Research On High-speed Permanent Magnet Synchronous Motor Drive And Contrl Technology Based On SiC MOSFET

The high-speed permanent magnet synchronous motor has the characteristics of large power density,high control accuracy and low heat generation.It has been widely used in high-speed air compressors and other occasions.However,due to the characteristics of small stator inductance and high current fundamental freque ncy,HSPMSM has the problems of high phase current harmonic content,cr oss-coupling and digital delay in the drive control process.Based on the Si C MOSFET driver,this paper studies an HSPMSM drive control technology,which can effectively suppress and solve the above problems.First,based on the HSPMSM mathematical model in the d-q coordinate system,the article establish a complex vector model of the motor and an accurate current loop model considering cross-coupling and digital delay,which lays a theoretical foundation for the analysis of the current loop stability later.Modeling the turn-on process and turn-off process of Si C MOSFET separately,providing theoretical guidance for the following Si C MOSFET driving technology research.Secondly,the article study related problems in the design of Si C M OSFET drive circuit and propose solutions.Based on the theoretical basis of the Si C MOSFET switching process mathematical model and SIMetrix simulation as the analysis tool,the driving parameters of the Si C MOSFET,the problems of drain-source overvoltage and oscillation,and the problem of gate crosstalk are analyzed,Then an optimized scheme for adjusting the driving parameters,shunt absorption capacitors and adding Miller clamps is proposed.Then,the article study the current loop stability of HSPMSM and design a current regulator combining cross-coupling and digital delay issues.By using Si C MOSFET to increase the switching frequency to reduce the current harmonics,and using FFT analysis to verify the effectiveness of the scheme;based on HSPMSM complex quantity model and current loop accurate model,the root locus method is used to analyze the cross-coupling of motor and digital delay to the current loop Influence of stability,design the current regulator considering the influence of digital delay and cross-coupling,and verify the correctness of theoretical analysis through simulation.Finally,based on the XMC4500 controller and Si C MOSFET,the article design the HSPMSM drive control system.This article introduce the overall design of the system,explain the design of the main circuit,sampling circuit and drive circuit,and design the software flow chart.Using SIMtrix and MATLAB to carry out the overall simulation of the motor drive control system,Simulation shows that the design scheme in this paper can effectively suppress the problem of drain-source overvoltage and gate crosstalk in the drive system,effectively solve the problem of cross-coupling and digital delay in the control system,and greatly improve the stability of the current loop.