Hi,
We have designed a 50kW 3 level boost converter for our fuel cell EV application with liquid cooling. It is an IP65 module of dimensions 400mm x 300mm x 85mm. Its internal ambient temperature is rising very high. There is no specific component that emitting abnormal heat it seams, but we could not figure out how to handle this.

I wonder if there are any specific practices to mitigate the high temperature issue in such a high density power converters. Please suggest any literature if there are any techniques.

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Thanks in advance,
RAGHUCHANDAR.

 

If a 50kW converter is 99% efficient, which is never the case, it is losing 500W as heat.

 

If a 50kW converter is 99% efficient, which is never the case, it is losing 500W as heat.

Thank you for your reply MrChips. I did not understand what you are intended in the above message.

However, the efficiency is around 97.5%. Most of the losses has to be dissipated into the liquid coolant flow, as the semiconductors and inductor are placed on the cold plate which has liquid path underneath them.

 

Then you must reduce the thermal resistance between any components that are overheating and the coolant.
Not just the inductors and the semiconductors.

 

If the efficiency is 98% that is worse than 99%. Now the converter has to dissipate 1000W.
It would appear to me that coolant has to flow across the entire assembly.