基于脉冲频率响应的同步电机定转子绕组短路故障无损检测与诊断方法的基础研究

Winding inter-turn and ground short circuit fault are common fault types of synchronous machine, however, the existing ordinary offline fault detection methods have the technical limitations of low sensitivity, single diagnostic information and pulling out the rotor, which becomes the bottleneck for severely constraining the accurate diagnosis of the state of synchronous machine. This project is based on the pulsed power generation and measurement technology, and intensively studies the key basic scientific problems of short circuit fault characteristic, detection and diagnosis method for the stator and rotor winding of synchronous machine. The detail content is as follows: study the broadband frequency equivalent electrical model of stator and rotor winding of synchronous machine and the influence law of rotor status on electrical parameters, obtain the optimal measurement scheme and parameter range of injection pulse. Develop the solid-state high voltage pulse power supply with adjustable and controllable output pulse parameters. Study the filtering, obtaining and feature extracting algorithms of impulse frequency response and build the diagnosis method of winding short circuit fault, by conducting the fault simulation experiment of synchronous machine in the lab. This project aims at revealing the basic principle and key technique of nondestructive detection and diagnosis for short circuit fault of synchronous machine stator and rotor winding based on impulse frequency response, which establishes the theoretical and technical foundation for developing the new synchronous machine winding fault detection method with completely independent intellectual property rights by our country, and has the important scientific significance and actual value for engineering.

绕组匝间和对地短路故障是同步电机常见的故障类型，然而，现有几种常规的离线故障检测方法各自存在灵敏度不高、诊断信息单一、检测需要抽出转子等技术局限，成为严重制约准确检测同步电机状态的瓶颈。本项目基于脉冲功率发生和测量技术，对同步电机定子和转子绕组短路故障特性、检测和诊断方法等关键基础科学问题进行深入研究。具体内容包括：研究同步电机定转子绕组宽频等值电路模型及转子状态对电路参数的影响规律，获得最优化测量方案和注入脉冲的参数范围；开发输出脉冲参数可控可调的全固态高压脉冲电源样机；通过实验室同步电机绕组故障模拟试验，研究脉冲频率响应去噪、获取及特征提取算法，建立起绕组短路故障诊断方法。本项目旨在揭示基于脉冲频率响应的同步电机定转子绕组短路故障无损检测与诊断的基本原理和关键技术，为我国开发拥有完全自主知识产权的同步电机新型绕组故障检测方法奠定理论和技术基础，具有重要的科学意义和工程实用价值。

同步电机是电力系统中主要的电气设备之一，为了提高同步电机定子和转子绕组短路故障的离线诊断水平，解决现有几种常规诊断方法存在的技术局限，同时为现场提供新的诊断技术和手段，本项目提出了一种基于脉冲频率响应的同步电机定转子绕组短路故障检测与诊断技术。本项目首先建立了5 kW凸级同步电机定子绕组的灰盒和集总参数的宽频等效电路模型，通过参数辨识得到的端口宽频特性与实测值之间具有比较良好的重合度。并揭示转子状态对绕组电路模型参数的影响规律，从而确立同步电机绕组的测试方案和脉冲电源样机的脉冲参数可调范围。基于此，研制了一台输出参数可控可调的全固态高压纳秒脉冲电源样机，能够稳定输出脉冲幅度为[0~3] kV，脉冲宽度为[100~1000] ns，重复频率为[1~1000] Hz。进一步考虑电机工作环境的温度、转子位置等因素对测试不确定度的影响。结果表明：在不同的时间和温度下测量的重复率达到97%以上，适用于实际工程测量；转子的位置会影响气隙和磁场的变化，从而影响定子绕组的宽频等效电路中的电感和电容参数。其次通过实际5 kW同步电机模拟了匝间短路、接地短路、早期绝缘劣化等故障类型，试验结果表明，该方法能够成功地反映出定子绕组的故障状态。最后研究了基于随机森林的同步电机状态异常诊断，以诊断绕组是否存在故障，与其他机器学习方法对比分析，该方法具有显著的优越性，其泛化能力较强，为实际应用中的同步发电机绕组短路故障的诊断奠定技术基础。.相关研究工作已经正式发表研究论文8篇,其中包括IEEE T Energy Conver., Electr. Power Syst. Res., Measurement，申请发明专利1项，培养硕士生2名。