Research And Implementation Of Active Power Filter In Three-phase Four-wire System

Without the support of the power system, there will not be rapid development of modern industry. However, with the increasingly widespread use of power electronic devices, electrical equipment requires more and more high power quality, and power pollution is increasingly valued by the people. How "green" power, has become increasingly important topic in the field of power systems. Harmonic content and reactive power are two important indicators of power quality. Active power filter is a new type of dynamic reactive power compensation and harmonic electrical installations and it plays an increasingly important role in the field of power quality.This article has described the generation and harm of harmonics, harmonic standards, domestic and international trends APF development, and the basic structure of the active power filter, principle, classification, simulation studies, the final production prototype verification.In this paper, three-phase four-wire grid system as the research object, focusing on the detection algorithm based on instantaneous reactive power theory and recursive discrete Fourier detection algorithm and its simulation study. And detection algorithm based on recursive discrete Fourier full harmonic compensation and certain compensation harmonic modes simulation study, draw two models can achieve compensation effect. Studied and simulated the diode clamp type three level structure, also improved this structure. This paper analyzes the structure of the main circuit and the capacitor midpoint formula H-bridge was integrated to obtain a higher cost -effective structure of the main circuit. This paper presents a insert the zero level control algorithm, has improved the effect of the compensation device.On the basis of simulation, the establishment of a main controller STM32F4 APF experimental model. Made software and hardware design, including a sampling of current and voltage, grid voltage lock,detecting harmonic current, DC capacitor voltage control, timing transient comparator follower algorithm, interruption protection etc.In this paper, the main experimental device selection of the filter inductor, DC capacitors, power switches, using theoretical calculations and the actual combination of methods.Finally, APF device debugging. Experimental results show that the proposed algorithm, the structure can effectively suppress harmonic, experimental verification of this article APF apparatus performs hardware and software and algorithms, structure design.