Research on leakage reactance of zero sequence filter based on finite element analysis

Due to the windings of zero sequence filter are linked with zigzag connection, the zero sequence leakage reactance is the key parameter that affects the effect of the zero sequence filter. The simulation of two-dimensional leakage magnetic field in one phase of 100kVA zero sequence filter were implemented by using finite element analysis software-ANSYS, through pre-processing, solving and post-processing, the distribution of the magnetic field in the core of the zero sequence filter, the leakage magnetic field distribution between iron core and winding and the leakage magnetic field distribution between internal and external windings were obtained, then the zero sequence leakage reactance was calculated by the magnetic field energy method. This analysis provides a new idea of reducing the short-circuit impedance of zero-sequence filter and improving the filtering effect, and it can achieve purposes of shortening the design cycle and saving design cost.