Optimization of Cooling Efficiency in Inverter Assembly Using Numerical and Experimental Analysis

In the coming years, moving towards a hundred percent electric vehicles will be one of the key areas in the automotive industry. The main advantages of using e-mobility are operational flexibility, lower carbon emission and regenerative energy. Thermal management in an e-vehicle plays a vital role for the reliability of the system and any thermal failure can cost a significant amount of money to a company per vehicle. Inverter assembly is widely used to convert Direct Current (DC) to Alternating Current (AC) in the e-mobility platform to operate the motor for vehicle propulsion. It consists of various electronic transmitters, controllers, capacitors, and semi-conductors which will emit an enormous amount of heat during their operation. Since inverters are highly temperature sensitive in nature, it is necessary to improve the temperature distribution in the device. For this reason, adequate cooling system and ventilation is inevitable to keep the components operational. In this study, the thermal characteristic of the inverter was determined using transient thermal analysis considering three different fin geometry used in the heat sink. The two major heat sources are capacitors and Insulated Gate Bipolar Transistor (IGBT), and the heat transfer in the inverter assembly is due to conduction, convection, and radiation. This paper deals with the optimization of inverter fin to meet the cooling efficiency. Also, experimental validation was performed to verify the simulation results and correlation study was carried out to find the results accuracy of the numerical method. Simulation methodology was standardized for the thermal management of an inverter which can be effectively used in the electric vehicle industry.