CN117039823A - Overvoltage protection circuit of power device and overvoltage protection method based on overvoltage protection circuit - Google Patents
Overvoltage protection circuit of power device and overvoltage protection method based on overvoltage protection circuit Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
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Abstract
The present disclosure relates to an overvoltage protection circuit of a power device and an overvoltage protection method based thereon, the circuit comprising: the device comprises a first voltage acquisition unit, a second voltage acquisition unit, a first comparison unit, a second comparison unit and a control unit; the first voltage acquisition unit is used for acquiring a voltage value of a first node; the second voltage acquisition unit is used for acquiring a voltage value of a second node; the first comparison unit is used for outputting a first signal according to the comparison result of the voltage value of the first node and the first reference voltage value; the second comparison unit is used for outputting a second signal according to the comparison result of the voltage value of the second node and the second reference voltage value; the control unit is used for adjusting the output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device. According to the overvoltage protection method and device for the power device, overvoltage protection of the power device can be achieved under the condition that the breakdown voltage value of the TVS tube is not dependent, the accuracy of the overvoltage protection of the power device is improved, and the safety and stability of an electric drive system are improved.
Description
Technical Field
The disclosure relates to the technical field of power devices, in particular to an overvoltage protection circuit of a power device and an overvoltage protection method based on the overvoltage protection circuit.
Background
In the related art, an overvoltage protection method of a power device is voltage active clamp protection, and the principle of the active clamp protection is that when the turn-off voltage value of the power device is too high, the turn-off speed of the power device is controlled by using the breakdown current of a TVS (Transient Voltage Suppressor ) tube as a feedback quantity, if the breakdown current value is larger, the turn-off speed is slower, so that the turn-off peak voltage value of the power device is controlled, and the overvoltage protection of the power device is realized.
However, this has the following disadvantages: the overvoltage protection of the power device is seriously dependent on the breakdown voltage value of the TVS tube, wherein when the breakdown voltage value of the TVS tube is lower, the overvoltage protection is easy to occur in advance, so that the turn-off speed of the power device under normal working conditions can be increased, the turn-off loss of the power device is further increased, the heating of the power device is increased, the stability of an electric drive system is reduced, and the power device is also damaged thermally in extreme cases; when the breakdown voltage value of the TVS tube is higher, the protection response is delayed, so that the turn-off voltage is too high, and the power device is damaged.
Disclosure of Invention
The overvoltage protection circuit and the overvoltage protection method based on the overvoltage protection circuit can realize the overvoltage protection of the power device under the condition of not depending on the breakdown voltage value of the TVS tube, improves the overvoltage protection accuracy of the power device, and improves the safety and stability of an electric drive system. The technical scheme of the present disclosure is as follows:
an embodiment of a first aspect of the present disclosure provides an overvoltage protection circuit of a power device, including: the device comprises a first voltage acquisition unit, a second voltage acquisition unit, a first comparison unit, a second comparison unit and a control unit; the first end of the first comparison unit is connected with the first signal input end of the control unit, the second end of the first comparison unit is respectively connected with a first voltage source and the first end of the first voltage acquisition unit to form a first node, the first end of the second comparison unit is connected with the second signal input end of the control unit, the second end of the second comparison unit is respectively connected with the second voltage source and the first end of the second voltage acquisition unit to form a second node, the second end of the first voltage acquisition unit and the second end of the second voltage acquisition unit are respectively connected with the first end of the power device, the signal output end of the control unit is connected with the control end of the power device, and the second end of the power device is grounded;
The first voltage acquisition unit is used for acquiring a voltage value of the first node;
the second voltage acquisition unit is used for acquiring the voltage value of the second node;
the first comparison unit is used for outputting a first signal according to the comparison result of the voltage value of the first node and a first reference voltage value;
the second comparison unit is used for outputting a second signal according to the comparison result of the voltage value of the second node and a second reference voltage value;
and the control unit is used for adjusting the output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device.
In one embodiment of the disclosure, the control unit is configured to adjust an output signal according to the first signal and the second signal, and includes:
acquiring a first time point when the first signal changes;
acquiring a second time point when the second signal changes;
calculating the absolute value of the difference between the second time point and the first time point as a time difference;
calculating the absolute value of the difference between the voltage value of the second voltage source and the voltage value of the first voltage source as a voltage difference;
Calculating the ratio between the voltage difference value and the time difference value as the rising slope of the turn-off voltage of the power device;
and adjusting the output signal according to the rising slope.
In one embodiment of the disclosure, the control unit is configured to adjust the output signal according to the rising slope, and includes:
and under the condition that the rising slope is larger than the set rising slope, the output signal is regulated to reduce the output voltage value or the output current value of the signal output end of the control unit.
In one embodiment of the present disclosure, the first voltage acquisition unit includes: a first resistor and a first diode; wherein,
a first end of the first resistor is used as a first end of the first voltage acquisition unit;
the second end of the first resistor is connected with the anode of the first diode, and the cathode of the first diode is used as the second end of the first voltage acquisition unit.
In one embodiment of the present disclosure, the second voltage acquisition unit includes: a second resistor and a second diode; wherein,
the first end of the second resistor is used as the first end of the second voltage acquisition unit;
The second end of the second resistor is connected with the anode of the second diode, and the cathode of the second diode is used as the second end of the second voltage acquisition unit.
In one embodiment of the present disclosure, the first comparing unit includes: a first comparator; wherein,
the non-inverting input end of the first comparator is used as a second end of the first comparison unit;
the reverse input end of the first comparator is used for inputting the first reference voltage value;
the output end of the first comparator is used as a first end of the first comparison unit.
In one embodiment of the present disclosure, the second comparing unit includes: a second comparator; wherein,
the non-inverting input end of the second comparator is used as a second end of the second comparison unit;
the reverse input end of the second comparator is used for inputting the second reference voltage value;
the output end of the second comparator is used as the first end of the second comparison unit.
In one embodiment of the present disclosure, the above circuit further includes: a third resistor and a fourth resistor; wherein,
a first end of the third resistor is connected with the first node;
the first end of the fourth resistor is connected with the second node;
And the second end of the third resistor is connected with the second end of the fourth resistor and then connected with the second end of the power device.
In one embodiment of the present disclosure, the above circuit further includes: a fifth resistor; wherein,
the first end of the fifth resistor is connected with the output end of the control unit, and the second end of the fifth resistor is connected with the control end of the power device.
In one embodiment of the present disclosure, the power device includes: a transistor and a transient voltage suppression diode; wherein,
the first end of the transistor is connected with the cathode of the transient voltage suppression diode and then used as the first end of the power device;
the second end of the transistor is connected with the anode of the transient voltage suppression diode and then used as the second end of the power device;
the control end of the transistor is used as the control end of the power device;
wherein the transistor is an IGBT (Insulated Gate Bipolar Transistor ) or a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor, metal-Oxide semiconductor field effect transistor) transistor.
An embodiment of a second aspect of the present disclosure provides an overvoltage protection method of an overvoltage protection circuit based on a power device, including the steps of:
Acquiring a first signal output by a first comparison unit; the first signal is a signal obtained by the first comparison unit according to a comparison result between the voltage value of the first node and a first reference voltage value, which is acquired by the first voltage acquisition unit;
acquiring a second signal output by a second comparison unit; the second signal is a signal obtained by the second comparison unit according to a comparison result between the voltage value of the second node and a second reference voltage value, which is acquired by the second voltage acquisition unit;
and regulating an output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device.
In one embodiment of the disclosure, the adjusting the output signal according to the first signal and the second signal includes:
acquiring a first time point when the first signal changes;
acquiring a second time point when the second signal changes;
calculating the absolute value of the difference between the second time point and the first time point as a time difference;
calculating the absolute value of the difference between the voltage value of the second voltage source and the voltage value of the first voltage source as a voltage difference;
Calculating the ratio between the voltage difference value and the time difference value as the rising slope of the turn-off voltage of the power device;
and adjusting the output signal according to the rising slope.
In one embodiment of the disclosure, the adjusting the output signal according to the rising slope includes:
and under the condition that the rising slope is larger than the set rising slope, the output signal is regulated to reduce the output voltage value or the output current value of the signal output end of the control unit.
An embodiment of a third aspect of the present disclosure proposes an electronic device, including: a processor and a memory;
wherein the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, for implementing the overvoltage protection method of the overvoltage protection circuit based on the power device of the second aspect embodiment.
An embodiment of a fourth aspect of the present disclosure proposes a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the overvoltage protection method of the power device based overvoltage protection circuit of the embodiment of the second aspect.
A fifth aspect embodiment of the present disclosure proposes a computer program product which, when executed by an instruction processor in the computer program product, performs the overvoltage protection method of the power device based overvoltage protection circuit of the second aspect embodiment.
The technical scheme provided by the embodiment of the disclosure at least brings the following beneficial effects:
by the embodiment of the disclosure, the overvoltage protection circuit of the power device comprises: the device comprises a first voltage acquisition unit, a second voltage acquisition unit, a first comparison unit, a second comparison unit and a control unit; the first end of the first comparison unit is connected with the first signal input end of the control unit, the second end of the first comparison unit is connected with the first voltage source and the first end of the first voltage acquisition unit respectively to form a first node, the first end of the second comparison unit is connected with the second signal input end of the control unit, the second end of the second comparison unit is connected with the second voltage source and the first end of the second voltage acquisition unit respectively to form a second node, the second end of the first voltage acquisition unit and the second end of the second voltage acquisition unit are connected with the first end of the power device respectively, the signal output end of the control unit is connected with the control end of the power device, and the second end of the power device is grounded; a first voltage acquisition unit for acquiring a voltage value of a first node; the second voltage acquisition unit is used for acquiring a voltage value of a second node; the first comparison unit is used for outputting a first signal according to the comparison result of the voltage value of the first node and the first reference voltage value; the second comparison unit is used for outputting a second signal according to the comparison result of the voltage value of the second node and the second reference voltage value; and the control unit is used for adjusting the output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device. Therefore, the overvoltage protection of the power device can be realized under the condition of not depending on the breakdown voltage value of the TVS tube, the overvoltage protection accuracy of the power device is improved, and the safety and stability of the electric drive system are improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure and do not constitute an undue limitation on the disclosure.
Fig. 1 is a schematic diagram of an overvoltage protection circuit of a power device according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of a motor controller according to one embodiment of the present disclosure;
FIG. 3 is a schematic diagram of a power device off voltage according to one embodiment of the present disclosure;
fig. 4 is a schematic diagram of an overvoltage protection circuit of a power device according to one embodiment of the present disclosure;
fig. 5 is a flow chart of an overvoltage protection method for a power device based overvoltage protection circuit according to an embodiment of the present disclosure.
Detailed Description
In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings.
It should be noted that the terms "first," "second," and the like in the description and claims of the present disclosure and in the foregoing figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the disclosure described herein may be capable of operation in sequences other than those illustrated or described herein. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the accompanying claims.
An overvoltage protection circuit of a power device and an overvoltage protection method based thereon according to an embodiment of the present disclosure are described below with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of an overvoltage protection circuit for a power device according to an embodiment of the present disclosure.
It should be noted that, the overvoltage protection circuit of the power device in the embodiment of the disclosure may be applied to control and protection of an electric driving power device of an electric vehicle, where the electric vehicle includes a pure electric vehicle and a hybrid vehicle, and the power device includes an IGBT tube or a MOS tube. The technical scheme of the disclosure can also be expanded to motor controllers (shown in fig. 2) in the industrial field, and controllers of power devices such as photovoltaic inverters, wind power inverters, energy storage inverters and the like in the energy field.
As shown in fig. 1, the overvoltage protection method of the power device according to the embodiment of the disclosure includes: a first voltage acquisition unit 10, a second voltage acquisition unit 20, a first comparison unit 30, a second comparison unit 40, and a control unit 50.
The first end of the first comparing unit 30 is connected to the first signal Input end Input1 of the control unit 50, the second end of the first comparing unit 30 is connected to the first voltage source VCC1 and the first end of the first voltage obtaining unit 10 respectively to form a first node J1, the first end of the second comparing unit 40 is connected to the second signal Input end Input2 of the control unit 50, the second end of the second comparing unit 40 is connected to the second voltage source VCC2 and the first end of the second voltage obtaining unit 20 respectively to form a second node J2, the second end of the first voltage obtaining unit 10 and the second end of the second voltage obtaining unit 20 are connected to the first end of the power device 60 respectively, the signal output end OUT of the control unit 50 is connected to the control end of the power device 60, and the second end of the power device 60 is grounded;
A first voltage acquisition unit 10 for acquiring a voltage value V1 of a first node J1;
a second voltage acquisition unit 20 for acquiring a voltage value V2 of the second junction J2;
a first comparing unit 30 for outputting a first signal according to a comparison result of the voltage value V1 of the first node J1 and the first reference voltage value Vref 1;
a second comparing unit 40 for outputting a second signal according to a comparison result of the voltage value V2 of the second junction J2 and the second reference voltage value Vref 2;
the control unit 50 is configured to regulate the output signal according to the first signal and the second signal, so as to implement overvoltage protection for the power device 60.
In this embodiment, the control unit 50 may be a gate driving chip having a first signal Input terminal Input1, a second signal Input terminal Input2, and a signal output terminal OUT for controlling the power device 60. The voltage value Vds at both ends (between the first end of the power device 60 and the second end of the power device 60) is shown in fig. 3 when the power device 60 is turned off, and the voltage value Vds at both ends is the saturation voltage value Vsat when the power device 60 is turned on, and then the voltage value Vds at both ends gradually rises during the turn-off process, for example, the voltage value Vds at both ends may generate an overcharge voltage due to the influence of a loop inductance (not shown in the figure) in the circuit, and finally reaches the dc bus voltage value Vdc. Before the power device 60 is turned off, since the voltage value Vds at the two ends of the power device 60 is the saturation voltage value Vsat, the voltage value of the first node J1 is clamped by the power device 60, the sum of the voltage drops of the Vsat and the components in the first voltage obtaining unit 10 is used as V1, and the voltage value of the second node J2 is also clamped by the power device 60, the sum of the voltage drops of the Vsat and the components in the second voltage obtaining unit 20 is used as V2. By setting Vcc2> Vcc1> > (V1, V2), before the power device 60 starts to turn off, the voltage values V2 of the first and second nodes J1 and J2 are clamped at V1 and V2, respectively, and the first and second reference voltage values Vref1 and Vref2 are set to be slightly lower than the voltage values Vcc1 and Vcc2 of the first and second voltage sources Vcc1 and Vcc2, respectively. When the voltage value V1 of the first node J1 and the voltage value V2 of the second node J2 are lower than the corresponding first reference voltage value Vref1 and the second reference voltage value Vref2, respectively, the first signals output by the first comparing unit 30 and the second comparing unit 40 are low-level signals, that is, the first signals and the second signals input to the gate driving chip by the first comparing unit 30 and the second comparing unit 40 are low-level signals before the power device 60 is turned off. After the turn-off process of the power device 60 starts, the voltage value Vds at both ends starts to rise, and sequentially exceeds Vcc1 and Vcc2, the voltage value V1 of the first node J1 and the voltage value V2 of the second node J2 are no longer clamped by the power device 60, the voltage value V1 of the first node J1 and the voltage value V2 of the second node J2 rise to Vcc1 and Vcc2, respectively, and are higher than the reference voltage value of the corresponding comparison unit, and the signals input to the gate driving chip by the two comparison units are changed from low level signals to high level signals.
In the turn-off process of the power device 60, when the voltage value Vds at two ends of the power device 60 reaches Vcc1, the voltage value V1 of the first node J1 is no longer clamped, if the voltage value V1 of the first node J1 reaches Vcc1, the first signal output by the first comparing unit 30 is changed from a low level signal to a high level signal, and the gate driving chip detects the change moment of the port state through the first input signal end, and at this time, the first moment is used as a first time point T1 when a timer (not shown in the figure) starts to count; since Vcc2 > Vcc1, the voltage V2 at the second node J2 is still clamped, the second signal output by the second comparing unit 40 is still a low level signal, and when the voltage Vds at the two ends continues to rise to Vcc2, the second signal output by the second comparing unit 40 is changed from the low level signal to the high level signal, and the gate driving chip detects the port change time through the second signal Input terminal Input2 and uses it as the second time point T2 for ending the timer. Then, the absolute value of the difference between the second time point T2 and the first time point T1 is calculated as a time difference Δt= |t2-t1|, and the absolute value of the difference between the voltage value VCC2 of the second voltage source VCC2 and the voltage value VCC1 of the first voltage source VCC1 is calculated as a voltage difference Δv= |vcc2-VCC1|, and then the ratio between the voltage difference Δv and the time difference Δt is calculated as a rising slope dv/dt= Δv/|Δt of the off voltage of the power device 60, and whether or not to adjust the output signal is determined based on the rising slope. Wherein, in the case that the rising slope is smaller than or equal to the set rising slope (the set rising slope may be set according to the actual situation, and is not limited here specifically), the output signal is not adjusted; when the rising slope is larger than the set rising slope, it indicates that the turn-off speed of the power device 60 is too high, and at this time, the output voltage value or the output current value of the signal output end of the control unit is reduced by adjusting the output signal, so as to reduce the turn-off speed of the power device and reduce the turn-off voltage, thereby realizing overvoltage protection of the power device.
Therefore, the overvoltage protection of the power device is realized without depending on the breakdown voltage value of the TVS tube when the power device is in overvoltage protection, so that the overvoltage protection accuracy of the power device is improved, and the safety and stability of an electric drive system are improved. In addition, because the voltage active clamping scheme of the related art is that overvoltage detection is at the tail end of the turn-off process, overvoltage is often not protected, the overvoltage detection of the scheme disclosed by the invention occurs in the initial stage of the turn-off process, and the occurrence of the overvoltage is predicted through the detection of the rising slope dv/dt of the turn-off voltage of the power device, so that the overvoltage can be discovered earlier and the corresponding work can be carried out, and the effect is better compared with that of the traditional scheme.
Fig. 4 is a schematic diagram of an overvoltage protection circuit for a power device according to one embodiment of the present disclosure.
As shown in fig. 4, the first voltage acquisition unit 10 includes: a first resistor R1 and a first diode D1; wherein a first end of the first resistor R1 is used as a first end of the first voltage acquisition unit 10; the second terminal of the first resistor R1 is connected to the anode of the first diode D1, and the cathode of the first diode D1 serves as the second terminal of the first voltage acquisition unit 10.
As shown in fig. 4, the second voltage acquisition unit 20 includes: a second resistor R2 and a second diode D2; wherein the first end of the second resistor R2 is used as the first end of the second voltage acquisition unit 20; the second terminal of the second resistor R2 is connected to the anode of the second diode D2, and the cathode of the second diode D2 serves as the second terminal of the second voltage acquisition unit 20.
As shown in fig. 4, the first comparing unit 30 includes: a first comparator COMP1; wherein the non-inverting input terminal of the first comparator COMP1 is used as the second terminal of the first comparing unit 30; the reverse input end of the first comparator COMP1 inputs a first reference voltage value Vref1; the output of the first comparator serves as a first end of the first comparing unit 30.
As shown in fig. 4, the second comparing unit 40 includes: a second comparator COMP2; wherein the non-inverting input terminal of the second comparator COMP2 is used as the second terminal of the second comparing unit 40; the inverting input terminal of the second comparator COMP2 inputs a second reference voltage value Vref2; the output of the second comparator serves as a first end of the second comparing unit 40.
As shown in fig. 4, the above circuit further includes: a third resistor R3 and a fourth resistor R4; wherein, the first end of the third resistor R3 is connected with the first node J1; the first end of the fourth resistor R4 is connected with the second node J2; the second end of the third resistor R3 is connected to the second end of the fourth resistor R4 and then to the second end of the power device 60.
As shown in fig. 4, the above circuit further includes: a fifth resistor R5; the first end of the fifth resistor R5 is connected to the output terminal OUT of the control unit 50, and the second end of the fifth resistor R5 is connected to the control terminal of the power device 60.
As shown in fig. 4, the power device 60 includes: a transistor S1 and a transient voltage suppression diode TVS; wherein, the first end of the transistor S1 is connected to the cathode of the TVS and then used as the first end of the power device 60; the second end of the transistor S1 is connected to the anode of the TVS and then serves as the second end of the power device 60; the control terminal of the transistor S1 is used as the control terminal of the power device 60; the transistor S1 is an IGBT or MOS transistor.
In this embodiment, during the on-state of the transistor S1, the voltage V1 at the first node J1 is clamped to V1 by the power device 60, v1=vsat+v R1 +V D1 Wherein V is R1 Is the voltage value of the two ends of the first resistor R1, V D1 Is the on-voltage drop value of the first diode D1, and the voltage V2 of the second junction J2 is clamped to V2 by the power device 60, v2=vsat+v R2 +V D2 Wherein V is R2 Is the voltage across the second resistor R2Value V D2 The voltage value V1 of the first node J1 and the voltage value V2 of the second node J2 are respectively lower than the corresponding first reference voltage value Vref1 and the second reference voltage value Vref2, and the first signals output by the first comparator COMP1 and the second comparator COMP2 are low-level signals.
In the turn-off process of the transistor S1, when the voltage value Vds at two ends of the transistor S1 reaches Vcc1, the voltage of the first node J1 is no longer clamped, the voltage of the first node J1 reaches Vcc1, and at this time, the first signal output by the first comparator COMP1 changes; since Vcc2 > Vcc1, the voltage V2 at the second junction J2 is still clamped, the second signal output by the second comparing unit 40 is still a low level signal, and the second signal output by the second comparing unit 40 is changed when the voltage Vds at both ends continues to rise to Vcc 2. The control unit 50 calculates an interval time during which the Input signals of the first signal Input terminal Input1 and the second signal Input terminal Input2 are changed as a time difference Δt, and calculates a rising slope dv/dt= Δv/. DELTA.T of the off-voltage of the transistor S1, wherein Δv = Vcc2-Vcc1, and when the rising slope dv/dt is greater than the set rising slope, it indicates that the off-voltage of the transistor S1 is too fast, and at this time, the output voltage value or the output current value of the signal output terminal of the control unit is reduced by adjusting the output signal so as to reduce the off-speed of the power device, thereby reducing the off-voltage.
In summary, the overvoltage protection circuit of the power device according to the embodiment of the disclosure is composed of a first voltage acquisition unit, a second voltage acquisition unit, a first comparison unit, a second comparison unit and a control unit; the first end of the first comparison unit is connected with the first signal input end of the control unit, the second end of the first comparison unit is connected with the first voltage source and the first end of the first voltage acquisition unit respectively to form a first node, the first end of the second comparison unit is connected with the second signal input end of the control unit, the second end of the second comparison unit is connected with the second voltage source and the first end of the second voltage acquisition unit respectively to form a second node, the second end of the first voltage acquisition unit and the second end of the second voltage acquisition unit are connected with the first end of the power device respectively, the signal output end of the control unit is connected with the control end of the power device, and the second end of the power device is grounded; a first voltage acquisition unit for acquiring a voltage value of a first node; the second voltage acquisition unit is used for acquiring a voltage value of a second node; the first comparison unit is used for outputting a first signal according to the comparison result of the voltage value of the first node and the first reference voltage value; the second comparison unit is used for outputting a second signal according to the comparison result of the voltage value of the second node and the second reference voltage value; and the control unit is used for adjusting the output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device. Therefore, the overvoltage protection of the power device can be realized under the condition of not depending on the breakdown voltage value of the TVS tube, the overvoltage protection accuracy of the power device is improved, and the safety and stability of the electric drive system are improved.
Fig. 5 is a flow chart of an overvoltage protection method for a power device based overvoltage protection circuit according to an embodiment of the present disclosure.
As shown in fig. 5, an overvoltage protection method of an overvoltage protection circuit based on a power device according to an embodiment of the disclosure includes the following steps:
s501, acquiring a first signal output by a first comparing unit, where the first signal is a signal obtained by the first comparing unit according to a comparison result between the voltage value of the first node acquired by the first voltage acquiring unit and a first reference voltage value.
S502, acquiring a second signal output by a second comparison unit, wherein the second signal is a signal obtained by the second comparison unit according to a comparison result between the voltage value of the second node acquired by the second voltage acquisition unit and a second reference voltage value.
And S503, adjusting the output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device.
In one embodiment of the present disclosure, adjusting the output signal based on the first signal and the second signal includes:
acquiring a first time point when the first signal changes;
acquiring a second time point when the second signal changes;
Calculating the absolute value of the difference between the second time point and the first time point as a time difference;
calculating the absolute value of the difference between the voltage value of the second voltage source and the voltage value of the first voltage source as a voltage difference;
calculating the ratio between the voltage difference value and the time difference value as the rising slope of the turn-off voltage of the power device;
the output signal is adjusted according to the rising slope.
In one embodiment of the present disclosure, determining an output signal from a rising slope includes:
when the rising slope is larger than the set rising slope, the output signal is regulated to reduce the output voltage value or the output current value of the signal output end of the control unit.
It should be noted that, for details not disclosed in the overvoltage protection method of the overvoltage protection circuit based on the power device in the embodiment of the disclosure, please refer to details disclosed in the overvoltage protection circuit of the power device in the embodiment of the disclosure, and detailed descriptions thereof are omitted herein.
According to the overvoltage protection method of the overvoltage protection circuit based on the power device, a first signal output by a first comparison unit is firstly obtained, the first signal is an output signal obtained by the first comparison unit according to a comparison result between a voltage value of a first node and a first reference voltage value obtained by a first voltage obtaining unit, and a second signal output by a second comparison unit is obtained by the second comparison unit according to a comparison result between a voltage value of a second node and a second reference voltage value obtained by a second voltage obtaining unit, and then the output signal is regulated according to the first signal and the second signal so as to realize overvoltage protection of the power device. Therefore, the overvoltage protection of the power device can be realized under the condition of not depending on the breakdown voltage value of the TVS tube, the overvoltage protection accuracy of the power device is improved, and the safety and stability of the electric drive system are improved.
Based on the above embodiments, the present disclosure further proposes an electronic device.
The electronic device of the embodiment of the disclosure comprises: a processor and a memory;
the processor executes a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to be used for the overvoltage protection method of the overvoltage protection circuit based on the power device.
According to the electronic equipment disclosed by the embodiment of the disclosure, by adopting the overvoltage protection method of the overvoltage protection circuit based on the power device, the overvoltage protection of the power device can be realized under the condition of not depending on the breakdown voltage value of the TVS tube, the overvoltage protection accuracy of the power device is improved, and the safety and stability of an electric drive system are improved.
Based on the above embodiments, the present disclosure also proposes a computer-readable storage medium.
The computer readable storage medium of the embodiment of the disclosure stores a computer program, which when executed by a processor, implements the overvoltage protection method of the overvoltage protection circuit based on the power device.
According to the computer readable storage medium, by adopting the overvoltage protection method of the overvoltage protection circuit based on the power device, the overvoltage protection of the power device can be realized under the condition of not depending on the breakdown voltage value of the TVS tube, the overvoltage protection accuracy of the power device is improved, and the safety and stability of an electric drive system are improved.
Based on the above embodiments, the present disclosure also proposes a computer program product.
The above-described overvoltage protection method of the power device-based overvoltage protection circuit is performed when an instruction processor in a computer program product of an embodiment of the present disclosure executes.
According to the computer program product of the embodiment of the disclosure, by adopting the overvoltage protection method of the overvoltage protection circuit based on the power device, the overvoltage protection of the power device can be realized under the condition of not depending on the breakdown voltage value of the TVS tube, the overvoltage protection accuracy of the power device is improved, and the safety and stability of an electric drive system are improved.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless explicitly specified otherwise.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and additional implementations are included within the scope of the preferred embodiment of the present disclosure in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the embodiments of the present disclosure.
Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program is printed, as the program may be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.
It should be understood that portions of the present disclosure may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As with the other embodiments, if implemented in hardware, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.
Those of ordinary skill in the art will appreciate that all or a portion of the steps carried out in the method of the above-described embodiments may be implemented by a program to instruct related hardware, where the program may be stored in a computer readable storage medium, and where the program, when executed, includes one or a combination of the steps of the method embodiments.
Furthermore, each functional unit in the embodiments of the present disclosure may be integrated in one processing module, or each unit may exist alone physically, or two or more units may be integrated in one module. The integrated modules may be implemented in hardware or in software functional modules. The integrated modules may also be stored in a computer readable storage medium if implemented in the form of software functional modules and sold or used as a stand-alone product.
The above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, or the like. Although embodiments of the present disclosure have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the present disclosure, and that variations, modifications, alternatives, and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the present disclosure.
Claims (15)
1. An overvoltage protection circuit for a power device, comprising: the device comprises a first voltage acquisition unit, a second voltage acquisition unit, a first comparison unit, a second comparison unit and a control unit; the first end of the first comparison unit is connected with the first signal input end of the control unit, the second end of the first comparison unit is respectively connected with a first voltage source and the first end of the first voltage acquisition unit to form a first node, the first end of the second comparison unit is connected with the second signal input end of the control unit, the second end of the second comparison unit is respectively connected with the second voltage source and the first end of the second voltage acquisition unit to form a second node, the second end of the first voltage acquisition unit and the second end of the second voltage acquisition unit are respectively connected with the first end of the power device, the signal output end of the control unit is connected with the control end of the power device, and the second end of the power device is grounded;
The first voltage acquisition unit is used for acquiring a voltage value of the first node;
the second voltage acquisition unit is used for acquiring the voltage value of the second node;
the first comparison unit is used for outputting a first signal according to the comparison result of the voltage value of the first node and a first reference voltage value;
the second comparison unit is used for outputting a second signal according to the comparison result of the voltage value of the second node and a second reference voltage value;
and the control unit is used for adjusting the output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device.
2. The circuit of claim 1, wherein the control unit is configured to adjust the output signal based on the first signal and the second signal, and comprises:
acquiring a first time point when the first signal changes;
acquiring a second time point when the second signal changes;
calculating the absolute value of the difference between the second time point and the first time point as a time difference;
calculating the absolute value of the difference between the voltage value of the second voltage source and the voltage value of the first voltage source as a voltage difference;
Calculating the ratio between the voltage difference value and the time difference value as the rising slope of the turn-off voltage of the power device;
and adjusting the output signal according to the rising slope.
3. The circuit of claim 2, wherein the control unit is configured to adjust the output signal according to the rising slope, and comprises:
and under the condition that the rising slope is larger than the set rising slope, the output signal is regulated to reduce the output voltage value or the output current value of the signal output end of the control unit.
4. The circuit of claim 1, wherein the first voltage acquisition unit comprises: a first resistor and a first diode; wherein,
a first end of the first resistor is used as a first end of the first voltage acquisition unit;
the second end of the first resistor is connected with the anode of the first diode, and the cathode of the first diode is used as the second end of the first voltage acquisition unit.
5. The circuit of claim 1, wherein the second voltage acquisition unit comprises: a second resistor and a second diode; wherein,
The first end of the second resistor is used as the first end of the second voltage acquisition unit;
the second end of the second resistor is connected with the anode of the second diode, and the cathode of the second diode is used as the second end of the second voltage acquisition unit.
6. The circuit of claim 1, wherein the first comparison unit comprises: a first comparator; wherein,
the non-inverting input end of the first comparator is used as a second end of the first comparison unit;
the reverse input end of the first comparator is used for inputting the first reference voltage value;
the output end of the first comparator is used as a first end of the first comparison unit.
7. The circuit of claim 1, wherein the second comparison unit comprises: a second comparator; wherein,
the non-inverting input end of the second comparator is used as a second end of the second comparison unit;
the reverse input end of the second comparator is used for inputting the second reference voltage value;
the output end of the second comparator is used as the first end of the second comparison unit.
8. The circuit of claim 1, further comprising: a third resistor and a fourth resistor; wherein,
A first end of the third resistor is connected with the first node;
the first end of the fourth resistor is connected with the second node;
and the second end of the third resistor is connected with the second end of the fourth resistor and then connected with the second end of the power device.
9. The circuit of claim 1, further comprising: a fifth resistor; wherein,
the first end of the fifth resistor is connected with the output end of the control unit, and the second end of the fifth resistor is connected with the control end of the power device.
10. The circuit of claim 1, wherein the power device comprises: a transistor and a transient voltage suppression diode; wherein,
the first end of the transistor is connected with the cathode of the transient voltage suppression diode and then used as the first end of the power device;
the second end of the transistor is connected with the anode of the transient voltage suppression diode and then used as the second end of the power device;
the control end of the transistor is used as the control end of the power device;
wherein, the transistor is an IGBT tube or an MOS tube.
11. Overvoltage protection method based on an overvoltage protection circuit of a power device according to any of the claims 1-10, characterized by comprising the steps of:
Acquiring a first signal output by a first comparison unit; the first signal is a signal obtained by the first comparison unit according to a comparison result between the voltage value of the first node and a first reference voltage value, which is acquired by the first voltage acquisition unit;
acquiring a second signal output by a second comparison unit; the second signal is a signal obtained by the second comparison unit according to a comparison result between the voltage value of the second node and a second reference voltage value, which is acquired by the second voltage acquisition unit;
and regulating an output signal according to the first signal and the second signal so as to realize overvoltage protection of the power device.
12. The method of claim 11, wherein adjusting the output signal based on the first signal and the second signal comprises:
acquiring a first time point when the first signal changes;
acquiring a second time point when the second signal changes;
calculating the absolute value of the difference between the second time point and the first time point as a time difference;
calculating the absolute value of the difference between the voltage value of the second voltage source and the voltage value of the first voltage source as a voltage difference;
Calculating the ratio between the voltage difference value and the time difference value as the rising slope of the turn-off voltage of the power device;
and adjusting the output signal according to the rising slope.
13. The method of claim 12, wherein said adjusting the output signal based on the rising slope comprises:
and under the condition that the rising slope is larger than the set rising slope, the output signal is regulated to reduce the output voltage value or the output current value of the signal output end of the control unit.
14. An electronic device, comprising:
a processor and a memory;
wherein the processor runs a program corresponding to executable program code stored in the memory by reading the executable program code for implementing the method according to any of claims 10-13.
15. A computer readable storage medium, characterized in that the computer program, when executed by a processor, implements the method according to any of claims 10-13.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310956243.1A CN117039823A (en) | 2023-07-31 | 2023-07-31 | Overvoltage protection circuit of power device and overvoltage protection method based on overvoltage protection circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310956243.1A CN117039823A (en) | 2023-07-31 | 2023-07-31 | Overvoltage protection circuit of power device and overvoltage protection method based on overvoltage protection circuit |
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| CN117039823A true CN117039823A (en) | 2023-11-10 |
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| CN202310956243.1A Pending CN117039823A (en) | 2023-07-31 | 2023-07-31 | Overvoltage protection circuit of power device and overvoltage protection method based on overvoltage protection circuit |
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