A Hybrid Vehicle is one of the solutions to improve efficiency of a cruse and to reduce CO2 gas by regenerative breaking and operating the engine in optimum condition. It is requested to decrease the motor size and increase the maximum torque for minimizing the driving units. For these purpose permanent magnet applied motors have been commonly used recently.
This paper describes the reluctance torque largely employed new motor named PRM [1]-[3], namely permanent magnet reluctance motor for a hybrid truck. The PRM will be mounted between a diesel engine and a transmission. This condition imposes a large diameter and thin length on a motor design. Generally, it is difficult to produce a large torque in this shape. By optimizing the magnet position and magnetic circuit design, it delivered large reluctance torque and achieved maximum torque of 350Nm. Furthermore it is as 1.4 times as large as a current induction motor’s. It can provide 400Nm for a short period if necessary. Its size reduces two thirds of induction motor’s. They satisfy the specifications of the HEV truck. Commercial manufacturing of this motor drive system and the will begin in 2006.