Three Level Hysteresis Function based Sliding Mode Control of Three Phase PWM Inverter for Shunt Active Power Filter Application in Distribution Network

In this paper, a Three-Level Hysteresis based Sliding (TLHSM) function approach to regulate output currents of three-phase capacitor powered Voltage Source Inverter (VSI) is analyzed and implemented. VSI functions as shunt active power filter to compensate for harmonic currents generated by a nonlinear load in the power distribution network. The performance of the control is compared with conventional two-level hysteresis-based control through simulation in MATLAB/Simulink. Sliding Mode Control (SMC) is recognized as robust controller with a high stability over a wide range of load and source variations. The set-back of unfixed switching frequency problem with conventional two-level hysteresis control is disregarded in this approach. Switching frequency prediction is observed to be accurate. The tracking error and Total Harmonic Distortion (THD) in source currents are the measurable parameters for evaluation of control effort and is within the limits specified by IEEE519:2014 recommendations.