Reliability evaluation of power MOSFETs used for an initial charge method using multiple short-circuits in each leg

Abstract

This paper evaluates the power device reliability under the initial charge method which makes multiple short-circuits one after the other to suppress overvoltage. The initial charge method using multiple short-circuits is tested more than 10,000 cycles on the practical power converter. The experimental results exhibit that the cycle number until the on-resistance changes by 20% is increased from 200 to more than 10,000 by the multiple short-circuits. As a result, the multiple short-circuits can reduce degradation of MOSFETs and increase the lifetime of power converter.