Calculation of peak output current of short circuit test equipment used for the low-voltage switching devices

The low-voltage switching devices are widely used in all aspects of the power system. It is essential to verify performance after design, manufacture or repair. In our national standards and the international IEC standard, short-circuit test of the electrical products for use in the power system is very important, so it is necessary to research and develop the short-circuit test equipment and this issue was of course paid much attention by domestic and foreign researchers. In the process of the research and manufacturing of the short-circuit test equipment, the calculation of the expected output current is an essential part. In this paper, the expected short-circuit current of the test equipment is computed and simulated. Firstly, the impedances of the test system are calculated, then the model is created. From the quantified calculation results, the influencing factors which differentiate the actual output current from the expected value are analyzed. The results provide a theoretical basis for the development of this new test apparatus.