Research On Key Technology Of The Doubly Salient DC Generator System For Automobile Application

The onboardgenerator system is the significant technical characteristicsof the new energy vehicles,especially the hybrid, compared to the conventional ICE vehicle.Simple configuration, flexible control,high power density and efficiency, and acceptable cost are the basic requirement for the onboardgenerator system. The key technologie of the doubly salient dc generator system for small hybrid andheavy-dutyextended-range electric busare investigated in this paper.The generators and associated generator systems for the conventional ICE vehicle and the hybridvehicle are systematically summarized. The state of art of the new variable reluctance machines isgiven. It indicates that the doubly salient brushless dc generator employed in the new energy vehicleonboard generator system is a promising scheme.The optimal design method of the doubly salientelectro-magnet machineemployed in the smallhybrid vehicle generator system is proposed. The influences of the broadend rotor width on the outputcharacteristics of the generator in different rectifier topologies are researched. Since no constraint ofphase number is posed to the dc generator system, the output characteristics of12/8-pole and16/12-pole doubly salient dc generator are compared and analysed. The inherent issue of asymmetryphase voltage is investigated.The operation mode of the extended-range electric buspowertrain is given. The constant ouputpower/current strategy for generator system and optimal operating region/line strategy for ICE areproposed. The traction power requirementand the corresponding power match of the generatorsystemare given.The influence of series winding of the doubly salient dc generator with split fieldwindings on the outputwaveform and constant voltage/current regulating characteristicsis investigated.The onboard generator system configuration based on the new doubly salient dc generator with splitfield windings is given. Then the hardware and software of the generatorsystemcontroller are designed.A prototype of the3kW12/8-pole doubly salient dc generator employed in small hybrid vehicle,and the45kW24/16-poe doubly salient dc generator with split field windings and the associatedcontroller employed in heavy-duty extended-range electric bus are developed. The test rig isconstructed.The experimental results validate that the doubly salient dc generator system takesadvantages of simple and reliable structureand flexible control which meets the requirement for thenew energy vehicle.