Design And Research Based On High Switching Frequency SiC MOSFET Three-Phase Bridge PWM Rectifier

Three-Phase bridge voltage source PWM rectifier, due many advantages such as high power factor, low harmonics content, are widely used in industry and aeronautics application. SiC MOSFET which emerged in recent years highlights with low forward voltage, high blocking voltage, low switching loss and high operational case temperature, are of vital importance to increase power density and efficiency. With its continuous technological development, SiC devices will get attentions in more and more areas.An appropriate driving circuit is important premise for using power electronic devices.Compared to Si devices, SiC MOSFET requires different driving performance and are usually used in high frequency applications, which often cause erroneous triggering and gate breakdown. This article selects SiC MOSFET with 1200 V rated voltage and 120 A rated current as working object, and then according to its switching behavior and application environment, designed SiC MOSFET driving circuits which makes comprehensive consideration in circuit structure, resistor selecting, driving voltage levels and reliability.On this basis SiC MOSFET are applied in Three-Phase PWM rectifier, and its digital controlling system is designed. To increase switching frequency, on one hand, SVPWM is simplified, on the other hand, controller parameters of current loop and voltage loop are designed in natural coordinate system. Among them, current loop are separately designed with P-controller and also PI-controller,the influence of inductance, switching frequency and P coefficient to steady-state error and dynamic performance are calculated in details.Switching loss model and calculating methodology of Three-Phase PWM rectifier which including conduct loss, switching loss and filtering inductor loss are created. On this basis, SiC MOSFET and Si IGBT under the same power ratings and switching frequency are compared with respect to loss and efficiency.Finally, a full digital controlled 5kW Three-Phase PWM rectifier prototype is designed and its hardware and software design are explained in details. Experiments are done with this prototype,results show that calculation and simulation matches experimental results, which effectively proves the validity of analysis.