Optimal Placement and Sizing of Solar Photovoltaic System in Radial Distribution Network for Active Power Loss Reduction

Abstract

The integration of Distributed Generation into electric power systems has considerably increased to meet the increasing load requirements and provide environmental benefits. More attention has been given to Solar Photovoltaic (SPV) energy in the last decade because SPV technology provides the most direct way to convert solar energy into electrical energy without carbon dioxide emissions, or greenhouse effects; it also provides reliable, clean, efficient and continuous source of electrical energy to consumers. Optimal placement of SPV in the radial distribution system considerably reduces the active power loss and also improves the voltage profile. However, a limited study has been carried out on this. Therefore, the analysis of the optimal placement of SPV becomes mandatory to maximise the benefits of the DG integration. In this thesis, strategically siting and sizing of the SPV for loss reduction in a radial distribution network (RDN) were studied with various loading cases and tested on a standard IEEE 33-bus test RDN system, while considering constraints on the power generation capacity and the voltage limits of the SPV penetration. The technique used the branch current loss formula to evaluate the power loss and the size of the DG to be placed to reduce the power loss. The initial total power loss of the system was evaluated through the load flow analysis using Backward/Forward sweep method. The total power loss with the DGs injected was subtracted from the total initial losses to get the total loss saving for each DG placed at each node and the candidate node with the highest power loss saving was identified for the optimal placement of the DG. Furthermore, the optimal DG size was evaluated using the branch current injected at the optimal node. Results obtained in this analysis show a power loss reduction of 49% and a voltage improvement from 0.9134 p.u to 0.9507 p.u when injecting the SPV of 2.4752 MW at node 6. Clearly, optimal placement and sizing of SPV leads to reduced power losses and improved voltage profile.