采用微线结构传感器的高压电机定子绝缘监测系统的研究

局部放电在线检测技术是高压旋转电机定子绕组绝缘监测的有效方法。介绍了一套对大型汽轮发电机和高压异步电动机进行在线局放检测的系统 ,该系统采用一种基于微线理论的新型放电传感器 (简称 MSL S)获取局放信号。详细地研究了该传感器的特性 ,并在实验的基础上研究了该系统的抗干扰能力 ,结果表明该系统有更好的抗干扰性能。同时 ,对放电量的标定问题进行了讨论 ,指出检测系统的输出信号受检测电路的频率特性、局放信号本身的频谱和从放电点到传感器的传递函数诸因素的影响。对于电机这一类绕组型的绝缘结构 ,视在放电量的标定是与放电点的定位密切相关的。

Monitoring system for stator winding insulation in high voltage electrical machines with novel sensor

On line Partial Discharge (PD) detection is a common method for insulation monitoring in high voltage electrical machines. The paper presents a new type of PD detection sensor which is a micro strip line device embedded in the stator slot (referred to as MSLS) and an insulation monitoring system using the new sensor. The MSLS characteristics are described in detail. The experimental results in the lab and in a plant show that the monitoring system with the new sensor has better noise rejection performance than other methods. Based on the test results, the paper discusses the calibration problem of PD in the stator windings of high voltage electrical machines. The output of the monitoring system signal is affected by the frequency characteristics of the detection circuit, the frequency spectrum characteristics of PD, and the transfer performance from the PD site to the sensor. The calibration of the apparent charge in the stator windings of electrical machines is relative to the location of PD site.