Research On Key Technologies Of Active Power Filter Based On Repetitive Control

Due to the rapid development of power electronic science and technology,the large-scale application of power electronic equipment will have a major impact on urban power supply conditions.Active power filter(APF)have become a key research topic in harmonic management due to their ability to suppress harmonics,compensate reactive power,and improve power environment.This chapter takes the shunt active power filter as the main research scope,focusing on the parameter setting of the active power filter,the harmonic current detection link,the current tracking control link,the DC voltage control link and other aspects of research work.This paper firstly introduces the classification and topology of the active power filter,as well as the working principle and mathematical model of the active power filter,and then analyzes and designs the main parameters of the circuit.Secondly,the theory of instantaneous reactive power is introduced,and the p-q detection method and the ipiq detection method are compared and analyzed.Aiming at the problem of detection accuracy of traditional phase-locked loop in ip-iq method,this article proposes a phaselocked loop based on an improved SOGI-PLL,which improves the ability to quickly lock the frequency under different working conditions,because the improved SOGI can filter out DC components and harmonics,and string them into the detection route of the ip-iq method to further improve the detection accuracy of the first harmonics by the ipiq method.The model is built by Matlab simulation,and the correctness of the proposed improvement strategy is verified.Secondly,the structure and principle of repetitive control of current tracking control are introduced,and the auxiliary compensator and compensator in the control structure are analyzed and designed.An APF composite control strategy based on frequency self-adaptation is proposed to solve the problem of frequency adaptation of repetitive controllers and improve the system’s ability to track signals.Then,on the basis of analyzing the DC voltage control,the APF DC voltage is stably controlled by using the active disturbance rejection control theory instead of the traditional PI algorithm,which provides a good foundation for the current loop tracking control.Finally,the overall simulation model is simulated on MATLAB/Simulink software,and the PI+ repetitive control method and the APF composite control strategy based on frequency adaptation proposed in this paper are simulated and analyzed respectively to analyze the effectiveness and feasibility of the strategy.The simulation results show that the proposed control method can improve the harmonic suppression effect,promote the improvement and optimization of the power grid environment,and provide a reference for the future work in the field of harmonic suppression in engineering.Fig.ure [52] table [6] reference [81]...