Research On Permanent Magnet Synchronous Motor Drive System Based On Silicon Carbide Power Device

As the most typical wide bandgap semi-conductor devices,silicon carbide MOSFETs have been more and more widely used in high frequency or high temperature switching situation in recent years.Using SiC MOSFETs in PMSM control system can firstly reduce drive loss and improve system efficiency.Secondly,the switching frequency can be increased to enlarge the power density of the motor and reduce the current harmonics.In addition,the maximum working temperature of the system can be increased meanwhile the volume of heat sink can be reduced.In this paper,a type of PMSM control system based on SiC power devices is proposed in order to verify the advantages of SiC power devices in the field of motor drive,and to seek the suitable situations of SiC power devices.Depending on researching the working and parameter characteristics of SiC MOSFETs and SiC SBDs,and referring to foreign modeling strategy,the Spice modeling method of SiC MOSFETs with both physical properties and equivalent circuit is established.A circuit model for the SiC module BSM300D12P2E001 is set up whose characteristics are verified by comparing with the simulation results and the curves of device datasheet.The loss composition of inverter is studied and the estimation method of SiC MOSFET loss is deduced.Through single-variable simulation,the factors that influence on-state loss and switching loss are obtained.The device losses of SiC MOSFET and Si IGBT under the same working conditions were compared.It is proved that the use of SiC device can reduce the loss of inverter and improve the efficiency of motor system.The drive requirements of SiC MOSFET are proposed.The issue of parasitic turn-on caused by crosstalk in three-phase inverter bridge circuit is explored thoroughly.Several effective solutions to restrain this issue are put forward and the effects of each method are compared and analyzed.The influence of dead-band effect on motor performance with high switching frequency is studied.And an effective dead-band compensation method for SiC motor driver is proposed.Through simulation and experiment,it is proved that this compensation method can reduce the current harmonic content and reduce the torque fluctuation of the motor.The structure of the motor system and the functions of each part are analyzed.The drive circuit and protection circuit of inverter are designed.The motor control system is set up to complete the comparison experiment between SiC MOSFETs and Si IGBTs.It is shown that SiC power devices can improve the efficiency of system by reducing the inverter loss and optimize the motor performance by increasing the switching frequency and reduce the dead-band time.