Power inverters operate under dynamic loads, the varying loads cause thermal expansion and contraction, which stress the internal boundaries between the material layers in the semiconductor. Eventually, the stress wears out the semiconductor module which ultimately leads to thermally induced failure. The primary goal of this research is to present thermal model for the IRF 3205 MOSFET chip switching operation for a power inverter. The solution of the models is implemented mathematically in MATLAB environment to obtain the transient temperature profile. The transient device temperatures are recorded with a K-type thermocouple and a three channel temperature logger, MTM-380SD, with real time data logger. Results show that the transient temperature response follows as exponential build up function and increases as the inverter load increases. At an inverter load of 1500W corresponding to 75% rating of the inverter the simulated steady state temperature and experimental steady state temperature are 54.8oC and 54.4oC respectively
Keywords: Power inverter, IRF 3205 MOSFET, Stress, Thermally induced failure, Transient temperature, Pulse load.