Study On Control And Detecting Method For Active Power Filter

Recently, energy efficiency is greatly increased due to the application of many power electronic equipments in electric power system. However, the harmonic pollution caused by those facilities has catched people's attention. In these facilities used to reduce harmonic pollution, active power filter (APF) will become the focus in the future study because of its favorable dynamic response and compensating characteristics.In this dissertation, first, the APF's concept, principle and development are separately described in detail, and a practicality real-time precision harmonic current detecting method is presented, which is based on the instantaneous reactive power theory and the balance of power and no need to take complex computation. Secondly, the control loop of APF is optimized and a variable structure control model is adopted, so the dynamic response of power circuit is ameliorated. In the end, a design idea of power module based on IGBT technology is bring forward to increase APF's capability, and a optimized harmonic compensating plan according to real project can be obtained. Afterwards, the concrete process of constructing a shunt APF is given. parameters of the main circuit are discussed in detail, hardware platform based on open-standard CPCI bus is established and the local bus used in communication of each circuit board utilizing user-defined CPCI interface is designed to ensure data sharing and real-time characteristic of shunt APF. schemes of each single circuit board and configuration of software based on the hardware platform given above are realized.In practice, the electric power simulation software MATLAB which is widely accepted by researchers is used to analyze the harmonic current detecting method, control structure and power circuit topology mentioned in this dissertation. Such, this plan is proved to be feasible.