A driving protection circuit and control method for a power semiconductor device

Abstract

The present invention provides a driving protection circuit and a control method for a power semiconductor device, which includes a turn-on and turn-off module, a static protection unit, and a dynamic protection unit. The turn-on and turn-off module, the static protection unit, and the dynamic protection unit are connected in parallel with each other, and are all connected to the power semiconductor device, and are all arranged between the gate and the cathode of the power semiconductor. The dynamic protection unit is also connected to the anode of the power semiconductor device. The driving protection circuit of the present invention realizes that the gate potential of the power semiconductor device is lower than the cathode during the period when the driving of the power semiconductor device is completely powered off, during the power-on process, and during the power-off process, or realizes that the potential difference between the gate and the cathode is less than the gate-cathode conduction voltage of the power semiconductor, so as to ensure reliable turn-off of the power semiconductor device, thereby protecting the power semiconductor device.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic circuits, and particularly relates to a driving protection circuit and a control method for a power semiconductor device. Background Art

[0002] In the existing gate drive circuits (hereinafter referred to as "drives") of thyristor-type power semiconductor devices (thyristors, integrated gate-commutated thyristors IGCTs, etc., hereinafter referred to as "devices"), in the normal power supply state, when turning off, a gate potential lower than the cathode potential can be provided for the device to ensure reliable turn-off of the device. However, during the period when the drive is completely powered off, or during the power-on process and the power-off process, the drive cannot provide a reliable gate potential lower than the cathode potential for the device, so that the ability of the device to withstand voltage and the rate of voltage change will not reach the rated value. Therefore, devices without a drive protection circuit require external high-voltage isolated power supply for the drive, so that the drive completes power-on earlier than the main circuit, which severely limits the application scenarios.

[0003] In the drive circuit, during normal power-on, the turn-on and turn-off module can ensure that the potential difference between the gate and the cathode of the power semiconductor device is less than the conduction voltage between the gate and the cathode of the power semiconductor, and the power semiconductor device will not be mis-triggered when a large instantaneous voltage appears at the anode of the power semiconductor device. During the power-off period, or during the power-on process and the power-off process, the turn-on and turn-off module is disconnected from the gate and the cathode of the power semiconductor device, and cannot provide a reliable gate potential lower than the cathode potential for the device, so that the ability of the device to withstand voltage and the rate of voltage change will not reach the rated value. When a large instantaneous voltage appears at the anode of the power semiconductor device, the power semiconductor device is extremely likely to be mis-triggered.

[0004] Patent CN108718193A provides a feasible driving protection circuit for a power semiconductor device, but the implementation method of its so-called "start-stop module" is too simple. Although it has certain benefits for the rate of voltage change that the device withstands during the power-on process and the power-off process, there are also the following deficiencies: (1) The start-stop module only includes a single switching element, and it is necessary to provide a trigger signal for the control module to conduct or maintain conduction before the voltage reaches the threshold, and at the same time, it is necessary to turn off after the voltage reaches the threshold. It is difficult to select components, and it is difficult to balance the action speed and the default state; (2) The start-stop module can only provide protection for the device during the power-on and / or power-off process, and does not provide corresponding protection capabilities during the period when the drive is completely powered off; (3) The combination of the start-stop module and the anode structure of the device itself may cause the device to lose the reverse blocking ability, resulting in reverse current flow under certain application conditions, increasing the risk of device failure. Summary of the Invention

[0005] In view of the above problems, the present invention proposes a driving protection circuit and a control method for a power semiconductor device.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A drive protection circuit for a power semiconductor device, comprising a turn-on and turn-off module, a static protection unit, and a dynamic protection unit;

[0008] The turn-on and turn-off module, the static protection unit, and the dynamic protection unit are connected in parallel with each other, are all connected to a power semiconductor device, and are all arranged between the gate and the cathode of the power semiconductor;

[0009] The dynamic protection unit is also connected to the anode of the power semiconductor device.

[0010] Preferably, the static protection unit is a parallel circuit of multiple switching elements, or a series-parallel circuit of multiple switching elements, or a series-parallel circuit of multiple switching elements and a unidirectional current-carrying element, and the dynamic protection unit is a series circuit of a switching element and a voltage mutual inductor device, or a series-parallel circuit of a switching element, a voltage mutual inductor device, an energy storage capacitor, and a unidirectional current-carrying element.

[0011] Preferably, the parallel circuit of multiple switching elements includes a first branch and a second branch arranged in parallel. The first branch is provided with a first switching element S1, the second branch is provided with a second switching element S2, and both the first branch and the second branch are respectively electrically connected to the gate and the cathode of the power semiconductor device.

[0012] Preferably, the series-parallel circuit of multiple switching circuits includes a first branch and a second branch connected in parallel. The first branch is provided with a first switching element S1, and both ends of the first branch are respectively connected to the gate and the cathode of the power semiconductor device. The second branch includes a second switching element S2 and a third switching element S3 connected in series, and both ends of the second branch are respectively electrically connected to the gate and the cathode of the power semiconductor device.

[0013] Preferably, the series-parallel circuit of multiple switching elements and a unidirectional current-carrying element includes a first branch and a second branch connected in parallel. The first branch includes a first switching element S1 and a unidirectional current-carrying element D1 connected in series. The second branch includes a second switching element S2 and a third switching element S3 connected in series. One end of both the first branch and the second branch is connected to the gate of the power semiconductor device, and the other end is connected to the cathode of the power semiconductor device.

[0014] Preferably, the series circuit of a switching element and a voltage mutual inductor device includes a fourth switching element S4 and a voltage mutual inductor device VT. The voltage mutual inductor device VT includes a secondary side and a primary side. One end of the fourth switching element S4 is connected in series with the secondary side, and the other end is connected to the gate of the power semiconductor device. One end of the secondary side is connected to the cathode of the power semiconductor device, and both ends of the primary side are respectively connected to the anode and the cathode of the power semiconductor device.

[0015] Preferably, the switching element is connected in series and parallel with a voltage mutual inductance device, an energy storage capacitor, and a unidirectional current - flowing element series - parallel circuit, including a fourth switching element S4, a voltage mutual inductance device VT, a third unidirectional current - flowing element D3, an over - voltage protection element T2, an energy storage capacitor C1, and a first series branch. The voltage mutual inductance device VT includes a secondary side and a primary side. The two ends of the primary side are respectively connected to the anode and the cathode of the power semiconductor device. The first series branch includes a series - connected secondary side and a second unidirectional current - flowing element D2. One end of the fourth switching element S4 is connected in series with a parallel combination of the first series branch, the over - voltage protection element T2, the third unidirectional current - flowing element D3, and the energy storage capacitor C1, and the other end of the fourth switching element S4 is connected to the gate of the power semiconductor device. One end of the first series branch is connected to the cathode of the power semiconductor device.

[0016] Preferably, the power semiconductor device includes a thyristor, a gate - turn - off thyristor, an integrated gate - commutated thyristor, an emitter - turn - off thyristor, and an insulated - gate bipolar transistor.

[0017] Preferably, the drive protection circuit includes one or a combination of a static protection unit and a dynamic protection unit.

[0018] A control method for a drive protection circuit of a power semiconductor device. When there is a complete power failure, the static protection unit and the dynamic protection unit operate, and the turn - on and turn - off module does not operate.

[0019] During the power - on process, first, the static protection unit and the dynamic protection unit operate. When the power - on is completed, the switch and turn - off module is put into operation, and the static protection unit and the dynamic protection unit stop operating.

[0020] Or when the power - on is completed, the dynamic protection unit stops operating first, then the turn - on and turn - off module is put into operation, and at the same time the static protection unit stops operating.

[0021] Or when the power - on is completed, the dynamic protection unit stops operating first, then the turn - on and turn - off module is put into operation, and finally the static protection unit stops operating.

[0022] Before power - off, the turn - on and turn - off module ensures that the potential difference between the gate and the cathode of the power semiconductor device is less than the turn - on voltage between the gate and the cathode of the power semiconductor device.

[0023] During the power - off process, the static protection unit and the dynamic protection unit operate, and at the same time the turn - on and turn - off module stops operating.

[0024] Or during the power - off process, the static protection unit is put into operation first, at the same time the turn - on and turn - off module stops operating, and finally the dynamic protection unit is put into operation.

[0025] Or during power-down, the static protection unit is first put into operation, then the turn-on and turn-off module stops operating, and finally the dynamic protection unit is put into operation.

[0026] Preferably, during complete power loss, power-on, and power-down, the static protection unit is used to ensure that the potential difference between the gate and the cathode of the power semiconductor device is less than the conduction voltage between the gate and the cathode of the power semiconductor, and the dynamic protection unit is used to ensure that when a large instantaneous voltage appears at the anode of the power semiconductor device, the gate potential of the power semiconductor device is lower than the cathode potential.

[0027] Advantages of the present invention:

[0028] 1. The drive protection circuit of the present invention makes the gate potential of the power semiconductor device lower than the cathode during complete power loss, power-on, and power-down of the power semiconductor device drive, or makes the potential difference between the gate and the cathode less than the conduction voltage between the gate and the cathode of the power semiconductor, thereby ensuring reliable turn-off of the power semiconductor device and protecting the power semiconductor device.

[0029] 2. The static protection unit components of the present invention have the advantages of convenient component selection, simple control, and rapid cooperation of each part of the circuit, which can ensure that the gate and cathode of the power semiconductor device are never in a floating state under any circumstances, greatly improving the reliability of device turn-off, reducing the failure risk, and significantly reducing the leakage current of the static protection unit when it is not working, which is beneficial to the normal turn-on operation of the power semiconductor device. Moreover, it can prevent the combination of the static protection unit and the anode structure of the device itself from causing the device to lose the reverse blocking ability during complete power loss of the drive, and avoid reverse current flow under certain special working conditions.

[0030] 3. The dynamic protection unit of the present invention has the advantages of convenient component selection, simple control, and strong dv / dt resistance. It can generate a negative gate-cathode voltage specifically at the moment when a large dv / dt appears at the anode, reducing the failure risk, reducing the requirement for the total impedance of the entire circuit, having a better protection effect, having a memory effect, and at the same time being able to prevent the combination of the static protection unit and the anode structure of the device itself from causing the device to lose the reverse blocking ability during complete power loss of the drive, avoiding reverse current flow under certain special working conditions, and reducing the device failure risk.

[0031] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, claims, and drawings. Brief Description of the Drawings

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 The structural schematic diagram of a driving protection circuit of a power semiconductor device of the present invention is shown;

[0034] Figure 2 The parallel circuit of multiple switching elements of the static protection unit is shown;

[0035] Figure 3 The series-parallel circuit of multiple switching elements of the static protection unit is shown;

[0036] Figure 4 The series-parallel circuit of multiple switching elements of the static protection unit and a unidirectional current-carrying element is shown;

[0037] Figure 5 The series circuit of the switching element of the dynamic protection unit and a voltage mutual inductance device is shown;

[0038] Figure 6 The series-parallel circuit of the switching element of the dynamic protection unit, a voltage mutual inductance device, an energy storage capacitor, and a unidirectional current-carrying element is shown. Detailed implementation manners

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0040] A driving protection circuit of a power semiconductor device, as Figure 1 shown, includes a turn-on and turn-off module, a static protection unit, and a dynamic protection unit;

[0041] The turn-on and turn-off module, the static protection unit, and the dynamic protection unit are connected in parallel with each other, are all connected to a power semiconductor device, and are all arranged between the gate and the cathode of the power semiconductor;

[0042] The dynamic protection unit is also connected to the anode of the power semiconductor device.

[0043] It should be noted that the drive protection circuit can be divided into a static protection unit and a dynamic protection unit, and both the static protection unit and the dynamic protection unit are connected between two or three of the gate, cathode, and anode of the power semiconductor device.

[0044] Furthermore, the static protection unit is a parallel circuit of multiple switching elements, a series-parallel circuit of multiple switching elements, or a series-parallel circuit of multiple switching elements and unidirectional current-carrying elements, and the dynamic protection unit is a series circuit of a switching element and a voltage mutual inductor device, or a series-parallel circuit of a switching element, a voltage mutual inductor device, an energy storage capacitor, and a unidirectional current-carrying element.

[0045] Furthermore, as Figure 2 shown, the parallel circuit of multiple switching elements includes a first branch and a second branch arranged in parallel. The first branch is provided with a first switching element S1, the second branch is provided with a second switching element S2, and both the first branch and the second branch are electrically connected to the gate and cathode of the power semiconductor device respectively.

[0046] It should be noted that the static protection unit is composed of the switching element S1 and the switching element S2 connected in parallel. Among them, the on-resistance of S1 is extremely low, and it can ensure reliable closing during the power loss of the drive, and there is no special requirement for its switching time; the on-resistance of S2 is relatively low, and it can respond quickly when a switching drive signal is applied, and there is no special requirement for its normally open or normally closed characteristic. One selection scheme for S1 is a normally closed mechanical relay, one selection scheme for S2 is a solid-state relay, and another selection scheme for S2 is an enhanced MOSFET.

[0047] Control method of the parallel circuit of multiple switching elements: During the complete power loss of the drive and during the power-on and power-off processes, S1 remains closed; during the power-on process, S2 changes from open to closed, and during the power-off process, S2 changes from closed to open; when the power-on is completed, S1 disconnects first, at this time S2 still remains closed, and after S1 is completely disconnected, S2 disconnects again, and at the same time other circuits (turn-on and turn-off modules) of the drive are put into operation, and the two achieve delay-free switching; when power-off is required, other circuits of the drive are cut off from operation, and at the same time S2 closes quickly, and the two achieve delay-free switching, and then S1 closes again to maintain the entire power-off process until the drive is completely powered off. This circuit has the advantages of convenient component selection, simple control, and rapid cooperation of each part of the circuit, and can ensure that the gate-cathode of the power semiconductor device is not in a floating state under any circumstances, greatly improving the reliability of device turn-off and reducing the failure risk.

[0048] Furthermore, as Figure 3As shown, the multiple-switch circuit series-parallel circuit includes a first branch and a second branch connected in parallel. The first branch is provided with a first switching element S1, and both ends of the first branch are respectively connected to the gate and the cathode of the power semiconductor device. The second branch includes a second switching element S2 and a third switching element S3 connected in series, and both ends of the second branch are respectively electrically connected to the gate and the cathode of the power semiconductor device.

[0049] It should be noted that Figure 3 Based on Figure 2 this, a switching element S3 is connected in series to the S2 branch. The on-resistance of S3 is extremely low, and the leakage current is extremely small when it is off. There are no special requirements for its switching time and normally open / normally closed characteristics. One option for S3 is a normally open mechanical relay.

[0050] Control method for the multiple-switch circuit series-parallel circuit: During the power-on and power-off processes, when the series branch needs to be closed, S3 closes before S2; when the series branch needs to be opened, S3 and S2 open simultaneously; to ensure that the on-off characteristics of the entire series branch are determined by S2 with extremely fast response speed. The remaining control logic is the same as that of Figure 2 the solution.

[0051] This circuit has all the advantages of the above solution, and significantly reduces the leakage current of the static protection unit when it is not working, which is beneficial to the normal turn-on operation of the power semiconductor device and reduces the loss at the same time.

[0052] Furthermore, as Figure 4 shown, the multiple-switch element and unidirectional current element series-parallel circuit includes a first branch and a second branch connected in parallel. The first branch includes a first switching element S1 and a unidirectional current element D1 connected in series, and the second branch includes a second switching element S2 and a third switching element S3 connected in series. One end of the first branch and the second branch are both connected to the gate of the power semiconductor device, and the other end is both connected to the cathode of the power semiconductor device.

[0053] It should be noted that Figure 4 Based on Figure 3 this, a unidirectional current element D1 is connected in series to the S1 branch to form a second series branch. The on-voltage of D1 is as low as possible, and the surge current capacity is strong. There are no special requirements for other characteristics. One option for D1 is a Schottky diode.

[0054] The control method is as follows: During the period when the drive is completely powered off and during the power-on and power-off processes, S1 remains closed; during the power-on process, S3 changes from open to closed before S2, and during the power-off process, S2 and S3 change from closed to open simultaneously; when the power-on is completed, S2 and S3 are disconnected, and at the same time, other circuits (turn-on and turn-off modules) of the drive are put into operation, and then S1 is disconnected to achieve delay-free switching; when power-off is required, drive S1 to close first, wait for stability, then cut off the operation of other circuits (turn-on and turn-off modules), and at the same time, S2 closes quickly, and the two achieve delay-free switching to maintain the entire power-off process until the drive is completely powered off.

[0055] This circuit has all the advantages of the above scheme, and can prevent the combination of the static protection unit and the anode structure of the device itself during the period when the drive is completely powered off, resulting in the device losing its reverse blocking ability, avoiding reverse current flow under certain special working conditions, and reducing the risk of device failure.

[0056] Furthermore, as Figure 5 shown, the series circuit of the switching element and the voltage mutual inductance device includes a fourth switching element S4 and a voltage mutual inductance device VT. The voltage mutual inductance device VT includes a secondary side and a primary side. One end of the fourth switching element S4 is connected in series with the secondary side, and the other end is connected to the gate of the power semiconductor device. One end of the secondary side is connected to the cathode of the power semiconductor device, and the two ends of the primary side are respectively connected to the anode and the cathode of the power semiconductor device.

[0057] It should be noted that the dynamic protection unit is composed of the switching element S4 and the voltage mutual inductance device VT in series. Among them, the on-resistance of S4 is extremely low, and it can ensure reliable closing during the period when the drive is powered off, and there are no special requirements for its switching time; VT can induce a certain voltage on the low-voltage side when there is a large dv / dt on the high-voltage side, and the high-voltage side has a DC blocking characteristic.

[0058] One selection scheme for S1 is a normally closed mechanical relay, one selection scheme for VT is a capacitive coupling type voltage mutual inductance device, and another selection scheme for VT is a transformer with capacitive isolation.

[0059] The control method of the series circuit of the switching element and the voltage mutual inductance device: During the period when the drive is completely powered off and during the power-on and power-off processes, S4 remains closed; when a positive dv / dt appears at the anode of the device, VT generates a negative voltage and applies it between the gate and the cathode of the device, so as to draw the displacement current caused by the anode dv / dt from the gate. After the drive power-on is completed, S4 is disconnected, and VT no longer functions.

[0060] This circuit has the advantages of convenient component selection, simple control, and strong ability to resist dv / dt. It can generate a negative gate-cathode voltage specifically at the moment when a large dv / dt appears at the anode, reduce the risk of failure, reduce the requirement for the total impedance of the entire circuit, and have a better protection effect.

[0061] Furthermore, as Figure 6 shown, the switching element is connected in series and parallel with the voltage mutual inductor device, the energy storage capacitor, and the unidirectional current - flowing element circuit, including the fourth switching element S4, the voltage mutual inductor device VT, the third unidirectional current - flowing element D3, the over - voltage protection element T2, the energy storage capacitor C1, and the first series branch. The voltage mutual inductor device VT includes a secondary side and a primary side. The two ends of the primary side are respectively connected to the anode and the cathode of the power semiconductor device. The first series branch includes the secondary side and the second unidirectional current - flowing element D2 connected in series. One end of the fourth switching element S4 is connected in series with the first series branch, the over - voltage protection element T2, the third unidirectional current - flowing element D3, and the energy storage capacitor C1 connected in parallel with each other, and the other end of the fourth switching element S4 is connected to the gate of the power semiconductor device. One end of the first series branch is connected to the cathode of the power semiconductor device.

[0062] It should be noted that, based on the Figure 5 scheme, Figure 6 in the scheme, a unidirectional current - flowing element D2 is connected in series in the VT branch to form the first series branch, and then the series branch is connected in parallel with the unidirectional current - flowing element D3, the over - voltage protection element T2, and the energy storage capacitor C1. Among them, the conduction voltages of D2 and D3 are as low as possible, the surge current capacity is strong, and there are no special requirements for other characteristics; the protection threshold of T2 is less than or equal to the reverse breakdown voltage between the gate and the cathode of the power semiconductor element; there are no special requirements for C1.

[0063] It should be noted that one selection scheme for D2 and D3 is a Schottky diode, one selection scheme for T2 is a TVS tube, and one selection scheme for C1 is an MLCC.

[0064] It should be noted that the control method of the switching element and the series - parallel circuit of the voltage mutual inductor device, the energy storage capacitor, and the unidirectional current - flowing element: based on the above - mentioned scheme, the reverse current generated by VT can be injected into C1 through D2 and stored, and the voltage of C1 does not exceed the protection threshold of T2, which has a memory effect on resisting dv / dt and increases the time when the gate potential of the power semiconductor device is lower than the cathode potential.

[0065] This circuit has the advantages of strong dv / dt resistance ability and low risk of device gate - cathode breakdown. It can generate a negative gate - cathode voltage specifically at the moment when a large dv / dt appears at the anode, reduce the failure risk, and has a memory effect. At the same time, D2 and D3 can prevent the combination of the static protection unit and the anode structure of the device itself from causing the device to lose the reverse blocking ability during the complete power loss of the drive, avoid reverse current - flowing under certain special working conditions, and reduce the device failure risk.

[0066] Furthermore, the power semiconductor device includes but is not limited to thyristors, gate - turn - off thyristors, integrated gate - commutated thyristors, emitter - turn - off thyristors, and insulated - gate bipolar transistors.

[0067] Further, the drive protection circuit includes one or a combination of a static protection unit and a dynamic protection unit.

[0068] It should be noted that the drive protection circuit can be implemented by any one of the above-mentioned static protection unit and dynamic protection unit alone, or by the combination of the two. It should be noted that the above-mentioned solutions are all embodiments. Any circuit that can achieve a gate potential of the power semiconductor device lower than the cathode during the complete power loss of the drive of the power semiconductor device, during the power-on process, and during the power-off process, or achieve a potential difference between the gate and the cathode less than the gate-cathode conduction voltage of the power semiconductor is within the protection scope.

[0069] It should be noted that the implementation scheme of the static protection unit can be composed of multiple switching elements and unidirectional current-carrying elements connected in series, parallel, or in a hybrid connection. The switching elements include, but are not limited to, mechanical and semiconductor normally open and normally closed switching elements.

[0070] The implementation scheme of the dynamic protection unit can be composed of multiple switching elements, unidirectional current-carrying elements, voltage mutual inductance devices, energy storage capacitors, etc. connected in series, parallel, or in a hybrid connection. The switching elements include, but are not limited to, mechanical and semiconductor normally open and normally closed switching elements. The voltage mutual inductance devices include, but are not limited to, transformers, capacitive coupling type voltage mutual inductance devices, magnetic coupling type voltage mutual inductance devices, optoelectronic coupling type voltage mutual inductance devices, etc.

[0071] A control method for a drive protection circuit of a power semiconductor device. When the power is completely lost, the static protection unit and the dynamic protection unit operate, and the turn-on and turn-off module does not operate;

[0072] During the power-on process, first the static protection unit and the dynamic protection unit operate. When the power-on is completed, the switch and turn-off module is put into operation, and the static protection unit and the dynamic protection unit stop operating;

[0073] Or when the power-on is completed, the dynamic protection unit stops operating first, and then the turn-on and turn-off module is put into operation, and at the same time the static protection unit stops operating;

[0074] Or when the power-on is completed, the dynamic protection unit stops operating first, and then the turn-on and turn-off module is put into operation, and then the static protection unit stops operating;

[0075] Before power-off, the turn-on and turn-off module ensures that the potential difference between the gate and the cathode of the power semiconductor device is less than the conduction voltage between the gate and the cathode of the power semiconductor device;

[0076] During the power-off process, the static protection unit and the dynamic protection unit operate, and at the same time the turn-on and turn-off module stops operating;

[0077] Or during the power-off process, the static protection unit is first put into operation, and at the same time the turn-on and turn-off module stops operating, and then the dynamic protection unit is put into operation;

[0078] Or during the power-down process, the static protection unit first starts to operate, then the turn-on and turn-off module stops operating, and then the dynamic protection unit starts to operate.

[0079] Furthermore, during complete power failure, the power-on process, and the power-down process, the static protection unit is used to ensure that the potential difference between the gate and the cathode of the power semiconductor device is less than the turn-on voltage between the gate and the cathode of the power semiconductor, and the dynamic protection unit is used to ensure that when a large instantaneous voltage appears at the anode of the power semiconductor device, the gate potential of the power semiconductor device is lower than the cathode potential.

[0080] It should be noted that during complete power failure, the static protection unit forms a path between the gate and the cathode of the power semiconductor device, ensuring that at any moment when a forward current is generated between the gate and the cathode, a current path is provided for this current, and the potential difference between the gate and the cathode is less than the turn-on voltage between the gate and the cathode of the power semiconductor; when a large instantaneous voltage appears at the anode of the device, the dynamic protection unit absorbs the energy of the instantaneous voltage, generates a short-time forward voltage between the cathode and the gate of the power semiconductor element, and ensures that the gate potential of the power semiconductor device is lower than the cathode potential; the turn-on and turn-off module does not operate.

[0081] During the power-on process, first, the static protection unit ensures that the potential difference between the gate and the cathode is less than the turn-on voltage between the gate and the cathode of the power semiconductor, and the dynamic protection unit ensures that when a large instantaneous voltage appears at the anode of the device, the gate potential of the power semiconductor device is lower than the cathode potential; when the power-on is completed, the turn-on and turn-off module starts to operate, and the turn-on and turn-off module ensures that the potential difference between the gate and the cathode is less than the turn-on voltage between the gate and the cathode of the power semiconductor, and at the same time, the static protection unit and the dynamic protection unit stop operating; or when the power-on is completed, the dynamic protection unit first stops operating, then the turn-on and turn-off module starts to operate, and at the same time, the static protection unit stops operating; or when the power-on is completed, the dynamic protection unit first stops operating, then the turn-on and turn-off module starts to operate, and then the static protection unit stops operating.

[0082] Before power-down, first, the turn-on and turn-off module ensures that the potential difference between the gate and the cathode is less than the turn-on voltage between the gate and the cathode of the power semiconductor; during the power-down process, the static protection unit ensures that the potential difference between the gate and the cathode is less than the turn-on voltage between the gate and the cathode of the power semiconductor, and the dynamic protection unit ensures that when a large instantaneous voltage appears at the anode of the device, the gate potential of the power semiconductor device is lower than the cathode potential, and at the same time, the turn-on and turn-off module stops operating; or during the power-down process, the static protection unit first starts to operate, and at the same time, the turn-on and turn-off module stops operating, and then the dynamic protection unit starts to operate; or during the power-down process, the static protection unit first starts to operate, then the turn-on and turn-off module stops operating, and then the dynamic protection unit starts to operate.

[0083] If the drive protection circuit of the power semiconductor device only includes a static protection unit, or only includes a static protection unit, then the corresponding dynamic protection unit, or the relevant description of the static protection unit can be removed in the above control method.

[0084] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A driving and protecting circuit for a power semiconductor device, characterized in that, It includes a turn-on and turn-off module, a static protection unit, and a dynamic protection unit; The turn-on and turn-off module, the static protection unit, and the dynamic protection unit are connected in parallel with each other, and are all connected to a power semiconductor device, and are all arranged between the gate and the cathode of the power semiconductor; The dynamic protection unit is also connected to the anode of the power semiconductor device; The static protection unit is a parallel circuit of multiple switching elements, or a series-parallel circuit of multiple switching elements, or a series-parallel circuit of multiple switching elements and a unidirectional current-carrying element. The dynamic protection unit is a series circuit of a switching element and a voltage mutual inductance device, or a series-parallel circuit of a switching element, a voltage mutual inductance device, an energy storage capacitor, and a unidirectional current-carrying element; The series-parallel circuit of multiple switching elements and a unidirectional current-carrying element includes a first branch and a second branch connected in parallel. The first branch includes a first switching element S1 and a unidirectional current-carrying element D1 connected in series. The second branch includes a second switching element S2 and a third switching element S3 connected in series. One end of the first branch and the second branch are both connected to the gate of the power semiconductor device, and the other end is both connected to the cathode of the power semiconductor device; The series-parallel circuit of a switching element, a voltage mutual inductance device, an energy storage capacitor, and a unidirectional current-carrying element includes a fourth switching element S4, a voltage mutual inductance device VT, a third unidirectional current-carrying element D3, an overvoltage protection element T2, an energy storage capacitor C1, and a first series branch. The voltage mutual inductance device VT includes a secondary side and a primary side. The two ends of the primary side are respectively connected to the anode and the cathode of the power semiconductor device. The first series branch includes a secondary side and a second unidirectional current-carrying element D2 connected in series. One end of the fourth switching element S4 is connected in series with the first series branch, the overvoltage protection element T2, the third unidirectional current-carrying element D3, and the energy storage capacitor C1 connected in parallel, and the other end of the fourth switching element S4 is connected to the gate of the power semiconductor device. One end of the first series branch is connected to the cathode of the power semiconductor device.

2. The drive protection circuit of a power semiconductor device according to claim 1, characterized in that, The parallel circuit of multiple switching elements includes a first branch and a second branch arranged in parallel. The first branch is provided with a first switching element S1, and the second branch is provided with a second switching element S2. The first branch and the second branch are respectively electrically connected to the gate and the cathode of the power semiconductor device.

3. The driving and protecting circuit of a power semiconductor device according to claim 1, characterized in that The series-parallel circuit of multiple switching elements includes a first branch and a second branch connected in parallel. The first branch is provided with a first switching element S1, and the two ends of the first branch are respectively connected to the gate and the cathode of the power semiconductor device. The second branch includes a second switching element S2 and a third switching element S3 connected in series, and the two ends of the second branch are respectively electrically connected to the gate and the cathode of the power semiconductor device.

4. The driving and protecting circuit of a power semiconductor device according to any one of claims 1-3, characterized in that The series circuit of a switching element and a voltage mutual inductance device includes a fourth switching element S4 and a voltage mutual inductance device VT. The voltage mutual inductance device VT includes a secondary side and a primary side. One end of the fourth switching element S4 is connected in series with the secondary side, and the other end is connected to the gate of the power semiconductor device. One end of the secondary side is connected to the cathode of the power semiconductor device, and the two ends of the primary side are respectively connected to the anode and the cathode of the power semiconductor device.

5. The drive protection circuit of a power semiconductor device according to claim 1, characterized in that The power semiconductor device includes thyristor, gate turn-off thyristor, integrated gate-commutated thyristor, emitter turn-off thyristor, and insulated gate bipolar transistor.

6. A control method for a driving and protecting circuit of a power semiconductor device, for the driving and protecting circuit of the power semiconductor device according to any one of claims 1-5, characterized in that, When there is a complete power outage, the static protection unit and the dynamic protection unit operate, and the turn-on and turn-off module does not operate. During the power-on process, first the static protection unit and the dynamic protection unit operate. When the power-on is completed, the switch and turn-off module is put into operation, and the static protection unit and the dynamic protection unit stop operating. Or when the power-on is completed, the dynamic protection unit stops operating first, then the turn-on and turn-off module is put into operation, and at the same time the static protection unit stops operating. Or when the power-on is completed, the dynamic protection unit stops operating first, then the turn-on and turn-off module is put into operation, and finally the static protection unit stops operating. Before power-off, the turn-on and turn-off module ensures that the potential difference between the gate and the cathode of the power semiconductor device is less than the conduction voltage between the gate and the cathode of the power semiconductor device. During the power-off process, the static protection unit and the dynamic protection unit operate, and at the same time the turn-on and turn-off module stops operating. Or during the power-off process, the static protection unit is put into operation first, and at the same time the turn-on and turn-off module stops operating, and finally the dynamic protection unit is put into operation. Or during the power-off process, the static protection unit is put into operation first, then the turn-on and turn-off module stops operating, and finally the dynamic protection unit is put into operation.

7. The control method of a driving protection circuit for a power semiconductor device according to claim 6, characterized in that, During complete power outage, power-on process, and power-off process, the static protection unit is used to ensure that the potential difference between the gate and the cathode of the power semiconductor device is less than the conduction voltage between the gate and the cathode of the power semiconductor, and the dynamic protection unit is used to ensure that when a large instantaneous voltage appears at the anode of the power semiconductor device, the gate potential of the power semiconductor device is lower than the cathode potential.

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