Harmonic Compensation And Key Techniques Of Parallel Hybrid Active Power Filter

With development of power electronics, related devices are increasingly used all over around. Because of the nonlinear characteristic of these devices, electric current of the power grid is badly polluted day after day, endangering the safety of the power supply.Firstly, three harmonic compensation technologies are presented, including Passive filter (PF), Active power filter (APF), Hybrid Active power filter (HAPF). Prime usage field of each compensation technology is summed up according to respective characteristic. In view of low power ration of the active filter part, favorable compensation effect and convenience for large harmonic current compensation, HAPF becomes the focus of this paper.Control methods and basic principle of the HAPF is presented. A practical 650 kW three phase rectifying nonlinear devices is given. In order to designing a useful HAPF system for such load, relations among the passive filter parameter, compensation effect and injecting reactive current is analyzed, relative simulation is given too. Some technique about the active filter part is presented, such as function of transformer, suppression of the turn-off surge voltage.Several new topologies of the HAPF system are proposed which come from the study on impedance-frequency characteristic of the passive filter of HAPF system. Relations of these new HAPF system, traditional HAPF system and APF system is illustrated by simulation.Finally, Experimental validation of the active part of the high power HAPF system and the new hybrid active filter technology is given, verifying the correctness of the related design in this paper.