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

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.