基于开关振荡的驱动电机匝绝缘故障诊断

Diagnosis of Turn Insulation Fault of Drive Motor Based on Switching Oscillation

绝缘失效会引起电机匝间、相地和对地故障,轻则造成设备停机,重则危害人身安全,产生灾难性的后果。为了在匝绝缘劣化的早期能够对劣化状态进行在线灵敏监测,提出一种基于开关振荡的多频率特征逆变器驱动电机匝绝缘故障诊断的新方法。首先,利用高频电压传感器和高频电流传感器对信号进行提取;然后,判断是否为开关暂态过程,如果是,则提取开关瞬态下的电流幅值峰值,利用带通滤波器对信号进行多频带处理,并计算一个周期下的电流幅值峰值点的平均值,根据结果选出绝缘故障敏感频率;最后,做出不同工况下的开关瞬态下电流峰值点均值图及开关事件下电流幅值的散点图。根据实验结果可知,当绝缘发生劣化,可通过多频率特征下的开关振荡电流信号对匝绝缘进行故障诊断。

Insulation failure can cause motor turn-to-turn,phase-to-ground and ground-to-ground faults,ranging from equipment downtime,or endangering personal safety,resulting in catastrophic consequences.In order to be able to carry out online sensitive monitoring of the deterioration state in the early stage of turn insulation deterioration,a new method for fault diagnosis of the turn insulation of the inverter drive motor with multi-frequency characteristics based on switching oscillation was proposed.First,the signal was extracted by the high-frequency voltage and current sensor.Then,it judged whether it is a switching transient process,if so,the peak current amplitude under the switching transient and bandpass filters were used to process signals in multiple bands,and it calculated the average value of the peak point of current amplitude in a cycle,and selected insulation fault sensitive frequency by the result.Finally,the average value of the current peak point under the switching transient under different operating conditions and the scatter plot of the current amplitude under the switching event were drawn.According to the experimental results,when the insulation is degraded,the fault diagnosis of the turn insulation can be performed through the switching oscillating current signal in the multi-frequency.