定子绕组匝间短路作为双馈风力发电机常见故障之一,直接影响双馈风力发电机组的安全和稳定运行。但是,由于供电电源客观上存在三相不对称问题,这会造成匝间短路故障的误判。为了消除电源不对称对定子绕组匝间短路故障诊断的影响,文章首先通过多回路分析方法建立双馈风力发电机的仿真模型,然后结合对称分量法进行故障机理分析,最后依据时域图和频域图,综合判断匝间短路故障的存在与否及故障程度。试验结果表明:该方法可以消除电源不对称的影响,准确地诊断出定子绕组匝间短路故障。
Stator inter-turn short-circuit fault is one of the common faults of doubly-fed induction generation(DFIG).It affect directly the stabilization and safety of wind power generation system.However,three-phase asymmetry exists in power supply,which may lead misjudge of stator interturn fault.In order to eliminate the influence of asymmetry of power supply,firstly a simulation model of DIFG with the help of coupled-circuit analysis is proposed,then the fault mechanism is analyzed,finally according to spectrum graph and time domain graph,whether a stator inter-turn short-circuit fault exists and its degree are diagnosed synthetically.Simulation result show that the method can eliminate the influence of asymmetry of power supply,and can detect the stator interturn short-circuit fault.