Lingqing Pan , Xizhou Du , Xing Lei , Ting Ye , Dawei Xiang , Hao Li
{"title":"Double-ring high-frequency common-mode switching oscillation current sensor for inverter-fed machine winding insulation monitoring","authors":"Lingqing Pan , Xizhou Du , Xing Lei , Ting Ye , Dawei Xiang , Hao Li","doi":"10.1016/j.gloei.2024.01.010","DOIUrl":null,"url":null,"abstract":"<div><p>Insulation failure significantly contributes to the unpredictable shutdown of power equipment. Compared to the partial discharge and high-frequency (HF) injection methods, the HF common-mode (CM) leakage current method offers a non-intrusive and highly sensitive alternative. However, the detection of HF CM currents is susceptible to interference from differential-mode (DM) currents, which exhibit high-amplitude and multifrequency components during normal operation. To address this challenge, this paper proposes a double-ring current sensor based on the principle of magnetic shielding for inverter-fed machine winding insulation monitoring. The inner ring harnesses the magnetic aggregation effect to isolate the DM current magnetic field, whereas the outer ring serves as the magnetic core of the Rogowski current sensor, enabling HF CM current monitoring. First, the magnetic field distributions of the CM and DM currents were analyzed. Then, a correlation between the sensor parameters and signal-to-noise ratio of the target HF CM current was established. Finally, an experimental study was conducted on a 3-kW PMSM for verification. The results indicate that the proposed double-ring HF CM sensor can effectively mitigate DM current interference. Compared to a single-ring sensor, a reduction of approximately 40% in the DM component was achieved, which significantly enhanced the precision of online insulation monitoring.</p></div>","PeriodicalId":36174,"journal":{"name":"Global Energy Interconnection","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2096511724000100/pdf?md5=c161af3a28e319f53181560b05335bb0&pid=1-s2.0-S2096511724000100-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Global Energy Interconnection","FirstCategoryId":"1087","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2096511724000100","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
Insulation failure significantly contributes to the unpredictable shutdown of power equipment. Compared to the partial discharge and high-frequency (HF) injection methods, the HF common-mode (CM) leakage current method offers a non-intrusive and highly sensitive alternative. However, the detection of HF CM currents is susceptible to interference from differential-mode (DM) currents, which exhibit high-amplitude and multifrequency components during normal operation. To address this challenge, this paper proposes a double-ring current sensor based on the principle of magnetic shielding for inverter-fed machine winding insulation monitoring. The inner ring harnesses the magnetic aggregation effect to isolate the DM current magnetic field, whereas the outer ring serves as the magnetic core of the Rogowski current sensor, enabling HF CM current monitoring. First, the magnetic field distributions of the CM and DM currents were analyzed. Then, a correlation between the sensor parameters and signal-to-noise ratio of the target HF CM current was established. Finally, an experimental study was conducted on a 3-kW PMSM for verification. The results indicate that the proposed double-ring HF CM sensor can effectively mitigate DM current interference. Compared to a single-ring sensor, a reduction of approximately 40% in the DM component was achieved, which significantly enhanced the precision of online insulation monitoring.
绝缘故障是造成电力设备不可预测停机的重要原因。与局部放电和高频(HF)注入法相比,高频共模(CM)泄漏电流法提供了一种非侵入性和高灵敏度的替代方法。然而,高频 CM 电流的检测容易受到差模 (DM) 电流的干扰,因为差模电流在正常工作时会表现出高振幅和多频成分。为了应对这一挑战,本文提出了一种基于磁屏蔽原理的双环电流传感器,用于逆变器供电的机器绕组绝缘监测。内环利用磁聚集效应隔离 DM 电流磁场,外环作为罗戈夫斯基电流传感器的磁芯,实现高频 CM 电流监测。首先,分析了 CM 和 DM 电流的磁场分布。然后,建立了传感器参数与目标高频 CM 电流信噪比之间的相关性。最后,在一台 3 千瓦 PMSM 上进行了实验研究,以进行验证。结果表明,所提出的双环高频 CM 传感器能有效缓解 DM 电流干扰。与单环传感器相比,DM 分量减少了约 40%,从而显著提高了在线绝缘监测的精度。