How critical is thermal management for electric vehicles?
Thomas Le Clerc - 15th October 2018
For the last decade, automotive market has been facing major transformation due to vehicle electrification and artificial intelligence implementation for driver assistance purpose with the ambition to develop fully autonomous vehicles. In this context, automotive companies are confronted with new technical challenges, directly linked to thermal.
1. Electric Vehicles: Extend autonomy and power capacity
For electric vehicles, autonomy is a major weakness preventing market adoption as it is not yet compatible with user habit. Today, lot of battery energy is devoted to non-engine components. Transferring this ratio in favor of engine components can significantly improve electric vehicle autonomy in addition to continuous battery technology improvement. Indeed, forced convection or water flow rate (pumped systems) are decreasing electric vehicle autonomy as they consume battery energy to operate. To further reduce energy consumption, heat recovery is considered for comfort application (heating). In parallel, weight reduction is a strategic work lead to achieve the best weight/power ratio. This involves electronic components compactification generating more heat densities (W/cm²). Entry level cooling technologies struggle to deal with such thermal specifications due their inherent characteristics.
On the other hand, power capacity is also depending on cooling as power level is up to thermal capacity to evacuate maximum power before reaching electronic component’s critical temperature. To ensure sufficient vehicle capacity, powertrain electronic components are requiring increasingly power levels and induce growing thermal challenges.
2. Toward autonomous vehicle: Embedded artificial intelligence
To offer comfortable driver and passenger experience, electric vehicles are using more and more electronic components to integrate artificial intelligence (park assist, sensors…). Subsequently, we observe electronic power levels comparable to High Performance Computing integrated in electric vehicles. To deal with such power levels, standard cooling technologies need to increase their footprint and/or energy consumption by adjusting flow rate, cold source temperatures…
Major pain points for EV companies are thermal performance capable to deal with dense and more powerful electronic components combined to together with the need for weight reduction and energy savings to extend electric vehicle autonomy. Additional limits are also taken into consideration such as reliability (pump, fan…), component lifetime, noise and mechanical integration. Indeed, automotive companies are actively seeking for new cooling technologies capable to offer them the best compromise. Thermal experts like Calyos support the automotive industry by providing them with thermal analysis (study, design, simulations...) and developing unique solutions relying on their proprietary technologies such as Calyos Loop Heat Pipe, Capillary Pumped Loop, Capillary Jet Loop...