变速抽水蓄能机组转子绕组内部短路故障保护

针对变速抽水蓄能机组转子绕组内部短路故障存在“弱保护”问题，提出一种基于定子侧分支环流的交流励磁电机转子绕组内部短路故障保护方法。根据多回路理论分析理论，从数字滤波器设计、保护判据、防误措施等方面研究了变速抽水蓄能机组转子绕组短路故障保护的关键技术，研制了保护样机，并搭建动模试验平台进行了验证。试验结果表明，该方法能可靠反映转子绕组匝间和相间短路故障，基于该原理的保护装置即将在国内某变速抽水蓄能机组上投入应用。

Internal Short Circuit Protection for Rotor Winding of Variable Speed Pumped-Storage Generator-Motor

To provide a solution to the imperfect protection problem of variable speed pumped-storage units when the rotor winding has internal short circuit faults, a stator-side branch circulation current based protection method is proposed for internal short circuit of AC excitation motor rotor winding. Based on the multi-loop theory, the key technologies for internal short circuit protection are studied in terms of digital filter design, protection criteria, error prevention measures. A protection prototype is developed and a dynamic simulation experiment platform is established for its verification. The experimental results show that the proposed method can reliably reflect the inter-turn and phase-phase short-circuit faults of the rotor winding. The protection devices developed based on the method will be applied in a variable speed pumped storage unit in China.