Monitoring of Inter-Turn Short Circuit of Rotor Windings in Synchronous Generators Without Stator Branch Current Transformer
Hao Liangliang1, Wu Junyong1, Sun Yuguang2, Wang Xiangheng2
1.Beijing Jiaotong University, Beijing 100044 China; 2.State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University, Beijing 100084 China
Abstract:The inter-turn short circuit of rotor windings is a normal electrical fault of a large turbine generator, and fault worsening will seriously hinder normal and safe operation of a generator. Since most of turbine generators in China are provided with no installation condition for a branch current transformer, application of the monitoring principle based on the stator unbalanced current RMS is limited. For solving the above problem, the paper provides a monitoring method of inter-turn short circuit of rotor windings in synchronous generators without stator branch current transformer. A fault monitoring criterion is formed according to change of excitation MMF before and after faults. In the calculation of real excitation MMF, only stator leakage reactance and no load characteristic curve of the generator are used, and influence upon calculation precision by the generator operating mode is smaller. Effectiveness of the monitoring method is verified through the experiment on a 12kW non-salient-pole synchronous generator with one pole. The method is also suitable for rotor two-point grounding fault protection.
郝亮亮, 吴俊勇, 孙宇光, 王祥珩. 无分支电流互感器的同步发电机转子匝间短路监测方法[J]. 电工技术学报, 2014, 29(3): 189-195.
Hao Liangliang, Wu Junyong, Sun Yuguang, Wang Xiangheng. Monitoring of Inter-Turn Short Circuit of Rotor Windings in Synchronous Generators Without Stator Branch Current Transformer. Transactions of China Electrotechnical Society, 2014, 29(3): 189-195.
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