Research And Realization On Active Power Filter And Power Factor Compensation Controller

With the increasing development of electric power systems, the problems of harmonic pollution in power systems are more and more serious. Active power filter (APF) is used widely in production and life because it is able to compensate and filter harmonic current and reactive power dynamically. However, the electronic equipments based on circuit structure of inverters need to output compensation current in different frequency and amplitude,so the request of electronic equipments on accuracy of control is high. And it is expensive for higher power level application.This paper firstly accounts for the principle of APF, then introduces Thyristor Switched Capacitor (TSC) to the active power filter and power factor compensation device on the basis of Shunt APF. The paper puts forward the APF + 3 TSC structural framing after the analysis the combination of APF and 3 TSC on application and establish mathematical model. The dynamic compensation performance of Active power filter is great and the compensation precision of it is high. TSC based on capacitors is able to compensate large capacity of reactive power. In the actual application, TSC is firstly used to preliminary adjust load side of reactive, then fine tuning of the harmonics and reactive in the use of APF, at the same time, compensation is needed to make up for harmonic waves produced by TSC.In actual work, the work of APF and TSC are of independence but interrelate with each other throughout the process. This paper studies both on APF part and TSC part. The method of mutative bandwidth hysteresis is adopted aiming at reducing switching loss which is brought by fixed bandwidth of APF’s inverts and improving control precision. In this method, fuzzy controller will set up different values of width according to different situations. In the TSC part,mathematical model of Thyristor Mechanically Switched Capacitors is analyzed and switching time of different conditions is confirmed.The last is the simulation study of the whole system’s control method in use of MATLAB simulation software. Through Simulation, the validity and feasibility of the theoretical analysis is tested.