Optimal Placement of Electric Vehicle Charging Station and Shunt Capacitor in Radial Distribution System

Abstract

Increasing sensitivity to climate change and rising fuel prices led to a greater demand for cleaner and sustainable energy sources. Technological advancement and environmental awareness are the main driving force in the transition from conventional vehicle to the electric vehicle. The rapid growth of electric vehicles has prompted the need for an efficient charging infrastructure. The integration of charging stations in the current distribution system is a critical aspect of promoting electric vehicle adoption as it poses threat to the grid stability and reliability. Active and reactive power demand of electric vehicle charging station increases the power loss in the existing distribution system and degrade the voltage profile of the individual buses. Hence, researchers are committed to optimize the integration of EVCS in the distribution system.

This study puts forward the application of genetic algorithm for the optimal placement of EVCS by formulating the objective function minimizing the voltage sensitivity index, reliability indices like ENS, AENS, SAIDI, SAIFI and CAIDI as well as active power losses. Further, using the GA, optimal placement and sizing of shunt capacitor has been proposed to improve the voltage profile and reduce the losses in EVCS integrated system. The optimization task has been performed in MATLAB. Initially, optimization work has been formulated for IEEE 33 bus system. The effectiveness has been validated by collating the voltage profile, active power loss and reactive power loss of base case system, random placement of EVCS, optimal placement of EVCS and optimal placement of shunt capacitor in EVCS merged system. Later the work has been authenticated in the Jawalakhel feeder. The optimal location of EVCS has been determined at bus no 2, 19 and 20 in IEEE 33 system and at bus no 3, 4 and 25 in Jawalakhel feeder. Similarly the buses for the installation of shunt capacitor of sizes 472.4 kVAR and 1061.3 kVAR is ascertained at 12 and 30 in IEEE 33 bus and 1244.4 kVAR and 1786.7 kVAR at bus 6 and 20 in Jawalakhel feeder. From the comparative study the voltage profile has appreciably enhanced by the optimal placement of EVCS and capacitor. The total active and reactive power losses reduced from 0.2027 MW to 0.1168 MW and 0.135 MVAR to 0.07 MVAR in IEEE 33 bus system and reduced from 0.177 MW to 0.1378 MW and 0.238 MVAR to 0.1853 MVAR in Jawalakhel feeder.