Fatigue strength prediction of power module for new type of brushless doubly-fed induction generator: Rotary converter generation system III

In rotary converter generation system (RCGS), power conditioning system (PCS) rotate with rotor and power modules, which are critical components in PCS, are subjected to cyclic acceleration loading. The aim of this study was to predict the fatigue strength of power modules under acceleration loading. We analyzed this fatigue strength using finite element analysis and predetermined fatigue lifetime equations. The failure materials of the power modules that we took into consideration are the main terminals and bonding wires. The results show that the fatigue strength of power modules is 286 G at 33,000 cycles and a factor limiting fatigue strength is the fatigue of the main terminals. We also carried out an experimental fatigue test to confirm that power modules withstand 286-G loading with 33,000 cycles and the power modules show no deterioration after 33,000 cycles.