The performance parameter of mining flameproof dry type transformers are adjusted in newly implementing standard,the academic analysis and calculation of short circuit impedance for transformer are processed.

This paper analyzed the requirements of short circuit impedance for distribution transformer in national standard, put forward a method to test the capacity of transformer with short circuit impedance and developed the measuring device.

When transformer gets short circuit impact,through short circuit impedance test and winding deformation test can detect whether the impacted transformer distorted,when the deformation has happened,can detect single phase leakage impedance of transformer to judge the appe.

The requirements of distribution transformer short impedance in national specifications were analyzed and transformer short-circuit impedance was used to test the capacity of transformer.

In order to calculate the short-circuit impedance of the transformer with split types of windings exactly,the multi-winding inductance matrix(IM) for the multi-branch of the high-voltage winding and one of the low-voltage split winding was first established by three-dimensional finite element method(FEM) with ANSYS software.

The impedance voltage and short-circuit impedance of transformer is calculated based on the analysis of distribution of leakage field.

This paper analyzes the require of distribution transformer short impedance in national standard and puts forward a method to test the capacity of transformer with steady impedance voltage.