WO2021217884A1

WO2021217884A1 - Intelligent switch and driving delay adjustment method therefor

Info

Publication number: WO2021217884A1
Application number: PCT/CN2020/101131
Authority: WO
Inventors: 刘钧; 冯颖盈; 姚顺; 徐金柱; 胡飞
Original assignee: 深圳威迈斯新能源股份有限公司
Priority date: 2020-04-30
Filing date: 2020-07-09
Publication date: 2021-11-04
Also published as: CN111510123A

Abstract

Disclosed are an intelligent switch and a driving delay adjustment method therefor. The intelligent switch comprises a wide-bandgap switching device, a silicon switching device and a driving module, wherein a source electrode and a drain electrode of the wide-bandgap switching device are respectively connected to a source electrode and a drain electrode of the silicon switching device, a gate electrode of the wide-bandgap switching device and a gate electrode of the silicon switching device are respectively connected to the driving module, and the driving module is used for sending a first driving signal and a second driving signal for driving the wide-bandgap switching device and the silicon switching device respectively. By means of the technical solution of the present invention, an intelligent switch with a high switching efficiency and a low cost can be obtained.

Description

Intelligent switch and its driving delay adjustment method

Technical field

The invention relates to the field of power electronics, in particular to an intelligent switch and a driving delay adjustment method thereof.

Background technique

In electric vehicle on-board power electronics, as the power demand increases and the overall efficiency requirements increase, multiple semiconductor switches in parallel can be used to provide high current, power capability, and reduce conduction losses. At the same time, with the increasing requirements for power density, the requirements for switching frequency are getting higher and higher. Known silicon devices (e.g., MOSFET, IGBT) do not operate such switches at a high switching frequency due to relatively high switching losses. Wide-bandgap (WBG) devices such as silicon carbide (SiC) and gallium nitride (GaN) devices are becoming more popular due to their higher switching than conventional silicon (Si) devices Frequency capability, lower switching loss. However, the current capability of WBG devices compared to silicon devices is still not high enough for some applications. High-current applications of WBG switches increase the cost significantly. How to balance efficiency and cost in high-power and high-power density applications is a problem that the industry needs to solve urgently.

Summary of the invention

The purpose of the present invention is to provide an intelligent switch and a driving delay adjustment method for the above technical problem that the semiconductor switch device of the prior art cannot balance efficiency and cost.

In an embodiment of the present invention, an intelligent switch is provided, which includes a wide band gap switching device, a silicon switching device, and a driving module. The source and drain of the wide band gap switching device are respectively connected to the source of the silicon switching device. The pole and the drain are connected, the gate of the wide band gap switching device and the gate of the silicon switching device are respectively connected with the driving module, and the driving module is used to send out driving the wide band gap switching device and The first driving signal and the second driving signal of the silicon switching device.

In the embodiment of the present invention, the wide band gap switching device is a silicon carbide switching device or a gallium nitride switching device.

In the embodiment of the present invention, the silicon switching device is a MOSFET tube, an IGBT tube, or an IGBT tube in parallel with a diode.

In the embodiment of the present invention, when the smart switch turns from off to on, the drive module controls the first drive signal and the second drive signal to change from low level to high level, and The time when the second driving signal turns to a high level has a first delay relative to the first driving signal.

In the embodiment of the present invention, when the smart switch turns from on to off, the drive module controls the first drive signal and the second drive signal to turn from a high level to a low level, and The time when the first driving signal turns to a low level has a second delay relative to the second driving signal.

In the embodiment of the present invention, a driving delay adjustment method of the above-mentioned smart switch is also provided, which includes:

Obtaining the power when the smart switch is turned on;

The first delay and the second delay are determined according to the power when the smart switch is turned on, wherein the relationship between the power of the smart switch and the first delay and the second delay The function is preset in the drive module.

In the embodiment of the present invention, the voltage and current of the smart switch are sampled, and the power of the smart switch is calculated according to the voltage and current obtained by the sampling.

In the embodiment of the present invention, the driving delay adjustment method of the smart switch further includes:

Obtain the temperature of the smart switch, and fine-tune the first delay and the second delay according to the temperature of the smart switch, wherein the temperature of the smart switch is the same as the first delay and the The adjustment relation function of the second delay is preset in the driving module.

In the embodiment of the present invention, there is also provided a driving delay adjustment method of the above-mentioned smart switch, which includes:

Acquiring the temperature of the smart switch;

The first delay and the second delay are determined according to the temperature of the smart switch, wherein the relationship function between the temperature of the smart switch and the first delay and the second delay is pre-determined Set in the drive module.

Sampling the voltage and current of the smart switch, and calculating the power of the smart switch;

The first delay and the second delay are fine-tuned according to the power of the smart switch, wherein the power of the smart switch is adjusted to the first delay and the second delay The function is preset in the drive module.

In summary, in the technical solution of the present invention, the smart switch includes a wide band gap switch device and a silicon switch device. The high switching speed of the wide band gap switch device is used to reduce switching loss, and the large current capacity of the silicon switch device is reduced. Current loss, can reduce loss overall, improve efficiency, simple and easy to implement, high reliability, economical and applicable; in addition, it adopts the detection of the temperature and power of the smart switch to control the wide band gap switching device and the silicon Adjusting the delay of the driving signal of the switching device can make the smart switch work in an optimal state.

Description of the drawings

Fig. 1 is a schematic structural diagram of a smart switch according to an embodiment of the present invention.

2(a)-FIG. 2(f) are schematic structural diagrams of multiple combinations of smart switches according to embodiments of the present invention.

Fig. 3 is a waveform diagram of a driving signal of a smart switch according to an embodiment of the present invention.

FIG. 4 is a flowchart of a first implementation manner of a driving delay adjustment method of a smart switch according to an embodiment of the present invention.

Fig. 5 is a flowchart of a second implementation manner of a method for adjusting a driving delay of a smart switch according to an embodiment of the present invention.

Fig. 6 is a flowchart of a third implementation manner of a method for adjusting a driving delay of a smart switch according to an embodiment of the present invention.

FIG. 7 is a flowchart of a fourth implementation manner of a method for adjusting a driving delay of a smart switch according to an embodiment of the present invention.

Detailed ways

As shown in FIG. 1, in the first embodiment of the present invention, an intelligent switch is provided, which includes a wide band gap switching device 1, a silicon switching device 2 and a driving module 3. The source and drain of the wide band gap switching device 1 are respectively connected with the source and the drain of the silicon switching device 2 to form a switching path.

The gates of the wide band gap switching device 1 and the gates of the two silicon switches are respectively connected to the driving module 3. The driving module 3 is used to issue a first driving signal Vgs1 and a second driving signal Vgs2 for driving the wide band gap switching device 1 and the silicon switching device 2 respectively. The first driving signal Vgs1 and the second driving signal Vgs1 The signal Vgs2 is used to control the levels of the gates of the wide bandgap switching device 1 and the gates of the silicon switch 2 respectively, thereby controlling the conduction of the wide bandgap switching device 1 and the silicon switching device 2 And disconnect. The driving module 3 may be implemented by using DSP, or may be implemented by combining DSP with other circuits.

As shown in FIG. 2(a)-FIG. 2(f), the wide band gap switching device 1 is a silicon carbide (SiC) switching device or a gallium nitride (GaN) switching device. The silicon switching device 2 is a MOSFET tube, an IGBT tube, or an IGBT tube in parallel with a diode (DIODE). The wide band gap switching device 1 and the silicon switching device 2 may adopt various combinations to form the smart switch.

As shown in FIG. 3, when the smart switch turns from off to on, the drive module 3 controls the first drive signal Vgs1 and the second drive signal Vgs2 to change from low level to high level. And the time t2 when the second driving signal Vgs2 turns to a high level has a first delay Ton_delay relative to the time t1 when the first driving signal Vgs1 turns to a high level. When the smart switch turns from on to off, the drive module controls the first drive signal Vgs1 and the second drive signal Vgs2 to turn from a high level to a low level, and the first drive The time t4 when the signal Vgs1 turns to a low level has a second delay Toff_delay relative to the time t3 when the second driving signal Vgs2 turns to a low level. By controlling the on-off time of the wide bandgap switching device 1 and the silicon switching device 2, the smart switch can be controlled. The high switching speed of the wide bandgap switching device 1 can be used to reduce the switching loss and The large current capacity of the silicon switching device 2 can be used to reduce the current loss, thereby reducing the overall switching loss and improving the switching efficiency.

FIG. 4 shows a flowchart of a first implementation manner of a method for adjusting a driving delay of a smart switch according to an embodiment of the present invention. The method includes:

Obtaining the power when the smart switch is turned on;

The first delay Ton_delay and the second delay Toff_delay are determined according to the power when the smart switch is turned on, wherein the power of the smart switch is the same as the first delay Ton_delay and the second delay. The relational function of time Toff_delay is preset in the driving module.

It should be noted that under different powers of the smart switch, using different first delay Ton_delay and second delay Toff_delay can optimize the switching efficiency of the smart switch. Therefore, in the driving module 3, the relationship function between the power of the smart switch and the first delay time Ton_delay and the second delay time Toff_delay can be preset, and the relationship function can be presented in the form of a table, It can also be presented by fitting a curve. In the embodiment of the present invention, the voltage and current of the smart switch are sampled, and the power of the smart switch is calculated according to the voltage and current obtained by the sampling.

Fig. 5 shows a flowchart of a second implementation manner of a method for adjusting a driving delay of a smart switch according to an embodiment of the present invention. Compared with the first implementation manner, the method further includes:

Acquire the temperature of the smart switch, and fine-tune the first delay Ton_delay and the second delay Toff_delay according to the temperature of the smart switch, wherein the temperature of the smart switch is the same as the first delay Ton_delay The adjustment relationship function with the second delay Toff_delay is preset in the driving module 3.

It should be noted that, in order to optimize the switching efficiency of the smart switch, the influence of the temperature of the smart switch needs to be considered. The first delay Ton_delay and the second delay can be adjusted according to different temperatures. Toff_delay is fine-tuned. The adjustment relation function between the temperature of the smart switch and the first delay Ton_delay and the second delay Toff_delay can be preset in the driving module 3, and a temperature sensor is provided in the smart switch to detect the State the temperature of the smart switch.

FIG. 6 shows a flowchart of a third implementation manner of a method for adjusting a driving delay of a smart switch according to an embodiment of the present invention. The method includes:

Acquiring the temperature of the smart switch;

The first delay Ton_delay and the second delay Toff_delay are determined according to the temperature of the smart switch, wherein the temperature of the smart switch is equal to that of the first delay Ton_delay and the second delay Toff_delay The relation function is preset in the driving module.

It should be noted that, in this embodiment, the first delay Ton_delay and the second delay Toff_delay are only set according to the temperature of the smart switch. The relationship function between the temperature of the smart switch and the first delay Ton_delay and the second delay Toff_delay may be presented in a form of a table, or may be presented in a manner of fitting a curve.

FIG. 7 shows a flowchart of a fourth implementation manner of a method for adjusting a driving delay of a smart switch according to an embodiment of the present invention. Compared with the third embodiment, the method further includes:

The first delay Ton_delay and the second delay Toff_delay are fine-tuned according to the power of the smart switch, wherein the power of the smart switch is the same as the first delay Ton_delay and the second delay The adjustment relation function of Toff_delay is preset in the driving module.

It should be noted that in this embodiment, the first delay Ton_delay and the second delay Toff_delay are determined by the temperature of the smart switch, and then the power of the smart switch is used to determine the The first delay Ton_delay and the second delay Toff_delay are fine-tuned.

The above descriptions are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims

An intelligent switch, characterized in that it comprises a wide band gap switch device, a silicon switch device, and a driving module. The source and drain of the wide band gap switch device are respectively in phase with the source and drain of the silicon switch device. Connected, the gate of the wide bandgap switching device and the gate of the silicon switching device are respectively connected to the driving module, and the driving module is used to issue the first driving module for driving the wide bandgap switching device and the silicon switching device. A driving signal and a second driving signal.
The smart switch of claim 1, wherein the wide band gap switching device is a silicon carbide switching device or a gallium nitride switching device.
The smart switch of claim 1, wherein the silicon switching device is a MOSFET tube, an IGBT tube, or an IGBT tube in parallel with a diode.
The smart switch of claim 1, wherein when the smart switch turns from off to on, the drive module controls the first drive signal and the second drive signal to change from a low level to a low level. Turning to a high level, and the time for the second driving signal to turn to a high level has a first delay relative to the first driving signal.
The smart switch of claim 4, wherein when the smart switch turns from on to off, the drive module controls the first drive signal and the second drive signal to change from a high level to a high level. The time when the first driving signal is turned to a low level has a second delay with respect to the second driving signal.
A method for adjusting the driving delay of an intelligent switch according to claim 5, characterized in that it comprises:

Obtaining the power when the smart switch is turned on;

The first delay and the second delay are determined according to the power when the smart switch is turned on, wherein the relationship between the power of the smart switch and the first delay and the second delay The function is preset in the drive module.
7. The driving delay adjustment method of a smart switch according to claim 6, wherein the voltage and current of the smart switch are sampled, and the power of the smart switch is calculated according to the voltage and current obtained by the sampling.
The driving delay adjustment method of a smart switch according to claim 6, characterized in that it further comprises:

Obtain the temperature of the smart switch, and fine-tune the first delay and the second delay according to the temperature of the smart switch, wherein the temperature of the smart switch is the same as the first delay and the The adjustment relation function of the second delay is preset in the driving module.
A method for adjusting the driving delay of an intelligent switch according to claim 5, characterized in that it comprises:

Acquiring the temperature of the smart switch;

The first delay and the second delay are determined according to the temperature of the smart switch, wherein the relationship function between the temperature of the smart switch and the first delay and the second delay is pre-determined Set in the drive module.
9. The driving delay adjustment method of a smart switch according to claim 9, further comprising:

Sampling the voltage and current of the smart switch, and calculating the power of the smart switch;

The first delay and the second delay are fine-tuned according to the power of the smart switch, wherein the power of the smart switch is adjusted to the first delay and the second delay The function is preset in the drive module.