Research on Single-phase Power Supply in Short-circuit Test of Transformer on Magnetic-force Coupling Field

Abstract

The short-circuit test is a test of the comprehensive technical ability of transformer manufacturing. The three-phase power supply is usually used for short-circuit test of transformer. To investigate the feasibility of using a single-phase power supply in the short-circuit test of transformer, in this paper, we modeled a 200 kVA power transformer in three dimensions, using the finite element method to calculate the short-circuit current and short-circuit electromagnetic force of the windings under different excitation modes when the three-phase short-circuit occurs in the low-voltage windings. Analyze and compare the short-circuit current and short-circuit electromagnetic force distribution characteristics of windings under different working conditions. The results show that when the three-phase short-circuit condition occurred in the low-voltage windings, regardless of the three-phase excitation or single-phase excitation exerted on the high-voltage windings, the short-circuit current and the short-circuit electromagnetic force of the voltage zero-crossing closing phase is basically the same. This proves that a single-phase power supply can be used instead of a three-phase power supply for short-circuit tests. the analysis result has certain reference significance for improving the short-circuit test of transformer.