中文摘要：

十二相整流同步发电机系统的安全可靠运行意义重大,分析了该系统中4Y移15°的定子绕组可能出现的一种内部故障——发生在同组星形连接三相绕组之间的内部相间短路。首先建立了十二相整流发电机同组星形连接绕组内部相间短路的多回路数学模型,考虑了故障附加回路对电机气隙磁场和系统回路拓扑结构的影响,实现了故障前后定子和转子绕组以及整流桥直流侧各处电压、电流的数字仿真。继而在特制的样机上进行了不同负载工况的故障实验研究。通过对比分析实验与仿真结果,说明了数学模型的正确性。最后结合仿真结果与理论分析,总结了十二相整流发电机同组星形连接绕组相间短路的故障特征,尤其是短路回路电流的特点及其影响因素,为故障的危害评估、检测或保护研究提供了依据。

英文摘要：

The safe and reliable operation of the twelve phase synchronous generator-rectifier system is of great significance. This paper analyzes a type of internal short circuit fault of the stator windings in the system, i.e. the phase to-phase short circuit between the three star-connected phases connected to the same bridge rectifier. A multi-loop mathematical model of twelve-phase synchronous generator-rectifier system with the short circuit fault is set up. In the model, the additional short circuit loop inside the fault phases and its effect on the air-gap magnetic field and circuit topology of the system are taken into account. With the help of the model, electric power quantities such as voltages and currents of stator windings, rotor windings and DC load can be calculated under the fault condition. A series of fault experiments are carried on a special model machine under various load conditions. The experiment data agree well with the simulation results, verifying the correctness of the mathematical model. Based on the simulation results and theoretical analysis, this paper summarizes the electric characteristics of the phase-to-phase short circuit fault between the same group of star-connected phase windings in the twelve-phase machine system. In particular, the features and influencing factors of the short circuit current are treated, which provides a basis for the risk assessment and fault protection of the system.