AN ADVANCED PERMANENT-MAGNET MOTOR DRIVE SYSTEM FOR BATTERY-POWERED ELECTRIC VEHICLES

Recent availability of high-energy neodymium-iron-boron (Nd-Fe-B) perm anent magnet (PM) material has focused attention on the use of the Phl synchronous motor (PMSM) drive for electric vehicles (EV's), A new Nd -Fe-B PMSM is proposed for the drive system, which possesses high powe r density and high efficiency, resulting in greater energy and space s avings, The design and optimization of the motor employ finite element analysis and computer graphics, Increasingly, a new PWM inverter algo rithm is developed for the drive system, which can handle the nonconst ant battery voltage source. An efficiency optimizing control is adopte d to further improve the energy utilization of the drive system, Both the control strategy and the PWM generation are implemented in a singl e-chip microcontroller. As a result, the motor drive achieves high pow er density, high efficiency, and compactness, A prototype of the 3.2-k W battery-powered drive system has been designed and built for an expe rimental mini-EV.