Research on a New Type of Magnetically Controlled Distribution Transformer

This paper proposes a compact magnetically controlled distribution transformer topology, which combines a controllable reactor with a distribution transformer to make a conventional distribution transformer with the ability to flexibly regulate reactive voltage in addition to the basic function of voltage transformation. Firstly, the structure of a new magnetically controlled distribution transformer is proposed in this paper. The equivalent circuit of the magnetically controlled distribution transformer is obtained through the analysis of its basic electromagnetic relationship. Then, the formula for calculating the permeability of the core and the air gap in the magnetic valve section under saturation condition is analyzed theoretically by using Schwartz—Christopher transformation. The leakage flux is included in the calculation of excitation inductance, and the influence of the air gap beside the magnetic valve on the excitation reactance is fully considered. Finally, the inductance characteristics of the magnetically controlled distribution transformer are studied, and the finite element electromagnetic simulation is also carried out.