十二相整流同步发电机定子匝间短路故障计算

Calculation of Stator Winding Inter-Turn Short Circuit in 12-Phase Synchronous Generators with Rectifier Load System

十二相整流同步发电机能提供大功率、高品质的直流电源,已广泛应用于舰船、飞机等移动平台中。鉴于对平台安全运行的高可靠性要求,本文对其中十二相电机可能发生的定子绕组匝间短路故障进行了理论和实验研究。建立了十二相整流发电机定子匝间短路的多回路数学模型,既可全面计及短路故障点位置和气隙磁场空间谐波,又能考虑正常及定子匝间故障情况下整流管不同通断状态引起的回路拓扑结构变化。用变步长的数值积分法求解了由时变系数微分方程组构成的数学模型,实现了系统正常及定子匝间短路故障时对发电机定、转子绕组及直流侧负载电压、电流等电气量的数字仿真。在一台特制的4kW十二相样机上进行了负载工况下定子匝间短路实验,实验结果与仿真结果吻合,验证了数学模型的正确性,并据此分析了十二相整流发电机定子匝间短路故障的电气特点。计算结果为十二相电机定子匝间短路故障的检测或保护研究提供了重要依据。

12-phase synchronous generator-rectifier-load systems are widely used in ships, aircraft and other mobile platforms, since they can supply high-power and high-quality DC source. In view of the highly reliable requirements for the safe operation of the platform, this paper deals with the inter-turn short circuit faults in stator winding of the 12-phase synchronous generators, including the theoretical and experimental research. This paper establishes the multi-loop mathematical model, considering short circuit location, space harmonics in air-gap magnetic field, as well as circuit topology varying with rectifier diodes on-and-off states under normal operation and stator inter-turn faults. Variable step algorithm of numerical integration method is used to solve the mathematic model composed of time-varying coefficient differential equations. The voltages and currents of the stator windings, rotor windings and DC load can be simulated digitally, in both normal operation and stator inter-turn faults. A series of stator inter-turn short circuit experiments are carried on a special 4kW model machine in load condition. The simulation results coincide well with the experiment data, which verifies the correctness of the mathematic model. Then the electric characteristics of the stator inter-turn faults in 12-phase machine systems are analyzed. The calculation results accomplished in this paper provides an important basis for the detection and protection research of stator inter-turn faults in 12-phase synchronous generator.