Electric vehicle operation modes with reactive power support using SMC in distribution generation

Abstract

In this work, a single phase 120 V rms, 60 Hz on-board Electric Vehicle (EV) battery charger with capacity 100 Ah for operation in Grid to Vehicle (G2V) and Vehicle to Grid (V2G) with Reactive Power Support using Sliding Mode Controller (SMC) is presented. The controller is chosen for its robustness and steady tracking precision. State space models of G2V and V2G of EV are derived and good stability margins are obtained using frequency response characteristics. SMC is found to be good in tracking the dc voltage in G2V and grid current in V2G with less steady state error. THD in grid current is 0.645 % during G2V and 1.95 % in V2G which are comparatively less than in Proportional plus Integral (PI) and Proportional plus Resonant (PR) controllers. Dynamic nature of SMC is found to be robust during grid frequency variations. It delivers less steady state error of 1.52 % and settling time of 0.1 s during charging and discharging operations. Phase planes are presented to understand finite convergence of SMC. Reactive power support to the grid operation is presented without affecting the state of charge (SOC) of the battery. Solar based charging circuit is discussed for EV charging. The SOC depicts changeover state from normal to solar charging reaching 100% within short period. SMC was designed to be robust against bounded perturbations and also guarantee stability and finite convergence. PSCAD v4.6 software is used.