Research On Hybrid Excitation Synchronous Generator Based On Third Harmonic

The permanent magnet synchronous generator(PMSG)has the advantages of high power density,high efficiency and simple structure.It is widely uesd in electric vehicles,wind power generation,servo drive and many other fields.However,due to the inherent properties of permanent magnet(PM),it is difficult to adjust the air gap magnetic field of PMSG.The hybrid excitation synchronous generator(HESG)combines the advantages of PMSG and electric excitation synchronous generator,and has good prospects in application.Therefore,the basic theory,harmonic excitation system design,operation performance calculation,prototype manufacture and experiment of a new type of HESG are studied.In this paper,a novel HESG utilizing the third harmonic magnetic field for excitation is proposed.The basic structure,the principle of air gap magnetic field regulation,and the generation mechanism of the third harmonic are studied.The condition of the maximum excitation current output of the third harmonic excitation system is analyzed.The design principles and methods of the stator third harmonic winding and the rotor excitation winding are given.The best scheme is obtained by comparing the simulation results under different turn number of third harmonic winding.Based on the finite element analysis software and the power electronic simulation software,the performance simulation of the novel HESG is carried out,including the simulation of no-load characteristics,external characteristics,regulating characteristics and excitation control system.The results show that the excitation principle of the HESG is correct,and it has high efficiency and a wide regulation range of armature voltage.According to the theoretical and simulation results,a HESG prototype is manufactured and one test platform is developed.The no-load characteristics,external characteristics,regulating characteristics and excitation control system of the prototype are tested respectively.The experimental results are compared with the simulation results.The comparison shows that the simulation results are consistent with the experimental results,which futher verifies the correctness of the excitation principle,its practical value and good prospects in application..