基于漏电流多频率特征的变频电机主绝缘状态在线监测方法  

Online monitoring of ground-wall insulation condition in inverter-fed motors using multi-frequency characteristics of leakage current

作　　者：张超凡 牛峰[1,2,3] 孙庆国 黄少坡 张健 李奎[1,2] 方攸同[3] ZHANG Chaofan;NIU Feng;SUN Qingguo;HUANG Shaopo;ZHANG Jian;LI Kui;FANG Youtong(Key Lab of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province,Hebei University of Technology,Tianjin 300130,China;State Key Lab of Reliability and Intelligence of Electrical Equipment,Hebei University of Technology,Tianjin 300130,China;Changshu Switch Manufacturing Co.,Ltd.,Changshu 215500,China;College of Information Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China;School of Electrical Engineering,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]河北工业大学河北省电磁场与电器可靠性重点实验室,天津300130 [2]河北工业大学省部共建电工装备可靠性与智能化国家重点实验室,天津300130 [3]常熟开关制造有限公司,江苏常熟215500 [4]北京石油化工学院信息工程学院,北京102617 [5]浙江大学电气工程学院,浙江杭州310027

出　　处：《电机与控制学报》2023年第8期64-72,共9页Electric Machines and Control

基　　金：国家自然科学基金(52077054);中国博士后科学基金(2020M681446);河北工业大学学科交叉方向研究生培养资助项目(HEBUT-Y-XKJC-2022104)。

摘　　要：定子主绝缘失效将导致变频电机发生严重短路故障,极大降低电机运行可靠性,甚至威胁人身安全。为了保障变频电机系统安全可靠运行,需要对变频电机主绝缘状态进行实时监测和故障预警。首先,通过变频电机定子主绝缘退化等效电路获得漏电流频域数学模型。然后,研究了变频电机电压及漏电流频率特征分布规律,分析了绝缘阻抗及退化位置变化对漏电流基波频率倍频、开关频率倍频及二者所构成边带频率特征的影响。进而提出一种基于漏电流多频率特征的变频电机主绝缘状态在线监测方法,不仅可以评估主绝缘退化程度,而且可以精准识别主绝缘退化位置。该方法在变频电机多种运行工况下进行了验证,实验测试与仿真结果一致,验证了所提出主绝缘在线监测方法的有效性和准确性。Stator ground-wall(GW)insulation failure will lead to severe short-circuit fault,greatly reducing the reliability of motor operation and even endangering personal safety.To ensure the safe and reliable operation of inverter-fed motor,it is necessary to monitor the GW insulation condition of inverter-fed motor in real time and provide fault warning.Firstly,through the GW insulation degradation equivalent circuit model of inverter-fed motor,the mathematical model of leakage current was established.Secondly,the frequency distribution of voltage and leakage current in inverter-fed motor was studied,and the influence of insulation impedance and degradation position on leakage current fundamental frequency multiplication,switching frequency multiplication and its sideband frequency was analyzed.Then,a monitoring method for GW insulation condition of inverter-fed motor based on multi-frequency characteristics of leakage current was proposed,which can not only assess the degree of insulation degradation,but also accurately identify insulation degradation position.Finally,this method was validated under various operating conditions of inverter-fed motor,and the experimental tests were consistent with the theoretical analysis,which verifies the effectiveness and accuracy of proposed online monitoring method for GW insulation.

关 键 词：变频电机 漏电流 频率特征 主绝缘 在线监测 状态评估 

分 类 号：TM344.6[电气工程—电机]