变压器局放特高频检测中检测频率和带宽的影响

Influences of center frequency and bandwidth on UHF PD detection for transformers

变压器局部放电特高频检测中,检测频率和带宽的选取对于放电信号的提取,进而对放电的标定及局部放电模式识别特征的保留具有决定作用。本文在实验室中建立了局部放电特高频检测系统和变压器典型局放模拟系统,对特高频检测中检测频率和带宽的选取原则进行了实验研究。实验结果表明,检测频率应选择局部放电特高频分量丰富且噪声小的频带,滤波器的带宽应在不引入干扰的前提下尽量选用较宽的带宽。

The selections of center frequency and bandwidth are very important to detection, calibration and pattern recognition of ultra-high-frequency (UHF) partial discharge (PD) signals in transformers. In this paper, an UHF PD detection system and a typical PD models simulated system are developed to study the influences of center frequency and bandwidth on UHF PD detection for transformers. Experimental results show, the selected center frequency should be in the frequency range that the UHF component of PD signals is rich and the noise is not very strong, the bandwidth of the filters should be as wide as possible unless the noise goes high.