IGCT gate driving device and method and electrical equipment

Abstract

The present invention discloses an IGCT gate drive device, electrical equipment, and IGCT gate drive method. The device includes: a detection unit that detects the IGCT gate current and generates an IGCT turn-on signal when the detected IGCT gate current reaches the IGCT's set turn-on current; a control unit that controls the IGCT to turn on based on the IGCT turn-on signal; the detection unit that generates an IGCT turn-on maintenance signal when the detected IGCT gate current continues to be less than the IGCT's set turn-on maintenance current; and the control unit that adjusts the IGCT gate current based on the IGCT turn-on maintenance signal to maintain the IGCT on. This solution can solve the problem of erroneous shutdown caused by the gate current being less than the maintenance current after the IGCT is turned on, thereby preventing the IGCT from erroneously shutting down due to the gate current being less than the maintenance current after the IGCT is turned on.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic circuits, and specifically relates to an IGCT gate drive device, an electrical device and an IGCT gate drive method thereof, and more particularly to an integrated gate-commutated thyristor gate drive circuit, an electrical device and an IGCT gate drive method thereof. Background Art

[0002] During the use of an integrated gate-commutated thyristor (IGCT), an external circuit injects a current pulse of a certain amplitude and rise rate into the gate as the driving current, triggering the thyristor to fully turn on. After the IGCT is fully turned on, due to the positive feedback generated by its internal structure, only a small holding current is required to maintain the IGCT on. However, if the gate current is less than the holding current, the IGCT will automatically shut down, which is undesirable in engineering.

[0003] The above content is only used to assist in understanding the technical solution of the present invention and does not constitute an admission that the above content is prior art. Summary of the Invention

[0004] The object of the present invention is to provide an IGCT gate drive device, an electrical device and an IGCT gate drive method thereof to address the above-mentioned defects, so as to solve the problem of false shutdown caused by the gate current being less than the holding current after the IGCT is turned on, thereby avoiding the false shutdown caused by the gate current being less than the holding current after the IGCT is turned on.

[0005] The present invention provides a gate drive device for an IGCT, comprising: a detection unit and a control unit; wherein the detection unit is used to detect the gate current of the IGCT when the IGCT is turned off and needs to be turned on; and to generate an IGCT turn-on signal when the detected IGCT gate current reaches a set turn-on current of the IGCT; the control unit is used to control the IGCT to turn on according to the IGCT turn-on signal; the detection unit is also used to continue to detect the gate current of the IGCT when the IGCT is turned on; and to generate an IGCT turn-on maintenance signal when the continuously detected IGCT gate current is less than the set turn-on maintenance current of the IGCT; the control unit is also used to adjust the IGCT gate current according to the IGCT turn-on maintenance signal to maintain the IGCT continued on.

[0006] Optionally, the detection unit includes: a sampling resistor; the sampling resistor is arranged between the power supply of the IGCT and the gate of the IGCT, and is used to detect the current flowing through itself and use the current flowing through itself as the gate current of the IGCT.

[0007] Optionally, the control unit includes: a controller, a switch module and a current maintaining module; the switch module is arranged between the gate of the IGCT and the first connection terminal of the power supply of the IGCT; the controller is used to control the switch module according to the opening signal of the IGCT, so as to control the opening of the IGCT through the switch module; the current maintaining module is arranged between the cathode of the IGCT and the second connection terminal of the power supply of the IGCT; the controller is also used to control the current maintaining module according to the opening maintenance signal of the IGCT, so as to adjust the gate current of the IGCT by adjusting the PWM duty cycle of the input current of the current maintaining module.

[0008] Optionally, the current maintaining module includes: a first switching tube and a second switching tube; the switching module includes: a third switching tube; the first switching tube is arranged between the second connection terminal of the power supply of the IGCT and the gate of the IGCT; the second switching tube is arranged between the gate of the IGCT and the cathode of the IGCT; the third switching tube is arranged between the gate of the IGCT and the first connection terminal of the power supply of the IGCT.

[0009] Optionally, the current maintaining module further includes: an energy storage module, a first discharge module and a second discharge module; the energy storage module is arranged between the first switch tube and the gate of the IGCT, and is used to store energy using the power supply when the first switch tube is turned on; the first discharge module is arranged between the first switch tube and the third switch tube; the second discharge module is arranged between the first switch tube and the second switch tube; the controller controls the IGCT to be turned on through the switch module, including: the controller controls the first switch tube to be turned off, the third switch tube to be turned off, and controls the second switch tube to be closed, so that the energy storage element discharges through the IGCT and the second discharge module to form a conduction path for the IGCT; the controller adjusts the gate current of the IGCT by adjusting the PWM duty cycle of the input current of the current maintaining module, including: the controller controls the first switch tube to be turned on, and controls the second switch tube to be turned off, so that the energy storage element discharges through the IGCT and the first discharge module to supplement the current for the gate of the IGCT.

[0010] Optionally, the switch module further includes: a back electromotive force module; the back electromotive force module is arranged between the third switch tube and the cathode of the IGCT, and is used to provide a back electromotive force when the IGCT is turned off.

[0011] Matching the above-mentioned device, the present invention further provides an electrical device, including: the gate driving device of the IGCT mentioned above.

[0012] Matching the above-mentioned electrical equipment, the present invention provides, on another aspect, a gate driving method for an IGCT of an electrical equipment, comprising: detecting the gate current of the IGCT by a detection unit when the IGCT is turned off and needs to be turned on; and generating an IGCT turn-on signal when the detected gate current of the IGCT reaches the set turn-on current of the IGCT; controlling the IGCT to be turned on according to the IGCT turn-on signal by a control unit; continuing to detect the gate current of the IGCT by the detection unit when the IGCT is still turned on; and generating an IGCT turn-on maintenance signal when the continued detected gate current of the IGCT is less than the set turn-on maintenance current of the IGCT; and adjusting the gate current of the IGCT by the control unit according to the IGCT turn-on maintenance signal to maintain the IGCT continued to be turned on.

[0013] Optionally, detecting the gate current of the IGCT by the detection unit includes: detecting the current flowing through the sampling resistor itself through a sampling resistor set between the power supply of the IGCT and the gate of the IGCT, and using the current flowing through the sampling resistor itself as the gate current of the IGCT.

[0014] Optionally, the controller controls the IGCT to be turned on through the switch module, including: the controller controls the first switch tube to be turned off, the third switch tube to be turned off, and controls the second switch tube to be closed, so that the energy storage element discharges through the IGCT and the second discharge module to form a conduction path of the IGCT; the controller adjusts the gate current of the IGCT by adjusting the PWM duty cycle of the input current of the current maintenance module, including: the controller controls the first switch tube to be turned on, and controls the second switch tube to be turned off, so that the energy storage element discharges through the IGCT and the first discharge module to supplement the current for the gate of the IGCT.

[0015] The solution of the present invention maintains the current flowing through the IGCT gate near the on-state gate holding current, provides the on-state gate holding current for the thyristor to maintain the conduction of the IGCT, prevents false shutdown, and improves the operating reliability of the IGCT.

[0016] Furthermore, the solution of the present invention, by adopting a real-time current detection circuit to control the opening and closing of the switch tube to ensure the maintenance of current stability, can prevent the IGCT from shutting down by itself during use, avoid the IGCT from shutting down by mistake during use, and improve the reliability of the IGCT.

[0017] Furthermore, the solution of the present invention can reduce energy loss by monitoring the working state of the IGCT, controlling the gate current in real time, and applying a minimum gate holding current to the gate.

[0018] Therefore, the solution of the present invention detects the gate input current of the IGCT and maintains the stability of the gate input current by adjusting the size of the gate input current, thereby solving the problem of false shutdown caused by the gate current being less than the holding current after the IGCT is turned on, thereby providing the IGCT with a dynamic gate holding current to maintain the conduction of the IGCT and avoiding false shutdown caused by the gate current being less than the holding current after the IGCT is turned on.

[0019] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of an embodiment of the gate driving device of an IGCT of the present invention;

[0022] Figure 2 It is the structural diagram of IGCT;

[0023] Figure 3 is a structural schematic diagram of an embodiment of an IGCT driving circuit;

[0024] Figure 4 1 is a control flow diagram of an embodiment of an IGCT driving circuit;

[0025] Figure 5 1 is a flow chart of an embodiment of a gate driving method of an IGCT according to the present invention; DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] According to an embodiment of the present invention, a gate driving device for an IGCT is provided. Figure 1 FIG2 is a schematic structural diagram of an embodiment of the device of the present invention. The gate driving device of the IGCT may include: a detection unit and a control unit.

[0028] Specifically, the detection unit can be used to detect the gate current of the IGCT when the IGCT is turned off and needs to be turned on; and generate an IGCT turn-on signal when the detected IGCT gate current reaches the set turn-on current of the IGCT.

[0029] Specifically, the control unit may be configured to control the IGCT to be turned on according to an IGCT turn-on signal.

[0030] Specifically, the detection unit may be further configured to continue detecting the gate current of the IGCT when the IGCT is turned on, and to generate an IGCT on-holding signal when the continuously detected IGCT gate current is less than a set on-holding current of the IGCT. The set on-holding current of the IGCT is the set on-holding current when the IGCT is turned on.

[0031] Optionally, the detection unit may include: a sampling resistor.

[0032] The sampling resistor is set between the power supply of the IGCT and the gate of the IGCT. It can be used to detect the current flowing through itself and use the current flowing through itself as the gate current of the IGCT.

[0033] For example, the three terminals G, A, and K of an IGCT (integrated gate-commutated thyristor) represent the thyristor gate, A the thyristor anode, and K the thyristor cathode. Resistive sampling allows real-time monitoring of the current flowing into the gate. The gate current detection circuit primarily measures the IGCT gate current through the gate drive resistor, compares it with the on-state gate holding current through an operational amplifier, and inputs the output signal into the FPGA.

[0034] Therefore, by using the gate drive resistor of the IGCT as a sampling resistor to sample the gate current of the IGCT, the gate current of the IGCT can be collected without adding additional sampling equipment, which is simple and convenient.

[0035] Specifically, the control unit can also be used to adjust the gate current of the IGCT according to the IGCT opening maintenance signal to keep the IGCT on, that is, to control the gate current of the IGCT to increase to above the set opening maintenance current to keep the IGCT on.

[0036] For example, an integrated gate-commutated thyristor gate drive circuit is proposed, which aims to provide the thyristor with a gate holding current in the on-state to maintain the conduction of the IGCT. By controlling the circuit, the gate current is dynamically changed to achieve stability, and by providing a stable gate current, the stable on-state of the switching device can be guaranteed to prevent the occurrence of false shutdown. Specifically, by adopting a real-time current detection circuit to control the on and off of the switch tube to ensure the stability of the maintenance current, the problem of the IGCT shutting down by itself during use can be prevented, thereby avoiding the false shutdown of the IGCT during use and improving its reliability. In addition, since the IGCT working state is monitored in real time and the gate current is controlled in real time, applying the minimum gate holding current to the gate can reduce energy loss, thereby avoiding the energy loss caused by the continuous excessively high IGCT gate current.

[0037] Therefore, by adjusting the gate current of the IGCT to keep the IGCT on when the detected gate current of the IGCT is less than the set on-hold current of the IGCT when the IGCT is on, the IGCT can be prevented from being shut down incorrectly, thereby improving the reliability of the IGCT operation.

[0038] Optionally, the control unit may include: a controller, a switch module, and a current maintaining module. For example, the controller may be a programmable logic device (FPGA).

[0039] Specifically, the switch module is provided between the gate of the IGCT and the first connection terminal of the power supply of the IGCT. The first connection terminal of the power supply of the IGCT may be the power supply V DC cathode.

[0040] Specifically, the controller may be configured to control the switch module according to an IGCT on-signal, so as to control the IGCT to be on through the switch module.

[0041] Specifically, the current maintaining module is provided between the cathode of the IGCT and the second connection terminal of the power supply of the IGCT. The second connection terminal of the power supply of the IGCT may be the power supply V DC anode.

[0042] Specifically, the controller can also be used to control the current maintenance module according to the IGCT's on-maintenance signal, so as to adjust the gate current of the IGCT by adjusting the PWM duty cycle of the input current of the current maintenance module to maintain the IGCT to continue to be turned on, that is, to control the gate current of the IGCT to increase to above the set on-maintenance current to maintain the IGCT to continue to be turned on.

[0043] For example, by adjusting the PWM duty cycle of the input switch tube to control the on and off of the switch tube, the purpose of regulating the gate current is achieved, and ultimately the current flowing through the IGCT gate is always maintained near the on-state gate holding current, thereby avoiding the IGCT's false shutdown caused by too low anode current.

[0044] Therefore, the switch of the IGCT is controlled by the switch module, and the gate current of the IGCT is maintained by the current maintaining module to ensure that the IGCT is reliably turned on, thereby improving the reliability of the use of the IGCT.

[0045] More optionally, the current maintenance module may include a first switching transistor and a second switching transistor. The switching module may include a third switching transistor. For example, the first switching transistor may be MOS1, the second switching transistor may be MOS2, and the third switching transistor may be MOS3. MOS1-MOS3 are first to third high-speed MOSFETs that can be used to open and close the circuit by receiving control signals.

[0046] The first switching transistor is disposed between the second connection terminal of the IGCT power supply and the gate of the IGCT. The second switching transistor is disposed between the gate of the IGCT and the cathode of the IGCT. For example, the holding current circuit controls the on / off states of MOS1 and MOS2 via an FPGA to maintain the current input to the gate near the steady-state gate holding current.

[0047] The third switching transistor is positioned between the IGCT gate and the first connection terminal of the IGCT power supply. For example, the on / off circuit controls the IGCT's turn-off by controlling the on / off of MOS 3. When MOS 3 is on, the IGCT gate potential is pulled to a negative potential by capacitor C, and the IGCT is turned off.

[0048] Therefore, by utilizing the switch tube to adjust the switching and gate current of the IGCT, the IGCT can be used reliably, with a simple structure and good control reliability.

[0049] Furthermore, the current maintenance module may optionally include an energy storage module, a first discharge module, and a second discharge module. For example, the energy storage module may be an inductor L. L is an inductor that acts as an energy storage element to provide energy to the IGCT. The first discharge module may be a diode D1. The second discharge module may be a diode D2.

[0050] Specifically, the energy storage module is provided between the first switch tube and the gate of the IGCT and can be used to store energy using the power supply when the first switch tube is turned on. DC Charge the inductor L, R L is a sampling resistor. When the current flowing through the resistor R LWhen the current reaches the IGCT turn-on pulse current, MOS1 and MOS3 are disconnected and MOS2 is closed. L , IGCT and diode D1 discharge, at this time IGCT is in full conduction state.

[0051] Specifically, the first discharge module is provided between the first switch tube and the third switch tube. The second discharge module is provided between the first switch tube and the second switch tube.

[0052] The controller controls the IGCT to be turned on through the switch module, which may include: the controller controls the first switch tube to be turned off, the third switch tube to be turned off, and controls the second switch tube to be turned on, so that the energy storage element discharges through the IGCT and the second discharge module to form a conduction path of the IGCT.

[0053] For example: Power supply V DC Charge the inductor L, R L is a sampling resistor. When the current flowing through the resistor R L When the current reaches the IGCT turn-on pulse current, MOS1 and MOS3 are disconnected and MOS2 is closed. L , IGCT and diode D1 discharge, at this time IGCT is in full conduction state.

[0054] In addition, the controller adjusts the gate current of the IGCT by adjusting the PWM duty cycle of the input current of the current maintenance module, which may include: the controller controls the first switch tube to turn on and controls the second switch tube to turn off, so that the energy storage element discharges through the IGCT and the first discharge module to supplement the current for the gate of the IGCT.

[0055] For example: sampling resistor R L All of them are collecting the current flowing through the resistor R L The current data is compared with the IGCT holding current. In order to avoid the IGCT from shutting down by mistake, when the circuit current is detected to be less than the IGCT opening holding current, a high level is given to the MOS1 tube to close and a low level is given to the MOS2 tube to disconnect. At this stage, the power supply V DC Charge the inductor L and set a reference current (greater than the IGCT holding current). When the detection current is greater than the reference current, a shutdown signal is given to the MOS1 tube, and the MOS2 tube is closed with a high level. The inductor L is discharged again through the IGCT and the diode D.

[0056] Therefore, by cooperating with the switch tube through the discharge module and the energy storage module, the switching control of the IGCT and the maintenance of the gate current are realized, so that the IGCT can be reliably opened and used, thereby improving the reliability and convenience of the use of the IGCT.

[0057] Furthermore, optionally, the switch module may further include a back electromotive force module. For example, the back electromotive force module may be a capacitor C. C is a capacitor that provides back electromotive force for hard shutdown of the IGCT.

[0058] Specifically, the back electromotive force module is provided between the third switch tube and the cathode of the IGCT, and can be used to provide a back electromotive force when the IGCT is turned off.

[0059] For example: In the initial stage, the IGCT is turned on. When it needs to be turned off, the control circuit gives the MOS3 tube a high level. The MOS3 tube is closed to pull down the IGCT gate potential. The IGCT gate is subjected to a reverse voltage, that is, the voltage across the capacitor C, so that V2 is cut off due to the reverse bias of the base. The anode current is turned off when the V1 base is open. At this time, the IGCT enters the cut-off state, thereby realizing the hard shutdown of the IGCT.

[0060] Therefore, the IGCT can be reliably shut down by combining the switch tube with the back electromotive force module, which makes the switching control of the IGCT more convenient.

[0061] After a large number of tests and verifications, the technical solution of the present invention is adopted, by making the current flowing through the IGCT gate always maintain near the on-state gate holding current, providing the thyristor with the on-state gate holding current to maintain the conduction of the IGCT, preventing the occurrence of false shutdown, and improving the operating reliability of the IGCT.

[0062] According to an embodiment of the present invention, an electrical device corresponding to the gate driving device of an IGCT is further provided. The electrical device may include: the gate driving device of the IGCT described above.

[0063] As a high-power semiconductor switching device, IGCT is widely used in high-power motor drive devices, DC transmission, AC transmission and other fields due to its low switching loss and short switching time.

[0064] Figure 2 It is the structural diagram of IGCT. Figure 2 As shown, the IGCT can be regarded as consisting of two transistors V1 and V2 composed of PNP and NPN.

[0065] The present invention proposes an integrated gate-commutated thyristor gate drive circuit, which aims to provide the thyristor with a gate holding current to maintain the conduction of the IGCT. By controlling the circuit, the gate current is dynamically changed to achieve stability. By providing a stable gate current, the stable on-state of the switching device can be guaranteed to prevent false shutdown.

[0066] Specifically, the present invention utilizes a real-time current detection circuit to control the on and off state of the switch to maintain current stability. This prevents the IGCT from shutting down automatically during operation, avoiding erroneous IGCT shutdowns and improving its reliability. Furthermore, by monitoring the IGCT's operating status and controlling the gate current in real time, energy loss can be reduced by applying a minimum gate holding current to the gate, thereby avoiding energy loss caused by continuously applying excessively high IGCT gate current.

[0067] Among them, the solution of the present invention proposes an integrated gate-commutated thyristor gate drive circuit, which uses resistor sampling to monitor the current flowing into the gate in real time, and controls the opening and closing of the switch tube by adjusting the PWM duty cycle of the input switch tube to achieve the purpose of regulating the gate current. Ultimately, the current flowing through the IGCT gate is always maintained near the on-state gate holding current, thereby avoiding incorrect shutdown of the IGCT due to too low anode current.

[0068] Figure 3 FIG. 1 is a structural diagram of an embodiment of an IGCT driving circuit.

[0069] Figure 3 In, V DC is a DC power supply. Of the three terminals G, A, and K of the IGCT (integrated gate-commutated thyristor), G is the thyristor gate, A is the thyristor anode, and K is the thyristor cathode. MOS1 to MOS3 are the first to third high-speed MOSFETs, which can be used to turn the circuit on and off by receiving control signals. L is an inductor, which acts as an energy storage element to provide energy for the IGCT. R L is the driving resistor. D1 and D2 are diodes. C is a capacitor that provides back electromotive force for the IGCT hard turn-off.

[0070] The gate drive circuit can be centered around a programmable logic device (FPGA). The on / off circuit is responsible for controlling the IGCT's on / off state by controlling the on / off state of MOS3. When MOS3 is on, the IGCT gate potential is pulled to a negative potential by capacitor C, turning the IGCT off. The gate current detection circuit primarily measures the IGCT gate current through a gate drive resistor, compares it with the on-state gate holding current through an operational amplifier, and inputs the output signal into the FPGA. The holding current circuit controls the on / off states of MOS1 and MOS2 via the FPGA, ensuring that the gate current remains near the steady-state gate holding current.

[0071] Figure 4 FIG. 1 is a schematic diagram of a control flow of an embodiment of an IGCT driving circuit.

[0072] like Figure 4As shown, the control process of the IGCT driving circuit can be referred to the following exemplary description.

[0073] In the initial stage, the IGCT is turned on. When it needs to be turned off, the control circuit gives the MOS3 tube a high level. The MOS3 tube is closed to pull down the IGCT gate potential. The IGCT gate is subjected to a reverse voltage, that is, the voltage across the capacitor C, so that V2 is cut off due to the reverse bias of the base. The anode current is turned off when the V1 base is open. At this time, the IGCT enters the cut-off state, thereby realizing the IGCT hard shutdown.

[0074] At this stage, the power supply V DC Charge the inductor L, R L is a sampling resistor. When the current flowing through the resistor R L When the current reaches the IGCT turn-on pulse current, MOS1 and MOS3 are disconnected and MOS2 is closed. L , IGCT and diode D1 discharge, at this time IGCT is in full conduction state.

[0075] During the whole process, the sampling resistor R L All of them are collecting the current flowing through the resistor R L The current data is compared with the IGCT holding current. In order to avoid the IGCT from shutting down by mistake, when the circuit current is detected to be less than the IGCT opening holding current, a high level is given to the MOS1 tube to close and a low level is given to the MOS2 tube to disconnect. At this stage, the power supply V DC To charge the inductor L, a reference current (greater than the IGCT holding current) is set. When the sensed current exceeds the reference current, a shutdown signal is given to MOS1, and a high-level signal is applied to MOS2, closing the inductor L. The inductor L is discharged again through the IGCT and diode D2. The purpose of setting D1 and D2 is to utilize the reverse cutoff characteristics of the diodes to define the discharge path.

[0076] In summary, by repeating the above process, the current flowing through the IGCT can be always maintained near the on-state gate holding current, thereby avoiding incorrect shutdown of the IGCT.

[0077] Since the processing and functions implemented by the electrical equipment of this embodiment are basically corresponding to the aforementioned Figure 1 The embodiments, principles and examples of the device shown are as follows. Therefore, for details not fully described in the description of this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0078] After a large number of tests and verifications, the technical solution of the present invention is adopted. By adopting a real-time current detection circuit, the opening and closing of the switch tube is controlled to ensure the maintenance of current stability. This can prevent the IGCT from shutting down automatically during use, avoid the IGCT from shutting down incorrectly during use, and improve the reliability of the IGCT.

[0079] According to an embodiment of the present invention, a gate driving method of an IGCT of an electrical device corresponding to the electrical device is also provided. Figure 5 FIG. 1 is a flow chart of an embodiment of the method of the present invention. The gate driving method of the IGCT of the electrical device may include: steps S110 to S140.

[0080] In step S110 , the detection unit detects the gate current of the IGCT when the IGCT is turned off and needs to be turned on; and generates an IGCT turn-on signal when the detected gate current of the IGCT reaches a set turn-on current of the IGCT.

[0081] Optionally, in step S110, detecting the gate current of the IGCT by the detection unit may include: detecting the current flowing through the sampling resistor itself through a sampling resistor provided between the power supply of the IGCT and the gate of the IGCT, and using the current flowing through the sampling resistor itself as the gate current of the IGCT.

[0082] For example, the three terminals G, A, and K of an IGCT (integrated gate-commutated thyristor) represent the thyristor gate, A the thyristor anode, and K the thyristor cathode. Resistive sampling allows real-time monitoring of the current flowing into the gate. The gate current detection circuit primarily measures the IGCT gate current through the gate drive resistor, compares it with the on-state gate holding current through an operational amplifier, and inputs the output signal into the FPGA.

[0083] Therefore, by using the gate drive resistor of the IGCT as a sampling resistor to sample the gate current of the IGCT, the gate current of the IGCT can be collected without adding additional sampling equipment, which is simple and convenient.

[0084] In step S120 , the control unit controls the IGCT to be turned on according to the IGCT turn-on signal.

[0085] At step S130, the detection unit continues to detect the IGCT gate current while the IGCT is on, and generates an IGCT on-holding signal if the detected IGCT gate current is less than the set on-holding current of the IGCT. The set on-holding current of the IGCT is the set on-holding current when the IGCT is on.

[0086] At step S140, the control unit also adjusts the gate current of the IGCT according to the IGCT on-maintaining signal to keep the IGCT on, that is, controls the gate current of the IGCT to increase to above the set on-maintaining current to keep the IGCT on.

[0087] For example, an integrated gate-commutated thyristor gate drive circuit is proposed, which aims to provide the thyristor with a gate holding current in the on-state to maintain the conduction of the IGCT. By controlling the circuit, the gate current is dynamically changed to achieve stability, and by providing a stable gate current, the stable on-state of the switching device can be guaranteed to prevent the occurrence of false shutdown. Specifically, by adopting a real-time current detection circuit to control the on and off of the switch tube to ensure the stability of the maintenance current, the problem of the IGCT shutting down by itself during use can be prevented, thereby avoiding the false shutdown of the IGCT during use and improving its reliability. In addition, since the IGCT working state is monitored in real time and the gate current is controlled in real time, applying the minimum gate holding current to the gate can reduce energy loss, thereby avoiding the energy loss caused by the continuous excessively high IGCT gate current.

[0088] Therefore, by adjusting the gate current of the IGCT to keep the IGCT on when the detected gate current of the IGCT is less than the set on-hold current of the IGCT when the IGCT is on, the IGCT can be prevented from being shut down incorrectly, thereby improving the reliability of the IGCT operation.

[0089] Optionally, in step S120, the controller controls the IGCT to be turned on through the switch module, which may include: the controller controls the first switch tube to be turned off, the third switch tube to be turned off, and controls the second switch tube to be turned on, so that the energy storage element discharges through the IGCT and the second discharge module to form a conduction path of the IGCT.

[0090] For example: For example: Power supply V DC Charge the inductor L, R L is a sampling resistor. When the current flowing through the resistor R L When the current reaches the IGCT turn-on pulse current, MOS1 and MOS3 are disconnected and MOS2 is closed. L , IGCT and diode D1 discharge, at this time IGCT is in full conduction state.

[0091] Optionally, in step S140, the controller adjusts the gate current of the IGCT by adjusting the PWM duty cycle of the input current of the current maintenance module, which may include: the controller controls the first switch tube to turn on and controls the second switch tube to turn off, so that the energy storage element discharges through the IGCT and the first discharge module to supplement the current for the gate of the IGCT.

[0092] For example: sampling resistor R L All of them are collecting the current flowing through the resistor R LThe current data is compared with the IGCT holding current. In order to avoid the IGCT from shutting down by mistake, when the circuit current is detected to be less than the IGCT opening holding current, a high level is given to the MOS1 tube to close and a low level is given to the MOS2 tube to disconnect. At this stage, the power supply V DC Charge the inductor L and set a reference current (greater than the IGCT holding current). When the detection current is greater than the reference current, a shutdown signal is given to the MOS1 tube, and the MOS2 tube is closed with a high level. The inductor L is discharged again through the IGCT and the diode D.

[0093] Therefore, by cooperating with the switch tube through the discharge module and the energy storage module, the switching control of the IGCT and the maintenance of the gate current are realized, so that the IGCT can be reliably opened and used, thereby improving the reliability and convenience of the use of the IGCT.

[0094] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned electrical equipment, for any details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0095] A large number of experiments have shown that the technical solution of this embodiment can reduce energy loss by monitoring the working state of the IGCT, controlling the gate current in real time, and applying the minimum gate holding current to the gate.

[0096] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0097] The foregoing description is merely an embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the claims.

Claims

1. A gate drive device for an IGCT, characterized in that: include: Detection unit and control unit; wherein, The detection unit is used to detect the gate current of the IGCT when the IGCT is turned off and needs to be turned on; and generate an IGCT turn-on signal when the detected IGCT gate current reaches a set turn-on current of the IGCT; A control unit, used for controlling the IGCT to be turned on according to an IGCT turn-on signal; The detection unit is further configured to continue detecting the gate current of the IGCT when the IGCT is turned on; and to generate an IGCT on-maintaining signal when the gate current of the IGCT that is continuously detected is less than a set on-maintaining current of the IGCT; The control unit is further configured to adjust the gate current of the IGCT to maintain the IGCT on according to the IGCT on-maintaining signal; the control unit includes: a controller, a switch module, and a current maintaining module; A switch module is provided between the gate of the IGCT and a first connection terminal of a power supply of the IGCT; The controller is used to control the switch module according to the IGCT opening signal, so as to control the IGCT to be opened through the switch module; A current maintaining module is provided between the cathode of the IGCT and the second connection terminal of the power supply of the IGCT; The controller is further configured to control the current maintaining module according to the on-maintaining signal of the IGCT, so as to adjust the gate current of the IGCT by adjusting the PWM duty cycle of the input current of the current maintaining module.

2. The gate driving device according to claim 1, wherein: The detection unit includes: a sampling resistor; The sampling resistor is set between the power supply of the IGCT and the gate of the IGCT. It is used to detect the current flowing through itself and use the current flowing through itself as the gate current of the IGCT.

3. The gate driving device according to claim 1, wherein: The current maintaining module includes: a first switch tube and a second switch tube; the switch module includes: a third switch tube; A first switching tube is provided between the second connection terminal of the power supply of the IGCT and the gate of the IGCT; The second switch tube is arranged between the gate of the IGCT and the cathode of the IGCT; The third switch tube is arranged between the gate of the IGCT and the first connection terminal of the power supply of the IGCT.

4. The gate driving device according to claim 3, wherein: The current maintaining module further includes: an energy storage module, a first discharging module and a second discharging module; An energy storage module is provided between the first switch tube and the gate of the IGCT, and is used to store energy using the power supply when the first switch tube is turned on; The first discharge module is provided between the first switch tube and the third switch tube; the second discharge module is provided between the first switch tube and the second switch tube; The controller controls the IGCT opening through the switch module, including: The controller controls the first switch tube to be turned off, the third switch tube to be turned off, and controls the second switch tube to be turned on, so that the energy storage element discharges through the IGCT and the second discharge module to form a conduction path of the IGCT; The controller regulates the IGCT gate current by adjusting the PWM duty cycle of the input current of the current maintenance module, including: The controller controls the first switch tube to turn on and controls the second switch tube to turn off, so that the energy storage element discharges through the IGCT and the first discharge module to supplement the current for the gate of the IGCT.

5. The gate driving device according to claim 3, wherein: The switch module further includes: a back electromotive force module; The back electromotive force module is provided between the third switch tube and the cathode of the IGCT, and is used to provide a back electromotive force when the IGCT is turned off.

6. An electrical device, characterized in that: include: The gate drive device of an IGCT according to any one of claims 1 to 5.

7. A gate driving method for an IGCT of an electrical device according to claim 6, characterized in that: include: The detection unit detects the gate current of the IGCT when the IGCT is turned off and needs to be turned on; and generates an IGCT turn-on signal when the detected gate current of the IGCT reaches the set turn-on current of the IGCT; The control unit controls the IGCT to be turned on according to the IGCT turn-on signal; The detection unit continues to detect the gate current of the IGCT when the IGCT is turned on, and generates an IGCT turn-on maintenance signal when the gate current of the IGCT that is still detected is less than a set turn-on maintenance current of the IGCT; The control unit also adjusts the gate current of the IGCT according to the IGCT on-maintaining signal to maintain the IGCT on.

8. The gate driving method according to claim 7, wherein: The gate current of the IGCT is detected by the detection unit, including: A sampling resistor is set between the power supply of the IGCT and the gate of the IGCT, and the current flowing through the sampling resistor itself is detected and used as the gate current of the IGCT.

9. The gate driving method according to claim 7 or 8, characterized in that: The controller controls the IGCT opening through the switch module, including: The controller controls the first switch tube to be turned off, the third switch tube to be turned off, and controls the second switch tube to be turned on, so that the energy storage element discharges through the IGCT and the second discharge module to form a conduction path of the IGCT; The controller regulates the IGCT gate current by adjusting the PWM duty cycle of the input current of the current maintenance module, including: The controller controls the first switch tube to turn on and controls the second switch tube to turn off, so that the energy storage element discharges through the IGCT and the first discharge module to supplement the current for the gate of the IGCT.

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