逆变电路中功率器件声发射信号分析

Analysis of Acoustic Emission Signal of Power Device in Inverter Circuit

逆变电路中最重要的部分是功率器件,功率器件在开通和关断时会有电磁声发射的现象产生,经过声发射仪器的采集和后期数据处理,可得出机械应力波的特征信息,有望实现通过电磁声发射无损检测技术对逆变电路进行状态监测。主要针对方波逆变电路和正弦波电路中功率器件工作时产生的机械应力波的特征参量进行研究,发现方波逆变电路中功率器件的时域峰值、能量和频域峰值都随着负载阻值的增大而减小,开通时刻上升时间和峰值频率几乎不变,关断时刻上升时间随负载阻值的增大而增大;正弦波逆变实验中应力波的时域峰值、能量、频域峰值和峰值频率几乎不变,基于以上研究结论,提供了一种逆变电路功率器件状态监测的新思路。

The most important part of the inverter circuit is the power device.When the power device is turned on and off, there will be electromagnetic acoustic emission phenomenon.Through the collection of acoustic emission instrument and later data processing, the characteristic information of mechanical stress wave is obtained, which is expected to realize the condition monitoring of the inverter circuit through electromagnetic acoustic emission nondestructive testing technology.The characteristic parameters of mechanical stress wave generated by power devices in square wave inverter circuit and sine wave circuit are mainly studied.It is found that the time domain peak, energy and frequency domain peak of power devices in square wave inverter circuit decrease with the increase of load resistance, the rise time and peak frequency at on time are almost unchanged, and the rise time at off time increases with the increase of load resistance.In the sine wave inverter experiment, the time domain peak, energy, frequency domain peak and peak frequency of stress wave are almost unchanged.Based on the above research conclusions, a new idea of condition monitoring of power devices in inverter circuit is provided.