Sliding Mode Control based Frequency Regulation in an Island Microgrid

In this study, a sliding mode control (SMC) based microgrid central controller (MGCC) proposes for frequency regulation in an island microgrid. The microgrid is farmed using a diesel generator with governor valve actuator system and plug-in vehicle charging station. The microgrid is considered a localized power system network and minimized the mismatch between the generation and loads. Thus, to achieve better performance and stability, a controller is designed to regulate the frequency in the microgrid. The proposed SMC based MGCC scheme develops via selection of nonlinear switching surface and closed loop system convergence is verified using the Lyapunov's stability criteria. The SMC slides on the switching surface with small chattering signals to minimize the effect of load disturbances and sustains microgrid system in stable region without any oscillations. In addition, the plug-in vehicle charging station is also controlled effectively in both charging and discharging mode using SMC based MGCC. Hence, the SMC based MGCC performances for closed loop microgrid system is demonstrated in presence of step change and random step change in microgrid load through MATLAB© simulations.