Research On Shunt Active Power Filter Harmonic Detection And Hysteresis Current Control Strategies

With the development of electronics devices manufacturing process and control theory, the extensive use of electronics devices becomes realty; however, the extensive use of power electronic devices will inevitably bring about power quality problems, resulting in unnecessary economic losses. APF (Active Power Filter, APF) is recognized as one of the most effective means to realize harmonic control and improve power quality, having become a research focus. Therefore, in this article extensive research on digital low pass filter in current detection, current control and implementation techniques have been conducted. These studies have an important significance on the products of the APF.This paper introduces the development status of APF in the research of topology structure, harmonic detection technology and control technology. The filtering effect and performance of different digital low pass filter are researched, and the elliptic digital low pass filter is designated. According to the performance of the microprocessor in digital low-pass filter and the requirements of harmonic detection, the IIR algorithm is selected as a digital low-pass filter algorithm. The dynamic performance of the detection algorithms are analyzed, put forward an improved elliptic filter with lead lag correction network harmonic detection method, the dynamic response is accelerated and good steady-state performance is get, simulation results that the rationality of the algorithm is verified.In the light of the switching principle of PWM of IGBT that is mainstream of APF switching element, ITAE control theory is used to build and analysis PWM converter. Using the MATLAB to build the model, the high frequency square wave signal is tracked, and the optimal control parameters are obtained. The harmonic linearization method and hysteresis current controller design is introduced, combined with the optimal control strategies and divergence law, a controller is designed to solve the problem of time delay, nonlinear and robustness. and the PSIM simulation software is used to prove the correctness.