Research And Design Of Three Phase Series Active Power Filter

As the rapid development of power electronics and the common use of power devices, there are more and more harmonic emerges in power system.All over the world,People become concerning about the power qulity issue.Active Power Filter(APF),as one effective method to correct the power harmonic,can dynamically trace and compensate any harmonic which is varying in frequency and amplitude,while network impedence has no effect on the compensation performance.Therefore,APF becomes an important trend to restrain power harmonic.Nowadays,the application and development of shunt APF is prevalent.At the same time, series APF spreads much slower than the former for its difficulty in control system. However,since the circuit structure characteristic of series APF,it triumphes over the shunt APF on compensating voltage type harmonic source.As there are more and more voltage type harmonic sources in power systems,it makes sense to do researches on series APF.Firstly,this article introduces the basic principle and structure of series APF,then presents a real time detecting method of harmonic voltage for three-phase circuit based on the instantaneous reactive power theory.By analyzing the simulation results,it is shown that the proposed detecting method has high precision and good real time performance, thus can precisely detect voltage type harmonic,and is especially suitable for the series active power filter.In chapter 3,the article introduces the control stratege of series APF,such as the control approach of detecting source harmonic current,the control approach of detecting load harmonic voltage and the composite control approach.Then the control scheme of the PWM converter and the DC side voltage is discussed.Through the researches which have been carried out for series active power filter in chapter 4,the selection of the main circuit switching components,DC bus voltage value, DC bus capacitor value,the design of the transformer and the high frequency filter,etc.are discussed detailedly.These parameters have great influences on the steady and dynamic compensation characteristics of series APF.Based on the former chapers,chapter 5 completes the modeling and simulation of the three-phase series APF using Matlab/Simulink.A comparative study on the diffrences between different control approaches' compensation performances is done.The results show that the real time detecting method of harmonic voltage and the control approaches proposed for the series APF are correct and feasible.