Development of BLDC motor drive for automotive applications

In order to save resources and prevent global warming, there has been a pressing need in recent years to reduce the volume of CO2 emissions, and to improve the fuel consumption of automobiles. Due to environmental concerns, the recent regulation on automobile fuel economy has been strengthened. The market demand for efficient vehicles is growing and automakers to improve engine fuel efficiency in the industry have been paying a lot of effort. Under these circumstances, the mechanical parts in the automobile industry are being replaced by electronic methods. In this paper, authors introduce two methods. First method is water pump. Especially, to improve vehicle engine efficiency, power transmission and around the field of devices according to driving conditions need to be properly cooled. Conventional mechanical water pump is directly connected by the engine belt. For this reason, regardless of coolant circulation, the conventional mechanical water pump is always operated. However, the electric water pump can be operated only when needed through the proper motor speed control. The way which the mechanical water pump is replaced by electric water pump could reduce energy consumption. Second method is VVA (Variable Valve Actuation) technology. To improve the fuel efficiency, it is necessary to reduce losses or to improve combustion efficiency of the engine. VVA technology enhances the engine's intake air flow, reduce pumping losses and mechanical friction losses. And also, VVA technology is the engine's low speed and high speed operation to implement each of appropriate valve lift. It improves the performance of engine in the entire operating range. This paper presents a design procedure of drive for water pump and VVA system and shows the validity of the result by experimental result with prototype.