Smart cooling with oil gives engines maximum power
Challenge: Optimising the power of electric motors
To optimise the power output of electric motors, it is essential to look for advanced ways to better cool those motors. Dana, manufacturer of drive systems, realises this all too well. Hence they are actively working with us to validate the results of the SingleOilCnL project, supported by the Flemish government.
Solution: cooling power electronics with lubricating oil
Our innovative strategy is to use the oil circuit for component lubrication also for cooling power electronics. First, this way you do not need a separate cooling circuit (using water-glycol as coolant), which improves energy efficiency. Second, it allows you to use direct contact cooling techniques, where the oil comes into direct contact with the heated parts and cools them better, to boost the engine's power output.
We first explored which concept would yield the best results using our HYPERTHERM toolbox for Simscape, a software package used as standard for working out physical systems. We took a systems approach, taking into account the dependencies between different parts. This allows you to effectively examine a whole of parts, instead of having to look at it component by component, which would be more time-consuming and less accurate.
Result: 20% lower temperature of motor and electronics
After several design and test phases, in which artificial intelligence (AI) played an important role, we arrived at a model in which the temperatures of the motor and power electronics were reduced by 20%. We specifically addressed the best options in terms of heat sinks, with the results of an innovative baffle heat sink being the most promising.
Finally, we also developed an innovative hydrodynamic sealing concept, a model validated by Dana. The concept allows the rotor to act as a small centrifugal air pump that keeps oil out of the air gap, leading to 80% less wind capture loss. Less wind capture loss means less loss of power. The result: more power for the electric motors.
Meanwhile, together we are already looking ahead to the future, to the next generations of cooling systems, such as oil immersion cooling and dielectric liquid cooling.