Gate source impedance dynamic adjustment active current sharing SiC MOSFET parallel drive circuit

Abstract

The invention discloses a gate source impedance dynamic adjustment active current sharing SiC MOSFET parallel drive circuit. Current is indirectly measured by measuring voltage drop of a shunt. A differential amplification isolation circuit is adopted to realize isolation and differential amplification of measurement signals; a current difference value feedback circuit is adopted to carry out current difference value processing and signal feedback; an NPN triode, a resistor and a capacitor are adopted to form a gate source low-impedance circuit, and dynamic adjustment of driving loop impedance is achieved in combination with a feedback signal. According to the invention, the phenomenon of non-current-sharing in parallel connection of the SiCMOSFETs caused by inconsistent device parameters, large stray inductance and the like in the circuit can be effectively suppressed, and the purpose of active current sharing is achieved; and the circuit has the characteristics of good regulation performance, strong real-time performance, low cost and the like.

Description

technical field [0001] The invention relates to a SiC MOSFET parallel driving circuit. Background technique [0002] With the development of power electronics technology, in recent years, new materials have begun to be applied to power devices, among which SiC MOSFET is the typical representative. SiC MOSFET is the third-generation wide bandgap semiconductor power device. Compared with traditional Si power devices, SiC MOSFET has the advantages of high switching frequency, low switching loss, low on-state resistance, strong voltage resistance, and high temperature resistance. It can adapt to Applications with high voltage level and high power density. [0003] Although SiC MOSFET is widely used due to its excellent performance, due to the limitation of production process and manufacturing cost, compared with IGBT power devices, the flow capacity of a single SiC MOSFET is limited. In actual industrial production, it is often necessary to adopt multiple SiC MOSFET single-tub...

AI Technical Summary

Problems solved by technology

Due to the differences in device parameters, differences in power loop parasitic parameters, and differences in drive loop parameters, etc., when SiC MOSFETs are connected in parallel, there will be problems with unbalanced currents in each branch, including dynamic current imbalances caused by switching processes and static currents after conduction. The imbalance of current may cause harm to SiC MOSFET devices, mainly reflected in the difference in loss and current stress, which will cause a single device to be damaged due to loss and excessive stress for a long time, and even affect the safe operation of the entire system

[0004] Traditionally, measures such as coupled inductors are used to share current. Although the method is simple and the effect is good, it increases the voltage overshoot of the system and sacrifices the rising speed of the turn-on current.

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