Simulation study of hybrid cascade multilevel active power filter DC bus voltage control

In the high-voltage large-capacity power grid environment, an improved hybrid cascaded multilevel APF topology has been adopted to reduce the requirement of DC bus voltage and reduce the power loss to improve APF performance. This topology contains the voltage source bridge and the current source bridge. These two parts are in series. In order to provide a low voltage for AC bus of the current source bridge, the voltage source bridge which consists of hybrid cascaded 27-level converter will provide a 27-level step wave of which the fundamental component is nearly sinusoidal and will offset the voltage of power grid. Based on this multilevel hybrid cascaded active power filter and matlab/simulink tool, simulation research on the DC bus voltage control and the APF performance via PI controller and the fuzzy PI controller is introduced in this paper.