26E+06 3.16E-01 5.50E-06 7.24E+02 1.97E+03 1.42E+06 3.56E-01 5.75E-06 7.14E+02 2.01E+03 1.43E+06 3.58E-01 6.00E-06 6.83E+02 2.01E+03 1.37E+06 3.43E-01 6.25E-06 6.83E+02 2.09E+03 1.43E+06 3.57E-01 6.50E-06 7.24E+02 2.13E+03 1.54E+06 3.85E-01 6.75E-06 7.14E+02 2.17E+03 1.55E+06 3.87E-01 7.00E-06 6.83E+02 2.25E+03 1.54E+06 3.84E-01 7.25E-06 6.83E+02 2.25E+03 1.54E+06 3.84E-01 7.50E-06 7.04E+02 2.29E+03 1.61E+06 4.03E-01 7.75E-06 6.83E+02 2.27E+03 1.55E+06 3.88E-01 8.00E-06 6.83E+02 2.41E+03 1.65E+06 4.12E-01 8.25E-06 6.73E+02 2.33E+03 1.57E+06 3.92E-01 8.50E-06 6.63E+02 2.41E+03 1.60E+06 4.00E-01 8.75E-06 6.83E+02 2.41E+03 1.65E+06 4.12E-01 9.00E-06 6.43E+02 2.41E+03 1.55E+06 3.88E-01 9.25E-06 7.14E+02 2.41E+03 1.72E+06 4.30E-01 9.50E-06 6.43E+02 2.45E+03 1.58E+06 3.94E-01 9.75E-06 6.53E+02 2.49E+03 1.63E+06 4.07E-01 1.00E-05 6.43E+02 2.41E+03 1.55E+06 3.88E-01 1.03E-05 6.83E+02 2.41E+03 1.65E+06 4.12E-01 1.05E-05 6.43E+02 2.45E+03 1.58E+06 3.94E-01 1.08E-05 6.43E+02 2.47E+03 1.59E+06 3.97E-01 1.10E-05 6.83E+02 2.49E+03 1.70E+06 4.26E-01 1.13E-05 6.43E+02 2.43E+03 1.56E+06 3.91E-01 1.15E-05 6.43E+02 2.41E+03 1.55E+06 3.88E-01 1.18E-05 6.43E+02 2.41E+03 1.55E+06 3.88E-01 1.20E-05 6.43E+02 2.33E+03 1.50E+06 3.75E-01 1.23E-05 6.43E+02 2.41E+03 1.55E+06 3.88E-01 1.25E-05 6.43E+02 2.41E+03 1.55E+06 3.88E-01 1.28E-05 6.43E+02 2.35E+03 1.51E+06 3.78E-01 1.30E-05 6.43E+02 2.33E+03 1.50E+06 3.75E-01 1.33E-05 6.43E+02 2.33E+03 1.50E+06 3.75E-01 1.35E-05 6.23E+02 2.25E+03 1.40E+06 3.51E-01 1.38E-05 6.43E+02 2.31E+03 1.49E+06 3.71E-01 1.40E-05 6.03E+02 2.25E+03 1.36E+06 3.39E-01 1.43E-05 6.13E+02 2.25E+03 1.38E+06 3.45E-01 1.45E-05 6.23E+02 2.21E+03 1.38E+06 3.44E-01 1.48E-05 6.43E+02 2.17E+03 1.39E+06 3.49E-01 86 Time(S) Volt(V) Current(A) Power(W) Energy(J) 1.50E-05 6.03E+02 2.17E+03 1.31E+06 3.27E-01 1.53E-05 6.03E+02 2.11E+03 1.27E+06 3.18E-01 1.55E-05 6.03E+02 2.13E+03 1.28E+06 3.21E-01 1.58E-05 6.03E+02 2.07E+03 1.25E+06 3.12E-01 1.60E-05 6.03E+02 2.09E+03 1.26E+06 3.15E-01 1.63E-05 6.13E+02 1.99E+03 1.22E+06 3.05E-01 1.65E-05 6.03E+02 1.93E+03 1.16E+06 2.91E-01 1.68E-05 6.03E+02 1.99E+03 1.20E+06 3.00E-01 1.70E-05 6.03E+02 1.93E+03 1.16E+06 2.91E-01 1.73E-05 6.03E+02 1.79E+03 1.08E+06 2.70E-01 1.75E-05 6.03E+02 1.89E+03 1.14E+06 2.84E-01 1.78E-05 5.63E+02 1.85E+03 1.04E+06 2.60E-01 1.80E-05 5.63E+02 1.85E+03 1.04E+06 2.60E-01 1.83E-05 5.73E+02 1.77E+03 1.01E+06 2.53E-01 1.85E-05 5.83E+02 1.69E+03 9.83E+05 2.46E-01 1.88E-05 5.73E+02 1.61E+03 9.20E+05 2.30E-01 1.90E-05 5.63E+02 1.69E+03 9.49E+05 2.37E-01 1.93E-05 5.63E+02 1.61E+03 9.04E+05 2.26E-01 1.95E-05 5.63E+02 1.57E+03 8.82E+05 2.20E-01 1.98E-05 5.93E+02 1.53E+03 9.05E+05 2.26E-01 2.00E-05 6.03E+02 1.53E+03 9.20E+05 2.30E-01 Total 2.40E+01 Time(S) Volt(V) Current(A) Power(W) Energy(J) 0.00E+00 2.81E+02 7.54E-01 -1.12E-05 -2.79E-12 2.50E-07 1.53E+03 7.54E-01 0.00E+00 0.00E+00 5.00E-07 1.95E+03 7.54E-01 0.00E+00 0.00E+00 7.50E-07 1.89E+03 1.62E+02 3.03E+05 7.57E-02 1.00E-06 1.49E+03 1.62E+02 2.38E+05 5.96E-02 1.25E-06 1.28E+03 4.03E+02 5.12E+05 1.28E-01 1.50E-06 1.21E+03 4.43E+02 5.32E+05 1.33E-01 1.75E-06 1.18E+03 5.64E+02 6.60E+05 1.65E-01 2.00E-06 1.17E+03 7.24E+02 8.42E+05 2.10E-01 2.25E-06 1.17E+03 8.25E+02 9.59E+05 2.40E-01 2.50E-06 1.15E+03 9.25E+02 1.06E+06 2.64E-01 2.75E-06 1.16E+03 1.13E+03 1.30E+06 3.25E-01 3.00E-06 1.09E+03 1.13E+03 1.22E+06 3.05E-01 3.25E-06 1.13E+03 1.27E+03 1.42E+06 3.56E-01 87 Time(S) Volt(V) Current(A) Power(W) Energy(J) 3.50E-06 1.13E+03 1.33E+03 1.49E+06 3.73E-01 3.75E-06 1.10E+03 1.45E+03 1.58E+06 3.96E-01 4.00E-06 1.05E+03 1.53E+03 1.60E+06 3.99E-01 4.25E-06 1.08E+03 1.61E+03 1.73E+06 4.32E-01 4.50E-06 1.07E+03 1.69E+03 1.80E+06 4.49E-01 4.75E-06 1.05E+03 1.77E+03 1.85E+06 4.62E-01 5.00E-06 1.05E+03 1.85E+03 1.93E+06 4.83E-01 5.25E-06 1.01E+03 1.85E+03 1.86E+06 4.64E-01 5.50E-06 1.03E+03 1.93E+03 1.98E+06 4.94E-01 5.75E-06 1.01E+03 2.01E+03 2.02E+06 5.05E-01 6.00E-06 1.01E+03 2.01E+03 2.02E+06 5.05E-01 6.25E-06 9.65E+02 2.03E+03 1.96E+06 4.89E-01 6.50E-06 9.45E+02 2.09E+03 1.98E+06 4.94E-01 6.75E-06 9.65E+02 2.17E+03 2.09E+06 5.23E-01 7.00E-06 9.25E+02 2.25E+03 2.08E+06 5.20E-01 7.25E-06 9.25E+02 2.19E+03 2.02E+06 5.06E-01 7.50E-06 9.25E+02 2.33E+03 2.15E+06 5.39E-01 7.75E-06 9.25E+02 2.33E+03 2.15E+06 5.39E-01 8.00E-06 9.25E+02 2.33E+03 2.15E+06 5.39E-01 8.25E-06 8.84E+02 2.41E+03 2.13E+06 5.33E-01 8.50E-06 8.64E+02 2.37E+03 2.05E+06 5.12E-01 8.75E-06 8.54E+02 2.41E+03 2.06E+06 5.15E-01 9.00E-06 8.44E+02 2.41E+03 2.04E+06 5.09E-01 9.25E-06 8.54E+02 2.47E+03 2.11E+06 5.28E-01 9.50E-06 8.24E+02 2.49E+03 2.05E+06 5.13E-01 9.75E-06 8.04E+02 2.49E+03 2.00E+06 5.01E-01 1.00E-05 8.04E+02 2.49E+03 2.00E+06 5.01E-01 1.03E-05 8.04E+02 2.41E+03 1.94E+06 4.84E-01 1.05E-05 8.04E+02 2.45E+03 1.97E+06 4.93E-01 1.08E-05 8.04E+02 2.49E+03 2.00E+06 5.01E-01 1.10E-05 7.64E+02 2.49E+03 1.90E+06 4.76E-01 1.13E-05 7.64E+02 2.47E+03 1.89E+06 4.72E-01 1.15E-05 7.64E+02 2.49E+03 1.90E+06 4.76E-01 1.18E-05 7.34E+02 2.49E+03 1.83E+06 4.57E-01 1.20E-05 7.64E+02 2.41E+03 1.84E+06 4.60E-01 1.23E-05 7.24E+02 2.41E+03 1.74E+06 4.36E-01 1.25E-05 6.83E+02 2.37E+03 1.62E+06 4.05E-01 1.28E-05 6.93E+02 2.33E+03 1.62E+06 4.04E-01 1.30E-05 6.83E+02 2.33E+03 1.59E+06 3.98E-01 1.33E-05 6.83E+02 2.33E+03 1.59E+06 3.98E-01 1.35E-05 6.83E+02 2.33E+03 1.59E+06 3.98E-01 88 Time(S) Volt(V) Current(A) Power(W) Energy(J) 1.38E-05 6.53E+02 2.33E+03 1.52E+06 3.80E-01 1.40E-05 6.83E+02 2.17E+03 1.48E+06 3.71E-01 1.43E-05 6.53E+02 2.17E+03 1.42E+06 3.54E-01 1.45E-05 6.63E+02 2.17E+03 1.44E+06 3.60E-01 1.48E-05 6.43E+02 2.17E+03 1.39E+06 3.49E-01 1.50E-05 6.43E+02 2.09E+03 1.34E+06 3.36E-01 1.53E-05 6.43E+02 2.17E+03 1.39E+06 3.49E-01 1.55E-05 6.23E+02 2.09E+03 1.30E+06 3.25E-01 1.58E-05 6.13E+02 2.07E+03 1.27E+06 3.17E-01 1.60E-05 6.03E+02 2.01E+03 1.21E+06 3.03E-01 1.63E-05 5.93E+02 2.03E+03 1.20E+06 3.01E-01 1.65E-05 5.83E+02 2.01E+03 1.17E+06 2.93E-01 1.68E-05 6.03E+02 1.93E+03 1.16E+06 2.91E-01 1.70E-05 5.63E+02 1.85E+03 1.04E+06 2.60E-01 1.73E-05 5.63E+02 1.87E+03 1.05E+06 2.63E-01 1.75E-05 5.83E+02 1.77E+03 1.03E+06 2.58E-01 1.78E-05 5.63E+02 1.85E+03 1.04E+06 2.60E-01 1.80E-05 5.23E+02 1.77E+03 9.24E+05 2.31E-01 1.83E-05 5.63E+02 1.69E+03 9.49E+05 2.37E-01 1.85E-05 5.63E+02 1.73E+03 9.72E+05 2.43E-01 1.88E-05 5.63E+02 1.69E+03 9.49E+05 2.37E-01 1.90E-05 5.23E+02 1.61E+03 8.40E+05 2.10E-01 1.93E-05 5.63E+02 1.61E+03 9.04E+05 2.26E-01 1.95E-05 5.23E+02 1.53E+03 7.97E+05 1.99E-01 1.98E-05 5.53E+02 1.53E+03 8.44E+05 2.11E-01 2.00E-05 5.63E+02 1.53E+03 8.59E+05 2.15E-01 Total 2.91E+01