单相并联型有源电力滤波器研究

Research on Single-phase Shunt Active Power Filter

针对在传统电流PI控制方式下,单相并联型APF不能充分补偿3次谐波的问题,在不影响系统控制性能及补偿效果的前提下,加入适当的比例-谐振(PR)控制器对原电流PI控制器进行改进,针对性地补偿3次谐波电流。利用LCL型滤波器的优越性在APF的交流侧替代了L型滤波器与电网相连;采用了适用于单相电路的SDFT谐波电流检测方法,从负载电流中提取基波和3次谐波;针对3次谐波电流进行了PR控制器设计,并分析了改进后整个电流闭环系统的控制性能。最后通过Matlab/Simulink验证了改进后控制方法的可行性。

For the problem of grid current harmonics mainly containing the third harmonic after the single-phase shunt APF compensation under the traditional current PI control mode,without affecting the performance of the control system and the effect of compensation,a method was proposed by adding an appropriate proportional resonant（PR）controller in the system to improve the original PI current controller and compensate the third harmonic. In view of the superiority of the LCL type filter,the L type filter was replaced with the LCL type filter in the AC side of APF. The harmonic current detection method based on SDFT for single-phase circuit was adopted to extract the fundamental frequency and the third harmonic from the load current. The PR controller was designed for the third harmonic current,and the control performance of the improved closed-loop system was analyzed. The simulation of the system was built in Matlab/Simulink,it is validated that the proposed control method is correct and feasibility by simulation results.