Fault Diagnosis Method of Stator Windings Short Circuit for Variable Speed Pumped Storage Unit Based on Park Transform

Abstract

Variable speed pumped storage unit is an important part of the new power system with renewable energy generation as the main body. In this paper, a fault diagnosis method of stator windings short circuit for variable speed pumped storage unit based on Park transform. During the normal operation of the variable speed pumped storage unit, the vector trajectory of the stator side current Park transform result is approximately a standard circle. When a fault occurs, the vector trajectory will become an ellipse. On this basis, the stator winding short-circuit fault is judged according to the variation degree of vector trajectory. Finally, taking a practical variable speed pumped storage unit as an example, the simulation verifies the effectiveness of the proposed method, which can sensitively reflect the small turn difference inter-turn short circuit fault with weak fault characteristics.