Development of BLDC motor and multi-blade fan for HEV battery cooling system

Abstract

Hybrid Electtic Vehicles (HEVs) have become one of the solutions to the environmental and fuel-consumption issues in current cars. However HEVs are quite complicated due to their combined power trains which may use both internal combustion engines and electric drive motors. HEVs’ thermal management system is very important for good energy use. Thermal management of HEV batteries, such as Ni-MH or Li-Ion, is especially essential for effective operation under load-drive conditions. Reliable battery operation thermal design is even more important. A variety of battery thermal control modules are currently on the market. In this paper, air cooling types for battery thermal management system have been chosen because of their simplicity, cost effectiveness, and easy applications. The performance of the blower unit as major part of the battery cooling system is studied by experiment and on a numerical basis. A prototype BLDC (brushless DC) motor is made, performance is examined and analyzed, and multi-blade fans are optimized using numerical analysis. The overall efficiency of a prototypr BLDC motor is 72%. Also, the effects of the leading edge angle, trailing edge angle, chord length and chord angle on the performance of the multi-blade fan were investigated numerically for the optimal design by using the FLUENT. Finally, the battery cooling system, characteristics of the torque, static pressure, and airflow volume at each specific rotational speed of the fan are examined and analyzed at blowing system.