Optimization of Electric Vehicle Radiator Fan Duty cycle using KULI 1D Transient Simulation

Abstract

As the whole world moves towards the electric drive in the automotive sector, it is important for us to focus on the performance of the electric vehicles in the buses segment. For the better efficiency and performance of the vehicle, the temperature balance of the traction motor & auxiliary power electronic components is of utmost important. One of the main contributor for the power electronic components and traction motor thermal system is the Radiator fan. Two electric fans of smaller diameter are used unlike a single fan in engine cooling system. Both these fans are driven by individual BLDC motors, RPM and power consumption of the two electric fans purely depends on the radiator coolant outlet temperature. At full engaged condition, these two electric fans alone consume nearly 26% of the total LV load available for a 250 KW traction motor. In this paper a methodology is defined to calculate the power consumption of the two electric fans in actual vehicle running condition using KULI 1D software. Fan revolution is controlled based on coolant temperature and this is optimized to obtain an optimum control logic.