The Research And Development Of Engine 12V BSG Start-stop System

As the fuel consumption and emission regulations of all the countries becomes more and more strict,it is difficult to achieve the regulation target only base on the advanced combustion technologies.In this context,the development of hybrid system becomes the research hot.And the traffic jam in cities,which lead to the fuel waste in idling mode,makes the start-stop system become the effective way to save oil.As the micro-hybrid system,the start-stop technology abolished the idling mode,and can save more fuel 3% to 5%.There are three kinds of start-stop technology.They are enhanced starter motor,BSG(Belt starter Generator)and GDI start-stop system.In this paper,the BSG system has been researched,and the work content as follows:First,the key component and signal of sensor and actuator of BSG system has been introduced.And the control strategy of start and stop has been researched and the enabled condition and trigger condition have been explained in detail.Second,the hardware and software development of start-stop system have been finished.In the hardware part,the control unit and power driver unit were designed together.In the software part,the PID control were used.Third,the 12 V BSG system model has been built with ADVISOR,a vehicle dynamics simulation software.And the models are as follows,the vehicle model,the engine model,the transmission model,the motor model,the cell model,control strategy model of start-stop and brake energy recovery.And the fuel-saving effect were analyzed.The result shows that the BSG start-stop can save 5% of fuel on NEDC test cycle.And it can save more than 2.4% of fuel with brake energy recovery.Fourth,transformed the alternator of one Magotan engine to a start-stop motor.And replaced the diode-bridge rectifier to three-phase inverting circuit.And then did some test of loading test on the platform.The result shows that the motor can supply 5Nm of torque at the speed of 1000r/min.If the transmission ratio of motor and crankshaft is 2.5,the motor can supply 12.5Nm of torque to the engine for start,which can meet the requirement of motorcycle and small displacement car.