High Performance Resistors (HPR), also known as brake resistors are used in zero emission vehicles (ZEVs) to dissipate excess electrical energy produced during regenerative braking, as heat energy. It is necessary to use a suitable cooling technique to release this heat energy into the atmosphere in a regulated manner. Currently in most of the ZEVs, liquid cooled HPR with its dedicated heat exchanger and other auxiliaries such as pump, surge tank, Coolant and coolant lines, is used which increases the cost, packaging space and assembly time.
This paper presents air cooling as a substitute heat-exchanging technique for high-performance resistors which eliminates the need of auxiliaries mentioned above, resulting in space optimization and reduction in assembly time. An air cooled HPR, designed for this study consists of a heat exchanger, which accommodates a resistor wire within its tubes. The design was made to fit commercial vehicle use, specific to trucks, due to packaging constraints in vehicle under hood. 1D simulation model made with MATLAB Simulink was used to analyse this design's heat rejection capabilities. The results conclude that for sufficient air flow rate, air cooled HPR can be used as an alternative in trucks.