Research And Design Of IGBT Active Gate Feed Forward Drive Circuit

With the improvement integration and manufacturing process technology of IGBT,IGBT is widely used in high-frequency and high-power applications.However,due to the objective existence of anti-parallel diode and stray inductance in the IGBT,the issues of current overshoot,voltage overshoot and switching losses at turn-on and turn-off are particularly prominent.The object of this paper is IGBT drive circuit,and the main research contents are as follows:1.The characteristics and model of IGBT is analyzed in detail,realizing the simulation and actual switch characteristics are basically consistent;Finally,the overshoot current,overshoot voltage and the device's loss formula in high frequency applications of IGBT is derived.2.The active gate feed forward drive circuit is designed to control the gate voltage in a real time to reduce overshoot voltage and overshoot current in the switching processes.The positive feedback signal is eliminated by the clipping circuit,thus,the response speed of the device is improved effectively and the switching losses of the device are reduced.This drive circuit can provide a reliable positive and negative 15V drive signal,electrical isolation between the control circuit and the main circuit can be realized,and the gate drive capability of the sufficient power can be enhanced.3.Overcurrent,overvoltage and overheating protection circuit is verified by simulation to prevent its failures that easily occur during the working processes of IGBT.Ensure that the IGBT is turned off reliably in case of failure,the reliability of the drive circuit is improved effectively.4.The active gate feed forward drive circuit and the traditional gate drive circuit is simulated and experimented respectively under die double-pulse test platform to compare and analyze the overshoot current,overshoot voltage and device loss.The simulation and experimental results verify the feasibility and effectiveness of the active gate feed forward drive circuit.