Design Of Automobile Generator Rctifier Based On Synchronous Rectifier

Synchronous rectification(SR)utilizes the power MOSFET with low on-state voltage drop as rectifiers,which has the advantages of high efficiency.It has been widely applied in certain rectification field but not in automobile generator.This thesis was aiming at giving a synchronous rectification technology architecture based on automobile generator.This thesis improved the conventional driving method of three-phase full-bridge rectifier,avoided the cumbersome rectification model and complex external driver circuit design,achieved a simpler,low-power,economical structure of synchronous rectifier.Main contents of this paper are as following:1、Firstly,this thesis analyzed the principle of synchronous rectification,described the structure,type and characteristics of the generator,and gives the mathematical models and simulation models.2、Give the design of comparator,logic modules(minimum current control module、minimum breakover time control module,,minimum shutdown time control module),the Band-Gap reference circuits,linear and stable voltage source and driving circuit module,define the functions of each module,give the specific circuit and simulate the analog circuit.Simulation results show that the logic circuit output periodically drive signal,drive circuit output was about 14 V.3、Synchronous rectifier structure is proposed,the whole circuit simulation.Simulation results indicated that under the condition that the input signal frequency is 60 Hz,amplitude is 14 V,load is 0.04Ω,rectifier output voltage value is 13.2V.The rectifier circuit takes effect.