Design and FE Analysis of Inverter for a Power Supply Unit

Long life and reliable operation are key requirements of any electronic system. Excessive heat dissipation in components can cause them to degrade or fail soon than would normally be expected. this report deals with an electronic component called low voltage inverter, total heat dissipation of the unit is 420 w. the heat transfer coefficient is calculated for natural convection using free convection simplified expression for air at atmospheric pressure. Thermal analyses have been done to predict the temperature profile in the electronic component using ANSYS. From the thermal mapping temperatures obtained are larger than the safe limit. The safe junction temperature for mosfet is 165 degrees c.actual temperatures are around 1000 degrees c for natural convection. Therefore thermally, the system fails if cooling is done through natural convection then the unit is redesigned for forced convection cooling thereby providing airflow path. The heat transfer coefficient is calculated using correlations for in line arrays for heated components. The thermal analysis has been made to predict the temperature profile in the mosfets using ANSYS. For mass flow rate of 8g/sand 1og/s, the junction temperature profiles have been calculated and found to be 141 degrees c. Therefore optimum mass flow rate have been found to be 8g/sec, the unit was developed and also tested experimentally for different mass flow rate, for which same 8g/s of air is found optimum at ground testing center unit was set to function for which maximum junction temperature was less than the theoretical value by few units and hence unit is checked for its validity. (C) 2015 Published by Elsevier Ltd.