DE-112024002748-T5 - GATE DRIVE DEVICE

Abstract

A gate drive device that drives semiconductor elements of upper and lower arms comprises an impedance adjustment unit that individually controls the impedances of gate discharge paths of the upper and lower arms, wherein the impedance adjustment unit sets a first impedance of the gate discharge path of the other arm in a turn-on period of one arm of the upper and lower arms such that it is higher than a second impedance of the gate discharge path of the other arm in a turn-off period of one arm.

Inventors

• Hangxian Gao
• Shintaro Tanaka

Assignees

• ASTEMO, LTD.

Dates

Publication Date

20260513

Application Date

20240805

Priority Date

20231222

Claims (9)

1. Gate drive device for driving semiconductor elements of upper and lower arms, the gate drive device comprising: an impedance tuning unit that individually controls the impedances of gate discharge paths of the upper and lower arms, wherein the impedance tuning unit adjusts a first impedance of the gate discharge path of the other arm during a turn-on period of one arm of the upper and lower arms such that it is higher than a second impedance of the gate discharge path of the other arm during a turn-off period of one arm.
2. Gate control device according to Claim 1 , wherein the impedance adjustment unit changes the impedance of the gate discharge path of the other arm from the first impedance to the second impedance between the completion of the turn-on and the start of the turn-off of one arm.
3. Gate control device according to Claim 1 , wherein the impedance adjustment unit comprises a mirror clamp circuit which maintains an impedance between a gate and a source of the semiconductor element on the second impedance.
4. Gate control device according to Claim 1 , where the first impedance is set to a value at which the semiconductor element of the other arm is switched on by switching on the first arm itself.
5. Gate control device according to Claim 1 , wherein the impedance adjustment unit controls the impedance of the gate discharge path of the other arm based on gate information from one arm to the first and second impedances.
6. Gate control device according to Claim 1 , wherein the impedance tuning unit comprises a main voltage detector that detects main voltage information of the other arm and/or a main current detector that detects main current information of the other arm, and the impedance tuning unit controls the impedance of the gate discharge path of the other arm based on the main voltage information and/or the main current information to the first and second impedance.
7. Gate control device according to Claim 1 , wherein the impedance adjustment unit comprises a capacitive element as an impedance adjustment element.
8. Gate control device according to Claim 1 , wherein the impedance adjustment unit comprises a diode as an impedance adjustment element.
9. Gate control device according to Claim 1 , wherein each of the upper and lower arms comprises a plurality of semiconductor elements connected in parallel, and the gate impedances of the plurality of semiconductor elements of the other arm are adjusted such that the recovery peaks of the plurality of semiconductor elements are equal when one arm is turned on.

Description

Technical field The present invention relates to a gate drive device. State of the art A three-phase switching branch of a power conversion device has switching elements of an upper and a lower arm for each phase. However, if one of the switching elements of the upper and lower arm is switched, a phenomenon can occur where the switching element of the other arm is also switched on due to crosstalk. In this case, the upper and lower arms become conductive simultaneously, and a short-circuit current flows between the semiconductor elements of the upper and lower arms. This short-circuit current can increase the loss of the switching element. Therefore, patent literature 1 proposes a method for suppressing self-turn-on. In the technique described in patent literature 1, an impedance tuning circuit is provided in a gate drive device, and the gate-source impedance at the time of turn-on and turn-off is reduced by the impedance tuning circuit. Accordingly, when the switching element of one arm is turned on and off, self-turn-on of the switching element of the other arm and a negative spike of a gate voltage are suppressed. Citation list Patent literature PTL 1: JP 2021 - 151039 A Summary of the invention Technical problem However, if the impedance on the same arm is reduced at the time the opposite arm is switched on, as described above, a surge voltage (recovery surge) of the linkage increases. This surge occurs when a freewheeling diode of the switching element of the same arm transitions from a conducting state to a disengaging state. To suppress the rise of the recovery surge, it is necessary to reduce the switching speed, which leads to an increase in the switching loss. Solution to the problem A gate drive device according to one aspect of the present invention is a gate drive device that drives semiconductor elements of upper and lower arms, wherein the gate drive device comprises an impedance adjustment unit that individually controls the impedances of gate discharge paths of the upper and lower arms, wherein the impedance adjustment unit adjusts a first impedance of the gate discharge path of the other arm in a turn-on period of one arm of the upper and lower arms such that it is higher than a second impedance of the gate discharge path of the other arm in a turn-off period of one arm. Advantageous effects of the invention According to the present invention, it is possible to improve the switching speed while suppressing the recovery impulse of the own arm at the time of switching on the opposite arm, and it is possible to reduce the total switching loss on the side of the opposite arm and on the side of the own arm. Brief description of the drawings [ 1 ] 1 is a diagram illustrating an example of a power conversion device.[ 2 ] 2 is a diagram illustrating a conventional configuration of a single-phase circuit.[ 3 ] 3 is a diagram that illustrates a comparative example.[ 4 ] 4 is a diagram illustrating a first embodiment of a gate driver device.[ 5 ] 5 is a diagram to explain an impedance control operation and illustrates a waveform (A) to a waveform (D).[ 6 ] 6 is a diagram illustrating a first modification of the first embodiment.[ 7 ] 7 is a diagram illustrating a second modification of the first embodiment.[ 8A ] 8A is a diagram illustrating a first modification of an impedance matching circuit.[ 8B ] 8B is a diagram illustrating a second modification of the impedance matching circuit.[ 8C ] 8C is a diagram illustrating a third modification of the impedance matching circuit.[ 8D ] 8D is a diagram illustrating a fourth modification of the impedance matching circuit.[ 8E ] 8E is a diagram illustrating a fifth modification of the impedance matching circuit.[ 9 ] 9 is a diagram illustrating a second embodiment of a gate driver device.[ 10 ] 10 is a diagram illustrating a third embodiment of a gate driver device.[ 11 ] 11 is a diagram illustrating a fourth embodiment of a gate driver device.[ 12 ] 12 is a diagram illustrating a fifth embodiment of a gate driver device. Description of embodiments Embodiments of the present invention are described below with reference to the drawings. The following description and drawings are examples used to describe the present invention, and omissions and simplifications are appropriately made for the sake of clarity. Furthermore, the same or similar elements and processes are designated by the same reference numerals in the following description, and redundant descriptions may be omitted. It should be noted that the contents described below are merely examples of embodiments of the present invention, and the present invention is not limited to the following embodiments and can be implemented in other various forms. (First embodiment) 1 Figure 1 is a diagram illustrating an example of a power conversion device. In the first embodiment, a power conversion device 20 mounted on a vehicle 1000 is described as an example. The power conversion device 20 drives an electric mot