Research on the Electromagnetic Characteristics of an Integrated Multi-Winding Inductive Filtering Converter Transformer and Its Filter System

In this paper, the electromagnetic characteristics of a novel integrated multi-winding inductive filtering converter transformer, including two parallel-connected delta filter windings with zero impedance, are studied. First, based on Ansoft, a 3D FEM model of the novel converter transformer is built according to its structural parameters and material characteristics. Next, the external circuit connection based on the established 3D FEM model is realized so the corresponding field-circuit coupling model can be established under three different working conditions. On this basis, the electric field characteristics, magnetic field characteristics, winding electromagnetic force characteristics, and core loss characteristics of the novel converter transformer with different conditions are analyzed. The results show that because the harmonic current is effectively suppressed, the flux chain passing through the windings of the novel converter transformer is closer to the sinusoidal wave and the harmonic magnetic potential is effectively suppressed; the electromagnetic force received by each winding of the converter transformer and the high-frequency vibration component are significantly reduced; and the transformer core loss is also significantly reduced. The research on the internal electromagnetic characteristics of the integrated multi-winding inductive filter converter transformer reveals the mechanism of reducing vibration and noise.