Reliability improvement in 33kV network by introduction of optimally located load break switches

Abstract

According to observations made on the reliability level which is indicated by reliability indices such as System Average Interruption Duration Index (SAIDI) and System Average Interruption Frequency Index (SAIFI), 33kV network of the Ceylon Electricity Board shows poor performance on the aspect of network reliability. These observations have urged the necessity of analyzing the 33 kV network on reliability point of view and proposing a cost effective method to improve the reliability level of the 33kV network. In addition to improve consumer satisfaction, reliability improvement of the 33kV distribution network shall make significant positive impact on the economy of the country since the recovery of unserved electrical energy has provided considerable benefits to industrial and other consumer categories. For this study, 33kV network of North Central Province (NCP) was selected and analyzed focusing on the reliability of the network using the distribution planning software-SyneerGEE. This involves producing a model compatible to existing reliability level of 33 kV network by providing required data. Required data for model for reliability analysis shall be obtained by processing the available data relating to network reliability. Proposed method for the reliability improvement of the network is introduction of optimally located remote operated Load Break Switches (LBS). Fault indicators having remote communication facility are proposed to install and to be operated for the identification of fault location. Above methods were simulated on prepared model which is compatible to the existing reliability level of 33kV network of NCP and searched for the best cost effective option. Number of LBSs that should be installed for a particular feeder, locations at where those LBSs should be installed to get the maximum reliability improvement of the network and target reliability level of each feeder were mainly determined by considering the cost of unserved energy and the cost for the utility for the improvement of reliability up to the required level.