The Research On Brushless Electromagnetic And Built-in Permanent Magnetic Parallel Magnetic Circuit Hybrid Excitation Generator For Vehicles

Hybrid excitation generator is a new type of generator,which has two kinds of magnetic potential sources of permanent magnet and electric excitation winding,and with adjustable air gap magnetic field under the premise of high efficiency and low energy consumption,and it has wide application prospects in vehicle power system.According to the analysis of different topology of hybrid excitation generator,an advance hybrid excitation generator which has a stator and a combined parallel rotor with a brushless claw pole electric excitation rotor and a built-in tangential permanent magnet rotor was proposed and the main structural dimensions were determined.The magnetic isolation groove of permanent magnet rotor was designed to reduce the leakage flux in rotor core,increase the main air gap flux,and improve the generator efficiency.The equivalent circuit model of permanent magnet magnetic field,electric excitation magnetic field and resultant magnetic field of hybrid excitation generator were established.Based on the equivalent magnetic circuit model,the calculation method of magnetic permeance,effective flux,leakage flux and magnetic flux leakage coefficient in hybrid excitation generator were deduced,it can provide a theoretical basis for analyzing magnetic leakage factors,improving the magnetic field utilization rate and optimizing the structure of hybrid excitation generator.The simulation model of permanent magnet magnetic field,electric excitation magnetic field and resultant magnetic field were established using the magnetic field finite element analysis software.The magnetic field distribution diagram,the magnetic flux density vector diagram,flux density nephogram,air gap flux density waveform curve,and the armature winding current waveform and voltage waveform under no-load and load conditions were obtained,and the simulation results show that the hybrid excitation generator has a reasonable magnetic field distribution,and the electric excitation magnetic field can realize the function of "increasing magnetism" and "weak magnetism" to air gap magnetic field of hybrid excitation generator,by changing the direction of the electric excitation current.With the mutually independent of permanent magnetic circuit and the electric magnetic circuit,the brushless electromagnetic and built-in tangential permanent magnet hybrid excitation voltage stabilizing generator can provide stable voltage to vehicle storage battery and electric equipment under the changing generator speed and load with the design of voltage regulation circuit which can adjust the electric field in the air gap by controlling the bidirectional change of electric excitation current.