Design And Application Of Driving And Protection Circuit For Mosfet Module In Low Voltage And High Current Statement For Electric Vehicles

With the increasingly and serious energy crisis and environmental issues, the electric vehicle which is generically economic and environmental friendly, has become the most important hotspot in transportation vehicle research worldwide. Also it will become one of the most important transportation tools in the21st centuries. The motor and its drive&control system is one of the key technology of electric vehicles, which is the problem solving first to develop the electric vehicles. Inverter in electric vehicle motor control system is changing the battery DC power into AC electricity to drive the motor. The core component of the electric vehicle inverter is power MOSFET modules. Research on driving and protection circuit is very important for increasing equipment utilization and service life and lower failure rate.The main purpose of this thesis is to design a controller drive circuit and protection circuit based on power MOSFET module for7.5kW electric vehicles. This thesis research the driving and protection circuit from both sides of theoretical analysis and experiment. Firstly, outline the driving and protection MOSFET module background and significance of the research, and the development status of pure electric vehicle power devices and their protection.Secondly, the thesis describes the characteristics, main technical parameter and selection of the power MOSFET. Then study on the influence of parasitic parameters and driver parameters in parallel flow characteristic using OrCAD PSpice A/D power electronic circuit simulation software. And then analyzed driving requirements for the power MOSFET, calculate the parameters of driving circuit, select the appropriate components to complete the design of driving circuit. In addition, depending on your choice of driving voltage and requirements for driving circuit, design a double-side output fly-back switching power supply. In terms of power MOSFET protection, the over-current, over-voltage and the over-heat problems are discussed in this thesis. The protection schemes are given. Firstly, design centralized and decentralized over-current protection circuit. Secondly, calculate the snubber circuit parameters and gate voltage protection circuit. Thirdly, estimate the loss power MOSFET switch and then select the radiator and design the over-heat detection circuit.Finally, after completed design the drive circuit, no-load and load experiments have been made based on7.5kW three-phase asynchronous motor, which verify the correctness of the drive circuit. And the experiment verifies the reliability of protection circuit.