说明：  his 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 fdter is shown to improve power quality by lowering the distodon 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 fdter when it has a limited rating is then demonstrated. In one case the voltage distortion is made worse by the active fdter. The requirements that various transient events, including capacitor switching and induction motor starts, place on the shunt active tilter design ace outlined. These requirements are such that the required switching frequencies exceed those attainable with ICBTs and transient ratings dominate the active fdter design constraints.