Overcurrent and overvoltage-undervoltage drive protection system based on SiC MOSFET

Abstract

The invention discloses an overcurrent and overvoltage-undervoltage drive protection system based on a SiC MOSFET. The system comprises an overcurrent detection unit, an overvoltage-undervoltage detection unit, a control unit, a drive unit, a clamping and soft turnoff unit and a first MOSFET. In combination with the characteristics of overcurrent protection of the SiC MOSFET, overvoltage-undervoltage protection of a gate and strong anti-interference property of a detection system, clamping of the gate and soft turnoff of the SiC MOSFET are realized when the number of error states is accumulated to a preset value. When the number of error states is not accumulated to the preset value, the gate is clamped and periodically reset, so that the stability of the SiC MOSFET in an application circuit is improved and the anti-interference property of the system is detected and fed back.

Description

technical field [0001] The invention belongs to the field of electronic technology, and further relates to an overcurrent and overvoltage and undervoltage driving protection based on a SiC MOSFET (Silicon Carbide Metal Oxide Semiconductor Field Effect Transistor) in the field of power electronics technology system. The invention can be used to detect the overcurrent of the SiC MOSFET power tube and the overvoltage and undervoltage of the grid of the power tube, and count the error states. When a circuit fails, the invention can quickly and accurately cut off the work of the SiC MOSFET in the application circuit, and effectively protect the SiC MOSFET and the application circuit thereof. Background technique [0002] As a new generation of wide bandgap semiconductor material, SiC material has physical characteristics such as large bandgap width, high thermal conductivity, high breakdown voltage, and high carrier saturation drift speed compared with Si. At present, in the fi...

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Problems solved by technology

The disadvantage of this circuit is that it does not take into account the gate undervoltage protection of the MOSFET and the protection scheme to deal with the false triggering of the detection feedback, so the protection circuit has hidden dangers in terms of reliability.

However, the circuit still has the disadvantage that a single preventive mechanism cannot eliminate the false triggering of the detection feedback in the actual circuit work.

[0005] Therefore, the current driving and protection schemes for MOSFET power devices have different emphases, but there is no scheme that can simultaneously have the characteristics of overvoltage and undervoltage protection, overcurrent protection, and detection and feedback system with strong anti-interference, while for SiC MOSFET There is less research on the drive protection module of power devices, so the reliability of commercial SiC MOSFET devices in practical applications is not high

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