Research On SiC-based Driver Circuit Of Aerospace Laser

In a time of fierce competition in global aerospace technology,semiconductor lasers are playing an increasingly important role and are more common in many fields such as laser guidance and LIDAR,and their driver circuits are one of the key research elements in countries around the world.In this paper,we study the drive circuit of an aerospace semiconductor laser as a load.The main research includes the load characteristics,the optimization of the SiC MOSFET drive circuit design and the research and design of the laser drive circuit.The operating principle of a semiconductor laser is analysed,its equivalent circuit is modelled based on the rate equation,the parasitic parameters of the circuit are simulated and the design requirements of the laser drive circuit for astronautics are determined in relation to the operating characteristics of the laser.In view of the shortcomings of conventional Simaterials in terms of voltage and temperature resistance as well as poor resistance to radiation interference,the use of SiC diodes and SiC MOSFETs is proposed as an "all-SiC" module.The structural features and basic characteristics of SiC diodes and SiC MOSFETs are compared with those of SiC materials,and it is found that SiC materials have the advantages of high frequency,high voltage,high temperature,high integration and low on-state resistance.The driving circuits of SiC MOSFETs and SiMOSFETs are focused on the differences in their characteristics and applications,the choice of isolation method is considered,the driving voltage,optimum driving resistance and driving current are quantified through simulation,and a hardware test platform is built to test their driving signals.In view of the large ripple coefficient of the conventional Buck circuit,a four-phase interleaved parallel Buck circuit is proposed as the main power topology circuit,and the mathematical expressions for the output current ripple and output voltage ripple are derived by combining the interleaving principle.The main power topology circuit is modelled using the state space averaging method and the modelling results are verified by MATLAB.The compensation controller is designed for the main circuit topology according to the modelling results and the designed compensator meets the engineering requirements.Finally,a SiC-based drive circuit for an astronautical laser is designed,the advantages of the designed circuit are compared by simulation and the parameters are verified,and a hardware test prototype is built.A closed-loop test was carried out using average current control in a practical application context.With an input voltage of 400 V,the output voltage of 98.4V,a maximum single-phase current of 2.56 A and an output current of 10.02 A were measured,with a ripple coefficient of 0.014,a current balance of 98.73% and an overall circuit efficiency of 95.4%.The test results show that the designed laser driver circuit meets the performance requirements of small size,simple structure and stable output current.