Thyristor type device junction temperature monitoring circuit and method and power electronic device

Abstract

The invention discloses a thyristor type device junction temperature monitoring circuit and method and a power electronic device, and the circuit comprises a device turn-off module which is connected with a thyristor type device and forms a turn-off branch; the junction temperature monitoring module comprises a voltage source type avalanche generation module, the voltage source type avalanche generation module is connected with the gate pole and the cathode of the thyristor type device, and the voltage source type avalanche generation module is used for guiding avalanche breakdown under preset voltage; the junction temperature monitoring module is used for acquiring an avalanche threshold voltage under the condition that avalanche breakdown occurs to the thyristor device; the control logic processing module is connected with the control end of the device turn-off module and the junction temperature monitoring module, and the control logic processing module is used for determining the junction temperature value of the thyristor type device based on the first corresponding relation and the avalanche threshold voltage; the first corresponding relation is the corresponding relation between the pre-generated avalanche threshold voltage and the junction temperature. According to the invention, high-precision on-line monitoring of the junction temperature of the thyristor device can be realized.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a junction temperature monitoring circuit, method and power electronic device for thyristor devices. Background Technology

[0002] During the operation of a power electronic converter system containing turn-off thyristors, whether there are abnormalities in the internal temperature (junction temperature) of the thyristor devices can determine whether the power electronic system can operate reliably in the long term.

[0003] When the junction temperature of thyristor devices is too high, it will not only cause transient failures such as thermal runaway, but also accelerate the aging of device materials, and even lead to long-term failure of the device, which in turn will damage the power electronic converter system.

[0004] In related technologies, the thermocouple method and the temperature sensor method are mainly used to monitor the junction temperature of devices. The thermocouple method measures the temperature of the device by installing thermocouples on the device casing and estimates the junction temperature using the device's operating power and thermal impedance model. The temperature sensor method measures the surface temperature of the device (such as thermistors, fiber optic sensors, etc.) by installing temperature sensors on the device surface and equates it to the junction temperature.

[0005] Thermocouple methods suffer from low accuracy, and obtaining the operating power of devices during actual operation is extremely difficult. While temperature sensor methods offer improved accuracy compared to thermocouple methods, thyristors in power electronic systems are typically press-fit devices, making it difficult to deploy temperature sensors and thus unsuitable for junction temperature monitoring of thyristors. Therefore, how to perform online monitoring of the junction temperature of operating thyristors has become an urgent technical problem to be solved. Summary of the Invention

[0006] This application provides a junction temperature monitoring circuit, method, and power electronic device for thyristor devices, which can improve the technical problem of insufficient accuracy in junction temperature monitoring of thyristor devices in related technologies.

[0007] In a first aspect, this application provides a method for monitoring the junction temperature of thyristor devices, including:

[0008] Device shutdown module, which is connected to thyristor-type devices to form a shutdown branch;

[0009] The junction temperature monitoring module includes a voltage source avalanche generation module, which is connected to the gate and cathode of a thyristor-like device. The voltage source avalanche generation module is used to guide the gate and cathode of the thyristor-like device to undergo avalanche breakdown at a preset voltage. The junction temperature monitoring module is used to obtain the avalanche threshold voltage of the thyristor-like device when avalanche breakdown occurs.

[0010] The control logic processing module is connected to the control terminal of the device shutdown module and the output terminal of the junction temperature monitoring module. The control logic processing module is used to determine the junction temperature value of thyristor devices based on the first correspondence and the avalanche threshold voltage. The first correspondence is a pre-generated correspondence between the avalanche threshold voltage and the junction temperature.

[0011] Optionally, the control terminal of the voltage source type avalanche generator module is connected to the control logic processing module;

[0012] The voltage source type avalanche generation module is used to respond to the junction temperature monitoring signal sent by the control logic processing module and guide the gate and cathode of thyristor devices to undergo avalanche breakdown at a preset voltage.

[0013] Optionally, the junction temperature monitoring module also includes:

[0014] The voltage bias compensation module is electrically connected to the sampling interface of the voltage source avalanche generator module. The voltage bias compensation module is used to perform bias compensation on the acquired sampling signal to obtain the avalanche compensation voltage within a preset voltage range.

[0015] Optionally, the junction temperature monitoring module also includes:

[0016] The avalanche threshold sampling module has its sampling terminal electrically connected to the output terminal of the voltage bias compensation module, or its sampling terminal electrically connected to the sampling interface of the voltage source avalanche generator module. The avalanche threshold sampling module is used to process the avalanche compensation voltage output by the voltage bias compensation module or the sampling signal obtained by sampling the voltage source avalanche generator module to obtain the avalanche sampling voltage.

[0017] Optionally, the voltage source type avalanche generator module includes:

[0018] The first DC power supply is used to provide a DC voltage; wherein the DC voltage is greater than the maximum typical value of the avalanche threshold voltage;

[0019] Junction temperature monitoring switch, used to turn on in response to junction temperature monitoring signal;

[0020] A current limiting module is used to limit the current of DC voltage;

[0021] The first DC power supply, junction temperature monitoring switch, and current limiting module are connected in series between the gate and cathode of the thyristor-type device.

[0022] Optionally, the voltage source type avalanche generator module also includes:

[0023] The first sampling interface is used to sample the voltage at both ends of the first DC power supply;

[0024] The second sampling interface is used to sample the voltage across the current limiting module.

[0025] Optionally, the voltage source type avalanche generator module also includes:

[0026] The first protection unit, connected in parallel with the current limiting module, is used to limit the voltage across the current limiting module.

[0027] And / or,

[0028] The second protection unit is used to detect faults in the current branch formed by the first DC power supply, the junction temperature monitoring switch and the current limiting module, and send a fault signal to the control logic processing module when a fault is detected in the branch, so that the control logic processing module controls the junction temperature monitoring switch to disconnect based on the fault signal.

[0029] And / or,

[0030] The third protection unit is connected in series in the current branch formed by the first DC power supply, the junction temperature monitoring switch and the current limiting module; the third protection unit is used to limit the current direction to the first direction; the first direction is from the gate of the thyristor device to the cathode of the thyristor device.

[0031] Optionally, the device shutdown module includes:

[0032] The first transistor has its first terminal connected to the gate of a thyristor-type device, and its control terminal connected to a control logic processing module; the first transistor is used to turn on when a first control signal is received.

[0033] A turn-off capacitor is connected in series between the first terminal of the first transistor and the gate of the thyristor-like device, or the turn-off capacitor is connected in series between the second terminal of the first transistor and the cathode of the thyristor-like device.

[0034] Optionally, if the first transistor is a unidirectional blocking transistor, the device shutdown module further includes:

[0035] The first blocking unit, connected in series with the first transistor, is used to limit the current direction to unidirectional; wherein the blocking direction of the first blocking unit is opposite to that of the first transistor.

[0036] Secondly, this application provides a method for monitoring the junction temperature of thyristor devices, applied to the junction temperature monitoring circuit of the thyristor device in the first aspect, the method comprising:

[0037] In response to a system shutdown command, a first control signal is sent to the device shutdown module; the device shutdown module is used to turn on the shutdown branch of the thyristor-type device according to the first control signal.

[0038] The avalanche threshold voltage is obtained from the junction temperature monitoring module. The junction temperature monitoring module is used to obtain the avalanche threshold voltage of thyristor devices in the event of avalanche breakdown.

[0039] Based on the avalanche threshold voltage and the first correspondence, the junction temperature of thyristor devices is determined.

[0040] Optionally, the avalanche threshold voltage is obtained from the junction temperature monitoring module, including:

[0041] When the thyristor-type device is blocked, a junction temperature monitoring signal is sent to the voltage source avalanche generation module; the voltage source avalanche generation module is used to respond to the junction temperature monitoring signal and guide the gate and cathode of the thyristor-type device to undergo avalanche breakdown at a preset voltage.

[0042] In the event of avalanche breakdown at the gate and cathode of a thyristor-type device, the avalanche threshold voltage is obtained from the junction temperature monitoring module.

[0043] Send a junction temperature end signal to the voltage source avalanche generator module; the voltage source avalanche generator module is used to disconnect the junction temperature monitoring switch in response to the junction temperature end signal.

[0044] Optionally, before obtaining the avalanche threshold voltage from the junction temperature monitoring module, the following steps are also included:

[0045] A second control signal is sent to the device shutdown module; the device shutdown module is used to disconnect the shutdown branch of the thyristor-type device according to the second control signal.

[0046] Before sending the junction temperature termination signal to the voltage source avalanche generator module, the following steps are also included:

[0047] A first control signal is sent to the device shutdown module; the device shutdown module is used to turn on the shutdown branch of the thyristor-type device according to the first control signal.

[0048] Thirdly, this application provides a power electronic device, including a thyristor-type device and a junction temperature monitoring circuit for the thyristor-type device as described in the second aspect.

[0049] The junction temperature monitoring circuit, method, and power electronic device of this application for thyristor devices, when the thyristor device is in the on-state, allow the control logic processing module to send a first control signal to the control terminal of the device turn-off module. After the device turn-off module turns on the turn-off branch of the thyristor device based on the first control signal, the voltage source-type avalanche generation module of the junction temperature monitoring module can provide a preset voltage between the gate and cathode of the thyristor device to achieve avalanche breakdown. When avalanche breakdown occurs between the gate and cathode of the thyristor device, the junction temperature monitoring module obtains the avalanche threshold voltage between the gate and cathode. The control logic processing module can obtain the avalanche threshold voltage from the output terminal of the junction temperature monitoring module. Based on a pre-stored first correspondence between the avalanche threshold voltage and the junction temperature, the control logic processing module can determine the junction temperature value corresponding to the avalanche threshold voltage as the device junction temperature of the thyristor device, thereby realizing junction temperature monitoring of the thyristor device. Since there is a corresponding relationship between the avalanche threshold voltage and the junction temperature of thyristor devices within a certain range, by monitoring the avalanche threshold voltage between the gate and cathode after the thyristor device is turned off, the junction temperature of the thyristor device can be calculated based on the monitored avalanche threshold voltage without affecting the system operation, thus achieving high-precision online monitoring of the junction temperature of thyristor devices. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in one embodiment of this application;

[0052] Figure 2 This is a schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0053] Figure 3 This is a schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0054] Figure 4 This is one of the structural schematic diagrams of a junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0055] Figure 5 This is a second schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0056] Figure 6 This is a schematic diagram of the circuit structure of a voltage source type avalanche generator module provided in an embodiment of this application;

[0057] Figure 7 This is a schematic diagram of the circuit structure of a voltage source type avalanche generator module provided in another embodiment of this application;

[0058] Figure 8 This is the third schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0059] Figure 9 This is the fourth schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0060] Figure 10 This is the fifth schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0061] Figure 11 This is the sixth schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0062] Figure 12 This is the seventh schematic diagram of the junction temperature monitoring circuit for thyristor devices provided in another embodiment of this application;

[0063] Figure 13 This is a schematic diagram of the circuit structure of a device shutdown module provided in an embodiment of this application;

[0064] Figure 14 This is a schematic flowchart of a thyristor junction temperature monitoring method provided in an embodiment of this application;

[0065] Figure 15 This is an embodiment provided by this application. Figure 6 and Figure 13 The timing logic diagram corresponding to the embodiment;

[0066] Figure 16 This is provided by another embodiment of the present application. Figure 6 and Figure 13 The timing logic diagram corresponding to the embodiment;

[0067] In the attached image:

[0068] 10. Control logic processing module; 20. Device shutdown module; 30. Junction temperature monitoring module; 31. Voltage source type avalanche generation module; 32. Voltage bias compensation module; 33. Avalanche threshold sampling module; DC1, First DC power supply; Q2, Junction temperature monitoring switch; 311. Current limiting module; Q1, First transistor; Coff, Shutdown capacitor; 40. Thyristor devices. Detailed Implementation

[0069] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0071] During the operation of a power electronic converter system containing turn-off thyristors, whether there are abnormalities in the internal temperature (junction temperature) of the thyristor devices can determine whether the power electronic system can operate reliably in the long term.

[0072] When the junction temperature of thyristor devices is too high, it will not only cause transient failures such as thermal runaway, but also accelerate the aging of device materials, and even lead to long-term failure of the device, which in turn will damage the power electronic converter system.

[0073] In related technologies, the thermocouple method and the temperature sensor method are mainly used to monitor the junction temperature of devices. The thermocouple method measures the temperature of the device by installing thermocouples on the device casing and estimates the junction temperature using the device's operating power and thermal impedance model. The temperature sensor method measures the surface temperature of the device (such as thermistors, fiber optic sensors, etc.) by installing temperature sensors on the device surface and equates it to the junction temperature.

[0074] Thermocouple methods suffer from low accuracy, and obtaining the operating power of devices during actual operation is extremely difficult. While temperature sensor methods offer improved accuracy compared to thermocouple methods, thyristors in power electronic systems are typically press-fit devices, making it difficult to deploy temperature sensors and thus unsuitable for junction temperature monitoring of thyristors. Therefore, how to perform online monitoring of the junction temperature of operating thyristors has become an urgent technical problem to be solved.

[0075] To address at least one of the aforementioned technical problems, embodiments of this application provide a junction temperature monitoring circuit, method, and power electronic device for thyristor devices. This device can monitor the avalanche threshold voltage between the gate and cathode of a thyristor device in the blocking state, thereby achieving junction temperature monitoring. The junction temperature monitoring circuit for thyristor devices provided in this application embodiment is described below.

[0076] Figure 1 This application illustrates a junction temperature monitoring circuit for thyristor devices according to an embodiment of the present application. The junction temperature monitoring circuit for thyristor devices includes a device turn-off module 20, a junction temperature monitoring module 30, and a control logic processing module 10.

[0077] The device shutdown module 20 is connected to the thyristor-type device 40 to form a shutdown branch. A, G, and K of the thyristor-type device 40 are the anode, gate, and cathode, respectively.

[0078] When the thyristor-like 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 turn-off module 20. The device turn-off module 20 can control the turn-off branch of the thyristor-like device 40 to be turned on based on the first control signal. When the turn-off branch is turned on, the thyristor-like device 40 is in the OFF state.

[0079] The junction temperature monitoring module 30 includes a voltage source avalanche generator module 31, which can be connected to the gate and cathode of the thyristor-type device 40.

[0080] When the off-branch is turned on, the thyristor device 40 is in a blocking state. The voltage source type avalanche generation module 31 can provide DC voltage to the gate and cathode of the thyristor device 40 to guide the gate and cathode of the thyristor device 40 to undergo avalanche breakdown at a preset voltage.

[0081] When the turn-off branch is turned on and an avalanche breakdown occurs between the gate and cathode of the thyristor device 40, the junction temperature monitoring module 30 can obtain the voltage difference between the gate and cathode of the thyristor device 40, which is the avalanche threshold voltage of the thyristor device 40.

[0082] The control logic processing module 10 is connected to the control terminal of the device shutdown module 20 to control the on / off state of the device shutdown module.

[0083] The control logic processing module 10 can also be connected to the junction temperature monitoring module 30. For example, the control logic processing module 10 can be connected to both the control terminal and the output terminal of the junction temperature monitoring module 30. The control logic processing module 10 can receive system control commands and send corresponding control signals to the junction temperature monitoring module 30 based on the system control commands. For example, the control value logic processing module 10 can send a junction temperature monitoring signal to the control terminal of the junction temperature monitoring module 30 based on the system control value command, so that the junction temperature monitoring module 30 guides the gate and cathode of the thyristor-like device 40 to undergo avalanche breakdown at a preset voltage. The control logic processing module 10 pre-stores a first correspondence, which is the correspondence between the avalanche threshold voltage and the junction temperature generated based on the avalanche threshold voltage corresponding to the thyristor-like device 40 at different junction temperatures after experimental simulation of the thyristor-like device 40 as a sample. After the control logic processing module 10 obtains the current avalanche threshold voltage of the thyristor device 40 from the output terminal of the junction temperature monitoring module 30, it can obtain the junction temperature value corresponding to the avalanche threshold voltage based on the first correspondence. The junction temperature value is the current junction temperature of the thyristor device 40.

[0084] In this embodiment, when the thyristor-like 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 turn-off module 20. After the device turn-off module 20 turns on the turn-off branch of the thyristor-like device 40 based on the first control signal, the voltage source type avalanche generation module 31 of the junction temperature monitoring module 30 can provide a preset voltage between the gate and cathode of the thyristor-like device 40 to achieve avalanche breakdown. When avalanche breakdown occurs between the gate and cathode of the thyristor-like device 40, the junction temperature monitoring module 30 can obtain the avalanche threshold voltage between the gate and cathode. The control logic processing module 10 can obtain the avalanche threshold voltage from the output terminal of the junction temperature monitoring module 30. Based on the pre-stored first correspondence between the avalanche threshold voltage and the junction temperature, the control logic processing module 10 can determine the junction temperature value corresponding to the avalanche threshold voltage as the device junction temperature of the thyristor-like device 40, so as to realize the junction temperature monitoring of the thyristor-like device 40. Since there is a corresponding relationship between the avalanche threshold voltage and the junction temperature of the thyristor device 40 within a certain range, by monitoring the avalanche threshold voltage between the gate and the cathode after turning off the thyristor device 40, the junction temperature of the thyristor device 40 can be calculated based on the monitored avalanche threshold voltage without affecting the operation of the system, thus achieving high-precision online monitoring of the junction temperature of the thyristor device 40.

[0085] It should be noted that the device shutdown module 20 and the control logic processing module 10 mentioned above are only part of the device drive circuit of the thyristor device 40. The device shutdown module 20 and the control logic processing module 10 can also work with other parts of the device drive circuit to achieve other functions, such as leakage current sampling and detection, which are not limited here.

[0086] Please continue to refer to Figure 1 In some embodiments, the control terminal of the voltage source type avalanche generation module 31 is connected to the control logic processing module 10.

[0087] When the off-branch is turned on, the thyristor device 40 is in a blocking state. The control logic processing module 10 can send a junction temperature monitoring signal to the voltage source avalanche generation module 31. In response to the junction temperature monitoring signal sent by the control logic processing module 10, the voltage source avalanche generation module 31 can provide a preset voltage to the gate and cathode of the thyristor device 40 to guide the gate and cathode of the thyristor device 40 to undergo avalanche breakdown at the preset voltage.

[0088] In the above embodiment, the voltage source type avalanche generation module 31 can provide a preset voltage, thereby causing avalanche breakdown of the gate and cathode of the thyristor device 40 under the preset voltage. At this time, the junction temperature of the thyristor device 40 can be calculated based on the avalanche threshold voltage between the gate and cathode of the thyristor device 40.

[0089] Please refer to Figure 2 In some embodiments, the junction temperature monitoring module 30 may further include a voltage bias compensation module 32.

[0090] Based on the fact that the junction temperature monitoring module 30 already includes the voltage source avalanche generator module 31, the voltage source avalanche generator module 31 is pre-set with a sampling interface, and the sampling end of the voltage bias compensation module 32 can be electrically connected to the sampling interface of the voltage source avalanche generator module 31.

[0091] When the voltage source avalanche generation module 31 guides the gate and cathode of the thyristor-type device 40 to undergo avalanche breakdown at a preset voltage, the sampling terminal of the voltage bias compensation module 32 can obtain the corresponding sampling signal from the corresponding sampling interface. The voltage bias compensation module 32 can perform bias compensation on the obtained sampling signal to obtain the avalanche compensation voltage within the preset voltage range.

[0092] When a thyristor device 40 experiences avalanche breakdown, the typical value of the avalanche threshold voltage between the gate and cathode is usually much larger than the voltage range in which the avalanche threshold voltage varies with junction temperature. For example, the typical range of the avalanche threshold voltage for a certain thyristor device 40 is -27V to -23V, while the voltage range in which this typical value varies with junction temperature is only 4V. Since the absolute value of the typical value is much larger than the voltage range, directly sampling the avalanche threshold voltage would result in low accuracy due to the excessively large sampling voltage range, ultimately leading to an inaccurate calculated junction temperature. Therefore, by setting the voltage bias compensation module 32, voltage compensation can be performed when the absolute value of the typical avalanche threshold voltage is too large, thereby extracting the voltage offset in the avalanche threshold voltage that varies with junction temperature, improving the accuracy of voltage acquisition and the accuracy of junction temperature monitoring.

[0093] As an example, taking the typical range of the avalanche threshold voltage of the thyristor-type device 40 as -27V to -23V, the voltage bias compensation module 32 can compensate for the higher reverse bias voltage value of the avalanche threshold voltage. For example, the voltage bias compensation module 32 can superimpose a compensation voltage of +27V on the avalanche threshold voltage, in which case the voltage range of the avalanche compensation voltage output by the voltage bias compensation module 32 is 0V to 4V. As another example, the compensation voltage can also be +25V, then the voltage range of the avalanche compensation voltage is -2V to 2V.

[0094] As an optional implementation, the voltage bias compensation circuit described above can be an operational amplifier, a subtractor (differential amplifier), an adder, a potentiometer, a voltage divider, a reference voltage source, a digital potentiometer, a digital-to-analog converter, an isolation amplifier, a voltage source, or other circuits capable of achieving voltage bias compensation. It can also be a circuit composed of combinations of the above circuits or devices, and there are no restrictions on this.

[0095] Please refer to Figures 3 to 4 In some embodiments, the junction temperature monitoring module 30 may further include an avalanche threshold sampling module 33.

[0096] like Figure 3 As shown, based on the fact that the junction temperature monitoring module 30 already includes the voltage source type avalanche generation module 31, the sampling end of the avalanche threshold sampling module 33 can be electrically connected to the sampling interface of the voltage source type avalanche generation module 31.

[0097] like Figure 4 As shown, based on the junction temperature monitoring module 30 which already includes a voltage source type avalanche generation module 31 and a voltage bias compensation module 32, the sampling end of the avalanche threshold sampling module 33 is electrically connected to the output end of the voltage bias compensation module 32.

[0098] The avalanche threshold sampling module 33 can sample voltage directly from the sampling interface of the voltage source type avalanche generation module 31, or it can sample voltage from the output of the voltage bias compensation module 32.

[0099] After the avalanche threshold sampling module 33 acquires the avalanche compensation voltage output by the voltage bias compensation module 32 or the sampling signal obtained by sampling the voltage source type avalanche generation module 31, the acquired voltage signal can be processed to obtain the avalanche sampling voltage.

[0100] The avalanche threshold sampling module 33 can perform signal processing on the acquired voltage signal based on the actual needs of backend signal processing and data processing. For example, the avalanche threshold sampling module 33 can perform one or more of the following processing methods on the voltage signal: scaling, isolated output, filtering, analog-to-digital conversion, buffering, shaping, and sample-and-hold, so that the processed avalanche sampling voltage can meet the signal processing and data processing requirements of the backend. The avalanche threshold sampling module 33 can also perform other signal processing methods based on the actual needs of the backend, which are not limited here.

[0101] It is understandable that the signal processing of the avalanche threshold sampling module 33 can be achieved through operational amplifier circuits, adjustable gain amplifiers, isolation amplifiers, optocoupler isolation circuits, active / passive filters, analog-to-digital converter chips, buffer amplifiers, comparators, Schmitt triggers, sample-and-hold circuits, adders, subtractors, potentiometers, voltage dividers, reference voltage sources, digital potentiometers, digital-to-analog converters, level conversion circuits, etc., or it can be a circuit composed of the above circuits or devices, without any restrictions.

[0102] As another alternative implementation method, please refer to Figure 5 Since the junction temperature monitoring module 30 already includes the voltage source avalanche generator module 31, the sampling terminal of the avalanche threshold sampling module 33 can be electrically connected to the sampling interface of the voltage source avalanche generator module 31, and the output terminal of the avalanche threshold sampling module 33 is connected to the sampling terminal of the voltage bias compensation module 32. That is, the avalanche threshold sampling module 33 first samples the voltage from the voltage source avalanche generator module 31, and then inputs the sampled voltage to the voltage bias compensation module 32 for bias compensation.

[0103] Please refer to Figure 6 In some embodiments, the voltage source type avalanche generation module 31 may include a first DC power supply DC1, a junction temperature monitoring switch Q2, and a current limiting module 311.

[0104] The first DC power supply DC1, the junction temperature monitoring switch Q2, and the current limiting module 311 are connected in series between the gate and the cathode of the thyristor device 40.

[0105] Junction temperature monitoring switch Q2 can be turned on in response to a junction temperature monitoring signal. When junction temperature monitoring switch Q2 is on, the first DC power supply DC1 can provide a DC voltage that is greater than the maximum typical value of the avalanche threshold voltage. That is, the DC voltage provided by the first DC power supply DC1 can reverse bias the PN junction between the gate and cathode of the thyristor-type device 40, causing it to enter the avalanche breakdown stage.

[0106] When the circuit is on, the current limiting module 311 can limit the DC voltage, that is, the current limiting module 311 can prevent the device junction temperature from rising due to excessive current in the circuit. In addition, the current limiting module 311 can also act as a voltage divider, that is, the sum of the voltage on the circuit and the gate-cathode voltage of the thyristor-type device 40 is the DC voltage provided by the first DC power supply DC1.

[0107] As an optional implementation, the first DC power supply DC1 can be a power module such as a linear voltage regulator chip, a DC-DC converter chip / module, an integrated power module, a reference voltage source chip, or an isolated power module, or it can be an energy storage element such as a battery or capacitor, or other devices or modules that can provide a stable DC voltage, without any limitations.

[0108] The current limiting module 311 can be a resistor, fuse, PTC thermistor, NTC thermistor, inductor, constant current diode or active current limiting circuit, etc., and there are no restrictions here.

[0109] The junction temperature monitoring switch Q2 can be any electrically controlled component with turn-on / turn-off capability, such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), a BJT (Bipolar Junction Transistor), an IGBT (Insulated-Gate Bipolar Transistor), or an electronically controlled switch. It can also be any other device or module capable of switching between on and off states, and there are no restrictions on that.

[0110] As an example, the following explanation uses the current limiting module 311 as a resistor.

[0111] When the junction temperature monitoring switch Q2 is turned on, the first DC power supply DC1 can apply a reverse voltage to the gate and cathode of the thyristor-like device 40, causing avalanche breakdown of junction J3 in the PN junction of the thyristor-like device 40. At this time, the avalanche threshold voltage V is reached between the gate and cathode of the thyristor-like device 40. GKThe remaining voltage is applied across the current limiting module 311. That is, the voltage across the current limiting module 311 is equal to the avalanche threshold voltage V of the thyristor-type device 40. GK The sum of these is the DC voltage provided by the first DC power supply DC1.

[0112] Please refer to Figure 7 In some embodiments, the voltage source type avalanche generation module 31 may further include a first sampling interface and a second sampling interface.

[0113] The first sampling interface can sample the voltage across the two ends of the first DC power supply DC1, and the second sampling interface can sample the voltage across the two ends of the current limiting module 311.

[0114] In the above embodiments, whether the voltage bias compensation module 32 is connected to the sampling interface of the voltage source avalanche generation module 31 or the avalanche threshold sampling module 33 is connected to the sampling interface of the voltage source avalanche generation module 31, the avalanche threshold voltage between the gate and cathode of the thyristor device 40 can be calculated based on the sampling voltage of each sampling interface. For example, the first sampling voltage and the second sampling voltage can be obtained in the first sampling interface and the second sampling interface, respectively. Therefore, the avalanche threshold voltage is the difference between the first sampling voltage and the second sampling voltage.

[0115] Right now:

[0116] V GK =Vs2-Vs1;

[0117] Where Vs1 and Vs2 are the first sampling voltage and the second sampling voltage, respectively, V GK This is the avalanche threshold voltage.

[0118] Understandably, when a thyristor-type device 40 experiences avalanche breakdown, the cathode potential is higher than the gate potential, therefore the avalanche threshold voltage V... GK It is a negative voltage.

[0119] It is understandable that among the multiple voltage sampling interfaces mentioned above, a single voltage sampling interface can sample the voltage of the junction temperature monitoring switch Q2 simultaneously. For example, taking the second sampling interface as an example, when both the junction temperature monitoring switch Q2 and the current limiting module 311 are located between the first DC power supply DC1 and the gate of the thyristor-like device 40, or when both the junction temperature monitoring switch Q2 and the current limiting module 311 are located between the first DC power supply DC1 and the cathode of the thyristor-like device 40, the second sampling interface can sample the total voltage of the junction temperature monitoring switch Q2 and the current limiting module 311. As another implementation, since the voltage drop of the junction temperature monitoring switch Q2 when it is turned on is close to 0V, voltage sampling of the junction temperature monitoring switch Q2 may not be necessary.

[0120] In some embodiments, the voltage source type avalanche generation module 31 may further include at least one of a first protection unit, a second protection unit, and a third protection unit.

[0121] The first protection unit can be connected in parallel with the current limiting module 311 to limit the voltage across the current limiting module 311. In the event of abnormal operating conditions such as a sudden change in the blocking withstand voltage of the current limiting module 311, it absorbs displacement current and limits the voltage, preventing the gate cathode voltage of the thyristor-type device 40 from being forward biased and causing the device to turn on erroneously. For example, the first protection unit can be a Zener diode, a TVS (Transient Voltage Suppressor) diode, a varistor, a transient voltage suppressor, a metal oxide varistor (MOV), etc., without specific limitations.

[0122] The second protection unit can be connected in series in the current branch formed by the first DC power supply DC1, the junction temperature monitoring switch Q2, and the current limiting module 311. It performs fault detection on the circuit branch and sends a fault signal to the control logic processing module 10 when a fault is detected. The control logic processing module 10 can control the junction temperature monitoring switch Q2 to open based on the fault signal, thereby disconnecting the current branch.

[0123] When the junction temperature monitoring switch Q2 is disconnected, the control logic processing module 10 can also control the device shutdown module 20 to maintain the conduction state, so as to continue to maintain the blocking state of the thyristor-type device 40 through the shutdown branch.

[0124] The third protection unit can be connected in series in the current branch formed by the first DC power supply DC1, the junction temperature monitoring switch Q2, and the current limiting module 311, and restricts the current direction in the current branch to a first direction. The first direction can be from the gate of the thyristor-type device 40 to the cathode of the thyristor-type device 40. The third protection unit can be an electronic component with unidirectional blocking capability, such as a diode, MOSFET, IGBT, BJT, thyristor, relay, etc. By unidirectionally blocking the current direction, reverse current in the current branch can be avoided.

[0125] Please refer to Figure 8 In some embodiments, the junction temperature monitoring module 30 may include a voltage bias compensation module 32.

[0126] Based on the junction temperature monitoring module 30 excluding the voltage source type avalanche generation module 31, the sampling terminal of the voltage bias compensation module 32 can be directly connected to the gate and cathode of the thyristor-type device 40.

[0127] When the device shutdown module 20 is turned on, the shutdown branch can also guide the gate and cathode of the thyristor-like device 40 to undergo avalanche breakdown. At this time, the voltage bias compensation module 32 can directly obtain the sampled signal as the avalanche threshold voltage of the gate and cathode of the thyristor-like device 40. The voltage bias compensation module 32 can perform bias compensation on the sampled signal to convert the sampled signal into an avalanche compensation voltage within a preset voltage range.

[0128] As an example, such as Figure 9 As shown, the voltage bias compensation module 32 may include a voltage processing unit 321 and a bias compensation unit 322 connected in series. The voltage processing unit 321 can acquire voltage signals from the sampling interface of the voltage source type avalanche generation module 31, and convert the acquired multiple sampled voltage signals to obtain a gate cathode voltage signal. Since the reverse bias value of this gate cathode voltage signal is too large, the high reverse bias value of the avalanche breakdown voltage can be compensated and eliminated by the bias compensation unit 322, resulting in a voltage signal with a smaller amplitude range that varies with junction temperature, so that it can be sampled and processed by the subsequent avalanche threshold sampling module 33 or control logic processing module 10.

[0129] As another example, such as Figure 10 As shown, the sampling interface of the voltage source type avalanche generation module 31 can directly send the voltage signal to the bias compensation unit 322. The bias compensation unit 322 can also perform the function of the voltage processing unit 321 mentioned above, obtain the avalanche breakdown voltage based on multiple sampled voltage signals, and compensate and eliminate the high reverse bias value.

[0130] The voltage processing unit 321 described above can be a differential amplifier, adder, potentiometer, voltage divider, a combination of reference voltage source and operational amplifier, digital potentiometer, digital-to-analog converter or other circuits capable of voltage addition and subtraction operations, or a circuit composed of the above circuits or components, without specific limitations.

[0131] The bias compensation unit 322 may be an operational amplifier, a subtractor (differential amplifier), an adder, a potentiometer, a voltage divider, a reference voltage source, a digital potentiometer, a digital-to-analog converter, an isolation amplifier, a voltage source, or other circuits capable of achieving voltage bias compensation, or a circuit composed of the above circuits or components, without specific limitations.

[0132] Please refer to Figure 11 In some embodiments, the junction temperature monitoring module 30 may also include an avalanche threshold sampling module 33.

[0133] Based on the junction temperature monitoring module 30 including a voltage bias compensation module 32 but excluding a voltage source-type avalanche generation module 31, the sampling terminal of the voltage bias compensation module 32 can be directly connected to the gate and cathode of the thyristor-type device 40, and the sampling terminal of the avalanche threshold sampling module 33 is electrically connected to the output terminal of the voltage bias compensation module 32. The avalanche threshold sampling module 33 can perform signal processing on the avalanche compensation voltage output by the voltage bias compensation module 32 to obtain the avalanche sampling voltage.

[0134] Please refer to Figure 12 In some embodiments, the junction temperature monitoring module 30 may include an avalanche threshold sampling module 33.

[0135] Based on the junction temperature monitoring module 30 excluding the voltage source type avalanche generation module 31, the sampling terminal of the avalanche threshold sampling module 33 can be connected to the gate and cathode of the thyristor-type device 40.

[0136] Based on the junction temperature monitoring module 30, which includes a voltage source type avalanche generation module 31, the sampling end of the avalanche threshold sampling module 33 is electrically connected to the sampling interface of the voltage source type avalanche generation module 31.

[0137] The avalanche threshold sampling module 33 can perform signal processing on the acquired voltage signal to obtain the avalanche sampling voltage.

[0138] In the above embodiments, the junction temperature monitoring module 30 may include one or more of the following: a voltage source avalanche generation module 31, a voltage bias compensation module 32, and an avalanche threshold sampling module 33.

[0139] It is understandable that when the junction temperature monitoring module 30 includes an avalanche threshold sampling module 33, the output of the avalanche threshold sampling module 33 can be connected to the control logic processing module 10, and the control logic processing module 10 obtains the avalanche sampling voltage from the avalanche threshold sampling module 33 as the avalanche threshold voltage.

[0140] When the junction temperature monitoring module 30 does not include the avalanche threshold sampling module 33, but includes the voltage bias compensation module 32, the output of the voltage bias compensation module 32 can be connected to the control logic processing module 10. The control logic processing module 10 obtains the avalanche compensation voltage from the voltage bias compensation module 32, and after performing corresponding signal processing on the avalanche compensation voltage, obtains the avalanche threshold voltage.

[0141] When the junction temperature monitoring module 30 does not include the avalanche threshold sampling module 33 and the voltage bias compensation module 32, but includes the voltage source type avalanche generation module 31, the sampling interface of the voltage source type avalanche generation module 31 can be connected to the control logic processing module 10. The control logic processing module 10 obtains multiple sampling voltages from the voltage source type avalanche generation module 31, calculates the voltage value based on the multiple sampling voltages, and performs corresponding bias compensation and signal processing on the voltage signal to obtain the avalanche threshold voltage.

[0142] Please refer to Figure 13 In some embodiments, the device shutdown module 20 described above may include a first transistor Q1 and a shutdown capacitor Coff.

[0143] The first terminal of the first transistor Q1 is connected to the gate of the thyristor-like device 40, and the control terminal of the first transistor Q1 is connected to the control logic processing module 10. The turn-off capacitor Coff is connected in series between the second terminal of the first transistor Q1 and the cathode of the thyristor-like device 40, or the turn-off capacitor Coff is connected in series between the first terminal of the first transistor Q1 and the gate of the thyristor-like device 40.

[0144] The control terminal of the first transistor Q1 can be connected to the control logic processing module 10. The first transistor Q1 turns on when it receives a first control signal.

[0145] When the thyristor-type device 40 is in the on state, the first transistor Q1, which is connected in series with the gate of the thyristor-type device 40, is turned off.

[0146] After the control logic processing module 10 sends the first control signal, the first transistor Q1 switches to the on state. The current in the thyristor device 40 is commutated from the cathode to the gate, ultimately causing the thyristor device 40 to switch from the on state to the blocking state.

[0147] When the first transistor Q1 is turned on, the first transistor Q1 and the turn-off capacitor Coff can provide a current path for the gate of the thyristor-like device 40, that is, the turn-off branch is turned on at this time. Correspondingly, when the first transistor Q1 is turned off, the turn-off branch is turned off.

[0148] The first transistor Q1 mentioned above can be a controllable switch, such as a MOSFET, BJT, IGBT, or electronically controlled switch.

[0149] It should be noted that the first transistor Q1 and the turn-off capacitor Coff mentioned above are only one topology of the device turn-off module 20. The device turn-off module 20 can also be other topologies that can turn off thyristor-type devices 40, and there are no restrictions here.

[0150] In some embodiments, when the first transistor is a unidirectional blocking transistor, the device shutdown module 20 further includes a first blocking unit.

[0151] The first blocking unit is connected in series with the first transistor, and the first blocking unit can restrict the current direction to unidirectional. The blocking direction of the first blocking unit is opposite to that of the first transistor.

[0152] Taking the first transistor as a MOSFET as an example, when the first transistor is in the blocking state, the reverse bias diode of the MOSFET can only achieve unidirectional blocking. At this time, a first blocking unit can be set. The blocking direction of the first blocking unit is opposite to that of the reverse bias diode of the MOSFET, so that when the first transistor is in the blocking state, the device turn-off module 20 can achieve bidirectional current blocking.

[0153] This application also provides a method for monitoring the junction temperature of thyristor devices, which is applied to the junction temperature monitoring circuit of the thyristor device in the above embodiments. Figure 14 A flowchart illustrating a method for monitoring the junction temperature of thyristor devices is shown. This method may include the following steps:

[0154] S110, in response to a system shutdown command, sends a first control signal to the device shutdown module; the device shutdown module is used to turn on the shutdown branch of the thyristor-type device according to the first control signal;

[0155] S120, obtain the avalanche threshold voltage from the junction temperature monitoring module; the junction temperature monitoring module is used to obtain the avalanche threshold voltage of the thyristor device in the event of avalanche breakdown.

[0156] S130, based on the avalanche threshold voltage and the first correspondence, determines the junction temperature value of thyristor devices.

[0157] For power electronic converter systems containing thyristor devices, the following methods can be used to monitor the junction temperature of thyristor devices online during normal system operation.

[0158] In this embodiment, based on the system shutdown command, the shutdown branch of the thyristor-type device can be turned on by the first control signal control device shutdown module, so that the thyristor-type device switches to the blocking state. In the blocking state, the avalanche breakdown voltage between the gate and cathode of the thyristor-type device can be obtained from the junction temperature monitoring module. Based on the avalanche threshold voltage and the first correspondence, the current junction temperature of the thyristor-type device can be determined, thereby achieving real-time and accurate measurement of the junction temperature of the thyristor-type device without affecting the system operation.

[0159] The specific implementation methods for each of the above steps are described below.

[0160] In S110, when the thyristor-type devices in the system are in the normal conducting state, they can receive the system shutdown command and, in response to the system shutdown command, send the first control signal to the device shutdown module.

[0161] The aforementioned system shutdown command can be generated by a host computer or by other modules with junction temperature monitoring capabilities. Taking the host computer as an example, the host computer can send the system shutdown command based on preset rules, or it can send the system shutdown command based on user operation when the user triggers the junction temperature monitoring operation. That is, junction temperature monitoring can be achieved by sending a system shutdown command when preset rules are met or when a user command is received.

[0162] The aforementioned receiver of the system shutdown command may be a control logic processing module. Based on the received system shutdown command, the control logic processing module may send a first control signal to the device shutdown module.

[0163] The device shutdown module can control the shutdown branch of thyristor-type devices. When the shutdown branch is on, the thyristor-type devices are in a blocked state.

[0164] It should be noted that since the turn-off branch is used to control the turn-off of thyristor-type devices, when the turn-off branch is on, it can keep the thyristor-type devices in a blocking state. However, when the turn-off branch is off, the thyristor-type devices may be in a conducting state or still in a blocking state.

[0165] When a thyristor-type device is in the normal conducting state, the turn-off branch is in the blocked state. If the device turn-off module receives the first control signal, it can turn on the turn-off branch, so that the thyristor-type device changes from the conducting state to the blocked state.

[0166] The aforementioned thyristor devices can be thyristor devices with a non-gate cathode short-circuit structure, such as ETO (Emitter Turn-Off Thyristor), GTO (Gate Turn-Off Thyristor), IGCT (Integrated Gate Commutated Thyristor), or other types of thyristors, without limitation.

[0167] In S120, after the turn-off branch of the thyristor-type device is turned on, the thyristor-type device switches from the on state to the blocking state. In the blocking state, the junction temperature monitoring module can obtain the avalanche breakdown voltage between the gate and cathode of the thyristor-type device when avalanche breakdown occurs, and the control logic processing module can obtain the avalanche threshold voltage from the junction temperature monitoring module.

[0168] In some embodiments, the above-described S120 may include:

[0169] S210, when the thyristor-type device is blocked, sends a junction temperature monitoring signal to the voltage source avalanche generation module; the voltage source avalanche generation module is used to respond to the junction temperature monitoring signal and guide the gate and cathode of the thyristor-type device to undergo avalanche breakdown at a preset voltage.

[0170] S220: In the event of avalanche breakdown at the gate and cathode of a thyristor-type device, the avalanche threshold voltage is obtained from the junction temperature monitoring module.

[0171] S230 sends a junction temperature termination signal to the voltage source avalanche generator module; the voltage source avalanche generator module is used to disconnect the junction temperature monitoring switch in response to the junction temperature termination signal.

[0172] In this embodiment, when junction temperature monitoring is achieved through a voltage source avalanche generation module, after the turn-off branch is turned on and the thyristor-type device is blocked, the voltage source avalanche generation module can be controlled to guide the gate and cathode of the thyristor-type device to undergo avalanche breakdown at a preset voltage, and the avalanche threshold voltage can be obtained through the junction temperature monitoring module.

[0173] In S210, thyristor-type devices are in a blocking state when the off-branch is turned on. The control logic processing module can send a junction temperature monitoring signal to the voltage source avalanche generation module. When the voltage source avalanche generation module receives the junction temperature monitoring signal, it can guide the gate and cathode of the thyristor-type devices to undergo avalanche breakdown at a preset voltage.

[0174] In S220, when avalanche breakdown occurs at the gate and cathode of a thyristor-type device, the junction temperature monitoring module can monitor the avalanche threshold voltage between the gate and cathode, and the control logic processing module can obtain the avalanche threshold voltage from the junction temperature monitoring module.

[0175] In S230, the control logic processing module can send a junction temperature termination signal to the voltage source avalanche generator module. When the voltage source avalanche generator module receives the junction temperature termination signal, it can turn off the junction temperature monitoring switch, thereby disconnecting the current branch of the junction temperature monitoring.

[0176] It is understood that in the above implementation, when the control logic processing module controls the turn-off branch of the thyristor-like device to be turned on so that the thyristor-like device is in a blocking state, the avalanche threshold voltage of the thyristor-like device can be directly obtained while continuously switching the turn-off branch on and off. Throughout the entire monitoring process of the avalanche threshold voltage, the turn-off branch remains in a conducting state.

[0177] In some embodiments, prior to S120 above, the following may also be included:

[0178] S310, send a second control signal to the device shutdown module; the device shutdown module is used to disconnect the shutdown branch of the thyristor-type device according to the second control signal;

[0179] Prior to S230 above, it may also include:

[0180] S320, send a first control signal to the device shutdown module; the device shutdown module is used to turn on the shutdown branch of the thyristor-type device according to the first control signal;

[0181] In this embodiment, before the junction temperature monitoring switch of the voltage source avalanche generation module is turned on, the turn-off branch of the thyristor-type device can be disconnected by the device turn-off module. After obtaining the avalanche threshold voltage of the thyristor-type device, the turn-off branch of the thyristor-type device can be turned on again, and the junction temperature monitoring switch of the voltage source avalanche generation module can be disconnected.

[0182] In S310, the control logic processing module can send a second control signal to the device shutdown module. Upon receiving the second control signal, the device shutdown module can disconnect the shutdown branch of the thyristor-type device.

[0183] Understandably, the turn-off branch is connected to the gate and cathode of thyristor-type devices. During junction temperature monitoring, current flows through both the junction temperature monitoring current branch and the turn-off branch. Therefore, to prevent the turn-off branch from affecting the junction temperature monitoring results when it is in the on state, the control logic processing module can use a second control signal to control the turn-off module to disconnect the turn-off branch.

[0184] As an optional implementation, a corresponding dead time can be set based on the device parameters. After the current branch of junction temperature monitoring is turned on and the dead time has elapsed, the control logic processing module can control the device turn-off module to disconnect the branch, so as to avoid the thyristor device being turned on again when the current branch of junction temperature monitoring is not turned on or is fully turned on.

[0185] In S320, after acquiring the avalanche threshold voltage, the control logic processing module can send a first control signal to the device shutdown module. Based on the first control signal, the device shutdown module can re-enable the shutdown branch. After the shutdown branch is re-enabled, the control logic processing module can send a junction temperature end signal to the voltage source avalanche generation module. When the voltage source avalanche generation module receives the junction temperature end signal, it can turn off the junction temperature monitoring switch, thereby disconnecting the current branch for junction temperature monitoring.

[0186] While thyristor devices can maintain a blocking state during the period when only the junction temperature monitoring current branch is on, the devices on the junction temperature monitoring current branch are only for short-term turn-off of the thyristor for junction temperature monitoring. After the junction temperature monitoring process is complete, the current branch for junction temperature monitoring can be switched to the turn-off branch to achieve stable turn-off of the thyristor through the devices on the turn-off branch.

[0187] As an optional implementation, a corresponding dead time can be set based on the device parameters. After the turn-off branch is turned on again and the dead time has elapsed, the control logic processing module can control the junction temperature monitoring current branch to disconnect, so as to avoid the junction temperature monitoring current branch being disconnected when the turn-off branch is not turned on or fully turned on, thus causing the thyristor-type device to turn on again.

[0188] In S130, the control logic processing module pre-stores a first correspondence. This first correspondence is the relationship between avalanche threshold voltage and junction temperature, generated based on the avalanche threshold voltage corresponding to the thyristor device at different junction temperatures after experimental simulation of the thyristor device as a sample. After obtaining the current avalanche threshold voltage of the thyristor device from the junction temperature monitoring module, the control logic processing module can obtain the junction temperature value corresponding to the avalanche threshold voltage based on the first correspondence. This junction temperature value is the current junction temperature of the thyristor device.

[0189] Please refer to Figure 15 and Figure 16 , Figure 15 The following is an example of shutdown mode A. Figure 6 and Figure 13 The corresponding control signal timing diagram; Figure 16 This shows the shutdown mode B. Figure 6 and Figure 13 The corresponding control signal timing diagram.

[0190] like Figure 15 As shown, the system control command is the command signal received by the control logic processing module 10. When the system control command changes from high level to low level, it corresponds to the system shutdown command.

[0191] The shutdown signal is the first control signal and the second control signal received by the device shutdown module 20. The first control signal is low level and the second control signal is high level. The shutdown signal is the control signal for the first transistor Q1, and the junction temperature monitoring signal is the control signal for the junction temperature monitoring switch Q2.

[0192] When the system control command transitions to a low-level signal, the control logic processing module 10 sets the shutdown signal high based on the system shutdown command. At this time, the first transistor Q1, a thyristor-like device, switches to the blocking state. After the thyristor-like device is stably disconnected, the control logic processing module 10 sets the junction temperature monitoring signal high. At this time, the junction temperature monitoring switch Q2 is turned on, making the current branch of junction temperature monitoring conduct.

[0193] After the junction temperature monitoring current branch is turned on, after a preset dead time, the control logic processing module 10 sets the turn-off signal low to disconnect the turn-off branch. At this time, only the junction temperature monitoring current branch is turned on, and the avalanche threshold voltage of the gate cathode can be monitored through the junction temperature monitoring current branch. After the avalanche threshold voltage monitoring is completed, the control logic processing module 10 sets the turn-off signal high to turn the turn-off branch back on, and after a preset dead time, sets the junction temperature monitoring signal low. At this time, the turn-off branch is turned on, the junction temperature monitoring current branch is disconnected, and the thyristor-type device maintains a stable blocking state.

[0194] It is understandable that when a thyristor device completes junction temperature monitoring and maintains a blocking state, if the system control command received by the control logic processing module 10 changes to a high-level signal again, the control logic processing module 10 will set the turn-off signal low so that the thyristor device can be turned on again.

[0195] like Figure 16 As shown, the turn-off signal is the first control signal and the second control signal received by the first transistor Q1. The junction temperature monitoring signal is the control signal of the junction temperature monitoring switch Q2.

[0196] With the above Figure 15 The corresponding timing control method is similar. When the system control command transitions to a low-level signal, the control logic processing module 10 sets the shutdown signal high based on the system shutdown command. At this time, the first transistor Q1 is turned on, and the thyristor-like devices switch to the blocking state. After the thyristor-like devices are stably turned off, the control logic processing module 10 sets the junction temperature monitoring signal high. At this time, the junction temperature monitoring switch Q2 is turned on, making the current branch of junction temperature monitoring conduct.

[0197] After the current branch for junction temperature monitoring is turned on, the gate cathode avalanche threshold voltage of thyristor devices can be monitored, and the junction temperature of the device can be determined based on the monitoring results.

[0198] After completing the avalanche threshold voltage monitoring, the control logic processing module 10 sets the junction temperature monitoring signal low. At this time, the junction temperature monitoring switch Q2 is turned off, which turns off the current branch of the junction temperature monitoring.

[0199] When the thyristor-type device completes junction temperature monitoring and maintains the current branch for junction temperature monitoring in a blocked state, if the system control command received by the control logic processing module 10 jumps back to a high-level signal, the control logic processing module 10 will set the turn-off signal low so that the thyristor-type device can be turned on again.

[0200] It should be noted that, with Figure 15 and Figure 16 Taking the timing diagram as an example, during a single conduction of the junction temperature monitoring current branch, multiple avalanche threshold voltages can be monitored through the junction temperature monitoring current branch. That is, multiple avalanche threshold voltages can be generated within the effective range of a single junction temperature monitoring signal.

[0201] When the control logic processing module 10 sets the shutdown signal high based on the system shutdown instruction, causing the thyristor-type device to be in a blocked state, the junction temperature monitoring current branch can be turned on once or multiple times. That is, during a single blocking process of the thyristor-type device, the junction temperature monitoring current branch can be controlled to be turned on once or multiple times, and during each turn-on process of the junction temperature monitoring current branch, the avalanche threshold voltage can be acquired once or multiple times.

[0202] During the aforementioned timing control process, when each protection unit of the voltage source type avalanche generation module triggers a protection signal, the control logic processing module 10 can make corresponding adjustments to the timing signal.

[0203] The transistors mentioned in the above embodiments can be controllable switches. For example, they can be MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), BJTs (Bipolar Junction Transistors), IGBTs (Insulated-Gate Bipolar Transistors), electronically controlled switches, etc.

[0204] It should be noted that the transistors in the above embodiments are not limited to the same device type. That is, any two transistors among the multiple transistors may be of the same type, such as both being MOSFETs, or they may be transistors of different types, which is not limited here.

[0205] As another alternative implementation, the transistors in the above embodiments can also be replaced with other switching devices, such as optocoupler switches, disconnect switches, etc.

[0206] In the above embodiments, by controlling the thyristor-like devices to be in a blocking state and monitoring their avalanche threshold voltage, online monitoring of the junction temperature of the thyristor-like devices can be achieved. This monitoring method features small component size, simple and reliable circuitry, low operating losses, and low cost. Furthermore, the thyristor junction temperature monitoring circuit can be integrated into the drive circuit of the thyristor-like devices, without needing to be connected to the main circuit of the power electronic converter system, thus not affecting system operation and having a wide range of applications. Moreover, the above embodiments also feature high monitoring accuracy and adjustable monitoring range, effectively meeting the needs of online evaluation of the blocking characteristics of thyristor-like devices, and have broad application value in power electronic converter projects that include thyristors.

[0207] Based on the same inventive concept, this application also provides a power electronic device, including a thyristor-type device and the junction temperature monitoring circuit of the thyristor-type device in the above embodiments.

[0208] In some embodiments, the thyristor devices described above are thyristor devices with a non-gate cathode short-circuit structure, such as ETO (Emitter Turn-Off Thyristor), GTO (Gate Turn-Off Thyristor), IGCT (Integrated Gate Commutated Thyristor), ACT (Avalanche Controlled Thyristor), or other types of thyristors, without limitation.

[0209] The functional blocks shown in the above-described structural 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 this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0210] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0211] This document uses specific examples to illustrate the principles and implementation methods of this application. The examples are merely for the purpose of helping to understand the method and core ideas of this application. The above are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, and the existence of an infinite number of specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, 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 situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A junction temperature monitoring circuit for thyristor-type devices, characterized in that, include: A device shutdown module, wherein the device shutdown module is connected to a thyristor-type device and forms a shutdown branch; The junction temperature monitoring module includes a voltage source avalanche generation module, which is connected to the gate and cathode of the thyristor-like device. The voltage source avalanche generation module is used to guide the gate and cathode of the thyristor-like device to undergo avalanche breakdown at a preset voltage. The junction temperature monitoring module is used to obtain the avalanche threshold voltage of the thyristor-like device when avalanche breakdown occurs. The control logic processing module is connected to the control terminal of the device shutdown module and the junction temperature monitoring module. The control logic processing module is used to determine the junction temperature value of the thyristor-type device based on a first correspondence and the avalanche threshold voltage. The first correspondence is a pre-generated correspondence between the avalanche threshold voltage and the junction temperature.

2. The junction temperature monitoring circuit for thyristor devices according to claim 1, characterized in that, The control terminal of the voltage source avalanche generator module is connected to the control logic processing module. The voltage source avalanche generation module is used to respond to the junction temperature monitoring signal sent by the control logic processing module and guide the gate and cathode of the thyristor-type device to undergo avalanche breakdown at a preset voltage.

3. The junction temperature monitoring circuit for thyristor devices according to claim 2, characterized in that, The junction temperature monitoring module also includes: A voltage bias compensation module is provided, wherein the sampling terminal of the voltage bias compensation module is electrically connected to the sampling interface of the voltage source type avalanche generator module, and the voltage bias compensation module is used to perform bias compensation on the acquired sampling signal to obtain an avalanche compensation voltage within a preset voltage range.

4. The junction temperature monitoring circuit for thyristor devices according to claim 2 or 3, characterized in that, The junction temperature monitoring module also includes: An avalanche threshold sampling module is provided, wherein the sampling terminal of the avalanche threshold sampling module is electrically connected to the output terminal of the voltage bias compensation module, or the sampling terminal of the avalanche threshold sampling module is electrically connected to the sampling interface of the voltage source avalanche generator module; the avalanche threshold sampling module is used to process the avalanche compensation voltage output by the voltage bias compensation module or the sampling signal obtained by sampling the voltage source avalanche generator module to obtain the avalanche sampling voltage.

5. The junction temperature monitoring circuit for thyristor devices according to claim 2, characterized in that, The voltage source type avalanche generator module includes: A first DC power supply is used to provide a DC voltage; wherein the DC voltage is greater than the maximum typical value of the avalanche threshold voltage; A junction temperature monitoring switch is used to turn on in response to the junction temperature monitoring signal; A current limiting module is used to limit the current of the DC voltage; The first DC power supply, the junction temperature monitoring switch, and the current limiting module are connected in series between the gate of the thyristor-like device and the cathode of the thyristor-like device.

6. The junction temperature monitoring circuit for thyristor devices according to claim 5, characterized in that, The voltage source type avalanche generator module also includes: The first sampling interface is used to sample the voltage at both ends of the first DC power supply. The second sampling interface is used to sample the voltage across the current limiting module.

7. The junction temperature monitoring circuit for thyristor devices according to claim 5, characterized in that, The voltage source type avalanche generator module also includes: The first protection unit is connected in parallel with the current limiting module and is used to limit the voltage across the current limiting module. And / or, The second protection unit is used to detect faults in the current branch formed by the first DC power supply, the junction temperature monitoring switch, and the current limiting module, and to send a fault signal to the control logic processing module when a branch fault is detected, so that the control logic processing module controls the junction temperature monitoring switch to disconnect based on the fault signal. And / or, The third protection unit is connected in series in the current branch formed by the first DC power supply, the junction temperature monitoring switch and the current limiting module; the third protection unit is used to limit the current direction to a first direction; the first direction is from the gate of the thyristor device to the cathode of the thyristor device.

8. The junction temperature monitoring circuit for thyristor devices according to claim 1, characterized in that, The device shutdown module includes: A first transistor, the first terminal of which is connected to the gate of the thyristor-like device, and the control terminal of which is connected to the control logic processing module; the first transistor is used to turn on when a first control signal is received. A turn-off capacitor is connected in series between the first terminal of the first transistor and the gate of the thyristor-like device, or the turn-off capacitor is connected in series between the second terminal of the first transistor and the cathode of the thyristor-like device.

9. The junction temperature monitoring circuit for thyristor devices according to claim 8, characterized in that, When the first transistor is a unidirectional blocking transistor, the device shutdown module further includes: A first blocking unit, connected in series with the first transistor, is used to limit the current direction to unidirectional; wherein the blocking direction of the first blocking unit is opposite to that of the first transistor.

10. A method for monitoring the junction temperature of thyristor devices, characterized in that, The method, applied to the junction temperature monitoring circuit of a thyristor-type device according to any one of claims 1-9, comprises: In response to a system shutdown command, a first control signal is sent to the device shutdown module; the device shutdown module is used to turn on the shutdown branch of the thyristor-type device according to the first control signal. The avalanche threshold voltage is obtained from the junction temperature monitoring module; the junction temperature monitoring module is used to obtain the avalanche threshold voltage of the thyristor device when the thyristor device experiences avalanche breakdown. Based on the avalanche threshold voltage and the first correspondence, the junction temperature value of the thyristor-type device is determined.

11. The method for monitoring the junction temperature of thyristor devices according to claim 10, characterized in that, The step of obtaining the avalanche threshold voltage from the junction temperature monitoring module includes: When the thyristor-type device is blocked, a junction temperature monitoring signal is sent to the voltage source avalanche generation module; the voltage source avalanche generation module is used to respond to the junction temperature monitoring signal and guide the gate and cathode of the thyristor-type device to undergo avalanche breakdown at a preset voltage. In the event of avalanche breakdown at the gate and cathode of the thyristor-type device, the avalanche threshold voltage is obtained from the junction temperature monitoring module; A junction temperature termination signal is sent to the voltage source avalanche generation module; the voltage source avalanche generation module is used to disconnect the junction temperature monitoring switch in response to the junction temperature termination signal.

12. The method for monitoring the junction temperature of thyristor devices according to claim 11, characterized in that, Before obtaining the avalanche threshold voltage from the junction temperature monitoring module, the method further includes: A second control signal is sent to the device shutdown module; the device shutdown module is used to disconnect the shutdown branch of the thyristor-type device according to the second control signal; Before sending the junction temperature termination signal to the voltage source avalanche generation module, the method further includes: A first control signal is sent to the device shutdown module; the device shutdown module is used to turn on the shutdown branch of the thyristor-type device according to the first control signal.

13. A power electronic device, characterized in that, This includes thyristor-type devices and junction temperature monitoring circuits for thyristor-type devices as described in any one of claims 1-9.

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