Research on Short-Circuit Impedance Analysis Method of Auto-transformer for Side Column Voltage Regulation

Abstract

Abstract In order to realize the accurate analysis of the impedance of transformers with complex connection relations, this paper derives the impedance calculation method of low-voltage excitation side column linear voltage regulating autotransformer by using the power method. The transformer network with different taps is analyzed, and the calculation formulas of transformer HV-MV impedance, HV-LV impedance and MV-LV impedance are derived. The analysis is simplified to the solution of concentric column coil impedance and magnetic potential of each coil. By comparing the calculated data of actual products with the measured data, the calculation deviation of this method is controlled within 2.03%; By using the finite element method, the impedance of the transformer with the measures to control the magnetic shielding is analyzed and calculated. By comparing the impedance of the transformer with different measures, it can be confirmed that the magnetic leakage measures have an impact on the impedance of the transformer.