Robust Sliding Mode Controller and Shunt Active Power Filter for Improvement of Power Quality Indices of an Autonomous Microgrid

The exploding population and vast increase in industrialization have led to a many fold increase in the utilization of electrical energy in recent decades. The utilization of small renewable generating units owing to the depletion of nonrenewable energy resources has given rise to the microgrid. The increase in complexity and quantity of the nonlinear loads and the deep penetration of the microgrid in traditional grid systems has given rise to power quality issues due to the complementary converters and FACT devices associated with the microgrid. These power quality issues must be taken care of for the healthy and efficient operation of the grid system; otherwise, they may cause maloperation of the equipment associated with the generation and distribution system. The Shunt Active Power Filter (SAPF) is a device used to improve the power quality of the distribution network by injecting compensating current into the system. In this study, the sliding mode control approach is utilized to tune the SAPF and improve the power quality issues associated with a PV and wind power-based microgrid. In addition, the efficiency of the proposed controller is verified by comparing the outcomes with that of PI controller-based SAPF. The power quality issues considered in this study are active power (P), reactive power (Q), voltage deviation (%), and Total Harmonic Distortion (THD). The proposed MG model has been simulated for two cases: increased line impedance and increased active power to verify the suggested controller operation. The results obtained for both cases are compared with PI- and SMC-based SAPF controllers.