Simulation-based design of inverter heat sink for two operating conditions

This study focuses on an automotive inverter capable of meeting dual operational requirements: battery preheating in low-temperature environments and motor driving. Circuit simulations were performed in SIMULINK to quantify the loss distribution characteristics of MOSFET modules under both operating conditions, revealing the difference in inverter losses between battery preheating (low-frequency bidirectional pulsed current) and motor driving (continuous sinusoidal wave loads). Subsequently, a multi-channel dual-U-shaped model of a liquid-cooled heatsink with simplified fin structures was developed in ANSYS Fluent to investigate its thermal performance under harsh environmental conditions. Results show that total losses under preheating conditions are approximately 15% higher than those under driving conditions, with switching losses accounting for a larger proportion. The liquid-cooled heatsink designed for battery preheating retains a significant thermal margin even during sustained motor operation.