基于Delta算子的并联型有源电力滤波器H_∞控制器设计

Design of H_∞ controller for shunt active power filter based on Delta operator

针对并联型有源电力滤波器(SAPF)的数字化控制问题,基于补偿性原理,将负载的谐波电流当作扰动,电源谐波电流作为系统的期望输出,建立了SAPF的Delta算子离散化状态空间方程模型,利用线性矩阵不等式(LMI)方法设计SAPF的H∞控制器。对所设计的H∞控制器的补偿效果与基于传统Z变换方法设计的H∞控制器的补偿效果进行仿真比较分析。仿真结果表明,快速采样时,基于Delta算子方法设计的SAPF的谐波总畸变率小于基于传统Z变换方法设计的SAPF的谐波总畸变率。

For the digital control of SAPF（Shunt Active Power Filter）,the Delta operator state-space model of SAPF is built based on the compensation principle,which regards the load harmonic current as disturbance and the source harmonic current as the expected output of power system. Its H∞ controller is designed with LMI（Linear Matrix Inequality） method. The compensation performance of the designed H∞ controller is compared with that of H∞ controller based on traditional Z transformation. Simulative results show that the total harmonic distortion of SAPF with Delta operator-based H∞ controller is less than that with traditional Z transformation-based H∞ controller.