变压器绕组松动的振动实验分析

Experimental Research of Transformer's Vibration due to the Winding Looseness

变压器绕组故障是变压器故障中的重要部分,基于振动信号分析的方法可以实现变压器绕组运行状态的在线测量。阐述绕组的振动机理及传播路径,通过人为设置绕组松动故障,实测负载时不同松紧程度下的变压器油箱表面的振动信号。利用小波变换(WT)、经验模态分解(EMD)和总体经验模态分解(EEMD)三种方法对信号进行处理,并对信号能量熵求解,对比结果发现:针对绕组振动信号,三种能量熵变化规律与100 Hz处幅值均可作为初步判断绕组松动的指标。

The winding fault is an important part of transformer faults. Analysis of vibration signal can realize onlinemonitoring of the winding operation. In this paper, the vibration mechanism of winding and the propagation path of vibrationare introduced. By making the winding faults artificially, vibration signals of the oil tank surface of the transformer aremeasured under different winding looseness. These signals are processed with wavelet transform (WT), empirical modedecomposition (EMD) and ensemble empirical mode decomposition (EEMD). And the energy entropies of the three methodsare also calculated. Comparison of the results shows that both variation laws of three kinds of energy entropy and theamplitude at 100Hz can be used as the criteria for preliminary estimation of the looseness of the winding.