应用组合广义形态学滤波器抑制变压器局放信号窄带干扰

Depression of Narrowband Interference in Partial Discharge Signals of Transformers with Combined Generalized Morphological Filters

为了抑制变压器局部放电(PD)信号中常见的窄带周期性干扰,根据PD信号和窄带周期性干扰的频谱特性不同,在开闭和闭开形态学滤波器的基础上,构造和采用组合广义形态学滤波器,在频域中滤除窄带周期性干扰形成的离散谱线,保留PD信号本身宽频带特性,从而达到抑制窄带周期性干扰的效果。用去噪前后的信噪比和波形相似系数对仿真PD信号的干扰抑制结果进行了评价,结果表明,组合广义形态学滤波器可以有效地抑制窄带周期性干扰。

In order to depress narrowband interference in partial discharge signals of transformers, combined general- ized morphological filters were designed based on morphological open-close and close-open filters according to the difference between partial discharge and narrowband signals. In frequency domain, every spectral line of periodic narrow bandwidth noise could be smoothed, and partial discharge signal could be reserved by the morphological fil- ters. The effectiveness of noise depression on simulating signals was evaluated by SNR and NCC, and results show that the filters designed can eliminate narrowband interferences effectively.