| As the next generation power devices, silicon carbide (SiC) devices feature higher blocking voltage, better high-frequency performance, lower on-state loss and increased operating temperature. In recent years, with the innovation of commercial SiC devices, studies on SiC device applications are emerging. Gate driver is one of the key technologies in semiconductor device study, on which the research is of great significance for the application of new semiconductor devices.First, the driving characteristics of SiC MOSFET were analyzed. Then, each part of the gate drive circuit was described in detail, based on this, a gate driver was designed with discrete devices. In addition, overcurrent protection of SiC MOSFET was also studied. Both desaturation detection and inductance detection were discussed in this section. After that, a complete overcurrent protection circuit was proposed, simulation experiments of the circuit were conducted based on OrCAD PSPICE.Based on study above, a double-pulse test platform was built to evaluate the performance of the gate driver. According to the design flaws reflected in test results, the optimization design of gate driver was carried out. Consequently, the oscillations and spikes in gate voltage VGS as well as Drain current ID were effectively controlled while drive performance improved in optimized gate driver. Furth more, overcurrent protection experiments were conducted, which proved that the proposed protection circuit could cut off gate signal timely and accurately when the current of SiC MOSFET reached protection threshold.In this thesis, a complete and feasible implementation scheme of gate driver and over current protection was proposed on the basis of theoretical study, circuit simulation and experiment, which provided strong support to the application of SiC MOSFET in power electronic circuits. |
