Prognosis of wire bond lift-off fault of an IGBT based on multisensory approach

The safe and continuous operation of the power switches of the inverter units is vital in assisting the functioning of the inverter units. This paper proposes an algorithm for the condition monitoring and prognosis of wire-bond fault in an IGBT- extensively used power switch in inverter systems. The proposed algorithm employs both on-state collector emitter voltage and collector current in the estimation of IGBT junction temperature. These two signals complement each other as thermal sensitive electrical parameters and results in better estimation of junction temperature. This algorithm has integrated a stochastic method and Coffin Manson model to introduce criticality matrix which is used to determine the necessity for IGBT replacement. Both simulation result and experiment data verified the proposed. The proposed algorithm has the scope to be further modified for the condition monitoring of a more complex system in the future.