Sliding Mode Control for Frequency Support in a Microgrid with Penetration of Electric Vehicle Aggregator

To support sustainable development goals, the penetration of electric vehicles (EVs) increases day by day on the microgrids (MGs). As a result, MGs have deficiency in inertia and it can further degrade frequency stability. Thus, a supplementary Sliding Mode Control (SMC) strategy is implemented in the secondary loop for microgrid frequency regulation in the presence of an EV aggregator system. Using suggested SMC scheme, the penetration levels of EVs are regulated according to microgrid frequency deviations. The SMC switching law is formulated using grid frequency deviation for both MG and EV aggregator system. The asymptotic stability of the proposed control approach is ensured through the Lyapunov stability theorem. The effectiveness of the SMC strategy is evaluated through MATLAB simulations under varying load conditions. Simulation results demonstrate that the proposed SMC scheme significantly improves frequency regulation by minimizing overshoot, undershoot, and settling time, even under system uncertainties caused by load variations. The results validate the effectiveness of the proposed SMC approach for frequency stability in MGs with high EV aggregator penetrations.