Research on hybrid active power filter with low frequency suppression for EAST power supply

Aiming at the problem that the low-order harmonics generated by EAST poloidal field power supply is difficult to control, a new method combining active filter and passive filter is proposed. The topological structure and filtering principle of the low frequency suppression hybrid active power filter are described in detail. A three-level space voltage vector modulation algorithm for reducing the voltage fluctuation at the DC side midpoint is introduced, and the method for calculating the basic vector time is given. Combined with the algorithm, the output filter of the hybrid active power filter is simulated, and the feasibility of the low frequency suppression scheme and the effectiveness of the output filter design are verified.