Research on the fault characteristics of the generator motor during the self starting process of the variable speed pumped storage unit under pumping conditions and its adaptability to relay protection

Variable speed pumped storage adjusts the power generation or pumping by changing the speed of the unit, thereby achieving rapid response and power balance to the power grid. The variable speed pumped storage unit utilizes its own excitation system and control strategy to achieve the start-up of pumping conditions. The electrical characteristics of the stator and rotor during the start-up process are different from those of conventional fixed speed pumped storage units, and no in-depth research has been conducted yet. This article studies the rotor fault characteristics during the self starting process of variable speed pumped storage units under pumping conditions, and conducts simulation in PSCAD. Through adaptability research on the relay protection of conventional pumped storage units and doubly fed fans, specialized rotor protection needs to be configured during the self starting process.