Research On Active Power Filter Based On DSP

The harmonic pollution problem of the power system is severe day by day, and the people's demand of power reliability and power quality is higher than before. The traditional passive filter could not meet the users' demand of power quality. Active Power Filter (APF) may overcome the disadvantages of the traditional approaches for eliminating harmonics (such as, the passive filter). With the superexcellent performance, APF has obtained more attention. With the fast development of digital signal processing technology, digital controlled APF becomes a new research focus in the power electronics field.The shunt voltage-type APF has been analyzed in this paper, in terms of the working principle, the compensation characteristics, the harmonic current detection approaches, the current compensation strategies and the dc-link voltage control. Digital PWM control technology has been used to design the control circuit. Based on a TMS320F240 EVM board, the hysteresis control algorithm has been implemented. In order to ensure the good compensation characteristic of APF, the dc-link voltage feedback control loop is employed. The approach of detecting harmonic current, which has favorable real-time characteristic, is simple to be realized by hardware.In this paper, simulation on the compensation control of load current has been carried out. The simulation results show that APF could achieve good compensation performance based on the appropriate parameters.The paper is based on the research project "Development and Application of Active Power Filter" of JILIN Province Power Co. Ltd. A 380V 5kVA shunt voltage-type APF experiment prototype using TMS320F240 is implemented. The experimental tests verify the effectiveness of the compensation algorithm.