Performance evaluation of HCC & SVPWM current controllers for shunt APF under fault conditions

Different control strategies for shunt active power filter (APF) are reported in literature several of them have satisfactory response under normal operating conditions, but there is still some confusion regarding the preferable controller for the shunt APF under normal and fault conditions. This paper evaluates the performance of shunt active filter for two different control strategies namely Hysteresis Current Control (HCC) and Space Vector Pulse Width Modulation (SVPWM). Synchronous reference frame based controller for a three phase three wire voltage source shunt active power filter has been selected for the study. The APF is designed for a 30kVA load. Simulation has been performed under steady state and transient conditions for various loads. The APF with these controllers are found to meet IEEE 519 standards on harmonic levels. To evaluate their performance under fault condition, simulations under L-L and L-G fault conditions were carried out under different load conditions. Performances of the two controllers vary under fault conditions. The voltage stresses and peak currents under fault conditions provide valuable guideline for specifications & design of the converter elements and also for protection equipments ratings in the supply system. For the load conditions investigated, HCC controller seems to be a better performer when fault occurs.