基于UHF检测的变压器内部典型放电实验的谱图分析

Spectrogram analysis of transformer interior typical discharge based on ultra-high frequency detection

变压器超高频(UHF)局部放电检测法具有抗干扰能力强、灵敏度高等优点,适用于变压器局部放电的现场检测。基于虚拟仪器技术开发了一套UHF局部放电检测系统,并对针板放电、沿面放电和内部放电等五种典型的变压器局部放电模型进行试验,获得了相应的放电谱图。进一步对典型放电谱图进行分析,总结出了不同放电模型局放信号的相位特征,包括检测放电电压与放电相位的关系、放电次数与放电相位的关系、以及试验电压与放电相位、放电次数的关系等。分析结果表明,不同的放电类型对应不同的放电谱图,为进一步开展应用超高频法进行变压器局部放电的模式识别奠定基础。

Because the ultra-high frequency （UHF） method used in partial discharge detection, has intensive interference-free feature, high sensitivity, it is suitable for partial discharge detection at working situation. In this paper, Ultra-high frequency （UHF） partial discharge detection system based on virtual instrument technology is built. Pin-plate discharge model, creeping discharge model, internal discharge model and so on, these five typical transformer partial discharge models were experimented in laboratory. And the relative spectrograms were obtained. Analyzing the typical discharge spectrogram further, the phase characteristics of different discharge models＇ PD signals were concluded. The phase characteristics include the relationships of detection discharge voltage and discharge phase, discharge num- ber of times and discharge phase, and the relationship of experimental voltage, discharge phase and discharge number of times, and so on. The analytic result shows that different discharge styles correspond to respective discharge spec- trograms. It lays the foundation of transformer partial discharge＇ s pattern recognition based on UHF method for the further research.