Page - 145 - in Hybrid Electric Vehicles

Reader can refer to [38–40] in order to find more details about the classical theory govern- ing the thermal analysis and the development of the motor’s and cooling system’s thermal model. In Figure 13, the influence of coolant’s inlet temperature and flow rate in temperature distri- bution over different in-wheel motor parts is presented. Based on these results and the afore- mentioned considerations, the inlet temperature of 30oC along with a flow rate of 4 l/min has been chosen as the optimal combination. Moreover, the channel’s length, width and breadth have been specified to 30 mm, 10 mm and 1.5 mm, respectively. The derived requirements for heat exchanger, pump and pipe can be easily fulfilled by commercially available models. Figure 14 shows the maximum observed temperatures of motor’s parts for the same operating conditions without and with the application of the proposed cooling system. It can be easily observed that a significant temperature drop is achieved with the implementation of the cool- ing system at all the different loading conditions and the cooling system is considered efficient Figure 13. The influence of coolant’s flow rate and inlet temperature on the temperature developed at different in-wheel motor parts. Figure 14. Comparison of in-wheel motor’s temperature distribution: (a) without and (b) with the proposed here cooling system. Design, Optimization and Modelling of High Power Density Direct-Drive Wheel Motor for Light Hybrid Electric Vehicles http://dx.doi.org/10.5772/intechopen.68455 145