中文摘要：

励磁绕组匝间短路故障会造成发电机励磁电流增大、输出无功功率减小、振动加剧等。为实现故障在线监测与保护,需准确快速计算故障电流等电气量。应用交流电机的多回路理论,基于对故障时定、转子电流稳态特征的分析,得到各回路电流的稳态表达式;根据同频率量相等的原则,将稳态时的微分方程组转化为线性代数方程组,得到励磁绕组匝间短路故障的稳态数学模型;利用高斯消去法可直接求得所有回路电流中各种交、直流分量的稳态解,快速实现故障的稳态计算。对一台12kW、3对极的隐极同步发电机进行了空载时励磁绕组匝间短路实验,稳态仿真结果与实验吻合较好。该方法可比暂态仿真减少90%的计算时间,为同步发电机励磁绕组匝间短路故障的监测与保护奠定了基础。

英文摘要：

The inter-turn short circuit of field windings in synchronous machines will cause the field current to increase and reactive power output to decrease.It will also introduce the aggravation of vibration.To achieve online fault monitoring and protection,electrical quantities such as fault currents of stator and rotor must be calculated accurately and efficiently.In this paper,based on the multi-loop theory and the steady-state characteristics of stator and rotor fault currents,the steady-state expression of each loop current is obtained first.Then,differential equations in the steady-state system are reduced into linear equations to acquire the steady-state mathematical model on inter-turn short circuit of field windings.This is based on the principle that components of the same frequency are equal.By solving the linear equations using Gaussian elimination,the steady-state solution of the AC and DC components of each loop current can be obtained and the steady-state calculation of the fault can be achieved rapidly.The field winding inter-turn short circuit experiments have been carried out on a 12 kW synchronous machine with three pairs of non-salient poles on no-load.The results show very good match with that of steady-state simulations.The steady calculation method proposed can save nearly ninety percent of the computational time compared with the transient simulation approach.It provides a useful foundation for the inter-turn short circuit fault detection and protection of the field windings in synchronous machines.