EECon - 2018Electrical engineering conferencehttp://dl.lib.uom.lk/handle/123/173392024-03-28T08:56:33Z2024-03-28T08:56:33ZHigh performance AC-AC regenerative 5-level NPC converter with capacitor voltage balancingKarunadasa, JPBandara, IBHDayananda, WDDKumara, KGSUTennakoon, GMRhttp://dl.lib.uom.lk/handle/123/175482022-06-21T09:22:39Z2018-09-01T00:00:00ZHigh performance AC-AC regenerative 5-level NPC converter with capacitor voltage balancing
Karunadasa, JP; Bandara, IBH; Dayananda, WDD; Kumara, KGSU; Tennakoon, GMR
Samarasinghe, R; Abeygunawardana, S
Regenerative AC-AC converters are required for
serving AC loads that draw and return power during operation,
when input is also taken from an AC source. AC motor drives,
static VAR compensators, harmonic compensators and inverter
testbeds are some of the examples using regenerative AC-AC
converters. Generally, these are implemented as 2-level converters
and operated with Pulse Width Modulated (PWM) control,
incorporating higher switching frequencies. The use of higher
switching frequencies leads to correspondingly higher switching
losses and EMI issues. This paper describes the development
of a 5-level regenerative AC-AC converter that can deliver
equally good performance but operating at very low switching
frequencies. It was developed as part of a testbed for performance
testing of grid-tie solar PV inverters. The output specifications
were accordingly drawn to comply with the requirements of
IEEE1547. Input specifications were chosen to produce sinusoidal
current and inphase with input voltage all the times. The
converter employed back-to-back connected 5-level neutral point
clamped (NPC) structure with middle DC-link. The input stage is
operated with current control and the output stage with voltage
control. DC-link capacitors were equipped with separate voltagebalancing
circuits so that the voltage across each capacitor
could be regulated at the nominal value all the times. The
details of design, operation, control and simulation with operating
waveforms are presented in the paper.
2018-09-01T00:00:00ZDesign of a small electric vehicle charger with multi-portsWijesekera, ABinduhewa, Phttp://dl.lib.uom.lk/handle/123/175472022-06-21T09:22:45Z2018-09-01T00:00:00ZDesign of a small electric vehicle charger with multi-ports
Wijesekera, A; Binduhewa, P
Samarasinghe, R; Abeygunawardana, S
In developing countries, small vehicles such as three-wheelers are one of the most commonly used public transportation method and considered as an efficient way to travel in the traffic. Even though the commonly used type is based on fossil fuels, fully electric small vehicles are commercially available and developing. The biggest hurdle for the expansion of small Electric Vehicles (EVs) is the unavailability of charging stations around the country. This paper presents a charging station for small EVs. The proposed charging system has the capability of charging multiple small EVs simultaneously. Also, the charging station is capable of bi-directional power flow and thus small EVs can support grid when required. The performances of the controllers are verified by simulating the system in PSCAD/EMTDC. Finally, a cost analysis also was carried out to find out the financial feasibility.
2018-09-01T00:00:00ZModeling and simulation of an electromechanical system for a hybrid rubber tire gantry craneBolonne, SRAChandima, DPhttp://dl.lib.uom.lk/handle/123/175462022-06-21T09:22:07Z2018-09-01T00:00:00ZModeling and simulation of an electromechanical system for a hybrid rubber tire gantry crane
Bolonne, SRA; Chandima, DP
Samarasinghe, R; Abeygunawardana, S
This paper presents study on the modeling of a Rubber Tire Gantry Crane (RTGC) used in container terminals for container handling. The electrical systems and mechanical systems are modelled by specific blocks from the Power System and Driveline block-sets while the control systems are modeled using Simulink. An “average modeling” approach is selected to simplify the operation of the motor drives and to speed up the simulation for tuning control parameters during long simulations. The model has the potential to be used for simulating a hybrid power pack, incorporating an energy management system for RTGC.
2018-09-01T00:00:00ZDesign optimization of a power generator soundproofing enclosureDe Zoysa, ADNIroshan, KAPremaratne, UKEhelepola, Ihttp://dl.lib.uom.lk/handle/123/175452022-06-21T09:22:45Z2018-09-01T00:00:00ZDesign optimization of a power generator soundproofing enclosure
De Zoysa, ADN; Iroshan, KA; Premaratne, UK; Ehelepola, I
Samarasinghe, R; Abeygunawardana, S
It is a vital requirement to have passive noise control
enclosure in order to depress air borne noise of reciprocating
engine type power generators. The design of these enclosures
needs to be optimized in terms of the sound pressure level
and the designing cost. We have used the existing acoustic
equations to obtain the optimization based on the objective
functions derived for the sound pressure level and enclosure design
cost. Metaheuristic optimization algorithms such as genetic
algorithms and particle swarm algorithm are capable of solving
these optimization problems which have constraints for different
parameters. The results obtained for a real world design problem
confirms that particle swarm optimization provides better results
than genetic algorithm in terms of optimality of the solutions and
also the computational efficiency. Furthermore, it was observed
that there is a significant linear relationship (R-Squared = 99.3%,
p-value < 0.001) between the minimum enclosure design cost
and the sound pressure level of the enclosure (SPLE) for the
preferred range for SPLE values (65 to 70). The minimum
possible enclosure design cost increases linearly with decreasing
SPLE value. Therefore, the least possible SPLE value depends
on the available financial resources.
2018-09-01T00:00:00Z