Design and simulation of passive filter based on fundamental magnetic flux compensation

The harmonic problem becomes more and more serious in power grid, passive filter is one of the effective way to filter harmonic. This paper presented the design and simulation of passive filter based on the theory of fundamental magnetic flux compensation (FMFC). The primary winding of transformer is in series between the passive filter and the power supply, in the primary winding of series transformer, the fundamental current component of system was detected and tracked to produce a fundamental compensation current by inverter, which was injected into the secondary winding, when the injected fundamental current and the fundamental current component of the system satisfied the FMFC, the system fundamental current could pass transformer successfully, but most of the harmonic current was forced to flow into passive filter, thus achieved the purpose of harmonic isolation, and made most of the harmonic current flow into passive filter. Compared with the using of passive filter singly, it improved the efficiency of passive filter. The validity of the new method of filtering characteristics was verified by simulation through Matlab. The simulation results show that this method can filter out harmonic more efficiency in power systems when the waveform distortion is serious.