The transient and steady state performance of a shunt active filter using measured site data

This paper presents the analysis of real power system events recorded at a light industrial site to determine the effect of a shunt active filter on power quality. The shunt active filter is shown to improve power quality by lowering the distortion of the supply voltage in both the transient and steady state. The shunt active filter power rating and other design information are also determined. The performance degradation of the shunt active filter when it has a limited rating is then demonstrated. In one case the voltage distortion is made worse by the active filter. The requirements that various transient events, including capacitor switching and induction motor starts, place on the shunt active filter design are outlined. These requirements are such that the required switching frequencies exceed those attainable with IGBTs and transient ratings dominate the active filter design constraints.