基于波形分析法的变压器绕组匝绝缘在线检测及故障诊断

On-line test and fault diagnosis on turn insulation of transformerwindings based on wave analysis method

采用波形分析法判断变压器匝绝缘故障的技术近年来发展较快,通常人们对变压器绕组匝绝缘故障离线进行试验分析。但由于在试验中人为制造的高压、高频振荡波形与变压器实际运行所遭受的冲击波形有较大差别,因而测试结果尚不能真正反映变压器的实际运行状态。针对这种情况,研发了新型电子式电流互感器,它的制造技术融合了传感器技术和光电技术,产品结构简单,安装维护方便,分为测量级和保护级,可在线采集变压器暂态过程中的雷击波形作为变压器传递函数的输入、输出信号,建立变压器雷击电流波形频谱图库,分析变压器传递函数的变化趋势,这样就达到真正判断变压器绕组匝绝缘的电气性能状况的目的。

The technique of using wave analysis method to determine transformer turn insulation failures has undergone rapid development in recent years, and off-line test is the common practice. However,due to the considerable difference between the man-made high voltage/frequency oscillation wave in the test and the actual surge on transformers during operation, the off-line test results can not reflect the real operation state of transformers. Consequently, a new-type electronic current transformer integrating sensing and photoelectric techniques is developed, which is simply structured and easy to install and maintain. The product, having measurement grade and protection grade, can acquire on line lightning waveform in transient states of transformers as the I/O signals for transformer transfer function, establish spectrum library of transformer lightning current waveform, and analyze the variation tendency of transformer transfer function, thus enabling the correct determination on electric performance of transformer winding turn insulation.