Simulation Analysis of Output Filter in PAPF System

Parallel active power filters (PAPF) are used to eliminate current harmonics produced by loads,and thus reduce the harmonic contents of electrical grids and improve power quality. Generally,the main control circuit of a PAPF system uses Pulse Width Modulation (PWM) and produces harmonics around the switching frequency of the PWM. An output filter (OF) can eliminate these harmonics. The output filters used are usually second-order Butterworth low pass filters (LPF). Usually,most research focuses on the design of the OF,and it is rare that an analysis of the filter's influence is performed. A method for the design of output power filters was proposed,and the influence of the output filter on PAPF system performance was investigated. Simulation results have validated the analysis and design of the output filter.