Design and Implementation of Super Twisting Sliding Mode Control for PV Grid-connected Water Pumping System

This article proposes a super twisting sliding mode controller (ST-SMC) for its novel application in the domain of PV grid-connected water pumping system. The ST-SMC is intended to inject both active and reactive power with sinusoidal current of low total harmonic distortion (THD) to the non-linear load such as water pumping system. Excess active power generated by the PV array is fed to the grid and reactive power requirements of the load are fulfilled by the ST-SMC controlled inverter. The proposed control methodology is tested on the DC link voltage, maximum active power extracted from PV array, reactive power supplied by the inverter, and the THD of inverter current. The ST-SMC reduces chattering, provides easy real-time implementation, and offers insensitivity to parameter variations and model uncertainties. Thus, the proposed control strategy is able to maximize the extracted energy from PV while regulating DC–link voltages and achieving a power factor compensation and reduces the harmonics from inverter current. The proposed control methodology is implemented in MATLAB/Simulink and its performance is compared with conventional PI-based control method.