不平衡电压下双馈异步发电机定子绕组匝间短路故障的稳态仿真分析

摘要

When symmetric voltage double fed wind power generator stator winding inter turn short circuit fault occurd,used the negative sequence current produced by the stator current to detect the inter-turn short circuit fault,but when the voltage was unbalanced,would also produce negative sequence current.Based on this,established the voltage of doubly fed induction motor stator winding inter turn short circuit simulation model,the only set of voltage balance,inter turn short circuit and voltage balance of inter-turn short circuit,the simulation results,the rotor current waveform and rotor current harmonic analysis,comparison and analysis of three kinds of waveform and spectrum.Simulation results showed that:the two voltage unbalance and inter-turn short circuit would produce some of the same characteristics of frequency.When the voltage unbalance and the occurrence of inter turn short circuit,through monitoring these same frequency outside the other inter turn short circuit characteristic frequency discrimination of inter turn short circuit fault,but the frequency content was particularly small,extremely easy to by motor asymmetry factors cause a miscarriage of justice,therefore,could be through the observation of stator phase current waveform changes in the qualitative discrimination of voltage imbalance of inter turn short circuit fault.%电压对称情况下双馈风机发生定子绕组匝间短路故障时,可由电机定子三相电流产生的负序电流检测匝间短路故障,但当电压不平衡时,同样也会产生负序电流.基于此,建立了电压不平衡情况下双馈异步发电机定子绕组发生匝间短路时多回路仿真模型,通过仅设置电压不平衡、匝间短路、电压不平衡情况下发生匝间短路的三种情况,得到仿真结果中定、转子三相电流波形及转子电流谐波分析图,对比分析三种情况下波形图及频谱图.仿真结果得出:电压不平衡和匝间短路两种情况下会产生某些相同的特征频率;当电压不平衡且发生匝间短路时,可通过监测这些相同频率之外的其他匝间短路特征频率判别匝间短路故障,但这些频率含量特别小,极易由电机本身不对称等因素造成误判,因此,可通过观察定子三相电流的波形变化定性判别电压不平衡情况下发生的匝间短路故障.