非平稳振荡局放信号去噪效果评价参数研究

为克服目前常用的波形相似性参数(NCC)只能从整体上评价去噪前后波形相似程度,缺乏对波形振荡细节描述的缺点,弥补只用NCC作为评价参数的不足,基于信号去噪必须满足畸变小和信噪比高的基本原则,对PD信号去噪后带来的波形畸变程度进行了定量评价研究,提出并定义一种描述波形相似程度的变化趋势参数(VTP),给出了离散表达式并阐述了其数学意义。对4种仿真信号去噪前后功率谱的分析验证了VTP参数设置的合理性,而且对不同强度的染噪局放信号均可采用VTP参数来反映去噪效果的优劣性;将VTP与NCC配合使用并结合SNR,能更好地对PD信号去噪效果的理论研究进行综合评价。

Study on New Evaluation Parameters for De-noising Performance of Non-stationary Oscillating Partial Discharge

Based on the basic de-noising principles of smaller distortion and higher Signal Noise Ratio(SNR),this paper makes a quantitative evaluation on the de-noising effects of PD signals.However,traditional evaluation value,such as Normalized Correlation Coefficient(NCC) has been proposed according to evaluation of waveform similarity in total so that it is not suitable for describing waveform oscillation in detail.In order to describe the distortion of waveform more precisely,a new parameter-Variational Trend Parameter(VTP) is defined and proposed,and its discrete expression is provided and its mathematical meaning is interpreted.In addition,the validity of VTP is proved by the 4 simulative PD signals power spectrum analysis before and after de-noising.The de-nosing simulation shows that VTP,along with NCC and SNR,is better to make a synthetic evaluation on the de-noising effect of PD signals.