Comparison of Hybrid Active Power Filter topologies and principles

Active power and passive filters (APF and PF) are the traditional ways of compensating for harmonics. However, both of the two ways have some disadvantages, namely resonance and tuning problems in passive filters (PF), and capacity, initial and running cost in active power filter (APF). Hybrid Active Power Filter (HAPF) has been proposed to overcome the disadvantages of APF and PF. It is a combined system of PF and APF. Abundant research has been done recently to combine APF and PF. Various topologies of HAPF have been proposed and studied to reduce the capacity of APF and to improve the compensation characteristics in recent twenty years. In this paper, various topologies, compensation principles and control strategies of HAPF are presented and compared.