A parameter optimization design method for sic MOSFET drive circuit

Abstract

The invention provides a parameter optimization design method of a SiC MOSFET driving circuit, which is used for improving the design reliability of a SiC-based power electronic converter. The parameter design method includes: constructing the characteristic polynomial of the interference path transfer function; constructing a standard second-order system according to the characteristic polynomial; taking the input capacitance C of the SiC MOSFET iss and gate internal resistance R g Perform parameter per-unitization for the reference value; verify whether the stray inductance is small enough to ensure that the standard second-order system has sufficient damping ratio; design the per-unit value of the auxiliary parallel capacitor so that the standard second-order system has sufficient damping ratio , to obtain a moderate transition process with a short duration to ensure that the auxiliary shunt capacitor does not excessively affect the switching speed; design the per unit value of the driving resistance to balance and suppress the interference spikes and interference oscillations of the gate-source voltage, and prevent the drive circuit due to the cut-off frequency Too low will cause the gate-source voltage to change too slowly and increase the switching loss.

Description

technical field [0001] The invention relates to a parameter optimization design method of a SiC MOSFET drive circuit. Background technique [0002] At present, in practical application of SiC MOSFET, the drive design method of traditional SiC MOSFET is still used. However, SiC MOSFETs generally have faster switching speeds and higher voltage withstand capabilities, so they have a higher voltage change rate than Si devices, and the gate-source voltage interference problem is more prominent. [0003] The two main factors that limit the switching speed of their SiC MOSFETs are gate drive capability and gate-source voltage interference issues. Reference [1], Reference [2] and Reference [3], on the basis of traditional Si MOSFET drive circuit design, additionally add the verification link of the maximum change value of gate-source voltage, according to the voltage change rate, drive resistance and junction capacitance The equivalent circuit estimates the maximum variation of th...

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Problems solved by technology

[0004] These studies have explained the essential cause of gate-source voltage interference, and provided a conceptual basis for improving gate drive circuit design, eliminating interference, and increasing switching speed; however, these studies have not yet considered the key stray parameters that affect the dynamic characteristics of SiC MOSFETs, such as Gate internal resistance, drive loop inductance and power loop inductance, etc.

The optimization design method of SiC MOSFET drive circuit parameters is not yet complete, and it is urgent to explore the drive design method suitable for SiC MOSFET based on the characteristics of high switching speed of SiC MOSFET, so as to provide SiC MOSFET devices with higher power level and higher performance requirements in the future. Provide theoretical guidance and application technical support

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