Turn-off circuit, driving circuit, IGCT, electrical equipment and turn-off method

Abstract

The invention provides a turn-off circuit, a driving circuit, an IGCT, electrical equipment and a turn-off method. The turn-off circuit is used for a gate commutated thyristor, the gate commutated thyristor comprises a first leading-out electrode, a second leading-out electrode and a control electrode, and the turn-off circuit comprises a control device and a voltage regulation circuit. The control device is configured to output a control signal to the voltage regulation circuit; the voltage regulation circuit comprises a control sub-circuit, a voltage-bearing adjustable switch element and a voltage source, the first end of the voltage-bearing adjustable switch element is electrically connected to the control electrode of the gate commutated thyristor, the second end of the voltage-bearing adjustable switch element is electrically connected to the first end of the voltage source, the control end of the voltage-bearing adjustable switch element is electrically connected to the control sub-circuit, and the second end of the voltage source is electrically connected to the control sub-circuit. The second end of the voltage source is electrically connected to the first leading-out electrode of the gate commutated thyristor, and the control sub-circuit is configured to control the voltage-bearing adjustable switching element to be switched on or switched off or control the voltage-bearing adjustable switching element to be clamped at a preset voltage based on a control signal.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics technology, and in particular to a shutdown circuit, a drive circuit, an IGCT, an electrical device, and a shutdown method. Background Art

[0002] An integrated gate commutated thyristor (IGCT) is a device consisting of a gate commutated thyristor (GCT), a tube shell packaging structure and a drive circuit.

[0003] Figure 1 The diagram is a schematic diagram showing the connection topology between the electrode terminals of a gate-commutated thyristor chip and a drive circuit in the related art. Figure 1 FIG. 2 shows the connection topology between the GCT and the driving circuit in the related art. Figure 1 As shown, the GCT chip includes three lead-out electrodes, namely, a first lead-out electrode, a second lead-out electrode and a control electrode; the driving circuit mainly includes an opening loop and a closing loop.

[0004] Figure 2 Schematic diagram showing the working state of the gate-commutated thyristor. Figure 2 As shown in the figure, the working states of the GCT chip are divided into the on state, the off state and the blocking state. In the on state, there is current inside the device and the two ends of the device are basically not subjected to voltage; in the blocking state, there is basically no current inside the device and the two ends of the device are directly subjected to voltage; the off state is the switching process between the on state and the blocking state. These three states are continuously rotated to realize the conduction and shutdown of the main circuit current.

[0005] like Figure 2 As shown, the off state includes the commutation stage and the voltage establishment stage. In the commutation stage, the current originally flowing from the first lead-out electrode is converted to flow from the control electrode. That is, in the commutation stage, the cathode current is commutated to the gate electrode. At this time, it belongs to a "ready" state. There is current inside the device, and the device still does not bear voltage. In the voltage establishment stage, the voltage between the first lead-out electrode and the second lead-out electrode increases and stabilizes to the bus voltage, and the current in the chip gradually decays to zero. That is, the voltage establishment stage is the process of gradually establishing the voltage at both ends of the device, and the current inside the device gradually decays to 0.

[0006] The driving circuit is the core component for controlling the working state conversion of the above-mentioned GCT chip. The on-loop in the driving circuit controls the semiconductor to be actively turned on by injecting a trigger current into the control electrode of the GCT chip. The off-loop in the driving circuit applies a reverse bias voltage to the PN junction between the control electrode and the first lead-out electrode, forcing the current originally flowing from the first lead-out electrode to flow from the control electrode, so that the PN junction between the first lead-out electrode and the control electrode of the GCT chip is reversely cut off, thereby safely establishing the voltage between the first lead-out electrode and the second lead-out electrode of the GCT chip, and the current in the chip decays to zero, and the chip successfully enters the blocking state.

[0007] That is to say, during the shutdown process, the switch component is turned on so that the capacitor group applies a reverse bias voltage to the control electrode, forcing the device load current to commutate from the first lead electrode to the control electrode, thereby causing the device to shut down naturally. However, in the related art, it is difficult to take into account both the reliability of GCT shutdown and the safety of the PN junction between the control electrode and the first lead electrode. Summary of the invention

[0008] A technical problem solved by the present disclosure is that in the related art, it is difficult to take into account both the reliability of GCT shutdown and the safety of the PN junction between the control electrode and the first lead electrode.

[0009] According to one aspect of the present disclosure, a turn-off circuit is provided, wherein the turn-off circuit is used for a gate-commutated thyristor, the gate-commutated thyristor includes a first lead-out electrode, a second lead-out electrode and a control electrode, the turn-off circuit includes: a control device and a voltage regulation circuit; the control device is configured to output a control signal to the voltage regulation circuit; the voltage regulation circuit includes: a control subcircuit, a voltage-bearing adjustable switching element and a voltage source, wherein a first end of the voltage-bearing adjustable switching element is electrically connected to the control electrode of the gate-commutated thyristor, a second end of the voltage-bearing adjustable switching element is electrically connected to a first end of the voltage source, a control end of the voltage-bearing adjustable switching element is electrically connected to the control subcircuit, a second end of the voltage source is electrically connected to the first lead-out electrode of the gate-commutated thyristor, and the control subcircuit is configured to control the voltage-bearing adjustable switching element to be turned on or off based on the control signal, or to control the voltage-bearing adjustable switching element to be clamped at a predetermined voltage.

[0010] In some embodiments, the control subcircuit includes: a first subcircuit configured to control the voltage-adjustable switch element to be turned on or off; and a second subcircuit configured to control the voltage-adjustable switch element to be clamped at a predetermined voltage.

[0011] In some embodiments, the first subcircuit includes: a first switching device, a first end of the first switching device is electrically connected to a first voltage end, a second end of the first switching device is electrically connected to a control end of the voltage-bearing adjustable switching element, and the control end of the first switching device is electrically connected to the control device; a first resistor, a first end of the first resistor is electrically connected to the first voltage end, and a second end of the first resistor is electrically connected to the control end of the voltage-bearing adjustable switching element; and a second switching device, a first end of the second switching device is electrically connected to a second voltage end, a second end of the second switching device is electrically connected to the control end of the voltage-bearing adjustable switching element, and the control end of the second switching device is electrically connected to the control device; wherein the voltage level of the first voltage end is less than the voltage level of the second voltage end.

[0012] In some embodiments, the first sub-circuit further includes: a second resistor, which is arranged between the second end of the first switching device and the control end of the voltage-adjustable switching element.

[0013] In some embodiments, the first sub-circuit further includes: a third resistor, arranged between the second end of the second switch device and the control end of the voltage-adjustable switch element.

[0014] In some embodiments, the second sub-circuit includes one or more clamping sub-circuits, wherein each clamping sub-circuit includes: a third switching device, a first end of the third switching device is electrically connected to the control end of the voltage-bearing adjustable switching element, and the control end of the third switching device is electrically connected to the control device; a first diode, a cathode end of the first diode is electrically connected to the second end of the third switching device; and a Zener diode, a positive end of the Zener diode is electrically connected to the positive end of the first diode, and a cathode end of the Zener diode is electrically connected to the first end of the voltage-bearing adjustable switching element.

[0015] In some embodiments, the voltage zener diode is an avalanche breakdown diode.

[0016] In some embodiments, the voltage-adjustable switch element comprises a metal oxide semiconductor field effect transistor.

[0017] In some embodiments, the one or more clamping sub-circuits include a plurality of clamping sub-circuits, and breakdown voltage thresholds of Zener diodes in the plurality of clamping sub-circuits are not equal.

[0018] In some embodiments, the control device is configured to control the first switching device to turn on, control the second switching device to turn off, and control all third switching devices in the one or more clamping sub-circuits to turn off when the gate-commutated thyristor enters the conduction phase; control the first switching device to turn off, control the second switching device to turn on, and control all third switching devices in the one or more clamping sub-circuits to turn off when the gate-commutated thyristor enters the turn-off phase; and control the first switching device to turn off, control the second switching device to turn on, and control one third switching device in the one or more clamping sub-circuits to turn on when the gate-commutated thyristor enters the blocking phase.

[0019] In some embodiments, the conductivity type of the first doped region connected to the first lead-out electrode is opposite to the conductivity type of the second doped region connected to the control electrode; the control signal includes a first control signal and a second control signal; the control device is configured to output the first control signal in a first stage, and output the second control signal in a second stage after the first stage, wherein the first stage includes at least a part of a voltage building stage in a turn-off stage of the gate-commutated thyristor, and the at least a part of the voltage building stage is after the commutation stage in the turn-off stage and adjacent to the commutation stage; the voltage regulating circuit is configured to apply a first reverse bias voltage to a PN junction formed by the second doped region and the first doped region through the control electrode and the first lead-out electrode in the first stage after receiving the first control signal, and apply a second reverse bias voltage to the PN junction in the second stage after receiving the second control signal, wherein a voltage value of the first reverse bias voltage is greater than or equal to a breakdown voltage threshold of the PN junction, and a voltage value of the second reverse bias voltage is less than the breakdown voltage threshold of the PN junction.

[0020] In some embodiments, the first control signal includes a first sub-control signal, a second sub-control signal and a third sub-control signal; the control device is configured to output the first sub-control signal to the first switching device to control the first switching device to be turned off, output the second sub-control signal to the second switching device to control the second switching device to be turned on, and output the third sub-control signal to all third switching devices in the one or more clamping sub-circuits to control all third switching devices to be turned off.

[0021] In some embodiments, the second control signal includes a fourth sub-control signal, a fifth sub-control signal and a sixth sub-control signal; the control device is configured to output the fourth sub-control signal to the first switching device to control the first switching device to turn off, output the fifth sub-control signal to the second switching device to control the second switching device to turn off, and output the sixth sub-control signal to a third switching device in the one or more clamping sub-circuits to control the third switching device to turn on.

[0022] In some embodiments, the voltage of the voltage source is greater than a breakdown voltage threshold of the PN junction.

[0023] According to another aspect of the present disclosure, a drive circuit for a gate-commutated thyristor is provided, comprising: the turn-off circuit as described above.

[0024] According to another aspect of the present disclosure, an integrated gate-commutated thyristor is provided, comprising: the aforementioned turn-off circuit.

[0025] According to another aspect of the present disclosure, an electrical device is provided, comprising: the integrated gate-commutated thyristor as described above.

[0026] According to another aspect of the present disclosure, a shutdown method based on the shutdown circuit as described above is provided, including: when the gate-commutated thyristor enters the conduction stage, controlling the first switching device to be turned on, controlling the second switching device to be turned off, and controlling all third switching devices in the one or more clamping sub-circuits to be turned off; when the gate-commutated thyristor enters the shutdown stage, controlling the first switching device to be turned off, controlling the second switching device to be turned on, and controlling all third switching devices in the one or more clamping sub-circuits to be turned off; when the gate-commutated thyristor enters the blocking stage, controlling the first switching device to be turned off, controlling the second switching device to be turned off, and controlling a third switching device in the one or more clamping sub-circuits to be turned on.

[0027] In the above-mentioned shutdown circuit, the control device outputs a control signal to the control subcircuit, so that the control subcircuit controls the voltage-bearing adjustable switch element to turn on or off based on the control signal, or controls the voltage-bearing adjustable switch element to be clamped at a predetermined voltage, so that the PN junction between the control electrode and the first lead-out electrode of the GCT is at different voltages. In this way, when it is necessary to improve the reliability of the device shutdown, that is, to improve the commutation capacity of the GCT device, the above-mentioned PN junction can be placed under a larger reverse bias voltage, and in order to prevent the PN junction from being broken down for a long time, the above-mentioned PN junction can be changed from bearing a larger reverse bias voltage to bearing a smaller reverse bias voltage, so that the safety of the PN junction between the control electrode and the first lead-out electrode can be improved. In this way, the reliability of the GCT shutdown and the safety of the PN junction between the control electrode and the first lead-out electrode can be taken into account as much as possible, so that the reliability of the device shutdown and the safety of the PN junction can be improved.

[0028] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0030] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0031] Figure 1 is a schematic diagram showing the connection topology of the electrode terminals and the driving circuit of the gate-commutated thyristor chip in the related art;

[0032] Figure 2 is a schematic diagram showing the working state of a gate-commutated thyristor;

[0033] Figure 3 is a graph showing the relationship between current, voltage and time of a gate commutated thyristor at different working stages;

[0034] Figure 4 is a schematic diagram showing the structure of a gate-commutated thyristor according to some embodiments of the present disclosure;

[0035] Figure 5 is a connection diagram showing a turn-off circuit for a gate-commutated thyristor according to some embodiments of the present disclosure;

[0036] Figure 6 is a connection schematic diagram showing a turn-off circuit for a gate-commutated thyristor according to other embodiments of the present disclosure;

[0037] Figure 7is a connection schematic diagram showing a turn-off circuit for a gate-commutated thyristor according to other embodiments of the present disclosure;

[0038] Figure 8 is a connection schematic diagram showing a turn-off circuit for a gate-commutated thyristor according to other embodiments of the present disclosure;

[0039] Fig. 9 is a flow chart illustrating a shutdown method according to some embodiments of the present disclosure.

[0040] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0042] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0043] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other device without an intermediate device, or may not be directly connected to the other device but have an intermediate device.

[0044] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0045] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0046] The inventor of the present disclosure has found that in the related art, in the IGCT shutdown technology, the capacitor bank uses a constant capacitor voltage value. However, if the voltage of the capacitor bank is low, it may lead to insufficient commutation capacity of the GCT device, which may easily lead to failure of the GCT device to shut down; if the voltage of the capacitor bank is high, it may cause the PN junction between the control electrode and the first lead-out electrode of the GCT device to be broken down for a long time, which may burn the PN junction and cause device failure, making it difficult to take into account both the reliability of the GCT shutdown and the safety of the PN junction between the control electrode and the first lead-out electrode.

[0047] In view of this, an embodiment of the present disclosure provides a turn-off circuit for a gate-commutated thyristor, so as to take into account both the reliability of GCT turn-off and the safety of the PN junction between the control electrode and the first lead-out electrode as much as possible.

[0048] Figure 4 is a schematic diagram showing the structure of a gate-commutated thyristor according to some embodiments of the present disclosure. Figure 4As shown, the gate-commutated thyristor includes a first doping region 411, a second doping region 412, a third doping region 413 and a fourth doping region 414. The first doping region 411 is adjacent to the second doping region 412, the second doping region 412 is adjacent to the third doping region 413, and the third doping region 413 is adjacent to the fourth doping region 414. The conductivity type of the first doping region 411 is opposite to the conductivity type of the second doping region 412, the conductivity type of the second doping region 412 is opposite to the conductivity type of the third doping region 413, and the conductivity type of the third doping region 413 is opposite to the conductivity type of the fourth doping region 414. For example, the conductivity type of the fourth doping region 414 is P-type, the conductivity type of the third doping region 413 is N-type, the conductivity type of the second doping region 412 is P-type, and the conductivity type of the first doping region 411 is N-type, that is, the gate-commutated thyristor is a PNPN type gate-commutated thyristor. For another example, the conductivity type of the fourth doping region 414 is N-type, the conductivity type of the third doping region 413 is P-type, the conductivity type of the second doping region 412 is N-type, and the conductivity type of the first doping region 411 is P-type, that is, the gate-commutated thyristor is a NPNP-type gate-commutated thyristor.

[0049] like Figure 4 As shown, the gate-commutated thyristor further includes a first lead-out electrode 401, a second lead-out electrode 402, and a control electrode 403. The first lead-out electrode 401 is connected to the first doping region 411, the second lead-out electrode 402 is connected to the fourth doping region 414, and the control electrode 403 is connected to the second doping region 412. The conductivity type of the first doping region 411 connected to the first lead-out electrode 401 is opposite to the conductivity type of the second doping region 412 connected to the control electrode 403. The conductivity type of the second doping region 412 connected to the control electrode 403 is the same as the conductivity type of the fourth doping region 414 connected to the second lead-out electrode 402.

[0050] Figure 5 1 is a schematic diagram showing the connection of a turn-off circuit for a gate-commutated thyristor according to some embodiments of the present disclosure. The turn-off circuit is used for a gate-commutated thyristor, and the gate-commutated thyristor includes a first lead-out electrode, a second lead-out electrode, and a control electrode. Figure 5 As shown, the shutdown circuit 50 includes a control device 51 and a voltage regulating circuit 52 .

[0051] The control device 51 is configured to output a control signal to the voltage regulating circuit 52 .

[0052] The voltage regulation circuit 52 includes: a control subcircuit 120, a voltage-adjustable switch element 110 and a voltage source V C The first end of the voltage-adjustable switch element 110 is electrically connected to the control electrode 403 of the gate-commutated thyristor GCT, and the second end of the voltage-adjustable switch element 110 is electrically connected to the voltage source V CThe first end (eg, the negative end) of the voltage source V is connected to the control end of the voltage-adjustable switch element 110. C The second end (eg, the positive end) of is electrically connected to the first lead-out electrode 401 of the gate-commutated thyristor GCT. C Including capacitors. For example, the voltage source V C For capacitor bank.

[0053] In some embodiments, the pressure-adjustable switch element 110 includes a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, referred to as MOSFET). For example, the pressure-adjustable switch element is an NMOS (N-channel Metal Oxide Semiconductor) transistor. For another example, the pressure-adjustable switch element is a PMOS (P-channel Metal Oxide Semiconductor) transistor. Here, the pressure-adjustable switch element is a switch element with a saturation characteristic.

[0054] It should be noted that the pressure-adjustable switch element in the embodiment of the present disclosure is not limited to the types of switch elements mentioned above, and a suitable switch element with saturation characteristics can be selected as the pressure-adjustable switch element as needed.

[0055] The control subcircuit 120 is electrically connected to the control device 51. The control subcircuit 120 can receive a control signal from the control device 51. The control subcircuit 120 is configured to control the voltage-bearing adjustable switch element to be turned on or off, or to control the voltage-bearing adjustable switch element to be clamped at a predetermined voltage based on the control signal. In this way, the voltage-bearing adjustable switch element can be in an on state, an off state, or clamped at a predetermined voltage, so that the PN junction between the control electrode and the first lead-out electrode of the GCT can be at different voltages, so that the GCT can be in different states (for example, an on state, an off state, or a blocking state, etc.).

[0056] So far, a shutdown circuit according to some embodiments of the present disclosure is provided. The shutdown circuit is used for a gate-commutated thyristor, the gate-commutated thyristor includes a first lead-out electrode, a second lead-out electrode and a control electrode, the shutdown circuit includes: a control device and a voltage regulation circuit; the control device is configured to output a control signal to the voltage regulation circuit; the voltage regulation circuit includes: a control subcircuit, a voltage-bearing adjustable switching element and a voltage source, wherein the first end of the voltage-bearing adjustable switching element is electrically connected to the control electrode of the gate-commutated thyristor, the second end of the voltage-bearing adjustable switching element is electrically connected to the first end of the voltage source, the control end of the voltage-bearing adjustable switching element is electrically connected to the control subcircuit, the second end of the voltage source is electrically connected to the first lead-out electrode of the gate-commutated thyristor, and the control subcircuit is configured to control the voltage-bearing adjustable switching element to be turned on or off based on the control signal, or to control the voltage-bearing adjustable switching element to be clamped at a predetermined voltage. In the shutdown circuit, the control device outputs a control signal to the control subcircuit, so that the control subcircuit controls the voltage-bearing adjustable switch element to turn on or off based on the control signal, or controls the voltage-bearing adjustable switch element to be clamped at a predetermined voltage, so that the PN junction between the control electrode and the first lead-out electrode of the GCT is at different voltages. In this way, when it is necessary to improve the reliability of the device shutdown, that is, to improve the commutation capacity of the GCT device, the above-mentioned PN junction can be placed under a larger reverse bias voltage, and in order to prevent the PN junction from being broken down for a long time, the above-mentioned PN junction can be changed from bearing a larger reverse bias voltage to bearing a smaller reverse bias voltage, so that the safety of the PN junction between the control electrode and the first lead-out electrode can be improved. In this way, the reliability of the GCT shutdown and the safety of the PN junction between the control electrode and the first lead-out electrode can be taken into account as much as possible, so that the reliability of the device shutdown and the safety of the PN junction can be improved.

[0057] Figure 6 1 is a schematic diagram showing the connection of a turn-off circuit for a gate-commutated thyristor according to some other embodiments of the present disclosure. Figure 6 The voltage regulation circuit includes a control subcircuit 120, a voltage-adjustable switch element 110 and a voltage source V C For example, the pressure-adjustable switch element 110 is an NMOS transistor. It should be noted that: Figure 6 The control device is not shown in the figure, but as mentioned above, the shutdown circuit also includes a control device.

[0058] like Figure 6As shown, the control subcircuit 120 includes a first subcircuit 121 and a second subcircuit 122. The first subcircuit 121 can be configured to control the voltage-bearing adjustable switch element 110 to be turned on or off. For example, the first subcircuit 121 is used to apply a high-level or low-level control signal to the control end of the voltage-bearing adjustable switch element (for example, the gate of the MOSFET) to control the on or off of the voltage-bearing adjustable switch element. The second subcircuit 122 is configured to control the voltage-bearing adjustable switch element 110 to be clamped at a predetermined voltage. For example, the second subcircuit 122 is used to control the voltage-bearing adjustable switch element to enter a saturation state, wherein the voltage at which the voltage-bearing adjustable switch element is clamped is equal to the difference between the voltage of the voltage source and the voltage that the PN junction withstands. In this way, the control of the voltage-bearing adjustable switch element is achieved.

[0059] In some embodiments, Figure 6 As shown, the first sub-circuit 121 includes: a first switch device S drv1 , the first resistor R 1 and the second switching device S drv2 .

[0060] The first switching device S drv1 The first end of the first switching device S is electrically connected to the first voltage terminal 101. drv1 The second end of the first switching device S is electrically connected to the control end (eg, gate) of the voltage-adjustable switching element 110. drv1 The control end is electrically connected to the control device ( Figure 6 For example, the first switching device S drv1 is an NMOS transistor. For another example, the first switch device S drv1 The scope of the present disclosure is not limited to a specific type of the first switching device.

[0061] The first resistor R 1 The first end of the first resistor R is electrically connected to the first voltage terminal 101. 1 The second end is electrically connected to the control end of the voltage-adjustable switching element 110.

[0062] For example, the first resistor R 1 The resistance value of the first resistor may range from 1 kΩ (kilo ohm) to 10 kΩ. However, it should be noted that the resistance value range of the first resistor is only exemplary, and the scope of the present disclosure is not limited to the specific resistance value of the first resistor.

[0063] The second switching device S drv2 The first end of the second switching device S is electrically connected to the second voltage terminal 102. drv2 The second end of the second switch device S is electrically connected to the control end of the pressure-adjustable switch element 110. drv2The control end of the second switch device S is electrically connected to the control device. drv2 is a PMOS transistor. For another example, the second switch device S drv2 The scope of the present disclosure is not limited to a specific type of the second switching device.

[0064] For example, the voltage level of the first voltage terminal 101 is less than (i.e., lower than) the voltage level of the second voltage terminal 102. For example, the first voltage terminal 101 is a ground terminal, and the second voltage terminal 102 is a power supply voltage terminal. The second voltage terminal 102 can be used to increase the driving voltage V drive .

[0065] Figure 7 1 is a schematic diagram showing the connection of a turn-off circuit for a gate-commutated thyristor according to other embodiments of the present disclosure. Figure 7 As shown, the first sub-circuit 121 includes: a first switch device S drv1 , the first resistor R 1 and the second switching device S drv2 .

[0066] In some embodiments, Figure 7 As shown, the first sub-circuit 121 may further include a second resistor R 2 The second resistor R 2 Set in the first switching device S drv1 between the second end of the second resistor R and the control end of the pressure-adjustable switch element 110. 2 The first end is electrically connected to the first switching device S drv1 The second end of the second resistor R 2 The second end is electrically connected to the control end of the voltage-adjustable switching element 110.

[0067] For example, the second resistor R 2 The resistance value can range from 0 <R 1 ≤200 ohms. For example, the second resistor R 2 The resistance value of is 1 ohm. However, it should be noted that, here, the range of the resistance value of the second resistor is only exemplary, and the scope of the present disclosure is not limited to the specific resistance value of the second resistor.

[0068] In some embodiments, the first resistor R 1 The resistance value is greater than the second resistor R 2 resistance value.

[0069] In some embodiments, Figure 7 As shown, the first sub-circuit 121 may further include a third resistor R 3 The third resistor R 3 Set in the second switching device Sdrv2 between the second end of and the control end of the pressure-adjustable switch element 110. That is, the third resistor R 3 The first end is electrically connected to the second switching device S drv2 The second end of the third resistor R 3 The second end is electrically connected to the control end of the voltage-adjustable switching element 110.

[0070] For example, the third resistor R 3 The resistance value can range from 0 <R 3 ≤200 ohms. For example, the third resistor R 3 The resistance value of is 1 ohm. However, it should be noted that, here, the range of the resistance value of the third resistor is only exemplary, and the scope of the present disclosure is not limited to the specific resistance value of the third resistor.

[0071] In some embodiments, the first resistor R 1 The resistance value is greater than the third resistor R 3 resistance value.

[0072] In some embodiments, the second resistor R 2 The resistance value is equal to the third resistor R 3 resistance value.

[0073] The second resistor R 2 and the third resistor R 3 It can be used to adjust the turn-off speed and the turn-on speed of the pressure-adjustable switch element 110. For example, controlling the first switch device S drv1 Turn on and control the second switch device S drv2 The low level of the first voltage terminal 101 is applied to the control terminal of the adjustable pressure-bearing switch element 110, so that the adjustable pressure-bearing switch element 110 (here, the adjustable pressure-bearing switch element 110 is selected as an NMOS transistor) is turned off, and the second resistor R 2 The pressure-adjustable switch element 110 can have different turn-off speeds. drv1 The second switching device S is turned off and drv2 The high level of the second voltage terminal 102 is applied to the control terminal of the adjustable voltage-bearing switch element 110 (here, the adjustable voltage-bearing switch element 110 is selected as an NMOS transistor), so that the adjustable voltage-bearing switch element 110 is turned on, and the third resistor R 3 The voltage-adjustable switch element 110 can have different conduction speeds.

[0074] It should be noted that the second resistor R 2 and the third resistor R 3For example, the second resistor R may not be provided in the first sub-circuit 121. 2 and the third resistor R 3 (like Figure 6 Alternatively, a second resistor R may be provided in the first sub-circuit 121. 2 and the third resistor R 3 Alternatively, a second resistor R may be provided in the first sub-circuit 121. 2 and the third resistor R 3 (like Figure 7 as shown).

[0075] In some embodiments, the second subcircuit 122 includes one or more clamping subcircuits. For example, Figure 6 and Figure 7 A clamping subcircuit is shown in each of the following. Figure 6 or Figure 7 As shown, the clamping sub-circuit includes a third switching device S aux1 , the first diode D 1 and Zener diode TVS 1 Here, in order to distinguish it from the Zener diode, the diode D 1 It is called the first diode, or the diode D 1 It is called an auxiliary diode. In addition, a Zener diode can be used as a second diode.

[0076] The third switching device S aux1 The first end of the third switch device S is electrically connected to the control end of the pressure-adjustable switch element 110. aux1 The control end is electrically connected to the control device ( Figure 6 and Figure 7 For example, the third switching device S aux1 is an NMOS transistor. For another example, the third switch device S aux1 The scope of the present disclosure is not limited to a specific type of the third switching device.

[0077] The first diode D 1 The negative terminal is electrically connected to the third switching device S aux1 The second end.

[0078] Zener diode TVS 1 The positive terminal is electrically connected to the first diode D 1 The positive terminal of the voltage stabilizing diode TVS 1 The negative terminal of the voltage-adjustable switching element 110 is electrically connected to the first terminal of the voltage-adjustable switching element 110. That is, the voltage-stabilizing diode TVS 1 The negative terminal of is electrically connected to the control electrode 403 of the GCT.

[0079] For example, a voltage stabilizing diode TVS 1 It should be noted that the voltage stabilizing diode in the embodiment of the present disclosure may also be other types of voltage stabilizing diodes, and therefore, the scope of the present disclosure is not limited thereto.

[0080] A control device can be used to output corresponding control signals to the first switching device, the second switching device and the third switching device respectively, so as to control the on or off of the first switching device, the second switching device and the third switching device, and further control the on or off of the pressure-bearing adjustable switching element, or control the pressure-bearing adjustable switching element to be clamped at a predetermined voltage.

[0081] In some embodiments, when the second sub-circuit includes only one clamping sub-circuit, the control device is configured to control the first switching device to be turned on, the second switching device to be turned off, and the third switching device to be turned off when the gate-commutated thyristor enters the conduction stage; control the first switching device to be turned off, the second switching device to be turned on, and the third switching device to be turned off when the gate-commutated thyristor enters the turn-off stage; and control the first switching device to be turned off, the second switching device to be turned on, and the third switching device to be turned off when the gate-commutated thyristor enters the blocking stage.

[0082] Combine the following Figure 6 or Figure 7 , to bear the pressure adjustable switch element 110, the first switch device S drv1 and the third switching device S aux1 is an NMOS transistor, the second switch device S drv2 Taking the PMOS transistor as an example, the working process of the shutdown circuit is described.

[0083] For example, when the GCT enters the conduction phase, the control device switches the first switching device S drv1 Output a control signal (eg, a high level signal) so that the first switch device S drv1 The control device turns on the second switching device S drv2 Output a control signal (eg, a high level signal) so that the second switch device S drv2 In addition, the control device to the third switching device S aux1 Output a control signal (eg, a low level signal) so that the third switch device S aux1 In this way, the low level of the first voltage terminal 101 is applied to the control terminal of the pressure-adjustable switch element 110, so that the pressure-adjustable switch element 110 can be maintained in the off state. C The reverse bias voltage is not applied to the PN junction between the control electrode and the first lead electrode of the GCT, so the GCT can enter the conduction stage or maintain the conduction state.

[0084] For another example, when the GCT enters the off stage, the control device switches the first switch device S drv1 Output a control signal (eg, a low level signal) so that the first switch device S drv1 The control device turns off the second switching device S drv2 Output a control signal (eg, a low level signal) so that the second switch device S drv2 In addition, the control device to the third switching device S aux1 Output a control signal (eg, a low level signal) so that the third switch device S aux1 In this way, the driving voltage V drive Applied to the control end of the voltage-adjustable switch element 110, the voltage-adjustable switch element 110 can be maintained in the on state. C The reverse bias voltage is all applied to the PN junction between the control electrode and the first lead electrode of the GCT, so the GCT enters the turn-off stage.

[0085] For another example, when the GCT enters the blocking stage, the control device switches the first switching device S drv1 Output a control signal (eg, a low level signal) so that the first switch device S drv1 The control device turns off the second switching device S drv2 Output a control signal (eg, a high level signal) so that the second switch device S drv2 In addition, the control device to the third switching device S aux1 Output a control signal (eg, a high level signal) so that the third switch device S aux1 In this way, the voltage of the voltage-adjustable switch element 110 is clamped at a predetermined voltage by using the clamping sub-circuit, and the predetermined voltage is the voltage regulator diode TVS. 1 The sum of the breakdown voltage threshold (or breakdown threshold voltage) of the GCT and the threshold voltage of the voltage-adjustable switch element 110. In this way, the reverse bias voltage (the reverse bias voltage is the difference between the voltage of the voltage source and the predetermined voltage) borne by the PN junction between the control electrode and the first lead electrode of the GCT is lower than the voltage source V C In this way, the GCT enters the blocking stage.

[0086] In the above embodiment, the voltage value across the switching element can be adjusted. Since the voltage value of the voltage source is constant, the voltage value across the PN junction between the control electrode and the first lead-out electrode of the GCT changes inversely with the change of the active pressure value, thereby realizing the regulation of the voltage across the PN junction between the control electrode and the first lead-out electrode of the GCT by the shutdown circuit.

[0087] The control device outputs a control signal to the voltage regulating circuit to control the on or off of the switch device in the voltage regulating circuit. In this way, based on the adjustment of the voltage value actively borne by the switch component, the voltage applied to the shutdown circuit of the power semiconductor device is regulated. This can solve the problem of the capacitor voltage being unadjustable in the related art, and can reduce the complexity of the shutdown circuit, reduce the cost, and improve the reliability of the circuit.

[0088] Figure 8 1 is a schematic diagram showing the connection of a turn-off circuit for a gate-commutated thyristor according to other embodiments of the present disclosure. Figure 7 The shutdown circuit shown is similar to Figure 8 The voltage regulation circuit included in the shutdown circuit is shown, and the voltage regulation circuit includes a control subcircuit 120, a pressure-adjustable switch element 110 and a voltage source V C For example, the voltage-adjustable switch element 110 is an NMOS transistor.

[0089] like Figure 8 As shown, the control subcircuit 120 includes a first subcircuit 121 and a second subcircuit 122. For example, the first subcircuit 121 may be implemented as follows: Figure 7 Alternatively, the first sub-circuit 121 shown in FIG. Figure 6 The first sub-circuit 121 is shown. The first sub-circuit 121 has been described in detail above and will not be described again here.

[0090] and Figure 7 The second subcircuit shown differs in that: Figure 8 The second subcircuit shown includes a plurality of clamping subcircuits. For example, the second subcircuit includes N clamping subcircuits, where N is a positive integer. Each clamping subcircuit includes a third switching device, a first diode, and a voltage regulator diode. For example, Figure 8 N third switching devices S are shown aux1 To S auxN , N first diodes D 1 To D N And N voltage zener diodes TVS 1 To TVS N .like Figure 8 As shown, a plurality of clamping sub-circuits are connected in parallel between the control terminal and the first terminal of the voltage-adjustable switching element 110 .

[0091] For example, the N clamping sub-circuits include the first clamping sub-circuit to the Nth clamping sub-circuit. Here, the first clamping sub-circuit includes the third switch device S aux1 , the first diode D 1 and Zener diode TVS 1 The second clamping subcircuit includes a third switching device S aux2, the first diode D 2 and Zener diode TVS 2 , the Nth clamping sub-circuit includes a third switching device S auxN , the first diode D N and Zener diode TVS N ,etc.

[0092] In the case where the second sub-circuit includes multiple clamping sub-circuits, the control device is configured to control the first switching device to be turned on, the second switching device to be turned off, and all the third switching devices of the multiple clamping sub-circuits to be turned off when the gate-commutated thyristor enters the conduction stage; when the gate-commutated thyristor enters the turn-off stage, the first switching device is controlled to be turned off, the second switching device is controlled to be turned on, and all the third switching devices of the multiple clamping sub-circuits are controlled to be turned off; when the gate-commutated thyristor enters the blocking stage, the first switching device is controlled to be turned off, the second switching device is controlled to be turned off, and one of the third switching devices in the multiple clamping sub-circuits is controlled to be turned on, and at this time, the other third switching devices in the multiple clamping sub-circuits are all controlled to be turned off.

[0093] That is, when the clamping sub-circuit is working (for example, when the voltage-adjustable switch element needs to be clamped at a predetermined voltage), one third switch device of the plurality of clamping sub-circuits needs to be turned on, while the other third switch devices are turned off.

[0094] In some embodiments, the one or more clamping subcircuits include a plurality of clamping subcircuits, and the breakdown voltage thresholds (i.e., the regulated voltage values) of the voltage regulator diodes in the plurality of clamping subcircuits are not equal. That is, the breakdown voltage thresholds of the plurality of voltage regulator diodes in the plurality of clamping subcircuits are different from each other. In other words, the clamping voltages of the plurality of clamping subcircuits are different. In this way, according to the requirement of clamping the pressure-bearing adjustable switch element at the desired predetermined voltage, the third switch device of the corresponding clamping subcircuit can be selected to be turned on, and the remaining third switch devices can be turned off. In this way, the pressure-bearing adjustable switch element can be clamped at the desired predetermined voltage.

[0095] For example, if it is necessary to select the i-th (1≤i≤N, i is a positive integer) clamping sub-circuit to be turned on to clamp the voltage-adjustable switch element at a predetermined voltage, in addition to making the first switch device S drv1 The second switching device S is turned off and drv2 In addition to being turned off, the third switch device S of the i-th clamping sub-circuit is also turned off. auxi Therefore, the voltage borne by the pressure-adjustable switch element can be adjusted as needed by controlling the third switch device of the i-th clamping sub-circuit to be turned on, thereby adjusting the voltage across the control electrode and the first lead-out electrode of the GCT chip.

[0096] In some embodiments, the control device may output a control signal based on the state of the optical signal to control the GCT to switch from the on state to the off state or from the blocking state to the on state.

[0097] In some embodiments, the control device can control the GCT to switch from the off state to the blocking state by a fixed time length (or a predetermined time length) or based on the measurement result of the current detection device at the second lead-out electrode or the control electrode of the GCT (i.e., the magnitude of the current flowing through the second lead-out electrode or the current flowing through the control electrode measured by the current detection device). For example, the GCT can be controlled to switch from the off state to the blocking state after a set fixed time length (e.g., 5 microseconds) or after the current of the second lead-out electrode of the GCT drops to a predetermined percentage (e.g., 40%) of the original. Here, the predetermined percentage can be set according to actual needs, and the scope of the present disclosure is not limited to the specific value of the predetermined percentage.

[0098] Figure 3 It is a graph showing the relationship between current, voltage and time of a gate-commutated thyristor in different working stages. Figure 3 shows the current (eg, cathode current) I flowing through the first extraction electrode k , the current flowing through the control electrode (i.e. gate current) I g , the current flowing through the second lead (for example, the anode current) I a and the voltage V between the second lead-out electrode and the first lead-out electrode a The relationship curves between them and time. Figure 3 As shown, the horizontal axis is time (unit: seconds), and the vertical axis is voltage (unit: volts) and current (unit: amperes). Figure 3 , a conducting state (or referred to as a conducting phase) 21 , a commutation phase 22 , a voltage building phase 23 and a blocking state (or referred to as a blocking phase) 24 are shown.

[0099] In the related art, Figure 3 It can be seen that in the commutation stage, the current I flowing through the first lead-out pole k Decreases, the current I flowing through the control electrode g Increase; in the voltage establishment stage, the voltage V between the second lead-out electrode and the first lead-out electrode a Gradually increases, the current I flowing through the second lead-out electrode a After a period of time at the beginning of the commutation stage and the voltage establishment stage, it gradually decreases to 0.

[0100] The inventors of the present disclosure have discovered that Figure 3 As shown, during the voltage establishment phase, there may be a period of time when the voltage V between the second lead-out electrode and the first lead-out electrode is a Rapidly rising, and the current Ia In the case where a relatively large current is still maintained, it is easy for the current that has been commutated to the control electrode to be commutated back to flow through the first lead-out electrode, that is, in the off state, the PN junction between the control electrode and the first lead-out electrode may be reopened, causing the GCT chip to fail to shut down. This results in a low shut-off capability of the IGCT in the related art.

[0101] The mechanism of the above-mentioned PN junction reopening process is: in the voltage building stage, due to the voltage drop in other parts of the chip (for example, the P-type base region in the chip) during the large current shutdown process, the reverse bias voltage on the PN junction between the control electrode and the first lead-out electrode is reduced. When it is reduced to approximately equal to 0, the PN junction cannot guarantee the reverse bias state. At this time, the chip is reopened, resulting in a shutdown failure, and then causing chip damage.

[0102] The inventors of the present disclosure have found that, in an IGCT, increasing the voltage of the turn-off capacitor group in the turn-off loop has a beneficial effect on improving the turn-off capability of the device, especially increasing the voltage of the turn-off capacitor group in the voltage establishment stage, which can effectively suppress the turn-off failure of the GCT chip caused by the possible reopening of the PN junction between the control electrode and the first lead-out electrode in the turn-off state. This can be understood as increasing the total voltage on the loop by increasing the voltage of the turn-off capacitor group (i.e., the reverse bias voltage), thereby causing the above-mentioned PN junction to be kept in a reverse bias state even if a large current has a large voltage drop in other parts of the chip.

[0103] In view of this, the control device 51 can be configured to output a first control signal in a first stage, and output a second control signal in a second stage after the first stage. The first stage includes at least a portion of a voltage building stage in a turn-off stage of the gate-commutated thyristor, and at least a portion of the voltage building stage is after the commutation stage in the turn-off stage and adjacent to the commutation stage. Here, the control signal mentioned above includes a first control signal and a second control signal.

[0104] The voltage regulating circuit 52 can be configured to apply a first reverse bias voltage to a PN junction formed by a second doped region and a first doped region through a control electrode and a first lead-out electrode in a first stage after receiving a first control signal, and to apply a second reverse bias voltage to the PN junction in a second stage after receiving a second control signal, wherein a voltage value of the first reverse bias voltage is greater than or equal to a breakdown voltage threshold of the PN junction, and a voltage value of the second reverse bias voltage is less than the breakdown voltage threshold of the PN junction.

[0105] That is to say, in at least a part of the voltage establishment phase, a first reverse bias voltage is applied to the PN junction formed by the second doping region and the first doping region. Since the first reverse bias voltage is greater than or equal to the breakdown voltage threshold of the PN junction, the current of the GCT in the shutdown phase can be relatively fully switched from flowing through the first lead-out electrode to flowing through the control electrode, and it is not easy to switch from flowing through the control electrode to flowing through the first lead-out electrode. In at least a part of the voltage establishment phase, that is, the phase where the PN junction between the control electrode and the first lead-out electrode is easily reopened in the related art, after the first reverse bias voltage greater than or equal to the breakdown voltage threshold of the PN junction is applied to the PN junction, even if a part of the voltage is distributed to the impedance of other parts, the reverse bias voltage remaining on the PN junction can reduce the possibility of reopening the PN junction, thereby reducing the possibility of shutdown failure of the GCT chip.

[0106] Of course, in the above-mentioned first stage, the first reverse bias voltage is greater than or equal to the breakdown voltage threshold of the PN junction, which causes the PN junction to generate a reverse avalanche current. However, since the total duration of at least a part of the voltage establishment stage is very short, the duration of the breakdown phenomenon is very short. Therefore, the breakdown phenomenon will not cause damage to the gate-commutated thyristor.

[0107] In the subsequent second stage, the voltage between the second lead-out electrode and the first lead-out electrode (such as Figure 3 As shown in FIG. 1 , the reverse bias voltage applied to the PN junction has risen to a relatively large voltage. At this time, a second reverse bias voltage is applied to the PN junction. The voltage value of the second reverse bias voltage is less than the breakdown voltage threshold of the PN junction, and the PN junction is not easy to reopen. Moreover, since the reverse bias voltage applied to the PN junction is reduced to a voltage less than the breakdown voltage threshold of the PN junction, the aforementioned breakdown phenomenon can be prevented from continuing for a long time, thereby reducing the possibility of the GCT being damaged due to being in a breakdown state for a long time.

[0108] That is to say, the above-mentioned shutdown circuit can reduce the possibility of reopening the PN junction between the control electrode and the first lead electrode of the GCT in the shutdown state, thereby improving the shutdown capability of the IGCT and reducing the possibility of damage to the GCT due to being in the breakdown state for a long time.

[0109] In some embodiments, the first phase also includes a commutation phase.

[0110] In some embodiments, the voltage source V C The voltage is greater than the breakdown voltage threshold of the PN junction between the control electrode and the first lead electrode of the GCT.

[0111] In some embodiments, the first control signal includes a first sub-control signal, a second sub-control signal, and a third sub-control signal. The control device 51 can be configured to output the first sub-control signal to the first switching device to control the first switching device to be turned off, output the second sub-control signal to the second switching device to control the second switching device to be turned on, and output the third sub-control signal to all third switching devices in one or more clamping sub-circuits to control all third switching devices to be turned off.

[0112] For example, Figure 6 or Figure 7 As an example of the shutdown circuit shown in FIG. 1 , in the first stage, the control device 51 supplies the first switching device S drv1 Output the first sub-control signal to control the first switching device S drv1 Turn off, to the second switching device S drv2 Output the second sub-control signal to control the second switching device S drv2 The third switching device S aux1 Output the third sub-control signal to control the third switching device S aux1 In this way, the driving voltage V drive is applied to the pressure-adjustable switch element 110, so that the pressure-adjustable switch element 110 is turned on. In this way, the voltage source V C The voltage (as reverse bias voltage) is applied to the PN junction between the control electrode and the first lead electrode of the GCT. C The voltage is pre-set to a voltage greater than the breakdown voltage threshold of the PN junction between the control electrode and the first lead-out electrode of the GCT. Therefore, in the first stage, a first reverse bias voltage is applied to the above-mentioned PN junction through the control electrode and the first lead-out electrode, and the voltage value of the first reverse bias voltage is greater than or equal to the breakdown voltage threshold of the PN junction.

[0113] In some embodiments, the second control signal includes a fourth sub-control signal, a fifth sub-control signal, and a sixth sub-control signal. The control device 51 can be configured to output the fourth sub-control signal to the first switching device to control the first switching device to be turned off, output the fifth sub-control signal to the second switching device to control the second switching device to be turned off, and output the sixth sub-control signal to a third switching device in one or more clamping sub-circuits to control the third switching device to be turned on.

[0114] Here, regarding the case of controlling a third switching device to be turned on in the above-mentioned embodiment, it can be understood that: for the case where the second sub-circuit only includes one clamping sub-circuit, the third switching device in the clamping sub-circuit is controlled to be turned on; for the case where the second sub-circuit includes multiple clamping sub-circuits, while controlling one third switching device in the multiple clamping sub-circuits to be turned on, other third switching devices in the multiple clamping sub-circuits are also controlled to be turned off.

[0115] For example, Figure 6 or Figure 7 As an example of the shutdown circuit shown in FIG. 1 , in the second stage, the control device 51 can provide the first switching device S drv1 Output the fourth sub-control signal to control the first switching device S drv1 Turn off, to the second switching device S drv2 Output the fifth sub-control signal to control the second switching device S drv2 The third switching device S aux1 Output the sixth sub-control signal to control the third switching device S aux1 In this way, the voltage of the voltage-adjustable switch element 110 is clamped at a predetermined voltage by using the clamping sub-circuit, and the predetermined voltage is the voltage regulator diode TVS. 1 The breakdown voltage threshold of the voltage source V C The voltage of the first lead-out electrode of the GCT is set to a value less than the breakdown voltage threshold of the PN junction. In this way, the second reverse bias voltage is applied to the PN junction in the second stage, and the voltage value of the second reverse bias voltage is less than the breakdown voltage threshold of the PN junction.

[0116] In some embodiments, the control device controls the voltage-adjustable switch element (i.e., the switch element with saturation characteristics) to operate in an ideal conduction state by outputting a control signal to the voltage regulating circuit, so that the full voltage of the voltage source is applied to the PN junction between the control electrode and the first lead-out electrode of the GCT, so as to apply a first reverse bias voltage to the GCT; after a predetermined period of time or the current of the GCT chip decays to a predetermined percentage less than the maximum current (for example, the predetermined percentage ranges from 0 to 40%), the control device controls the voltage regulating circuit to make the voltage-adjustable switch element operate in a saturation region, so that the actual withstand voltage of the PN junction is lower than the breakdown voltage threshold of the PN junction, so as to apply a second reverse bias voltage to the GCT.

[0117] In some embodiments of the present disclosure, a drive circuit for a gate-commutated thyristor is further provided, and the drive circuit includes the turn-off circuit as described above.

[0118] In some embodiments of the present disclosure, an integrated gate-commutated thyristor is further provided. The integrated gate-commutated thyristor includes the turn-off circuit as described above.

[0119] In some embodiments of the present disclosure, an electrical device is further provided, the electrical device comprising the integrated gate-commutated thyristor as described above.

[0120] Fig. 9 1 is a flow chart showing a shutdown method according to some embodiments of the present disclosure. The shutdown method can be implemented based on the shutdown circuit as described above. Fig. 9 As shown, the shutdown method includes steps S910 to S930.

[0121] In step S910, when the gate-commutated thyristor enters the conduction phase, the first switch device is controlled to be turned on, the second switch device is controlled to be turned off, and all third switch devices in one or more clamping sub-circuits are controlled to be turned off.

[0122] In step S920, when the gate-commutated thyristor enters the turn-off phase, the first switch device is controlled to be turned off, the second switch device is controlled to be turned on, and all third switch devices in the one or more clamping sub-circuits are controlled to be turned off.

[0123] In step S930, when the gate-commutated thyristor enters the blocking stage, the first switch device is controlled to be turned off, the second switch device is controlled to be turned off, and a third switch device in one or more clamping sub-circuits is controlled to be turned on. Here, in the case where the turn-off circuit includes only one clamping sub-circuit, the third switch device in the clamping sub-circuit is controlled to be turned on; in the case where the turn-off circuit includes multiple clamping sub-circuits, one third switch device in the multiple clamping sub-circuits is controlled to be turned on, and the other third switch devices (i.e., the remaining third switch devices) in the multiple clamping sub-circuits are controlled to be turned off.

[0124] So far, a shutdown method based on the shutdown circuit as described above is provided. The shutdown method includes: when the gate-commutated thyristor enters the conduction stage, controlling the first switch device to be turned on, controlling the second switch device to be turned off, and controlling all third switch devices in one or more clamping sub-circuits to be turned off; when the gate-commutated thyristor enters the shutdown stage, controlling the first switch device to be turned off, controlling the second switch device to be turned on, and controlling all third switch devices in the one or more clamping sub-circuits to be turned off; when the gate-commutated thyristor enters the blocking stage, controlling the first switch device to be turned off, controlling the second switch device to be turned off, and controlling one third switch device in the one or more clamping sub-circuits to be turned on. In this way, the control of the conduction or shutdown of the switch device in the voltage regulation circuit of the shutdown circuit is realized, and then the reliability of the GCT shutdown and the safety of the PN junction between the control electrode and the first lead-out electrode can be taken into account as much as possible, thereby improving the reliability of the GCT shutdown and the safety of the PN junction.

[0125] In some embodiments, the conductivity type of the first doping region connected to the first lead-out electrode is opposite to the conductivity type of the second doping region connected to the control electrode. The shut-down method may also include: in a first stage, applying a first reverse bias voltage to a PN junction formed by the second doping region and the first doping region through the control electrode and the first lead-out electrode, wherein the first stage includes at least a portion of a voltage establishment stage in a shut-down stage of the gate-commutated thyristor, at least a portion of the voltage establishment stage is after the commutation stage in the shut-down stage and adjacent to the commutation stage, and the voltage value of the first reverse bias voltage is greater than or equal to the breakdown voltage threshold of the PN junction; and in a second stage after the first stage, applying a second reverse bias voltage to the PN junction, wherein the voltage value of the second reverse bias voltage is less than the breakdown voltage threshold of the PN junction.

[0126] In some embodiments, the first phase further includes the commutation phase.

[0127] In some embodiments, in the first stage, a first reverse bias voltage is applied to the PN junction formed by the second doped region and the first doped region through the control electrode and the first lead-out electrode, including: controlling the first switching device to turn off, controlling the second switching device to turn on, and controlling all third switching devices in the one or more clamping sub-circuits to turn off.

[0128] In some embodiments, in a second stage after the first stage, applying a second reverse bias voltage to the PN junction includes: controlling the first switch device to turn off, controlling the second switch device to turn off, and controlling a third switch device in the one or more clamping subcircuits to turn on.

[0129] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0130] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A shutdown circuit, wherein: The shut-off circuit is used for a gate-commutated thyristor, the gate-commutated thyristor comprises a first lead-out electrode, a second lead-out electrode and a control electrode, and the shut-off circuit comprises: a control device and a voltage regulating circuit; The control device is configured to output a control signal to the voltage regulating circuit; The voltage regulation circuit comprises: a control subcircuit, a voltage-adjustable switch element and a voltage source. The first end of the voltage-bearing adjustable switch element is electrically connected to the control electrode of the gate-commutated thyristor, the second end of the voltage-bearing adjustable switch element is electrically connected to the first end of the voltage source, and the control end of the voltage-bearing adjustable switch element is electrically connected to the control subcircuit. The second end of the voltage source is electrically connected to the first lead-out electrode of the gate-commutated thyristor, The control subcircuit is configured to control the voltage-adjustable switch element to be turned on or off, or to control the voltage-adjustable switch element to be clamped at a predetermined voltage based on the control signal.

2. The shutdown circuit according to claim 1, wherein: The control subcircuit comprises: A first sub-circuit is configured to control the voltage-adjustable switch element to be turned on or off; and The second sub-circuit is configured to control the voltage-bearing adjustable switch element to be clamped at a predetermined voltage.

3. The shutdown circuit according to claim 2, wherein: The first sub-circuit comprises: a first switch device, wherein a first terminal of the first switch device is electrically connected to a first voltage terminal, a second terminal of the first switch device is electrically connected to a control terminal of the voltage-adjustable switch element, and the control terminal of the first switch device is electrically connected to the control device; a first resistor, wherein a first end of the first resistor is electrically connected to the first voltage end, and a second end of the first resistor is electrically connected to a control end of the voltage-adjustable switch element; and a second switch device, wherein a first terminal of the second switch device is electrically connected to a second voltage terminal, a second terminal of the second switch device is electrically connected to a control terminal of the voltage-adjustable switch element, and the control terminal of the second switch device is electrically connected to the control device; Wherein, a voltage level of the first voltage terminal is lower than a voltage level of the second voltage terminal.

4. The shutdown circuit according to claim 3, wherein: The first sub-circuit further includes: The second resistor is arranged between the second end of the first switch device and the control end of the voltage-adjustable switch element.

5. The shutdown circuit according to claim 3, wherein: The first sub-circuit further includes: The third resistor is arranged between the second end of the second switch device and the control end of the voltage-adjustable switch element.

6. The shutdown circuit according to any one of claims 3 to 5, wherein: The second subcircuit includes one or more clamping subcircuits, wherein: Each clamp subcircuit includes: a third switch device, wherein a first end of the third switch device is electrically connected to a control end of the pressure-adjustable switch element, and a control end of the third switch device is electrically connected to the control device; a first diode having a cathode terminal electrically connected to the second terminal of the third switching device; and A voltage-stabilizing diode, wherein the positive terminal of the voltage-stabilizing diode is electrically connected to the positive terminal of the first diode, and the negative terminal of the voltage-stabilizing diode is electrically connected to the first end of the voltage-adjustable switching element.

7. The shutdown circuit according to claim 6, wherein: The voltage stabilizing diode is an avalanche breakdown diode.

8. The shutdown circuit according to claim 1, wherein: The voltage-adjustable switch element includes a metal oxide semiconductor field effect transistor.

9. The shutdown circuit according to claim 6, wherein: The one or more clamping sub-circuits include a plurality of clamping sub-circuits, and breakdown voltage thresholds of Zener diodes in the plurality of clamping sub-circuits are not equal.

10. The shutdown circuit according to claim 6, wherein: The control device is configured to, when the gate-commutated thyristor enters a conduction phase, control the first switching device to turn on, control the second switching device to turn off, and control all third switching devices in the one or more clamping sub-circuits to turn off; when the gate-commutated thyristor enters a turn-off phase, control the first switching device to turn off, control the second switching device to turn on, and control all third switching devices in the one or more clamping sub-circuits to turn off; when the gate-commutated thyristor enters a blocking phase, control the first switching device to turn off, control the second switching device to turn off, and control a third switching device in the one or more clamping sub-circuits to turn on.

11. The shutdown circuit according to claim 6, wherein: The conductivity type of the first doping region connected to the first lead-out electrode is opposite to the conductivity type of the second doping region connected to the control electrode; The control signal includes a first control signal and a second control signal; The control device is configured to output the first control signal in a first stage, and output the second control signal in a second stage after the first stage, wherein the first stage includes at least a part of a voltage building stage in a turn-off stage of the gate-commutated thyristor, and the at least a part of the voltage building stage is after a commutation stage in the turn-off stage and adjacent to the commutation stage; The voltage regulating circuit is configured to, after receiving the first control signal, apply a first reverse bias voltage to the PN junction formed by the second doped region and the first doped region through the control electrode and the first lead-out electrode in the first stage, and after receiving the second control signal, apply a second reverse bias voltage to the PN junction in the second stage, wherein a voltage value of the first reverse bias voltage is greater than or equal to a breakdown voltage threshold of the PN junction, and a voltage value of the second reverse bias voltage is less than the breakdown voltage threshold of the PN junction.

12. The shutdown circuit of claim 11, wherein: The first control signal includes a first sub-control signal, a second sub-control signal and a third sub-control signal; The control device is configured to output the first sub-control signal to the first switching device to control the first switching device to be turned off, output the second sub-control signal to the second switching device to control the second switching device to be turned on, and output the third sub-control signal to all third switching devices in the one or more clamping sub-circuits to control all third switching devices to be turned off.

13. The shutdown circuit of claim 11, wherein: The second control signal includes a fourth sub-control signal, a fifth sub-control signal and a sixth sub-control signal; The control device is configured to output the fourth sub-control signal to the first switching device to control the first switching device to be turned off, output the fifth sub-control signal to the second switching device to control the second switching device to be turned off, and output the sixth sub-control signal to a third switching device in the one or more clamping sub-circuits to control the third switching device to be turned on.

14. The shutdown circuit according to claim 11, wherein: The voltage of the voltage source is greater than a breakdown voltage threshold of the PN junction.

15. A drive circuit for a gate-commutated thyristor, comprising: A shutdown circuit as claimed in any one of claims 1 to 14.

16. An integrated gate-commutated thyristor, comprising: A shutdown circuit as claimed in any one of claims 1 to 14.

17. An electrical device comprising: An integrated gate-commutated thyristor as claimed in claim 15.

18. A shutdown method based on the shutdown circuit according to claim 6, comprising: When the gate-commutated thyristor enters the conduction phase, controlling the first switch device to be turned on, controlling the second switch device to be turned off, and controlling all third switch devices in the one or more clamping sub-circuits to be turned off; When the gate-commutated thyristor enters a turn-off phase, the first switch device is controlled to be turned off, the second switch device is controlled to be turned on, and all third switch devices in the one or more clamping sub-circuits are controlled to be turned off; When the gate-commutated thyristor enters the blocking stage, the first switching device is controlled to be turned off, the second switching device is controlled to be turned off, and a third switching device in the one or more clamping sub-circuits is controlled to be turned on.

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