Partial bootstrap gate drive circuit capable of reducing switching loss and control method

Abstract

The invention belongs to the technical field of gate drive circuits, and discloses a partial bootstrap gate drive circuit capable of reducing switching loss and a control method, and the partial bootstrap gate drive circuit capable of reducing switching loss comprises a switching device, a PWM, a power supply, a signal isolator, a non-isolated drive chip, a bootstrap structure, a drive resistor, a Mon and a Moff. Compared with voltage source type driving, the switching speed can be obviously improved, and the switching loss can be reduced; compared with current source type driving, the method has the characteristic of self-adaption, additional time sequence control is not needed, and the risk of switching device loss caused by overcharge does not exist; compared with complex active driving, the method has the advantages of being simple in result and high in reliability. A bootstrap structure is used, voltage-multiplying output can be achieved on the premise that a power supply is not added, the limitation that a wide bandgap device is larger in parasitic resistance in a gate pole is overcome, and switching loss can be remarkably reduced.

Description

technical field [0001] The invention belongs to the technical field of gate drive circuits, and in particular relates to a partial bootstrap gate drive circuit and a control method for reducing switching loss. Background technique [0002] At present, with the development of transportation electrification and new energy, more and more power electronic converters have been applied. Efficiency improvement of power electronic converters plays a crucial role in reducing energy consumption and carbon emissions, and reducing switching losses is one of the main ways to improve converter efficiency. The switching loss of the converter is directly related to the gate drive circuit used. By improving the gate drive circuit to reduce the switching loss, energy can be saved and carbon emissions can be reduced. Therefore, it is of great significance to develop gate drive techniques that can reduce switching losses. [0003] At present, the gate drive circuits at home and abroad mainly ...

AI Technical Summary

Problems solved by technology

However, on the one hand, the additional power supply greatly increases the cost of the driver. On the other hand, due to the stability of the gate oxide of the switching device, the voltage increase space used by the driver is very small.

[0008] (2) The drive circuit based on the current source needs to use an additional inductance to generate a constant current. On the one hand, the additional inductance increases the cost, and on the other hand, an additional control circuit is required

More importantly, if the charging time is not well controlled during the process of charging the gate with an inductor, it will lead to overcharging of the gate, and due to the stability of the gate oxide of the switching device, the excessively high gate Extreme voltage will damage the reliability of the device, and in serious cases will directly damage the device

[0009] (3) The existing active driving circuit with complex control logic needs to switch the output voltage or output current in real time according to the working state of the switching device. Although this method can provide the best driving performance in theory, its normal operation is extremely dependent on the Monitoring of working status of switching devices

On the one hand, additional monitoring hardware will increase the cost, on the other hand, the measured information needs to be calculated in the microcontroller, which will lead to the occupation of computing resources

[0010] (4) The traditional drive circuit only needs one control signal, while the existing current source drive circuit or active drive circuit often needs a large number of auxiliary control signals to ensure the normal operation of the circuit

Too many control signals will not only occupy more microcontroller port resources, but also make the anti-interference ability of the drive circuit worse

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