阅读说明：本技术 一种驱动保护电路及其保护方法 (Drive protection circuit and protection method thereof ) 是由 梁伙明 吴晓光 黄辉 于 2019-09-16 设计创作，主要内容包括：本发明公开了一种驱动保护电路。所述驱动保护电路包括驱动模块、状态检测模块及控制模块,所述驱动模块的一端与绝缘栅器件的栅极连接,所述驱动模块的另一端与控制模块连接,所述状态检测模块的一端与绝缘栅器件的栅极连接,所述状态检测模块的另一端与控制模块连接。所述状态检测模块用于获取绝缘栅器件的栅极电压,并根据栅极电压输出状态检测信号至控制模块,所述控制模块用于根据状态检测信号判断绝缘栅器件是否发生短路,并在绝缘栅器件发生短路时,控制驱动模块对绝缘栅器件的栅极输出高阻态。本发明还提供了一种驱动保护电路的保护方法,有效避免绝缘栅器件短路后的电流烧坏驱动电路,从而减小损失。(The invention discloses a drive protection circuit. The drive protection circuit comprises a drive module, a state detection module and a control module, wherein one end of the drive module is connected with the grid electrode of the insulated gate device, the other end of the drive module is connected with the control module, one end of the state detection module is connected with the grid electrode of the insulated gate device, and the other end of the state detection module is connected with the control module. The state detection module is used for obtaining the grid voltage of the insulated gate device and outputting a state detection signal to the control module according to the grid voltage, and the control module is used for judging whether the insulated gate device is short-circuited or not according to the state detection signal and controlling the driving module to output a high-resistance state to the grid of the insulated gate device when the insulated gate device is short-circuited. The invention also provides a protection method of the drive protection circuit, which effectively avoids the current after the insulated gate device is short-circuited from burning the drive circuit, thereby reducing the loss.)

1. A drive protection circuit is used for receiving a drive signal and controlling the drive signal to drive an insulated gate device to work, and is characterized by comprising a drive module, a state detection module and a control module, wherein one end of the drive module is electrically connected with a grid electrode of the insulated gate device, the other end of the drive module is electrically connected with the control module, one end of the state detection module is electrically connected with the grid electrode of the insulated gate device, and the other end of the state detection module is electrically connected with the control module;

the state detection module is used for acquiring the grid voltage of the insulated gate device and outputting a state detection signal to the control module according to the grid voltage of the insulated gate device; the control module is used for judging whether the insulated gate device is short-circuited according to the state detection signal and processing the driving signal according to a judgment result, and the driving module outputs different resistance states to the grid electrode of the insulated gate device under the control of the driving signal processed by the control module;

when the insulated gate device is not short-circuited, the driving module outputs a low-resistance state to the grid electrode of the insulated gate device; and

when the insulated gate device is short-circuited, the driving module outputs a high-resistance state to the grid electrode of the insulated gate device.

2. The driving protection circuit of claim 1, wherein the state detection module comprises a first comparator, a second comparator, a first voltage source and a second voltage source, a first input terminal of the first comparator and a first input terminal of the second comparator are electrically connected to the gate of the insulated gate device to obtain the gate voltage of the insulated gate device, a second input terminal of the first comparator is electrically connected to the first voltage source to obtain a first comparison reference, a second input terminal of the second comparator is electrically connected to the second voltage source to obtain a second comparison reference, and an output terminal of the first comparator and an output terminal of the second comparator are electrically connected to the control module to output the state detection signal to the control module.

3. The driving protection circuit according to claim 2, wherein the control module comprises an and gate, an or gate, an xor gate and a filter unit, a first input end of the and gate is electrically connected to a first input end of the or gate and is configured to receive the driving signal, a second input end of the and gate is electrically connected to the filter unit, a second input end of the or gate is connected to the filter unit after being inverted, an output end of the and gate and an output end of the or gate are both electrically connected to the driving module, an output end of the xor gate is electrically connected to the filter unit after being inverted, and an input end of the xor gate is electrically connected to an output end of the first comparator and an output end of the second comparator.

4. The driving protection circuit of claim 3, wherein the driving module comprises a first NOT gate, a second NOT gate, a first electronic switch, a second electronic switch, a first resistor and a second resistor, the input end of the first NOT gate is electrically connected with the output end of the AND gate, the input end of the second NOT gate is electrically connected with the output end of the OR gate, the output end of the first NOT gate is electrically connected with the first end of the first electronic switch, the second end of the second electronic switch is electrically connected with a first power supply, the third terminal of the first electronic switch is electrically connected to the gate of the insulated gate device through the first resistor, the output end of the second NOT gate is electrically connected with the first end of the second electronic switch, the second end of the second electronic switch is electrically connected with a second power supply, the third end of the second electronic switch is electrically connected to the grid electrode of the insulated gate device through the second resistor.

5. The driving protection circuit according to claim 2, wherein the first input terminal of the first comparator is an inverting input terminal, the second input terminal of the first comparator is a non-inverting input terminal, the first input terminal of the second comparator is an inverting input terminal, and the second input terminal of the second comparator is a non-inverting input terminal.

6. The driving protection circuit according to claim 2, wherein the first comparison reference is smaller than a minimum on-voltage of the gate when the insulated gate device normally operates, and the second comparison reference is larger than a maximum off-voltage of the gate when the insulated gate device normally operates.

7. The drive protection circuit of claim 1, wherein the control module is a programmable logic device or a field programmable gate array.

8. A protection method of a driving protection circuit is characterized by comprising the following steps:

acquiring a grid voltage of an insulated grid device, and outputting a state detection signal according to the grid voltage of the insulated grid device;

judging whether the insulated gate device is short-circuited according to the state detection signal, and processing the driving signal according to a judgment result so as to control the gate of the insulated gate device to output different resistance states;

if the insulated gate device is not short-circuited, the grid electrode of the insulated gate device outputs a low-resistance state;

and if the insulated gate device is short-circuited, the grid electrode of the insulated gate device outputs a high-resistance state.

Technical Field

The invention relates to the technical field of semiconductor device driving with an insulated gate structure, in particular to a driving protection circuit and a protection method thereof.

Background

An Insulated Gate device, such as an Insulated Gate Bipolar Transistor (IGBT), has become a mainstream power semiconductor device, and the Insulated Gate device has been widely applied to the thermal industry, such as photovoltaic, wind power generation, frequency conversion, and electric vehicles. In practical applications, a short-circuit protection circuit is designed for an insulated gate device to prevent the insulated gate device from breakdown failure due to overcurrent.

However, when the insulated gate device fails during operation, the gate and the drain of the insulated gate device may be shorted, which may cause the output of the driver to be shorted, and thus may burn the driving circuit and other electronic components of the insulated gate device, resulting in greater loss.

Disclosure of Invention

Therefore, it is desirable to provide a driving protection circuit and a protection method thereof, which can monitor the gate short circuit state of the insulated gate device in time and control to cut off the gate short circuit loop, so as to avoid the short circuit current from burning out the driving circuit and reduce the loss.

The technical scheme provided by the invention for achieving the purpose is as follows:

a drive protection circuit is used for receiving a drive signal and controlling the drive signal to drive an insulated gate device to work, and comprises a drive module, a state detection module and a control module, wherein one end of the drive module is electrically connected with a grid electrode of the insulated gate device, the other end of the drive module is electrically connected with the control module, one end of the state detection module is electrically connected with the grid electrode of the insulated gate device, and the other end of the state detection module is electrically connected with the control module;

the state detection module is used for acquiring the grid voltage of the insulated gate device and outputting a state detection signal to the control module according to the grid voltage of the insulated gate device; the control module is used for judging whether the insulated gate device is short-circuited according to the state detection signal and processing the driving signal according to a judgment result, and the driving module outputs different resistance states to the grid electrode of the insulated gate device under the control of the driving signal processed by the control module;

when the insulated gate device is not short-circuited, the driving module outputs a low-resistance state to the grid electrode of the insulated gate device; and

when the insulated gate device is short-circuited, the driving module outputs a high-resistance state to the grid electrode of the insulated gate device.

Further, the state detection module includes a first comparator, a second comparator, a first voltage source and a second voltage source, a first input terminal of the first comparator and a first input terminal of the second comparator are electrically connected to the gate of the insulated gate device to obtain a gate voltage of the insulated gate device, a second input terminal of the first comparator is electrically connected to the first voltage source to obtain a first comparison reference, a second input terminal of the second comparator is electrically connected to the second voltage source to obtain a second comparison reference, and an output terminal of the first comparator and an output terminal of the second comparator are electrically connected to the control module to output the state detection signal to the control module.

Further, the control module includes an and gate, an or gate, an xor gate and a filtering unit, a first input end of the and gate is electrically connected to a first input end of the or gate and is configured to receive the driving signal, a second input end of the and gate is electrically connected to the filtering unit, a second input end of the or gate is connected to the filtering unit after inverting, output ends of the and gate and the or gate are both electrically connected to the driving module, an output end of the xor gate is electrically connected to the filtering unit after inverting, and an input end of the xor gate is electrically connected to an output end of the first comparator and an output end of the second comparator.

Further, the driving module comprises a first not gate, a second not gate, a first electronic switch, a second electronic switch, a first resistor and a second resistor, the input end of the first NOT gate is electrically connected with the output end of the AND gate, the input end of the second NOT gate is electrically connected with the output end of the OR gate, the output end of the first NOT gate is electrically connected with the first end of the first electronic switch, the second end of the second electronic switch is electrically connected with a first power supply, the third terminal of the first electronic switch is electrically connected to the gate of the insulated gate device through the first resistor, the output end of the second NOT gate is electrically connected with the first end of the second electronic switch, the second end of the second electronic switch is electrically connected with a second power supply, the third end of the second electronic switch is electrically connected to the grid electrode of the insulated gate device through the second resistor.

Further, a first input end of the first comparator is an inverting input end, a second input end of the first comparator is a non-inverting input end, a first input end of the second comparator is an inverting input end, and a second input end of the second comparator is a non-inverting input end.

Further, the first comparison reference is smaller than the minimum turn-on voltage of the gate when the insulated gate device normally works, and the second comparison reference is larger than the maximum turn-off voltage of the gate when the insulated gate device normally works.

Further, the control module is a programmable logic device or a field programmable gate array.

A protection method of a driving protection circuit, comprising the steps of:

acquiring a grid voltage of an insulated grid device, and outputting a state detection signal according to the grid voltage of the insulated grid device;

judging whether the insulated gate device is short-circuited according to the state detection signal, and processing the driving signal according to a judgment result so as to control the gate of the insulated gate device to output different resistance states;

if the insulated gate device is not short-circuited, the grid electrode of the insulated gate device outputs a low-resistance state;

and if the insulated gate device is short-circuited, the grid electrode of the insulated gate device outputs a high-resistance state.

According to the drive protection circuit and the protection method thereof, the grid voltage of the insulated gate device is obtained through the state detection module, and a state detection signal is output according to the grid voltage; and judging whether the insulated gate device is short-circuited or not according to the state detection signal through a control module, and processing a driving signal when the insulated gate device is short-circuited so as to control the output of the driving module to be changed into a high-resistance state, thereby cutting off a grid short-circuit loop of the insulated gate device. Therefore, the driving module can be effectively prevented from being burnt by short-circuit current, and the loss is reduced.

Drawings

Fig. 1 is a block diagram of a preferred embodiment of the driving protection circuit of the present invention.

Fig. 2 is a circuit diagram of a preferred embodiment of the driving protection circuit of the present invention.

Fig. 3 is a flow chart of a protection method of the driving protection circuit according to a preferred embodiment of the present invention.

Description of the main elements

Drive protection circuit 100

Control module 10

Drive module 20

State detection module 30

AND gate AND

OR gate OR

XOR gate

Filter unit FILTER

NOT gate U1, U2

Electronic switches Q1, Q2

Resistors R1 and R2

Comparators COMP1, COMP2

Voltage sources V1, V2

Power source VCC, VSS

The following detailed description will further illustrate the invention in conjunction with the above-described figures.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, the present invention provides a driving protection circuit 100. The driving protection circuit 100 includes a control module 10, a driving module 20, and a status detection module 30.

One end of the control module 10 is configured to be electrically connected to a signal generating device (not shown) to obtain a driving signal output by the signal generating device, where in this embodiment, the driving signal is a Pulse Width Modulation (PWM) signal.

One end of the driving module 20 is electrically connected to the control module 10, and the other end of the driving module 20 is electrically connected to the gate of the insulated gate device. One end of the state detection module 30 is electrically connected to the control module 10, and the other end of the state detection module 30 is electrically connected to the gate of the insulated gate device.

The state detection module 30 is configured to obtain a gate voltage of the insulated gate device, and output a state detection signal to the control module 10 according to the gate voltage of the insulated gate device. The control module 10 determines whether the insulated gate device is short-circuited according to the state detection signal, and processes the driving signal according to a determination result. The driving module 20 outputs different resistance states to the gate of the insulated gate device under the control of the driving signal processed by the control module 10.

When the determination result indicates that the insulated gate device is not short-circuited, the driving module 20 outputs a low resistance state to the gate of the insulated gate device under the control of the driving signal processed by the control module 10, so that the insulated gate device continuously and normally operates.

When the determination result is that the insulated gate device is short-circuited, the driving module 20 outputs a high-resistance state to the gate of the insulated gate device under the control of the driving signal processed by the control module 10, so as to cut off a gate short-circuit loop of the insulated gate device. Therefore, the driving module 20 can be effectively prevented from being burnt by short-circuit current, and the loss is reduced.

Referring to fig. 2, fig. 2 is a circuit diagram of a preferred embodiment of the invention. The control module 10 includes an AND gate AND, an OR gate OR, an XOR gate XOR, AND a FILTER unit FILTER. A first input terminal of the AND gate AND is electrically connected to a first input terminal of the OR gate OR AND configured to receive a driving signal from the signal generating device (not shown), a second input terminal of the AND gate AND is electrically connected to an output terminal of the FILTER unit FILTER, AND a second input terminal of the OR gate OR is connected to an output terminal of the FILTER unit FILTER after being inverted. The output terminal of the AND gate AND the output terminal of the OR gate OR are electrically connected to the driving module 20. The input terminal of the exclusive or gate XOR is electrically connected to the status detection module 30. The output end of the exclusive or gate XOR is electrically connected to the input end of the FILTER unit FILTER after inversion.

The driving module 20 comprises two NOT gates U1-U2, two electronic switches Q1-Q2 and two resistors R1-R2. The input end of the NOT gate U1 is electrically connected to the output end of the AND gate AND. The input end of the not gate U2 is electrically connected to the output end of the OR gate OR. The output end of the not gate U1 is electrically connected to the first end of the electronic switch Q1, the second end of the electronic switch Q1 is electrically connected to the power source VCC, and the third end of the electronic switch Q1 is electrically connected to the gate of the insulated gate device through the resistor R1. The output end of the not gate U2 is electrically connected to the first end of the electronic switch Q2, the second end of the electronic switch Q2 is electrically connected to the power supply VSS, and the third end of the electronic switch Q2 is electrically connected to the gate of the insulated gate device through the resistor R2.

In this embodiment, the electronic switch Q1 is a P-channel enhancement mode fet, and the first terminal, the second terminal, and the third terminal of the electronic switch Q1 correspond to the gate, the source, and the drain of the P-channel enhancement mode fet, respectively. The electronic switch Q2 is an N-channel enhancement type field effect transistor, and the first end, the second end and the third end of the electronic switch Q2 correspond to the grid electrode, the source electrode and the drain electrode of the N-channel enhancement type field effect transistor respectively.

The state detection module 30 includes two comparators COMP1-COMP2 and two resistors R3-R4. A first input end of the comparator COMP1 and a first input end of the comparator COMP2 are both electrically connected to the gate of the insulated gate device. The power supply VCC is electrically connected to the second input terminal of the comparator COMP1 through the resistor R3 to provide a first comparison reference. The power supply VSS is electrically connected to the second input terminal of the comparator COMP2 through the resistor R4 to provide a second comparison reference. An output terminal of the comparator COMP1 is electrically connected to a first input terminal of the exclusive or gate XOR, and an output terminal of the comparator COMP2 is electrically connected to a second input terminal of the exclusive or gate XOR.

In this embodiment, the first comparison reference is smaller than the minimum turn-on voltage of the gate when the insulated gate device normally works, and the second comparison reference is larger than the maximum turn-off voltage of the gate when the insulated gate device normally works.

When the circuit works, the inverting input end of the comparator COMP1 and the inverting input end of the comparator COMP2 acquire the gate voltage of the insulated gate device in real time so as to compare the gate voltage with the first comparison reference and the second comparison reference.

When the insulated gate device is in an off state, the comparator COMP1 AND the comparator COMP2 both output a high level signal, the XOR gate XOR outputs a high level signal in an inverted manner, at this time, the driving signal is at a low level, the high level signal AND the low level driving signal are input to the AND gate AND the OR gate OR together, AND a low level signal is output to the driving module 20, at this time, the electronic switch Q1 is turned off, AND the electronic switch Q2 is turned on, so that the driving module 20 outputs a low resistance state to maintain the normal operation of the insulated gate device.

When the insulated gate device is in an on state, the comparator COMP1 AND the comparator COMP2 both output a low level signal, the XOR gate XOR outputs a high level signal in an inverted manner, at this time, the driving signal is at a high level, the high level signal AND the high level driving signal are input to the AND gate AND the OR gate OR together, AND a high level signal is output to the driving module 20, at this time, the electronic switch Q1 is turned on, AND the electronic switch Q2 is turned off, so that the driving module 20 outputs a low resistance state to maintain the normal operation of the insulated gate device.

When the insulated gate device is in a short-circuit state, the comparator COMP1 outputs a high level, the comparator COMP2 outputs a low level signal, the XOR gate XOR outputs a low level signal in an inverted phase, the low level signal AND the driving signal are input to the AND gate AND the OR gate OR together, AND the low level signal AND the high level signal are output to the driving module 20 through the AND gate AND the OR gate OR respectively, at this time, the electronic switch Q1 is turned off, the electronic switch Q2 is turned off, AND thus, the driving module 20 outputs a high impedance state to cut off a gate short-circuit loop of the insulated gate device.

In the present embodiment, when the insulated gate device is in the process of switching on and off, the state detection signal output by the state detection module 30 is the same as the state detection signal when the insulated gate device is in the short-circuit state. The FILTER unit FILTER is configured to FILTER a low level output after XOR inversion by the XOR gate when the insulated gate device is in on and off switching, so as to avoid erroneously determining a gate state of the insulated gate device at this time as a short circuit state.

In this embodiment, a first input terminal of the comparator COMP1 is an inverting input terminal, and a second input terminal of the comparator COMP1 is a non-inverting input terminal. A first input terminal of the comparator COMP2 is an inverting input terminal, and a second input terminal of the comparator COMP2 is a non-inverting input terminal. In other embodiments, the first input terminal of the comparator COMP1 may also be a non-inverting input terminal, the second input terminal of the comparator COMP1 is an inverting input terminal, the first input terminal of the comparator COMP2 is a non-inverting input terminal, and the second input terminal of the comparator COMP2 is an inverting input terminal.

In a preferred embodiment, the control module 10 can be a Complex Programmable Logic Device (CPLD) or a Field Programmable Gate Array (FPGA).

Referring to fig. 3, the present invention further provides a protection method of the driving protection circuit 100, including the following steps:

s100, the state detection module 30 obtains a gate voltage of the insulated gate device, and outputs a state detection signal according to the gate voltage of the insulated gate device.

And S102, the control module 10 judges whether the insulated gate device is short-circuited according to the state detection signal, processes the driving signal according to a judgment result, and if so, enters the step S104, otherwise, enters the step S106.

S104, the driving module 20 outputs a high resistance state to the gate of the insulated gate device under the control of the driving signal processed by the control module 10, so as to cut off the gate short circuit loop of the insulated gate device.

S106, the driving module 20 outputs a low resistance state to the gate of the insulated gate device under the control of the driving signal processed by the control module 10, so that the insulated gate device continuously and normally operates.

The driving protection circuit 100 and the protection method thereof obtain the gate voltage of the insulated gate device through the state detection module 30, and output a state detection signal according to the gate voltage; and the control module 10 is further used for judging whether the insulated gate device is short-circuited according to the state detection signal, and processing the driving signal when the insulated gate device is short-circuited, so that the driving module 20 outputs a high-resistance state to the gate of the insulated gate device under the control of the processed driving signal, and the gate short-circuit loop of the insulated gate device is cut off. Therefore, the driving module 20 can be effectively prevented from being burnt by short-circuit current, and the loss is reduced.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.