SiC MOSFET Drive Technology Research Of PMSM

The advantages of permanent magnet synchronous motors over other types of motors are reflected in the small size of the motor,high power factor,and reliable operation.Due to these advantages,permanent magnet synchronous motors are used in aviation,aerospace,electric vehicles,and home appliances.And other fields.With the development of the aerospace industry,the gradual popularization of electric vehicles,the performance requirements of permanent magnet synchronous motors are getting higher and higher,especially the efficiency,power density and reliability of the driver.The power device is the foundation of the entire drive system and the cornerstone of the improvement of the efficiency,power density and reliability of the entire drive.At present,based on traditional power devices,it has shown limitations in the field of high frequency and high power,so the wide Forbidden semiconductor power devices came into being.The advantages of wide-bandgap semiconductor power devices are reflected in their ability to withstand high voltage,low on-resistance,fast switching speed,and ability to withstand high temperatures.These advantages are the key to improving the performance of permanent magnet synchronous motor drive systems.However,as the switching frequency increases and the characteristics of the SiC MOSFET device itself,the permanent magnet synchronous motor driver based on the SiC MOSFET will also cause some problems,such as overvoltage caused by parasitic inductance,bridge arm crosstalk and other problems.This article mainly studies the design of permanent magnet synchronous motor drivers based on SiC MOSFETs.Based on extensive research on the progress of SiCbased PMSM drivers,it deeply analyzes some issues that must be considered and solved in the successful application of SiC power devices in PMSM motor drive systems Propose your own solutions to these problems.First,analyze the driving characteristics of the SiC MOSFET,and analyze and calculate the driving voltage,driving current,driving power,and driving resistance of the SiC MOSFET in actual application conditions in detail,and obtain the value in practical application;The three operating characteristics of SiC MOSFET under high switching frequency,such as crosstalk,short circuit and overvoltage,were studied on the basis of experiment and the protection circuit was designed.Then the device selection and the drawing of SiC MOSFET driver board were carried out.Then select DSP F28335 as the main control chip,design the main control circuit and make the PCB.In the power section,the design of the DC-side bus capacitor is combined with the calculation result of the capacitance value that meets the DC-side energy throughput and the frequency characteristics of the aluminum electrolytic capacitor to determine the specific capacitance value of the capacitor plate required in this article.Then the thermal design of the entire driver is carried out.In this chapter,a 56 V,8KW permanent magnet synchronous motor is used as an example to calculate the conduction loss of the driver at different currents and the switching loss at different switching frequencies.A thermal simulation model is established based on the actual situation The thermal design data is obtained.Finally,the SiC MOSFET driver is experimentally verified to prevent crosstalk and reduce parasitic inductance,and the heat dissipation of the entire PMSM driver based on SiC MOSFET is verified.