Analysis The Key Factors Of Motor Drive Based On GaN Power Device

Permanent magnet synchronous motors(PMSM)have been widely used in industrial production,aerospace and electric vehicles,etc.Rapidly developments of technology demands higher power density,efficiency and reliability in PMSM drivers.Compared with silicon power devices,GaN power devices offer higher switching speed,lower on-resistance and higher temperature operation,which is expected to improve the efficiency,power density and dynamic performance of PMSM drivers.With the development of GaN power device manufacturing technology,researchers paid more and more attentions on its applications in PMSM driver.The electrical characteristics of eGaN HEMT are firstly analyzed,the static and reverse conduction characteristics are explored by single pulse experimental platform.Switching waveforms after adding parasitic parameters are presented by detailed analysis,and quantitative analysis of the effect of circuit parameters on eGaN HEMT switching performance is carried out by double pulse test.In addition,a short-circuit test platform under hard-switching model is established to study the short-circuit characteristics,withstand capability and failure mechanism of eGaN HEMT.The thermal network model is used to analyze the junction temperature variation during the short-circuit process.The phase leg circuit is the basic unit of motor drivers.Therefore,the high-speed drive circuit design of the eGaN HEMT applied to the phase leg circuit is studied,from the drive IC,parameters design,layout design and crosstalk suppression,and a high speed drive circuit with crosstalk suppression is designed.Then aiming at the unique reverse conduction characteristics,the effects of different freewheeling modes on the conduction and switching characteristics of bridge arm circuits are studied,especially the influence of anti-paralleling SiC SBD.Based on theoretical analysis and experimental results,from the perspective of loss,the advantages and disadvantages of different freewheeling modes and applicable occasions are clarified.A 1.5kW GaN-based high-speed switch PMSM driver is built and test in the lad to verify the correctness and feasibility of high-speed drive circuit and freewheeling design,and the rationality and superiority of GaN-based high-speed switch PMSM driver.