Analysis of Coolant Transients Impact on SiC Power Module in Traction Inverter

Inhalt:
Booming application of electrical vehicles is driving the needs of power semiconductors, especially Silicon Carbide (SiC) devices due to its significantly reduced switching losses. Due to its smaller chip size, SiC’s loss is more concentrated compared with IGBT chip. This brings more challenges to the thermal management design for SiC power semiconductor modules. In the design stage for liquid cooling-based traction inverter, the state of art mainly assumes that the flowrate of the coolant is a fixed value, which can’t be always achieved in real application due to pump behavior. Coolant pump behavior always results in coolant flowrate transients. And the thermal network provided by most power semiconductor suppliers are still based on fixed coolant flowrate. In case of flowrate transients’ evaluation, finite element (FEM) simulation will be selected to calculate the transient coolant behavior impact on junction temper-ature of SiC power devices. This requires not only very precise 3D modeling of power semiconductor module package but also very long simulation time and costly hardware resources. This paper proposes an improved method to evaluate coolant flowrate transients’ impact on SiC junction temperature, which show not only a similar accuracy as FEM simulation but also as faster simulation speed, by using artificial intelligence (AI) algorithms to mimic the coolant flowrate transient impact on thermal network of power semiconductor modules.