Study Of HODFC And Its Application In The Shunt Active Power Filter

In the latest ten years, Active Power Filter (APF) is developed as a novel electronicdevice that can attenuate the harmonic and reactive currents. It can compensate theharmonics varying in amplitude and frequency, improve the power quality, enhance thereliability and stability of electrical equipments and improve the efficiency of the powersystem.This paper introduces two kinds of harmonic current detection methods based on theinstantaneous reactive power theory and the basic principles of shunt APF. And we alsopresent several major control strategies of the main circuit and the configuration ofsystems.Andthetwoharmoniccurrent detection methodsinthree-phasecircuitsbasedonthe instantaneous reactive power theory are modeled and simulated making use of PowerSystemToolbox(SimPowerSystem)inMATLAB/SIMULINK.To improve the control of APF and the effect of harmonic suppression, this paperproposes a high order differentiator (HOD), which does not depend on the system model,and designs a high order differential feedback controller (HODFC) based on the HOD.Both theoretical analysis and simulation results show that the HOD has good stability,high accuracy and good filter characteristics. And it can also extract one-order andhigh-order differential of the signal in high-quality. It can be proved that the HODFCsystem doesn't depend on the precise mathematical model of system and has strongrobustness.Finally, this paper first applies the proposed HODFC to the control of DC sidevoltage in shunt APF. Simulation results show that the control system of shunt APF basedon HODFC has good control effects, easier parameter adjustment, strong robustness andso on. The problem of applying HODFC to APF is discussed preliminarily in this paperand the feasibility and effectiveness of HODFC in the field of APF control are alsoverified.