Research On Novel Hybrid Excitation BSG Synchronous Motor In Micro-hybrid Vehicles

Domestic and foreign automobile manufacturers commonly used claw-polemotor as the motor of BSG system, which has a good ability to regulate the air-gapmagnetic field and low cost. There are also some problems, such as low power densityand low output efficiency. In order to improve the traditional claw pole motorefficiency, This paper proposed a new hybrid excitation BSG motor, Which weren’tonly have a high power density and efficiency, but also can solve the problem ofover-pressure safety when the BSG motor generated in the high-speed, it is animportant development direction of the BSG motor. In this paper, the new hybridexcitation BSG synchronous motor topology was proposed by scholars of theGrenoble electricity electrical laboratory in France. The air gap magnetic field of themachine is produced together by the tangential magnetization magnet and DCexcitation winding in rotor. The excitation winding is supplied by the brush and slipring in rotor, which can easily adjust the air gap magnetic field. There is no problemthat the EMF is more than safe voltage when the motor is out of control at high speedand magnet occur irreversible demagnetization. The characteristics of hybridexcitation BSG synchronous motor are strongly field weakening ability, easily torealize field weakening control and smaller iron loss. It inherits the advantages of theelectric excitation synchronous motor, at the same time, overcomes theirshortcomings.In this paper, first of all, The basic structure of the new hybrid excitation BSGsynchronous motor is introduced. Which magnetic field adjusting principle andproperties is analyzed. Three kinds coordination of poles and slots were designed andanalyzed by Maxwell2D software. Twelve poles and thirty slots of BSG motor isdetermined by comparing the air-gap flux density, the generating ability and thecharacter of torque. Which proportion of permanent magnetic field and electricalexcitation field are achieved by simulation. The generating ability and the ability ofoutputting torque of BSG motor are improved by add compensation permanentmagnet to rotor. The inductance of BSG motor is analysised by analytical method andfinite element method. And then,we can get a regulation that the change of the d-axisand q-axis inductance of armature reaction according to the change of the armaturecurrent. The temperature field and the stress field of BSG motor is analysised by thefinite element simulation based on Ansys. The production process of a1.8kW newhybrid excitation BSG synchronous motor is introduced. The generation experimentof no-load test, load test and the start experiment of load test is done by the prototypeand get some result. The ability of magnetic field adjusting when it is generating andthe ability of high-torque when it is starting is proved.