电力变压器局放超声定位中若干物理问题研究

A Study of Ultrasonic Location of Partial Discharge in Power Transformer

绝缘介质中的缺陷(气泡或气隙等)在高压下产生局部放电,该点故障若重复击穿和熄灭,长期运行,必导致整个绝缘结构损坏,酿成供电重大事故。所以,故障变压器超过某一局放(例如500 pC)级,必须修复。局放超声定位是确定故障部位的有效方法,世界各国已有许多报道和论著。作者研制了局放超声定位软硬件系统。文中介绍了局放超声定位中的若干物理问题,包括等值声速特性、超声频谱特性等。最后,通过实例应用反映了定位精度。

A system of ultrasonic location of partial discharge developed by the author is introduced. And the results of experimental investigation on equivalent sonic velocity characteristic, ultrasonic spectral characteristic and location accuracy of ultrasonic signal of partial discharges are presented. As an example, this system was used successfully for the insulating failure of on-line power transformer.