The Research And Simulation On Hysteresis Current Control For Shunt Active Power Filter With Constant Switching Frequency

With the development of power electronics, various power electronic devices are more widely used to the power system, making the harmonic pollution serious, power quality dropped drastically. As a compensation device, harmonic active power filter can effectively filter out the power system harmonics and reactive component, to improve power quality, active power filter with harmonic suppression has become a major power electronics technology research topic.This paper discusses the status of Active Power Filter and trends, describes the fundamental working method of active power filter, and the active power filter are classified from different perspectives, analyze their different characteristics.In the harmonic detection part, the paper discusses the theory of instantaneous reactive power based on the Harmonic and reactive current real-time detection method: p-q method and the ip-iq method, the two methods were compared.In the control strategy, the paper briefly describes several commonly used control methods of active power filter: hysteresis current control, triangular wave modulation, sinusoidal pulse width modulation, space vector PWM control, and the traditional hysteresis current control deficiencies, adopted a control method called constant switching frequency hysteresis current control, as the subject control method used in the paper, what is more, it introduces the main circuit DC bus voltage control.We choose digital signal processing chip TMS320LF 2407 as the core of the processor, design the active power filter system hardware circuit. Detailed sampling of current detection circuit, the sampling capacitor voltage detection circuit, the zero detection circuit, phase-locked frequency circuit and IPM module hardware design. The selection of home made circuit parameters of calculation. And design the software system of active power filter.Finally, we choose ip-iq method as harmonic detection method, use Matlab simulation software for parallel active power filter system simulation experiment, compare and analyze the simulation result of the traditional hysteresis current control and constant frequency hysteresis current control strategy, the results of the simulation and experiment validate the correctness and effectiveness of the active power filter harmonic detection algorithms and the control strategies.