A NEW APPROACH TO STABILITY LIMIT ANALYSIS OF A SHUNT ACTIVE POWER FILTER WITH MIXED NON-LINEAR LOADS

In this paper, a new approach to evaluate the operation of a shunt Active Power Filter (APF) is presented. The filter consists of a three-phase current-controlled voltage source inverter (CC-VSI) with a filter inductance at the ac output and a dc-bus capacitor. The CC-VSI is operated to directly control the ac line current to be sinusoidal and in phase with the grid voltage. The compensation is successful if the current and voltage controller operates within the stable and controllable area. The area boundaries are established from current control loop equations and voltage control loop transfer function. The simulation results indicate that the new approach is simple for analyzing the stability and controllability of the system for various loads and system parameters