Thermal Direct Oil Management of Power Electronics in Electric Mobility

Abstract

Efficient thermal management technologies in electric mobility promote sustainable transportation. The energy-efficient and lightweight direct cooling and heating of batteries, inverters and motors are enabling principals to achieve high power densities in the powertrain. Silicone oil is a key resource in terms of thermal, viscous and dialectical characteristics. The target is to integrate the necessary cooling through direct contact with the cooling liquid and the electrical conducting parts. This direct contact eliminates the need for a thermal conductor and electrical insulator between the metal and liquid and uses the sealed battery housing as a reservoir. The outlined concept is based on silicone oil direct cooling and heating in the housing of lithium-ion 18650 battery cells with an integrated thermoelectric element. The proposed setup is validated in two electrical motorcycles ethec alpha and ethec city from ETH Zurich.