Thyristor type device leakage current monitoring method and circuit and power electronic device

Abstract

The invention discloses a thyristor type device leakage current monitoring method and circuit and a power electronic device.The method comprises the steps that in response to a system turn-off instruction, a first control signal is sent to a device turn-off module; the device turn-off module is used for conducting a turn-off branch of the thyristor device according to the first control signal; acquiring a leakage current sampling signal from a leakage current monitoring module; the leakage current monitoring module is used for converting the gate current of the thyristor device into a leakage current sampling signal; and generating a leakage current monitoring result based on the leakage current sampling signal. According to the invention, real-time and accurate measurement of the leakage current can be realized on the premise of not influencing system operation.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a method, circuit, and power electronics device for monitoring leakage current of thyristor devices. Background Art

[0002] During the operation of power electronic converter systems containing thyristor-type switching devices, the blocking characteristics of these devices are prone to degradation due to device aging. This is mainly manifested by an increase in the leakage current of the thyristor device at the same blocking voltage.

[0003] When the blocking characteristics of thyristor devices fail to meet the system's withstand voltage requirements, they can damage the devices, leading to serious accidents such as converter failure. Therefore, online detection of leakage current in operating thyristor devices and evaluation of their blocking characteristics have become urgent technical challenges. Summary of the Invention

[0004] The present application provides a thyristor device leakage current monitoring method, circuit and power electronic device, which can improve the technical problem in the related art that the blocking characteristics of thyristor devices are degraded, resulting in device damage.

[0005] In a first aspect, the present application provides a method for monitoring leakage current of a thyristor device, comprising:

[0006] In response to a system shutdown instruction, a first control signal is sent to a device shutdown module; the device shutdown module is used to turn on a shutdown branch of a thyristor device according to the first control signal;

[0007] Obtaining a leakage current sampling signal from a leakage current monitoring module; the leakage current monitoring module is used to convert the gate current of a thyristor device into a leakage current sampling signal;

[0008] A leakage current monitoring result is generated based on the leakage current sampling signal.

[0009] Optionally, obtaining a leakage current sampling signal from a leakage current monitoring module includes:

[0010] When the thyristor device is blocked, a first leakage current detection signal is sent to the leakage current detection switch; the leakage current detection switch is used to turn on the leakage current detection branch according to the first leakage current detection signal, and the leakage current monitoring module is used to collect the gate current on the leakage current detection branch;

[0011] Sending a second control signal to the device shutdown module; the device shutdown module is used to disconnect the shutdown branch of the thyristor device according to the second control signal;

[0012] When the leakage current detection branch is turned on and the shutoff branch is turned off, a leakage current sampling signal is obtained from the leakage current monitoring module.

[0013] Optionally, when the leakage current detection branch is turned on and the shutoff branch is turned off, after obtaining the leakage current sampling signal from the leakage current monitoring module, the method further includes:

[0014] Sending a first control signal to a device shutdown module;

[0015] A second leakage current detection signal is sent to the leakage current detection switch; the leakage current detection switch is used to disconnect the leakage current detection branch according to the second leakage current detection signal.

[0016] Optionally, obtaining a leakage current sampling signal from a leakage current monitoring module includes:

[0017] When the thyristor device is blocked, a leakage current sampling signal is obtained from the leakage current monitoring module; the leakage current monitoring module is used to collect the gate current on the turn-off branch.

[0018] Optionally, after obtaining the leakage current sampling signal from the leakage current monitoring module, the method further includes:

[0019] A second control signal is sent to the device shutdown module.

[0020] In a second aspect, the present application provides a thyristor device leakage current monitoring circuit, which is used to implement the thyristor device leakage current monitoring method of the first aspect, comprising:

[0021] A device shutdown module, which is connected to a thyristor device to form a shutdown branch;

[0022] Leakage current monitoring module, used for contact connection or contactless connection with the gate of thyristor devices;

[0023] The control logic processing module is connected to the control end of the device shutdown module and the sampling output end of the leakage current monitoring module.

[0024] Optionally, the leakage current monitoring module includes:

[0025] A leakage current sampling module is connected to the shutoff branch;

[0026] or,

[0027] The leakage current sampling module is connected to the leakage current detection branch.

[0028] Optionally, the leakage current sampling module includes:

[0029] A non-contact sampling module is non-contactly connected to the shut-off branch or the leakage current detection branch;

[0030] Alternatively, the contact sampling module is connected in series to the shutoff branch or the leakage current detection branch.

[0031] Optionally, the contact sampling module includes one of a differential amplification sampling unit, an operational amplification sampling unit or a current mutual induction unit.

[0032] Optionally, the device shutdown module includes:

[0033] a second transistor, wherein a first terminal of the second transistor is connected to a gate of a thyristor device, and a control terminal of the second transistor is connected to a control logic processing module; the second transistor is configured to be turned on when receiving a first control signal;

[0034] A third transistor, wherein the first end of the third transistor is connected to the cathode of the thyristor device, the second end of the third transistor is connected to the second end of the second transistor, and the control end of the third transistor is connected to the control logic processing module; the third transistor is used to disconnect when receiving the first control signal.

[0035] Optionally, the leakage current monitoring module includes:

[0036] An eighth transistor, wherein a first end of the eighth transistor is connected to the gate of the thyristor device, and a second end of the eighth transistor is connected to the second end of the third transistor; the eighth transistor is configured to be turned on when receiving a first leakage current detection signal.

[0037] Optionally, the leakage current monitoring module includes:

[0038] a ninth transistor, wherein a first terminal of the ninth transistor is connected to a gate of a thyristor device; and the ninth transistor is configured to be turned on when receiving a first leakage current detection signal;

[0039] The third capacitor is connected between the second end of the ninth transistor and the second end of the second transistor.

[0040] Optionally, the device shutdown module includes:

[0041] a first transistor, wherein a first terminal of the first transistor is connected to a gate of a thyristor device, and a control terminal of the first transistor is connected to a control logic processing module; the first transistor is configured to be turned on when receiving a first control signal;

[0042] The turn-off capacitor is connected between the second end of the first transistor and the cathode of the thyristor device.

[0043] Optionally, the leakage current monitoring module includes:

[0044] A fourth transistor, wherein a first end of the fourth transistor is connected to the gate of the thyristor device, and a second end of the fourth transistor is connected to the cathode of the thyristor device; the fourth transistor is configured to be turned on when receiving the first leakage current detection signal.

[0045] Optionally, the leakage current monitoring module includes:

[0046] A fifth transistor, wherein a first end of the fifth transistor is connected to the gate of the thyristor device, and a second end of the fifth transistor is connected to the second end of the first transistor; the fifth transistor is configured to be turned on when receiving a first leakage current detection signal.

[0047] Optionally, the leakage current monitoring module includes:

[0048] a sixth transistor, wherein a first terminal of the sixth transistor is connected to a gate of a thyristor device; and the sixth transistor is configured to be turned on when receiving a first leakage current detection signal;

[0049] A first capacitor is connected between the second end of the sixth transistor and the cathode of the thyristor device.

[0050] Optionally, the leakage current monitoring module includes:

[0051] a seventh transistor, wherein a first terminal of the seventh transistor is connected to a gate of a thyristor device; and the seventh transistor is configured to be turned on when receiving a first leakage current detection signal;

[0052] The second capacitor is connected between the second end of the seventh transistor and the second end of the first transistor.

[0053] In a third aspect, the present application provides a power electronic device, including a thyristor device and the thyristor device leakage current monitoring circuit of the second aspect.

[0054] Optionally, the thyristor device is a thyristor device with a non-gate cathode short-circuit structure.

[0055] The present invention discloses a method, circuit, and power electronic device for monitoring leakage current of thyristor devices. Based on a system shutdown instruction, the device shutdown module can control a first control signal to conduct the shutdown branch of the thyristor device, thereby switching the thyristor device to a blocking state. In the blocking state, a leakage current sampling signal converted from the gate current of the thyristor device can be obtained from the leakage current monitoring module. Based on the leakage current sampling signal and the leakage current abnormality condition, it can be determined whether the leakage current is abnormal and a leakage current monitoring result can be generated, thereby achieving real-time and accurate measurement of the leakage current without affecting system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0057] Figure 1 This is a flow chart of a method for monitoring leakage current of a thyristor device provided in one embodiment of the present application;

[0058] Figure 2 1 is a flow chart of a method for monitoring leakage current of a thyristor device provided in another embodiment of the present application;

[0059] Figure 3 This is a flow chart of a method for monitoring leakage current of a thyristor device provided in another embodiment of the present application;

[0060] Figure 4 1 is a flow chart of a method for monitoring leakage current of a thyristor device provided in another embodiment of the present application;

[0061] Figure 5 This is a schematic diagram of the module structure of a thyristor device leakage current monitoring circuit provided in one embodiment of the present application;

[0062] Figure 6 This is a schematic diagram of the module structure of a thyristor device leakage current monitoring circuit provided by another embodiment of the present application;

[0063] Figure 7 This is a schematic diagram of the module structure of a thyristor device leakage current monitoring circuit provided by another embodiment of the present application;

[0064] Figure 8 This is a structural diagram of a non-contact sampling module provided in one embodiment of the present application;

[0065] Figure 9 This is a schematic structural diagram of a contact sampling module provided in one embodiment of the present application;

[0066] Figure 10 1 is a structural diagram of a differential amplification sampling unit provided in an embodiment of the present application;

[0067] Figure 11 1 is a schematic structural diagram of an operational amplifier sampling unit provided in one embodiment of the present application;

[0068] Figure 12 This is a schematic structural diagram of a current mutual induction unit provided in one embodiment of the present application;

[0069] Figure 13 1 is a schematic diagram of the circuit structure of a shutdown mode A of a device shutdown module provided in one embodiment of the present application;

[0070] Figure 14 1 is a circuit structure diagram of a shutdown mode B of a device shutdown module provided in one embodiment of the present application;

[0071] Figure 151 is a schematic diagram of the circuit structure of the leakage current detection branch of the shutdown mode A provided in one embodiment of the present application;

[0072] Figure 16 1 is a schematic diagram of the circuit structure of a leakage current detection branch of a shutdown mode A provided in another embodiment of the present application;

[0073] Figure 17 1 is a schematic diagram of the circuit structure of a leakage current detection branch of a shutdown mode A provided in another embodiment of the present application;

[0074] Figure 18 1 is a schematic diagram of the circuit structure of the leakage current detection branch of the shutdown mode B provided in one embodiment of the present application;

[0075] Figure 19 2 is a schematic diagram of the circuit structure of a leakage current detection branch of a shutdown mode B provided in another embodiment of the present application;

[0076] Figure 20 1 is a schematic diagram of the circuit structure of a leakage current detection branch of a shutdown mode B provided in another embodiment of the present application;

[0077] Figure 21 1 is a circuit diagram of a leakage current detection branch of a shutdown mode B provided in yet another embodiment of the present application;

[0078] Figure 22 1 is a schematic diagram of the circuit structure of a leakage current detection branch of a shutdown mode B provided in another embodiment of the present application;

[0079] Figure 23 yes Figures 16 and 17 A timing logic diagram corresponding to the embodiment;

[0080] Figure 24 yes Figures 19 to 22 A timing logic diagram corresponding to the embodiment;

[0081] In the attached figure:

[0082] 10. Control logic processing module; 20. Device shutdown module; 30. Leakage current monitoring module; 31. Leakage current sampling module; 311. Non-contact sampling module; 312. Contact sampling module; 32. Leakage current detection branch; 40. Thyristor device. DETAILED DESCRIPTION

[0083] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0084] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0085] During the operation of power electronic converter systems containing thyristor-type switching devices, the blocking characteristics of these devices are prone to degradation due to device aging. This is mainly manifested by an increase in the leakage current of the thyristor device at the same blocking voltage.

[0086] When the blocking characteristics of thyristor devices fail to meet the system's withstand voltage requirements, they can damage the devices, leading to serious accidents such as converter failure. Therefore, online detection of leakage current in operating thyristor devices and evaluation of their blocking characteristics have become urgent technical challenges.

[0087] In the prior art, the main method for detecting leakage current of thyristor devices is to monitor the anode current of the thyristor devices. For example, the anode of the thyristor device is connected in series with a resistor, and the voltage signal across the resistor is sampled to determine the anode leakage current of the thyristor device in the blocking state.

[0088] However, in the above technical solution, not only does it require connecting a resistance device in series in the main circuit where the thyristor device is located, which increases the complexity of the entire system, but when the thyristor device is in the on state, the series resistance will generate huge heat loss under large currents, thereby seriously affecting the energy conversion efficiency and the normal operation of the system.

[0089] To address at least one of the aforementioned technical issues, embodiments of the present application provide a method, circuit, and power electronic device for monitoring leakage current in thyristor devices. These methods are capable of monitoring the gate current of thyristor devices in the blocking state to implement leakage current monitoring. The following first introduces the method for monitoring leakage current in thyristor devices provided in embodiments of the present application.

[0090] Figure 1 A schematic flow chart of a method for monitoring leakage current of a thyristor device provided by an embodiment of the present application is shown. The method may include the following steps:

[0091] S110, in response to a system shutdown instruction, sending a first control signal to a device shutdown module; the device shutdown module is configured to turn on a shutdown branch of a thyristor device according to the first control signal;

[0092] S120, obtaining a leakage current sampling signal from a leakage current monitoring module; the leakage current monitoring module is used to convert the gate current of a thyristor device into a leakage current sampling signal;

[0093] S130: Generate a leakage current monitoring result based on the leakage current sampling signal.

[0094] For a power electronic converter system including thyristor switching devices, the following implementation can be used to perform online monitoring of the leakage current of the thyristor devices during normal operation of the system.

[0095] In this embodiment, based on a system shutdown instruction, a first control signal can be used to control the device shutdown module to conduct the shutdown branch of the thyristor device, thereby switching the thyristor device to a blocking state. In this blocking state, a leakage current sampling signal converted from the gate current of the thyristor device can be obtained from the leakage current monitoring module. Based on the leakage current sampling signal and the leakage current abnormality condition, it can be determined whether there is a leakage current abnormality and a leakage current monitoring result can be generated, thereby achieving real-time and accurate leakage current measurement without affecting system operation.

[0096] The specific implementation methods of the above steps are introduced below.

[0097] In S110 , when the thyristor devices in the system are in a normal conduction state, a system shutdown instruction may be received, and in response to the system shutdown instruction, a first control signal may be sent to the device shutdown module.

[0098] The system shutdown command can be generated by a host computer or another module with leakage current monitoring capabilities. For example, the host computer can issue the shutdown command based on preset rules or based on user actions when leakage current monitoring is triggered. In other words, leakage current monitoring can be implemented by issuing a system shutdown command when preset rules are met or when a user command is received.

[0099] The receiving unit of the system shutdown instruction may be a control logic processing module. The control logic processing module may send a first control signal to the device shutdown module based on the received system shutdown instruction.

[0100] The device shutdown module can control the shutdown branch of the thyristor device. When the shutdown branch is turned on, the thyristor device is in a blocking state.

[0101] It should be noted that since the shutdown branch is used to control the shutdown of the thyristor device, when the shutdown branch is turned on, the thyristor device can be in a blocked state. However, when the shutdown branch is disconnected, the thyristor device may be in either the on state or the blocked state.

[0102] When the thyristor device is in a normal conduction state, the shutdown branch is in a blocking state. If the device shutdown module receives a first control signal, the shutdown branch can be turned on to change the thyristor device from the conduction state to the blocking state.

[0103] The above-mentioned thyristor devices can be thyristor devices with non-gate cathode short-circuit structure, for example, they can be ETO (Emitter Turn-OFF Thyristor), GTO (Gate Turn-OFF Thyristor) or other types of thyristors, which are not limited here.

[0104] In S120, after the turn-off branch of the thyristor device is turned on, the thyristor device switches from the on state to the blocked state. In the blocked state, the leakage current monitoring module can sample the gate current of the thyristor device and convert the sampled signal into a leakage current sampling signal. The control logic processing module can obtain the leakage current sampling signal from the leakage current monitoring module.

[0105] When the thyristor device is in the blocking state, the gate current collected by the leakage current monitoring module can be regarded as the leakage current of the thyristor device. After the leakage current monitoring module converts the gate current into a leakage current sampling signal, the control logic processing module can determine the size of the gate current based on the leakage current sampling signal, that is, determine the leakage current of the thyristor device in the blocking state.

[0106] Please refer to Figure 2 In some embodiments, the above S120 may include:

[0107] S210, when the thyristor device is blocked, sending a first leakage current detection signal to the leakage current detection switch; the leakage current detection switch is used to turn on the leakage current detection branch according to the first leakage current detection signal, and the leakage current monitoring module is used to collect the gate current on the leakage current detection branch;

[0108] S220, sending a second control signal to the device shutdown module; the device shutdown module is used to disconnect the shutdown branch of the thyristor device according to the second control signal;

[0109] S230 , when the leakage current detection branch is turned on and the shutoff branch is turned off, obtaining a leakage current sampling signal from the leakage current monitoring module.

[0110] In this embodiment, when gate current detection is implemented through the leakage current detection branch, the leakage current detection switch can be controlled to turn on the leakage current detection branch after the shutdown branch is turned on and the thyristor device is blocked. After the leakage current detection branch is turned on, the device shutdown module can be controlled to turn off the switch branch so that the gate current flows only through the leakage current detection branch. The leakage current sampling signal is obtained from the leakage current monitoring module, thereby achieving complete sampling of the gate current.

[0111] In S210, the thyristor device is in a blocking state when the shutdown branch is turned on. The control logic processing module can send a first leakage current detection signal to the leakage current detection switch. The leakage current detection switch is located on the leakage current detection branch. When the leakage current detection switch receives the first leakage current detection signal, it can switch from a blocking state to a conducting state, thereby turning on the leakage current detection branch.

[0112] When the leakage current detection branch is turned on, the leakage current monitoring module can collect the gate current on the leakage current detection branch and convert it into a leakage current sampling signal.

[0113] In S220, the control logic processing module may send a second control signal to the device shutdown module. Upon receiving the second control signal, the device shutdown module may disconnect the shutdown branch of the thyristor device.

[0114] It is understandable that the leakage current detection branch is connected to the gate of the thyristor device, and the shutdown branch is also connected to the gate of the thyristor device. When both the leakage current detection branch and the shutdown branch are in the on state, the gate current of the thyristor device is actually the sum of the branch currents on the two branches. Therefore, the current on the leakage current detection branch collected by the leakage current monitoring module is only a portion of the gate current of the thyristor device. In order to enable the leakage current monitoring module to collect the complete gate current signal, the control logic processing module can control the device shutdown module to disconnect the shutdown branch through a second control signal.

[0115] As an optional implementation method, a corresponding dead time can be set based on the device parameters. After the leakage current detection branch is turned on and the dead time has passed, the control logic processing module can control the device shutdown module to disconnect the switch branch to avoid the thyristor device being turned on again due to the disconnection of the switch branch when the leakage current detection branch is not turned on or is fully turned on.

[0116] In S230, when the leakage current detection branch is on and the shutdown branch is off, only the leakage current detection branch is on, and the leakage current monitoring module can collect a complete gate current signal. Based on the leakage current sampling signal obtained from the leakage current monitoring module, the control logic processing module can determine the gate current of the thyristor device, that is, the leakage current of the thyristor device.

[0117] Please refer to Figure 3 In some embodiments, after the above S230, the following steps may also be included:

[0118] S310, sending a first control signal to a device shutdown module;

[0119] S320, sending a second leakage current detection signal to the leakage current detection switch; the leakage current detection switch is used to disconnect the leakage current detection branch according to the second leakage current detection signal.

[0120] In this embodiment, after the gate current sampling of the thyristor device is completed through the leakage current detection branch, the device shutdown module can be controlled to re-turn on the shutdown branch, and the leakage current detection switch can be controlled to disconnect the leakage current detection branch, so that the thyristor device maintains a blocked state under the turned-on shutdown branch.

[0121] In S310, after obtaining the leakage current sampling signal, that is, obtaining the leakage current of the thyristor device, the control logic processing module may send a first control signal to the device shutdown module. The device shutdown module may re-open the shutdown branch based on the first control signal.

[0122] In S320, the control logic processing module may send a second leakage current detection signal to the leakage current detection switch. When the leakage current detection switch receives the second leakage current detection signal, it may switch from a conducting state to a blocking state, thereby disconnecting the leakage current detection branch.

[0123] During the time period when only the leakage current detection branch is conducting, the thyristor device can maintain a blocked state. However, since the related devices on the leakage current detection branch are only used to achieve the short-term shutdown of the thyristor device for leakage current detection, after the leakage current detection process is completed, the leakage current detection branch can be switched to the shutdown branch to achieve stable shutdown of the thyristor device through the related devices on the shutdown branch.

[0124] As an optional implementation, a corresponding dead time can be set based on the device parameters. After the shutdown branch is turned on again and the dead time has passed, the control logic processing module can control the leakage current detection branch to be disconnected to avoid the leakage current detection branch being disconnected when the shutdown branch is not turned on or fully turned on, causing the thyristor device to be turned on again.

[0125] In the above embodiment, the gate of the thyristor device may be connected to the turn-off branch and the leakage current detection branch, and the leakage current monitoring module collects the gate current through the leakage current detection branch.

[0126] In the following embodiments, the gate of the thyristor device is connected only to the turn-off branch, and the leakage current monitoring module collects the gate current through the turn-off branch. That is, the turn-off branch can be reused as the leakage current detection branch when the thyristor device is blocked.

[0127] Please refer to Figure 4 In some embodiments, the above S120 may include:

[0128] S410 , when the thyristor device is blocked, obtaining a leakage current sampling signal from a leakage current monitoring module; the leakage current monitoring module is used to collect the gate current on the turn-off branch.

[0129] In this embodiment, when the shutdown branch is conducting, the thyristor device is in a blocked state. At this time, the leakage current monitoring module can collect the gate current on the shutdown branch. Because the gate of the thyristor device is connected only to the shutdown branch, the collected gate current is the leakage current of the thyristor device.

[0130] After the leakage current monitoring module converts the collected gate current into a leakage current sampling signal, the control logic processing module may obtain the leakage current sampling signal from the leakage current monitoring module.

[0131] In some embodiments, after the above S120, the following steps may also be included:

[0132] S510: Send a second control signal to the device shutdown module.

[0133] In this embodiment, after controlling the thyristor device to switch from the conducting state to the blocking state and acquiring the leakage current sampling signal in the blocking state, the control logic processing module may send a second control signal to the device shutdown module.

[0134] When receiving the second control signal, the device shutdown module can disconnect the shutdown branch of the thyristor device to make the thyristor device turn on again. After the thyristor device turns on again, it can continue to operate normally.

[0135] In S130 , after acquiring the leakage current sampling signal, the control logic processing module may determine the actual leakage current of the thyristor device based on the leakage current sampling signal, and generate a leakage current monitoring result based on the actual leakage current.

[0136] As an example implementation, after acquiring the leakage current sampling signal, the control logic processing module can convert the leakage current sampling signal into a digital signal through an ADC (Analog to digital converter), a voltage comparator, etc. After the corresponding digital signal is converted, the digital signal can be compared and evaluated with a pre-set leakage current abnormality condition to obtain a leakage current monitoring result indicating whether the leakage current is abnormal.

[0137] The above-mentioned leakage current abnormality condition can be that the leakage current reaches a certain preset current threshold, or the rate of change of the leakage current reaches a certain preset rate of change threshold. For example, when a certain preset current threshold is set as the leakage current abnormality condition, if it can be determined based on the digital signal that the actual leakage current is greater than the current threshold, then the leakage current monitoring result can be determined to be a leakage current abnormality. Similarly, when a certain preset rate of change threshold is set as the leakage current abnormality condition, if it is determined based on the sampled digital signal that the rate of change of the actual leakage current is greater than the rate of change threshold, then the leakage current monitoring result can also be determined to be a leakage current abnormality.

[0138] It is understood that the above-mentioned abnormal leakage current condition can also include multiple conditions, for example, a current threshold and a change rate threshold can be pre-set. When the actual leakage current is greater than the current threshold or the rate of change of the actual leakage current is greater than the change rate threshold, a leakage current abnormality can be determined. In addition, the above-mentioned abnormal leakage current condition can also include one or more other judgment conditions that can confirm the presence of an abnormal leakage current, which are not limited here.

[0139] In another exemplary embodiment, the control logic processing module can be connected to a host computer or other electronic device for communication. The control logic processing module can also store digital signals and send the stored digital signals to the host computer, which determines whether there is an abnormality in the leakage current of the thyristor device.

[0140] The aforementioned abnormal leakage current condition can be a pre-set abnormal leakage current threshold. Based on the acquired leakage current sampling signal, the gate current of the thyristor device can be calculated and used as the actual leakage current. Whether the actual leakage current exceeds the abnormal threshold can be used to determine whether the leakage current of the thyristor device is abnormally high, thereby enabling online detection of the leakage current of the thyristor device.

[0141] The present application also provides a thyristor device leakage current monitoring circuit, which can implement the thyristor device leakage current monitoring method in the above embodiment. Figure 5 The thyristor device leakage current monitoring circuit includes a device shutdown module 20 , a leakage current monitoring module 30 and a control logic processing module 10 .

[0142] The device shutdown module 20 is connected to the thyristor device 40 to form a shutdown branch. A, G, and K of the thyristor device 40 are the anode, gate, and cathode respectively.

[0143] The leakage current monitoring module 30 can be in contact connection or contactless connection with the gate of the thyristor device 40. When the thyristor device 40 is in a blocking state, the leakage current monitoring module 30 can monitor the gate current of the thyristor device 40.

[0144] The control logic processing module 10 is connected to the control terminal of the device shutdown module 20 and the sampling output terminal of the leakage current monitoring module 30 .

[0145] In this embodiment, when the thyristor device 40 is in the on state, the control logic processing module 10 can send a first control signal to the control terminal of the device shutdown module 20. After the device shutdown module 20 turns on the shutdown branch of the thyristor device 40 based on the first control signal, the leakage current monitoring module 30 can monitor the gate current of the thyristor device 40 and convert it into a leakage current sampling signal. The control logic processing module 10 can obtain the leakage current sampling signal from the sampling output terminal of the leakage current monitoring module 30. By sampling the gate current after the thyristor device 40 is turned off, real-time and accurate measurement of the leakage current of the thyristor device 40 can be achieved without affecting system operation.

[0146] Please refer to Figure 6In an optional implementation, the leakage current monitoring module 30 may include a leakage current sampling module 31 , and the leakage current sampling module 31 may be connected to the shutoff branch.

[0147] When the shutdown branch is turned on, the thyristor device 40 is in a blocking state. The loop current collected by the leakage current sampling module 31 on the shutdown branch is the gate current of the thyristor device 40, that is, the leakage current of the thyristor device 40 in the blocking state.

[0148] Please refer to Figure 7 In another optional embodiment, the leakage current monitoring module 30 may include a leakage current sampling module 31 and a leakage current detection branch 32. The leakage current detection branch 32 is connected to the thyristor device 40, and the leakage current sampling module 31 is connected to the leakage current detection branch 32.

[0149] When the shutdown branch is turned on, the thyristor device 40 is in a blocking state. At this time, the control logic processing module 10 can control the leakage current detection switch (not shown) to be turned on, so that the leakage current detection branch 32 is turned on. Since the gate current of the thyristor device 40 is the sum of the current on the shutdown branch and the current on the leakage current detection branch 32 when the leakage current detection branch 32 and the shutdown branch are turned on at the same time, the leakage current detection branch 32 can only collect part of the leakage current at this time, and leakage current monitoring cannot be achieved. Therefore, after the leakage current detection branch 32 is turned on, the control logic processing module 10 can control the shutdown branch to be disconnected. At this time, the current on the leakage current detection branch 32 is the gate current of the thyristor device 40, that is, the leakage current of the thyristor device 40 in the blocking state.

[0150] In the above embodiment, the leakage current monitoring module 30 may include a control terminal, and the control terminal of the leakage current monitoring module 30 may be electrically connected to the control logic processing module 10. The control logic processing module 10 may control the conduction and disconnection of the leakage current detection branch 32 by sending a control signal to the control terminal of the leakage current monitoring module 30.

[0151] When the leakage current detection branch 32 is in the on state, even if the shutoff branch is disconnected, the thyristor device 40 can be kept in the blocked state within the leakage current detection period.

[0152] Please continue to refer to Figure 6 and Figure 7 In an optional embodiment, the leakage current monitoring module 30 may further include a leakage current protection module 33. Figure 6As shown, when the leakage current monitoring module 30 only includes the leakage current sampling module 31 and the shutdown branch is reused as the leakage current detection branch 32, the leakage current protection module 33 is electrically connected to the device shutdown module 20, the leakage current sampling module 31 and the control logic processing module 10 respectively. Figure 7 As shown, when the leakage current monitoring module includes a leakage current detection branch 32, the leakage current protection module 33 is also electrically connected to the leakage current detection branch 32. The leakage current protection module can provide overcurrent protection for the leakage current monitoring module 30 to prevent damage to the components of the leakage current monitoring module 30.

[0153] The following Figure 7 The embodiment describes the leakage current protection module 33 .

[0154] In some embodiments, the leakage current protection module 33 includes at least one of a voltage limiting unit, a current limiting unit, or a fault detection unit. The voltage limiting unit, the current limiting unit, and the fault detection unit are described below respectively.

[0155] The leakage current protection module 33 may include a voltage limiting unit.

[0156] In the leakage current sampling module 31, Figure 9 In the illustrated contact sampling module 312 , the voltage limiting unit may be electrically connected to the sampling interface of the leakage current monitoring module 30 . For example, the voltage limiting unit may be connected in parallel across the sampling interface of the contact sampling module 312 .

[0157] The voltage limiting unit can limit the voltage when an excessively high voltage is generated across the sampling interface. For example, the voltage limiting unit can be a Zener diode, a TVS diode, a varistor, a transient voltage suppressor, a metal oxide varistor (MOV), etc., which implements the voltage limiting function when the voltage is too high to protect the leakage current monitoring module 30.

[0158] The leakage current protection module 33 may include a current limiting unit.

[0159] The current limiting unit can be connected in series to the leakage current detection branch 32. When the current of the leakage current detection branch 32 is too large, the current can be limited by the current limiting unit. The current limiting unit can include a PTC thermistor, a fuse, a split reactor, a split transformer, etc.

[0160] It should be noted that in Figure 6 In the embodiment shown where the multiplexed shutdown branch is used as the leakage current detection branch 32, the current limiting unit can be connected in series to the shutdown branch. Similarly, when the leakage current on the shutdown branch is too large, the current limiting unit can be used to limit the current to protect the shutdown branch and the leakage current monitoring module 30.

[0161] The leakage current protection module 33 may include a fault detection unit, a fault detection terminal of which is electrically connected to the leakage current detection branch 32 , and a fault signal output terminal of which is electrically connected to the control logic processing module 10 .

[0162] The fault detection unit can perform fault detection on the leakage current detection branch 32. When a branch fault is detected in the leakage current detection branch 32, the leakage current protection module 33 can send a fault signal to the control logic processing module 10, so that the control logic processing module 10 controls the leakage current detection branch 32 to be turned off, and controls the device shutdown module 20 to be turned on, so as to disconnect the leakage current detection branch 32 in time, and continue to maintain the blocking state of the thyristor device by shutting down the branch.

[0163] In the above embodiment, the fault detection unit in the leakage current protection module 33 can realize the fault detection of the leakage current detection branch 32 through a hardware circuit. Compared with the software processing process of the control logic processing module 10, it can quickly identify the fault abnormality of the leakage current detection branch 32, thereby timely switching to the shutdown mode of shutting down the branch conduction.

[0164] It should be noted that the above-mentioned leakage current protection module 33 is electrically connected to the device shutdown module 20, the leakage current sampling module 31 and the control logic processing module 10 respectively, which means that it includes corresponding protection units. For example, if the leakage current protection module 33 only includes a current limiting unit and a voltage limiting unit, the leakage current protection module 33 may not be electrically connected to the control logic processing module 10.

[0165] Please refer to Figure 8 and Figure 9 In some embodiments, the leakage current sampling module 31 may include a non-contact sampling module 311 or a contact sampling module 312 .

[0166] like Figure 8 As shown, when the leakage current sampling module 31 includes a non-contact sampling module 311, the non-contact sampling module 311 can be non-contactly connected to the shutoff branch or the leakage current detection branch 32. For example, the non-contact sampling module 311 can be a Rogowski current coil, a current transformer, a Hall sensor, a fluxgate sensor, an anisotropic magnetoresistive sensor, a giant magnetoresistive sensor, a tunnel magnetoresistive sensor, a magneto-optical crystal sensor, a fiber optic current sensor, a magnetosensitive element sensor, a superconducting quantum interference sensor, etc. The non-contact sampling module 311 can be mounted on the shutoff branch or the leakage current detection branch 32, and after acquiring the current signal on the corresponding branch, it converts it into a corresponding electrical signal and outputs it to the control logic processing module 10.

[0167] like Figure 9As shown, when the leakage current sampling module 31 includes a contact sampling module 312, the contact sampling module 312 can be in contact with the shutdown branch or the leakage current detection branch 32. For example, the contact sampling module 312 can be a sampling resistor module, a sampling resistor + differential amplifier module, a sampling resistor + signal amplifier module, a current detection amplifier module, a current mutual inductance module, etc. The contact sampling module 312 can be connected in series with the shutdown branch or the leakage current detection branch 32, obtain the current signal on the corresponding branch, and convert it into a corresponding electrical signal for output to the control logic processing module 10.

[0168] In some embodiments, the contact sampling module 312 may include a differential amplification sampling unit, an operational amplification sampling unit, or a current transformer unit. Figure 10 、 Figure 11 and Figure 12 Schematic diagrams of the circuit structures of a differential amplification sampling unit, an operational amplification sampling unit and a current mutual induction unit are shown respectively.

[0169] Please refer to Figure 13 and Figure 14 The above-mentioned thyristor device 40 can be turned off in the following manner: Figure 13 The shutdown method A shown can also be Figure 14 The following embodiment is for description of the shutdown method A.

[0170] Please refer to Figure 13 In some embodiments, the device shutdown module 20 may include a second transistor Q2 and a third transistor Q3.

[0171] A first end of the second transistor Q2 is connected to the gate of the thyristor device 40, and a control end of the second transistor Q2 is connected to the control logic processing module 10. A first end of the third transistor Q3 is connected to the cathode of the thyristor device 40, a second end of the third transistor Q3 is connected to the second end of the second transistor Q2, and a control end of the third transistor Q3 is connected to the control logic processing module 10.

[0172] The second transistor Q2 is turned on when receiving the first control signal, and the third transistor Q3 is turned off when receiving the first control signal.

[0173] When the thyristor device 40 is in the on state, the second transistor Q2 connected in series with the gate of the thyristor device 40 is turned off, and the third transistor Q3 connected in series with the cathode of the thyristor device 40 is turned on.

[0174] After the control logic processing module 10 sends the first control signal, the second transistor Q2 switches to the on state and the third transistor Q3 switches to the off state. The current of the thyristor device 40 commutates from the cathode to the gate, ultimately switching the thyristor device 40 from the on state to the off state.

[0175] The second transistor Q2 and the third transistor Q3 may be controllable switches, for example, MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), BJT (Bipolar junction transistor), IGBT (Insulate-Gate Bipolar Transistor), an electrically controlled switch, etc.

[0176] It is understood that when the second transistor Q2 is turned on, a current flow path can be provided for the gate of the thyristor device 40, that is, the second transistor Q2 can serve as a turn-off branch, and the turn-off branch is turned on. Correspondingly, when the second transistor Q2 is turned off, the turn-off branch is disconnected.

[0177] Please refer to Figure 15 As an optional implementation, in the above embodiment, if the leakage current monitoring module 30 does not include the leakage current detection branch 32, the leakage current sampling module 31 can be connected to the shutdown branch in a contact manner to implement gate current sampling of the thyristor device 40 through contact sampling. The leakage current sampling module 31 can also be connected to the shutdown branch in a contactless manner to implement gate current sampling of the thyristor device 40 through a contactless sampling manner. In this case, the shutdown branch can be reused as the leakage current detection branch 32.

[0178] Figure 15 The sampling interface 1 shown in FIG is the sampling interface in the non-contact sampling mode, and the sampling interface 2 is the sampling interface in the contact sampling mode. Figure 15 In order to illustrate the two sampling methods, two sampling interfaces are set. In the actual implementation, one of the two sampling interfaces can be selected for setting. Similarly, the corresponding embodiments of the following embodiments are Figures 16 to 22 Two sampling interfaces are shown in the figure. In actual implementation, you only need to select one of the two sampling interfaces for setting.

[0179] As another optional embodiment, the leakage current monitoring module 30 may include a leakage current detection branch 32, and the leakage current sampling module 31 may be connected to the leakage current detection branch 32 in a contact or contactless manner to implement gate current sampling of the thyristor device 40. Figures 16 and 17 , the leakage current monitoring module 30 including the leakage current detection branch 32 is described.

[0180] Please refer to Figure 16 In some embodiments, the leakage current monitoring module 30 may include an eighth transistor Q8.

[0181] A first end of the eighth transistor Q8 is connected to the gate of the thyristor device 40 , and a second end of the eighth transistor Q8 is connected to the second end of the third transistor Q3 .

[0182] The control logic processing module 10 may be connected to the control terminal of the eighth transistor Q8 and output a first leakage current detection signal.

[0183] The eighth transistor Q8 is turned on when receiving the first leakage current detection signal. At this time, the turned-on eighth transistor Q8 can serve as a leakage current detection branch 32 to provide a current flow path for the gate of the thyristor device 40 .

[0184] It should be noted that when the leakage current sampling module 31 samples the current on the leakage current detection branch 32, if the second transistor Q2 is in the on state, the current on the leakage current detection branch 32 is only a portion of the gate current. To sample the gate current, the second transistor Q2 needs to be switched to the off state before sampling the current on the leakage current detection branch 32.

[0185] Please refer to Figure 17 In some embodiments, the leakage current monitoring module 30 may include a ninth transistor Q9 and a third capacitor C3.

[0186] A first terminal of the ninth transistor Q9 is connected to the gate of the thyristor device 40. A third capacitor C3 is connected between a second terminal of the ninth transistor Q9 and a second terminal of the second transistor Q2. The ninth transistor Q9 can be turned on upon receiving the first leakage current detection signal. In this case, the ninth transistor Q9 and the third capacitor C3 can function as a leakage current detection branch 32, providing a current flow path for the gate of the thyristor device 40.

[0187] Likewise, in order to ensure that the leakage current sampling module 31 can collect the gate current on the leakage current detection branch 32 , the second transistor Q2 may be switched to a blocking state during the sampling process.

[0188] The transistors in the above embodiments may be MOSFETs, BJTs, IGBTs, electronically controlled switches, etc., which are not limited here.

[0189] The following embodiments are described with reference to the shutdown method B.

[0190] Please refer to Figure 14 In some embodiments, the device shutdown module 20 may include a first transistor Q1 and a shutdown capacitor Coff.

[0191] The first terminal of the first transistor Q1 is connected to the gate of the thyristor device 40 , and the control terminal of the first transistor Q1 is connected to the control logic processing module 10 . The off capacitor Coff is connected between the second terminal of the first transistor Q1 and the cathode of the thyristor device 40 .

[0192] The control terminal of the first transistor Q1 may be connected to the control logic processing module 10. The first transistor Q1 is turned on when receiving a first control signal.

[0193] When the thyristor device 40 is in the on state, the first transistor Q1 connected in series with the gate of the thyristor device 40 is disconnected.

[0194] After the control logic processing module 10 sends the first control signal, the first transistor Q1 switches to the on state, and the current of the thyristor device 40 commutates from the cathode to the gate, eventually switching the thyristor device 40 from the on state to the blocking state.

[0195] When the first transistor Q1 is turned on, the first transistor Q1 and the off capacitor Coff can provide a current flow path for the gate of the thyristor device 40, that is, the off branch is turned on. Correspondingly, when the first transistor Q1 is turned off, the off branch is turned off.

[0196] The first transistor Q1 may be a controllable switch, for example, a MOSFET, a BJT, an IGBT, an electronically controlled switch, etc.

[0197] Please refer to Figure 18 As an optional implementation, in the above embodiment, if the leakage current monitoring module 30 does not include the leakage current detection branch 32, the leakage current sampling module 31 can be connected to the shutdown branch in a contact manner to implement gate current sampling of the thyristor device 40 through contact sampling; the leakage current sampling module 31 can also be connected to the shutdown branch in a non-contact manner to implement gate current sampling of the thyristor device 40 in a non-contact sampling manner.

[0198] As another optional embodiment, the leakage current monitoring module 30 may include a leakage current detection branch 32, and the leakage current sampling module 31 may be connected to the leakage current detection branch 32 in a contact or contactless manner to implement gate current sampling of the thyristor device 40. Figures 19 to 22 , the leakage current monitoring module 30 including the leakage current detection branch 32 is described.

[0199] Please refer to Figure 19 In some embodiments, the leakage current monitoring module 30 may include a fourth transistor Q4.

[0200] A first terminal of the fourth transistor Q4 is connected to the gate of the thyristor device 40 , and a second terminal of the fourth transistor Q4 is connected to the cathode of the thyristor device 40 . A control terminal of the fourth transistor Q4 may be connected to the control logic processing module 10 .

[0201] When the control logic processing module 10 sends the first leakage current detection signal to the control terminal of the fourth transistor Q4, the fourth transistor Q4 is turned on. At this time, the turned-on fourth transistor Q4 can serve as a leakage current detection branch 32 to provide a current flow path for the gate of the thyristor device 40.

[0202] It should be noted that when the leakage current sampling module 31 samples the current on the leakage current detection branch 32, if the first transistor Q1 is in the on state, current also flows in the off branch. Therefore, the current on the leakage current detection branch 32 is only a portion of the gate current. To sample the gate current, the first transistor Q1 needs to be switched to the blocking state before sampling the current on the leakage current detection branch 32.

[0203] Please refer to Figure 20 In some embodiments, the leakage current monitoring module 30 may include a fifth transistor Q5.

[0204] A first end of the fifth transistor Q5 is connected to the gate of the thyristor device 40 , and a second end of the fifth transistor Q5 is connected to the second end of the first transistor Q1 .

[0205] When the control logic processing module 10 sends a first leakage current detection signal to the control terminal of the fifth transistor Q5, the fifth transistor Q5 is turned on. At this time, the branch formed by the turned-on fifth transistor Q5 and the off capacitor Coff can serve as a leakage current detection branch 32, providing a current flow path for the gate of the thyristor device 40.

[0206] Similarly, when collecting the gate current of the leakage current detection branch 32 , it is necessary to switch the first transistor Q1 to a blocking state before sampling the current on the leakage current detection branch 32 .

[0207] Please refer to Figure 21 In some embodiments, the leakage current monitoring module 30 may include a sixth transistor Q6 and a first capacitor C1.

[0208] A first terminal of the sixth transistor Q6 is connected to the gate of the thyristor device 40 , and a first capacitor C1 is connected between a second terminal of the sixth transistor Q6 and the cathode of the thyristor device 40 .

[0209] When the control logic processing module 10 sends the first leakage current detection signal to the control terminal of the sixth transistor Q6, the sixth transistor Q6 is turned on. At this time, the branch formed by the turned-on sixth transistor Q6 and the first capacitor C1 can serve as the leakage current detection branch 32, providing a current flow path for the gate of the thyristor device 40.

[0210] Please refer to Figure 22 In some embodiments, the leakage current monitoring module 30 may include a seventh transistor Q7 and a second capacitor C2.

[0211] A first terminal of the seventh transistor Q7 is connected to the gate of the thyristor device 40 , and the second capacitor C2 is connected between a second terminal of the seventh transistor Q7 and a second terminal of the first transistor Q1 .

[0212] When the control logic processing module 10 sends the first leakage current detection signal to the control terminal of the seventh transistor Q7, the seventh transistor Q7 is turned on. At this time, the branch formed by the turned-on seventh transistor Q7, the second capacitor C2 and the turn-off capacitor Coff can serve as the leakage current detection branch 32, providing a current flow path for the gate of the thyristor device 40.

[0213] The transistors in the above embodiments may be MOSFETs, BJTs, IGBTs, electronically controlled switches, etc., which are not limited here.

[0214] Please refer to Figure 23 and Figure 24 , Figure 23 shows the shutdown mode A, Figure 16 and Figure 17 Corresponding control signal timing diagram; Figure 24 Then it shows the shutdown mode B, Figures 19 to 22 Corresponding control signal timing diagram.

[0215] like Figure 23 As shown, the system control instruction is the instruction signal received by the control logic processing module 10. When the system control instruction changes from a high level to a low level, it corresponds to a system shutdown instruction.

[0216] Shutdown signal 1 and shutdown signal 2 are the first and second control signals received by the device shutdown module 20. The first control signal is at a low level, and the second control signal is at a high level. Shutdown signal 1 is the control signal for the second transistor Q2, and shutdown signal 2 is the control signal for the third transistor Q3. The leakage current detection signal is the control signal for the eighth transistor Q8 or the ninth transistor Q9.

[0217] When the system control command jumps to a low-level signal, the control logic processing module 10 sets the shutdown signal 1 high and the shutdown signal 2 low based on the system shutdown command. At this time, the second transistor Q2 is turned on and the third transistor Q3 is turned off, and the thyristor device switches to the blocking state. After the thyristor device is stably disconnected, the control logic processing module 10 sets the leakage current detection signal high. At this time, the eighth transistor Q8 or the ninth transistor Q9 is turned on, making the leakage current detection branch conductive.

[0218] After the leakage current detection branch is turned on, after a preset dead time, the control logic processing module 10 sets the shutdown signal 1 low, disconnecting the shutdown branch. At this point, only the leakage current detection branch is turned on, allowing gate current sampling through the leakage current detection branch. After completing gate current sampling, the control logic processing module 10 sets the shutdown signal 1 high, turning the shutdown branch back on. After a preset dead time, the control logic processing module 10 sets the leakage current detection signal low. At this point, the shutdown branch is turned on, the leakage current detection branch is disconnected, and the thyristor device maintains a stable blocking state.

[0219] It can be understood that when the thyristor device completes leakage current detection and maintains the blocking state, if the system control instruction received by the control logic processing module 10 jumps to a high-level signal again, the control logic processing module 10 sets the shutdown signal 1 to low and the shutdown signal 2 to high, so that the thyristor device is turned on again.

[0220] like Figure 24 As shown, the shutdown signal is the first control signal and the second control signal received by the first transistor Q1. The leakage current detection signal is the control signal of the fourth transistor Q4, the fifth transistor Q5, the sixth transistor Q6 or the seventh transistor Q7.

[0221] With the above Figure 23 The corresponding timing control method is similar. When the system control instruction jumps to a low-level signal, the control logic processing module 10 sets the shutdown signal high based on the system shutdown instruction. At this time, the first transistor Q1 is turned on, and the thyristor device switches to the blocking state. After the thyristor device is stably disconnected, the control logic processing module 10 sets the leakage current detection signal high. At this time, the fourth transistor Q4, the fifth transistor Q5, the sixth transistor Q6, or the seventh transistor Q7 is turned on, making the leakage current detection branch conductive.

[0222] After the leakage current detection branch is turned on, the control logic processing module 10 sets the shutdown signal low after a preset dead time, disconnecting the shutdown branch. At this point, only the leakage current detection branch is turned on, allowing gate current sampling through the leakage current detection branch. After completing gate current sampling, the control logic processing module 10 sets the shutdown signal high to turn the shutdown branch back on. After the preset dead time, the control logic processing module 10 sets the leakage current detection signal low. At this point, the shutdown branch is turned on, the leakage current detection branch is disconnected, and the thyristor device maintains a stable blocking state.

[0223] When the thyristor device completes leakage current detection and maintains the blocking state, if the system control instruction received by the control logic processing module 10 jumps to a high level signal again, the control logic processing module 10 sets the shutdown signal low to turn the thyristor device back on.

[0224] It should be noted that Figure 23 and Figure 24 Taking the timing sequence shown as an example, during a single conduction of the leakage current detection branch, multiple gate current sampling can be achieved through the leakage current detection branch. That is, multiple leakage current sampling signals can be generated within the valid interval of a single leakage current detection signal.

[0225] When the control logic processing module 10 sets the shutdown signal high based on the system shutdown instruction, placing the thyristor device in a blocking state, the leakage current detection branch can be turned on once or multiple times. That is, during a single blocking process of the thyristor device, the leakage current detection branch can be controlled to be turned on once or multiple times, and during each conduction process of the leakage current detection branch, one or more leakage current sampling signals can be acquired.

[0226] The transistors mentioned in the above embodiments, such as the first transistor Q1 to the ninth transistor Q9, may be controllable switches, such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), BJTs (Bipolar junction transistors), IGBTs (Insulate-Gate Bipolar Transistors), and electrically controlled switches.

[0227] It should be noted that the transistors in the above embodiments are not limited to be of the same device type. That is, any two transistors in the plurality of transistors may be of the same type, such as both MOSFETs, or of different types, which is not limited here.

[0228] As another optional implementation, the transistors in the above embodiment may also be replaced by other switching devices, such as an optocoupler switch, an isolating switch, etc.

[0229] In each of the above-mentioned embodiments, by controlling the thyristor device to be in a blocking state and monitoring the gate current of the thyristor device, online monitoring of the leakage current of the thyristor device can be achieved. The above-mentioned monitoring method has the characteristics of small component size, simple and reliable circuit, low operating loss, and low cost. In addition, the above-mentioned thyristor device leakage current monitoring circuit can be integrated into the drive circuit of the thyristor device, without the need to be connected to the main circuit of the power electronic converter system, without affecting the operation of the system, and has the advantage of a wide range of applications. In addition, the above-mentioned embodiment also has the characteristics of high monitoring accuracy and adjustable monitoring range, which can well meet the needs of online evaluation of the blocking characteristics of thyristor devices and has wide application value in power electronic converter projects containing thyristor devices.

[0230] Based on the same inventive concept, the present application also provides a power electronic device, including a thyristor device and the thyristor device leakage current monitoring circuit in the above embodiment.

[0231] In some embodiments, the above-mentioned thyristor device is a thyristor device with a non-gate cathode short-circuit structure, for example, it can be an ETO (Emitter Turn-OFF Thyristor), a GTO (Gate Turn-OFF Thyristor) or other types of thyristors, which are not limited here.

[0232] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium that can store or transmit information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0233] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0234] This article uses specific examples to illustrate the principles and implementation methods of this application. The above examples are only used to help understand the method and core ideas of this application. The above are only preferred implementation methods of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of this application, they can make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of this application to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A method for monitoring leakage current of a thyristor device, characterized in that: include: In response to a system shutdown instruction, sending a first control signal to a device shutdown module; The device shutdown module is used to turn on the shutdown branch of the thyristor device according to the first control signal; Obtaining a leakage current sampling signal from a leakage current monitoring module; the leakage current monitoring module is used to convert the gate current of the thyristor device into the leakage current sampling signal; A leakage current monitoring result is generated based on the leakage current sampling signal.

2. The method for monitoring leakage current of thyristor devices according to claim 1, wherein: The step of obtaining a leakage current sampling signal from the leakage current monitoring module includes: When the thyristor device is blocked, a first leakage current detection signal is sent to the leakage current detection switch; the leakage current detection switch is used to turn on the leakage current detection branch according to the first leakage current detection signal, and the leakage current monitoring module is used to collect the gate current on the leakage current detection branch; Sending a second control signal to the device shutdown module; the device shutdown module is used to disconnect the shutdown branch of the thyristor device according to the second control signal; When the leakage current detection branch is turned on and the shutoff branch is turned off, a leakage current sampling signal is obtained from the leakage current monitoring module.

3. The method for monitoring leakage current of thyristor devices according to claim 2, wherein: When the leakage current detection branch is turned on and the shut-off branch is turned off, after obtaining the leakage current sampling signal from the leakage current monitoring module, the method further includes: sending a first control signal to the device shutdown module; A second leakage current detection signal is sent to the leakage current detection switch; the leakage current detection switch is used to disconnect the leakage current detection branch according to the second leakage current detection signal.

4. The method for monitoring leakage current of thyristor devices according to claim 1, wherein: The step of obtaining a leakage current sampling signal from the leakage current monitoring module includes: When the thyristor device is blocked, a leakage current sampling signal is obtained from a leakage current monitoring module; the leakage current monitoring module is used to collect the gate current on the turn-off branch.

5. The method for monitoring leakage current of thyristor devices according to claim 1, wherein: After obtaining the leakage current sampling signal from the leakage current monitoring module, the method further includes: A second control signal is sent to the device shutdown module.

6. A thyristor device leakage current monitoring circuit, characterized in that: A method for monitoring leakage current of a thyristor device according to any one of claims 1 to 5, comprising: A device shutdown module, the device shutdown module is connected to a thyristor device to form a shutdown branch; A leakage current monitoring module, configured to be connected in contact or contactless fashion to the gate of the thyristor device; The control logic processing module is connected to the control end of the device shutdown module and the sampling output end of the leakage current monitoring module.

7. The thyristor device leakage current monitoring circuit according to claim 6, characterized in that: The leakage current monitoring module includes: A leakage current sampling module connected to the shutoff branch; or, A leakage current sampling module and a leakage current detection branch are connected.

8. The thyristor device leakage current monitoring circuit according to claim 7, characterized in that: The leakage current sampling module includes: a non-contact sampling module, which is contactlessly connected to the shutoff branch or the leakage current detection branch; Alternatively, the contact sampling module is connected in series to the shutoff branch or the leakage current detection branch.

9. The thyristor device leakage current monitoring circuit according to claim 8, characterized in that: The contact sampling module includes one of a differential amplification sampling unit, an operational amplification sampling unit or a current mutual induction unit.

10. The thyristor device leakage current monitoring circuit according to claim 7, characterized in that: The device shutdown module includes: a second transistor, wherein a first terminal of the second transistor is connected to the gate of the thyristor device, and a control terminal of the second transistor is connected to the control logic processing module; the second transistor is configured to be turned on when receiving a first control signal; A third transistor, wherein the first end of the third transistor is connected to the cathode of the thyristor device, the second end of the third transistor is connected to the second end of the second transistor, and the control end of the third transistor is connected to the control logic processing module; the third transistor is configured to be disconnected upon receiving a first control signal.

11. The thyristor device leakage current monitoring circuit according to claim 10, characterized in that: The leakage current monitoring module includes: An eighth transistor, wherein a first end of the eighth transistor is connected to the gate of the thyristor device, and a second end of the eighth transistor is connected to the second end of the third transistor; the eighth transistor is configured to be turned on when receiving a first leakage current detection signal.

12. The thyristor device leakage current monitoring circuit according to claim 10, characterized in that: The leakage current monitoring module includes: a ninth transistor, wherein a first end of the ninth transistor is connected to the gate of the thyristor device; the ninth transistor is configured to be turned on when receiving a first leakage current detection signal; A third capacitor is connected between the second end of the ninth transistor and the second end of the second transistor.

13. The thyristor device leakage current monitoring circuit according to claim 7, characterized in that: The device shutdown module includes: a first transistor, wherein a first terminal of the first transistor is connected to the gate of the thyristor device, and a control terminal of the first transistor is connected to the control logic processing module; the first transistor is configured to be turned on when receiving a first control signal; The turn-off capacitor is connected between the second end of the first transistor and the cathode of the thyristor device.

14. The thyristor device leakage current monitoring circuit according to claim 13, characterized in that: The leakage current monitoring module includes: A fourth transistor, wherein a first end of the fourth transistor is connected to the gate of the thyristor device, and a second end of the fourth transistor is connected to the cathode of the thyristor device; the fourth transistor is configured to be turned on when receiving a first leakage current detection signal.

15. The thyristor device leakage current monitoring circuit according to claim 13, characterized in that: The leakage current monitoring module includes: A fifth transistor, wherein a first end of the fifth transistor is connected to the gate of the thyristor device, and a second end of the fifth transistor is connected to the second end of the first transistor; the fifth transistor is configured to be turned on when receiving a first leakage current detection signal.

16. The thyristor device leakage current monitoring circuit according to claim 13, characterized in that: The leakage current monitoring module includes: a sixth transistor, a first end of the sixth transistor being connected to the gate of the thyristor device; the sixth transistor being configured to be turned on upon receiving a first leakage current detection signal; A first capacitor is connected between the second end of the sixth transistor and the cathode of the thyristor device.

17. The thyristor device leakage current monitoring circuit according to claim 13, characterized in that: The leakage current monitoring module includes: a seventh transistor, wherein a first end of the seventh transistor is connected to the gate of the thyristor device; the seventh transistor is configured to be turned on when receiving a first leakage current detection signal; A second capacitor is connected between the second end of the seventh transistor and the second end of the first transistor.

18. The thyristor device leakage current monitoring circuit according to claim 7, characterized in that: The thyristor device leakage current monitoring circuit further includes: A leakage current protection module is electrically connected to the device shutdown module, the leakage current monitoring module and the control logic processing module respectively; the leakage current protection module is used to perform overcurrent protection on the leakage current monitoring module.

19. The thyristor device leakage current monitoring circuit according to claim 18, characterized in that: The leakage current protection module includes at least one of a voltage limiting unit, a current limiting unit or a fault detection unit; The voltage limiting unit is electrically connected to the sampling interface of the leakage current monitoring module, and is used to limit the voltage when the voltage of the sampling interface is too high; In the case where the leakage current monitoring module includes a leakage current detection branch, the current limiting unit is connected in series to the leakage current detection branch; in the case where the leakage current monitoring module does not include a leakage current detection branch, the current limiting unit is connected in series to the shutdown branch; the current limiting unit is used to limit the current when the branch current is too large; In the case where the leakage current monitoring module includes a leakage current detection branch, the fault detection end of the fault detection unit is electrically connected to the leakage current detection branch; the fault signal output end of the fault detection unit is electrically connected to the control logic processing module; the fault detection unit is used to send a fault signal to the control logic processing module when a branch fault is detected, so that the control logic processing module turns on the shutdown branch and disconnects the leakage current detection branch based on the fault signal.

20. A power electronic device, characterized in that: The invention comprises a thyristor device and a thyristor device leakage current monitoring circuit as claimed in any one of claims 6 to 19.

21. The power electronic device according to claim 20, characterized in that The thyristor device is a thyristor device with a non-gate cathode short-circuit structure.

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