基于多小波的多态性局部放电信号提取算法

A Multi-wavelet Based Algorithm for Extracting Diversiform Partial Discharge Signals

受放电机理、传播路径等因素的影响,局部放电信号往往呈现出多种形态,基于单一小波基函数的小波分析难以处理这样多态性的问题。为此,文中引入了具有多个小波基函数的多小波。针对不同形态的局部放电信号,分别进行了大量的仿真分析,以均方误差为衡量指标,研究多小波在不同局部放电模型下的消噪效果,并寻求最佳的消噪参数。在此基础上,将多小波用于提取多态性的局部放电信号,并与已有的文献进行比较。仿真和实测信号的处理结果表明,选择合适的参数,在提取多态性局放信号时,多小波具有明显优于最优小波及小波集合的性能。

Influenced by factors such as different discharge mechanisms and transmitting routes, partial discharge signals can have multiple waveforms. Under such circumstances, single scaling function based wavelet cannot work. To solve the problem, in this paper a multiple scaling functions based multi-wavelet algorithm is introduced. A large number of simulations have been carried on in the paper for different forms of partial discharges. Noise-reduction performance of the proposed multi-wavelet algorithm under different PD modes is investigated by using the mean square error as the criterion to achieve optimal parameters in noise reduction. Extracting of multi-mode partial discharge signals and comparison with previously published results are also presented. The results obtained both in simulation and tests demonstrate that the multi-wavelet based algorithm with proper parameters can extract multi mode partial discharge signals effectively, significantly improve the performance of existing optimal wavelet based and wavelet-set based algorithms.