数字式匝间检测仪检测盲区及风力发电机匝间短路分析

Analysis of the Detection Blind Zone of Digital Inter-turn Insulation De⁃tector and Inter-turn Short Circuit of Wind Turbine

【目的】数字式匝间检测仪可为匝间绝缘检测提供直观的数据反馈,但实际检测过程中会出现检测显示匝间绝缘不合格但解剖线圈后无法找出绝缘问题或者检测显示合格但试验时匝间短路的情况,因此,急需排除检测干扰因素,提高检测结果的准确性。【方法】模拟了3种不同的线圈安装位置和2种不同的线圈安装状态来进行验证,并人为地制造线圈缺陷来测试设备的检测盲区。【结果】结果显示,圈式线圈安装位置和状态差异会导致数字式匝间绝缘检测仪的波形不重合度值升高,数字式匝间绝缘检测设备对人为制造的匝间绝缘缺陷无反馈。【结论】线圈附近的金属部件状态差异会对匝间波形不重合度值有很大影响,数字式匝间检测仪不能检测出未接触短路的匝间绝缘缺陷。通过对电机匝间绝缘事故原因进行分析,进一步证明了这一结论,验证结果对电机制造行业规避匝间绝缘缺陷具有积极作用。

[Purposes]The digital inter-turn detector can provide intuitive data feedback for inter-turn in-sulation detection,but in the actual detection process,there will be cases where the detection shows un-qualified inter-turn insulation but cannot find out the insulation problem after dissecting the coil or cases where the detection shows qualified but the inter-turn short circuit during the test.Therefore,it is urgent to eliminate the detection interference factors and improve the accuracy of the detection results.[Methods]Three different coil installation positions and two different coil installation states were simu-lated for verification,and coil defects were artificially manufactured to test the detection blind area of the equipment.[Findings]The results show that the difference of coil installation position and state will lead to the increase of waveform non-coincidence value of the digital inter-turn insulation detector,and the digital inter-turn insulation detection equipment has no feedback to the artificial inter-turn insulation defects.[Conclusions]The state difference of metal parts near the coil will have a great impact on the value of the turn-to-turn waveform non-coincidence,and the digital turn-to-turn detector cannot detect the turn-to-turn insulation defect without touching the short circuit.This conclusion is further proved by the analysis of the cause of the turn-to-turn insulation accident of the motor in this paper,and the verifi-cation results have a positive effect on the avoidance of turn-to-turn insulation defect in the motor manu-facturing industry.