Research on Selection of Electrical Equipment for Auxiliary Power Branch of Medium HPP

In view of the high amplitude and destructive nature of short-circuit current during short-circuiting of the auxiliary power branch of medium hydropower station, this paper analyzes in depth the characteristics of the auxiliary power branch of medium HPP under three-phase short-circuit fault conditions. Combined with the current power equipment production level, the measures to limit the three-phase shortcircuit current faults and the selection and calculation methods of electrical equipment when single-phase and three-phase equipment are used in the auxiliary power branch of medium HPP are studied in depth. The reliability of the calculation and selection methods of electrical equipment for auxiliary power branch circuits is verified through actual engineering cases. In this study, the practicality of design, safety of system operation and rationality of equipment selection are taken into account in the selection of electrical equipment for plant power.