Fault-tolerant Design And Research Of High-Reliability Electromagnetic Generator For Electric Vehicle Range Extenders

The range-extended electric vehicle combines the advantages of traditional vehicles and pure electric vehicles,solving the problems of short driving range and environmental pollution,and has broad development prospects.However,the permanent magnet generator used in the range extender has the disadvantages of difficult magnetic field adjustment and easy demagnetization.This dissertation proposes a multi-phase electromagnetic claw-pole generator for range extenders.And the research on performance of high-reliability generator for range extender is carried out.After fully considering the noise,loss,and the constraints of various parameters,the pole-slot fitting schemes and multi-phase fractional slot winding arrangements of four-phase,five-phase,and six-phase electromagnetic brushless claw-pole generators were given.Three-dimensional finite element analysis models of four-phase,five-phase,and six-phase claw-pole generators were established to analyze the inside three-dimensional magnetic field,no-load output voltage and load output voltage.The performance of multi-phase claw-pole generators was summaried.The key factors affecting the performance of the claw-pole generator were obtained through theoretical analysis.Take the four-phase generator as an example,the factors such as stator-rotor size matching relationship,polar arc coefficient,and claw-pole size of the multi-phase claw-pole generator were optimized.The optimal sizes of the multi-phase claw-pole generator were obtained.The purpose of reducing leakage magnetic flux,increasing the power density and improving the utilization of the material have been achieved.Theoretical analysis of generator short-circuit fault was carried out.The great harm of the short-circuit current was pointed out and the correctness of the theoretical analysis was verifed by simulation.The idea of converting short-circuit faults into open-circuit faults was proposed.The no-load output voltage waveforms and load carrying capacity of four-phase,five-phase and six-phase electromagnetic brushless claw-pole generators in the cases of diode open-circuit fault and armature winding open-circuit fault were analyzed.It proved that the multi-phase electromagnetic brushless claw-pole generator had a higher fault-tolerant capability.The co-simulation of finite element software and circuit analysis software was used to analyze different zener diodes,capacitors,and resistors.The effects of the Zener diode on the control transistor,resistor on power transistor and capacitor on the control transistor were summaried.And the voltage regulator of multi-phase electromagnetic claw-pole generator was completed.A voltage regulator and a four-phase electromagnetic brushless claw-pole generator prototype have been developed.An experimental platform was set up to carry out the verification of no-load voltage,load voltage and single-phase winding open-circuit fault-tolerant performance.