A method for health monitoring of power MOSFETs based on threshold voltage

The prognostics and health management (PHM) of airborne equipment plays an important role in ensuring the security of flight and improving the ratio of combat readiness. The widely use of electronics equipment in aircraft is now making the PHM technology for power electronics devices become more important. It is the main circuit devices that are proved to have high failure rate in power equipment. This paper does some research about the fault feature extraction of power metal oxide semiconductor field effect transistor (MOSFET). Firstly, the failure mechanism and failure feature of active power switches are analyzed in this paper, and the junction temperature is indicated to be an overall parameter for the health monitoring of MOSFET. Then, a health monitoring method based on the threshold voltage is proposed. For buck converter, a measuring method of the threshold voltage is proposed, which is simple to realize and of high precision. Finally, the simulation and experimental results verify the effectiveness of the proposed measuring method.