An Improved DC Side Series Active Power Filter

An improved series single-phase active power filter (APF) at DC side whose output voltage is adjustable is proposed,this kind of improved APF can perform power factor correction and harmonic elimination for single-phase rectifier load. The circuit topology and basic working principle of the proposed improved series APF are analyzed theoretically; the design of main parameters and their selection are given. The proposed improved APF is connected in series with rectifier bridge at its DC side,so the circuit structure is simplified and the number of active switches is reduced than those of traditional APF that is connected in series with rectifier bridge at its AC side; the controllability of output voltage is realized by the proposed improved series single-phase APF and its corresponding control and driving circuit is simplified than that of commonly used DC side series APF,and the capacity of energy storage capacitor is further reduced. Simulation and experiment results show that topology of this improved series APF is correct and reliable.