A kind of sic MOSFET adaptive driving circuit and adaptive driving method

Abstract

The invention discloses a SiC MOSFET self-adaptive driving circuit and self-adaptive driving method. An embedded system inputs PWM and outputs PWM1 and PWM2. PWM1 and PWM2 are respectively connected to bases of NPN tubes and PNP tubes through isolation amplifying circuits. NPN tubes The collectors of the NPN tube and the PNP tube are respectively connected to the positive and negative terminals of the power supply, the emitters of the NPN tube and the PNP tube are connected to the gate of the SiC MOSFET, and the source of the SiC MOSFET is grounded; obtained by isolating the sampling circuit and the differential circuit respectively The current change rate and voltage change rate of the SiC MOSFET drain; the embedded system adjusts the pulse width of PWM1 and PWM2 in real time according to the PWM level and the current change rate and voltage change rate of the SiC MOSFET drain, and then controls the SiC MOSFET on and off. The peak current or surge voltage generated in the process can be effectively regulated and controlled to realize the adaptive fast on-off operation of SiC MOSFET.

Description

technical field [0001] The invention relates to the technical field of power electronics, and more specifically relates to a SiC MOSFET self-adaptive drive circuit and a drive method. Background technique [0002] SiC MOSFET is a voltage-driven switching device, which has the characteristics of fast on-off speed, high withstand voltage and low on-resistance, and has a high operating frequency. A large peak current is likely to be generated during the fast turn-on process, and a large surge voltage is likely to be generated during the fast turn-off process, causing the SiC MOSFET operating track to exceed the safe operating area (SOA), thereby affecting the reliability and reliability of the SiC MOSFET itself. Safety, and at the same time, it will also cause serious electromagnetic interference to external devices. [0003] Based on this, the method of increasing the resistance value of the gate drive resistor is usually used to reduce the peak current when the SiC MOSFET is...

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Problems solved by technology

[0002] SiC MOSFET is a voltage-driven switching device, which has the characteristics of fast on-off speed, high withstand voltage and low on-resistance, and has a high operating frequency. A large peak current is likely to be generated during the fast turn-on process, and a large surge voltage is likely to be generated during the fast turn-off process, causing the SiC MOSFET operating track to exceed the safe operating area (SOA), thereby affecting the reliability and reliability of the SiC MOSFET itself. security, and will also cause serious electromagnetic interference to external devices

[0003] Based on this, the method of increasing the resistance value of the gate drive resistor is usually used to reduce the peak current when the SiC MOSFET is turned on, but this method reduces the turn-on speed of the SiC MOSFET and also increases the conduction loss; usually outside the SiC MOSFET Add a snubber circuit to reduce the surge voltage when the SiC MOSFET is turned off, but this method increases the difficulty and cost of implementation, and the snubber circuit itself also has energy loss

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