三相全桥电路中功率MOS管失效原因分析

Failure Analysis of Three-phase Full-bridge Circuit in Power MOS Tube

文中针对某风扇电机驱动电路高故障率的现象进行研究,并对其中三相全桥电路的失效原因进行分析,通过对失效现象的观察,着重对电路中的功率MOS管的失效原因进行分析。采用示波器观察波形的方法,首先采取对电路进行负载测试,以此来确保电路设计的正确性;然后对电路进行高压测试,模拟失效现象,分析其产生失效的原因。通过实验验证,提出了相应的解决办法,为工程人员提供了一种分析MOS管失效原因的参考方法。该方法适用于工程中大量使用的功率器件失效的疑难分析。最后,分别从硬件电路的设计以及软件的设计上提出了改进的方法。

Studied the phenomenon of the high failure rate for some fan motor drive circuit and analysed the reasons for the failure of the power MOS. Through observing the waveform of oscilloscope, focus on failure cause analysis of the power MOS tube of the circuit. A- dopting the oscilloscope waveform method, first take the circuit load test to ensure the correctness of the circuit design;then conduct the circuit high pressure test, simulate the failure phenomenon, analyze the causes of failure. Through the experiment, put forward the corre- sponding solutions, for the engineering staff provide a kind of reference method of analyzing MOS tube failure reason. This method is suitable for failure analysis for power device in engineering. Finally ,respectively from the hardware circuit design and software design put forward an improving method.