Application of H∞ control theory in active power filter

Harmonic suppression is one of the focal facets of power quality problems. An important trend of harmonic suppression is to apply the active power filter (APF) in power systems. The strategy of APF control is a researchful hotspot. H_infin control theory, which can make optimum design to control systems, has high control accuracy and satisfactory robustness. It also has clear physical meaning and strict mathematic foundation. A simulation model of shunt APF is designed and built, the control of shunt APF is studied based on the H_infin control theory, a robustness control model of the system is built. The H_infin robustness controller is used in the simulation model of the shunt APF. Simulation results show that this control method can improve the stability of system as well as the robustness of control system.