Semiconductor power device and converter

Abstract

The present application provides a semiconductor power device and a converter. The semiconductor power device includes: a switching structure including at least two turn-off semiconductor devices and at least two drivers. The at least two turn-off semiconductor devices are connected in series, and the drivers are electrically connected to the turn-off semiconductor devices in one-to-one correspondence. The drivers are configured to periodically send heartbeat signals to at least one other driver in the switching structure, and the drivers are further configured to control the corresponding turn-off semiconductor devices to remain in the conducting state at least when heartbeat signals from other drivers are not received within a predetermined period; a voltage clamping circuit is connected in parallel across the at least two turn-off semiconductor devices. The voltage clamping circuit breaks down all the remaining turn-off semiconductor devices in the switching structure when the breakdown voltage of the remaining turn-off semiconductor devices is less than the operating voltage of the voltage clamping circuit. The remaining turn-off semiconductor devices are the turn-off semiconductor devices in the switching structure that have not failed due to short circuit.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technologies, and in particular, to a semiconductor power device and a converter. Background Art

[0002] In high-capacity power electronic devices, turn-off semiconductor devices are widely used in high-voltage and high-current environments. These devices usually form a bridge arm circuit in a directly series-connected manner to achieve a higher voltage level and current handling capacity. In the bridge arm circuit, in order to protect the devices from being subjected to excessive voltage, a voltage clamping circuit is usually used to limit the voltage across the devices in the series branch. The breakdown voltage of multiple devices in the series branch determines the operating voltage of the voltage clamping circuit. When the number of failed devices in the series branch rises to a point where the operating voltage is greater than the total breakdown voltage of the remaining normal devices, all the devices in the series branch will be overvoltage broken down by the turn-off transient voltage clamping circuit during turn-off.

[0003] Therefore, there is a problem in the prior art that in a series circuit of turn-off semiconductor devices sharing a voltage clamping circuit, the failure of some devices will cause all the devices in the series circuit to be overvoltage broken down, resulting in a relatively high maintenance cost. Summary of the Invention

[0004] The main object of this application is to provide a semiconductor power device and a converter, so as to at least solve the problem in the prior art that in a series circuit of turn-off semiconductor devices sharing a voltage clamping circuit, the failure of some devices will cause all the devices in the series circuit to be overvoltage broken down.

[0005] To achieve the above object, according to one aspect of this application, a semiconductor power device is provided, including: a switching structure, including at least two turn-off semiconductor devices and at least two drivers, at least two of the turn-off semiconductor devices are connected in series, a first end of the driver is electrically connected to a control end of the turn-off semiconductor device in a one-to-one correspondence, a second end of the driver is electrically connected to an output end of the turn-off semiconductor device in a one-to-one correspondence, the driver is configured to periodically send a heartbeat signal to at least one other driver in the switching structure, and the driver is further configured to control the corresponding turn-off semiconductor device to remain in a conducting state at least when the heartbeat signal of the other driver is not received within a predetermined period; a voltage clamping circuit, connected in parallel across at least two of the turn-off semiconductor devices, the voltage clamping circuit breaks down all the remaining turn-off semiconductor devices in the switching structure when the breakdown voltage of the remaining turn-off semiconductor devices is less than the operating voltage of the voltage clamping circuit and the voltage across the voltage clamping circuit is greater than the operating voltage, and the remaining turn-off semiconductor devices are the turn-off semiconductor devices in the switching structure that are not short-circuited and failed.

[0006] Optionally, each of the drivers is configured to send the heartbeat signal to all the other drivers in the switching structure, and is further configured to determine the number of the heartbeat signals not received within the predetermined period. When the number is greater than or equal to a predetermined threshold, the corresponding turn-off semiconductor device is in the on state and a turn-off instruction is received, the corresponding turn-off semiconductor device is controlled to maintain the on state, and the turn-off instruction is used to indicate turning off the turn-off semiconductor device.

[0007] Optionally, the number of the turn-off semiconductor devices and the drivers is even. The drivers in the switching structure send the heartbeat signals to each other at regular intervals. The driver is further configured to control the corresponding turn-off semiconductor device to maintain the on state when the heartbeat signal is not received within the predetermined period, the corresponding turn-off semiconductor device is in the on state and a turn-off instruction is received, and the turn-off instruction is used to indicate turning off the turn-off semiconductor device.

[0008] Optionally, in the switching structure, any two of the drivers exchange the heartbeat signals through an isolation communication path.

[0009] Optionally, the isolation communication path includes one of the following: an optocoupler isolation path, a magnetic coupler isolation path, a capacitive coupler isolation path, a transformer isolation path, or a digital isolation path.

[0010] Optionally, the switching structure further includes: a network switch, which communicates with all the drivers in the switching structure, and the drivers interact the heartbeat signals with the other drivers through the network switch.

[0011] Optionally, the voltage clamping circuit includes one of the following: a lightning arrester, one end of which is electrically connected to the input end of the turn-off semiconductor device at the series head, and the other end of which is electrically connected to the output end of the turn-off semiconductor device at the series tail; a Zener diode, the cathode of which is electrically connected to the input end of the turn-off semiconductor device at the series head, and the anode of which is electrically connected to the output end of the turn-off semiconductor device at the series tail; a transient diode, the cathode of which is electrically connected to the input end of the turn-off semiconductor device at the series head, and the anode of which is electrically connected to the output end of the turn-off semiconductor device at the series tail; a gate clamping circuit, one end of which is electrically connected to the input end of the turn-off semiconductor device at the series head, and the other end of which is electrically connected to the output end of the turn-off semiconductor device at the series tail.

[0012] Optionally, the switching structure further includes: a plurality of first voltage equalizing circuits, corresponding to the turn-off semiconductor devices one by one, each first voltage equalizing circuit including a first resistor and an energy storage device, a first end of the first resistor being electrically connected to an input end of the turn-off semiconductor device, a second end of the first resistor being electrically connected to a first end of the energy storage device, and a second end of the energy storage device being electrically connected to an output end of the turn-off semiconductor device; a plurality of second voltage equalizing circuits, corresponding to the turn-off semiconductor devices one by one, each second voltage equalizing circuit including a second resistor, a first end of the second resistor being electrically connected to the input end of the turn-off semiconductor device, and a second end of the second resistor being electrically connected to the output end of the turn-off semiconductor device, the resistance value of the second resistor being smaller than the equivalent resistance of the turn-off semiconductor device in the blocking state.

[0013] Optionally, the turn-off semiconductor device includes at least one of the following: IGBT, HEMT, MOSFET, and turn-off thyristor, and the turn-off thyristor includes at least one of the following: IGCT, GTO, SGTO, ETO, and IETO.

[0014] According to another aspect of the present application, there is provided a converter, including: a plurality of bridge arms, each bridge arm including a plurality of any one of the semiconductor power devices connected in series.

[0015] Applying the technical solution of the present application, at least two turn-off semiconductor devices in the switching structure are connected in series, the turn-off semiconductor devices are connected to the drivers one by one, and the drivers periodically send heartbeat signals to each other. When a driver does not receive a heartbeat signal from other drivers within a predetermined period, the turn-off semiconductor device corresponding to the driver is controlled to remain in the conducting state. The voltage clamping circuit is connected in parallel at both ends of the series branch of the turn-off semiconductor devices. When the withstand voltage value of the non-failed turn-off semiconductor device in the series branch is less than the operating voltage of the voltage clamping circuit and the voltage across both ends of the voltage clamping circuit is greater than the operating voltage, the voltage clamping circuit will break down and fail all the non-failed turn-off semiconductor devices. In the present application, the drivers of the turn-off semiconductor devices in the series circuit periodically send heartbeat signals to each other. When a heartbeat signal is not received, it is considered that the turn-off semiconductor device corresponding to the driver that did not send the heartbeat signal has failed. At this time, the driver of the non-failed turn-off semiconductor device controls the turn-off semiconductor device to remain in the conducting state, thereby reducing the voltage across both ends of the voltage clamping circuit and making it lower than the operating voltage, avoiding the problem that in a series circuit of turn-off semiconductor devices sharing a voltage clamping circuit, the breakdown of non-failed devices is triggered by the failure of some devices, preventing the further expansion of the failure range, and solving the problem of high loss cost of turn-off semiconductor devices. Description of the Drawings

[0016] The accompanying drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0017] Figure 1 shows a schematic structural diagram of a semiconductor power device provided in an embodiment of this application;

[0018] Figure 2 shows a schematic structural diagram of another semiconductor power device provided in an embodiment of this application;

[0019] Figure 3 shows a schematic structural diagram of yet another semiconductor power device provided in an embodiment of this application.

[0020] Among them, the above-mentioned drawings include the following reference numerals:

[0021] 10, turn-off semiconductor device; 101, first turn-off semiconductor device; 102, second turn-off semiconductor device; 11, driver; 111, first driver; 112, second driver; 12, network switch; 13, voltage clamping circuit; 15, first voltage equalizing circuit; 16, first resistor; 17, energy storage device; 18, second resistor. Detailed implementation manners

[0022] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The following will describe this application in detail with reference to the drawings and in combination with the embodiments.

[0023] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the protection scope of this application.

[0024] It should be noted that in the description of the present application, the claims and the above-mentioned drawings, the terms "first", "second", etc. are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so as to implement the embodiments of the present application described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily limit to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] As introduced in the background art, in a series circuit of turn-off semiconductor devices sharing a voltage clamping circuit in the prior art, the failure of some devices will cause the overvoltage breakdown of all devices in the series circuit. To solve the above technical problems, embodiments of the present application provide a semiconductor power device and a converter.

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0027] Embodiments of the present application provide a semiconductor power device. Figure 1 Exemplarily, a schematic structural diagram of the semiconductor power device in the embodiments of the present application is shown, as Figure 1 shown, the above-mentioned semiconductor power device includes:

[0028] A switching structure, including at least two turn-off semiconductor devices 10 and at least two drivers 11. At least two of the above-mentioned turn-off semiconductor devices 10 are connected in series. The first ends of the above-mentioned drivers 11 are electrically connected to the control ends of the above-mentioned turn-off semiconductor devices 10 in one-to-one correspondence, and the second ends of the above-mentioned drivers 11 are electrically connected to the output ends of the above-mentioned turn-off semiconductor devices 10 in one-to-one correspondence. The above-mentioned drivers 11 are used to periodically send heartbeat signals to at least one other driver 11 in the above-mentioned switching structure. The above-mentioned drivers 11 are further used to control the corresponding above-mentioned turn-off semiconductor devices 10 to remain in the on state at least when the above-mentioned heartbeat signals of the above-mentioned other drivers 11 are not received within a predetermined period;

[0029] Specifically, the above-mentioned other driver 11 refers to at least one driver 11 other than the above-mentioned driver 11 in the switching structure. The above-mentioned driver 11 communicates with at least one other driver 11. The above-mentioned driver 11 periodically sends a heartbeat signal to the other drivers 11 with which it communicates, and the above-mentioned driver 11 also periodically receives the heartbeat signals sent by the other drivers 11 with which it communicates. The corresponding turn-off semiconductor device 10 is a turn-off semiconductor device electrically connected to the driver 11. In the case where the turn-off semiconductor device 10 fails, the driver 11 electrically connected to it cannot obtain electrical energy from the circuit, and thus cannot normally execute the logic of periodically sending heartbeat signals. Therefore, in the case where the above-mentioned heartbeat signal of the above-mentioned other driver 11 is not received within a predetermined period, it is considered that the turn-off semiconductor device electrically connected to the other driver 11 has failed.

[0030] The voltage clamping circuit 13 is connected in parallel across at least two of the above-mentioned turn-off semiconductor devices 10. The voltage clamping circuit 13 breaks down all the remaining turn-off semiconductor devices in the switching structure when the withstand voltage value of the remaining turn-off semiconductor devices is less than the operating voltage of the voltage clamping circuit 13 and the voltage across the voltage clamping circuit 13 is greater than the operating voltage. The remaining turn-off semiconductor devices are the turn-off semiconductor devices 10 in the switching structure that have not failed due to a short circuit.

[0031] Specifically, the voltage clamping circuit 13 is used to perform overvoltage clamping protection on the switching structure during the turn-off transient, specifically, when the series voltage (i.e., the voltage across the voltage clamping circuit 13) is greater than the operating voltage. In the case where some of the turn-off semiconductor devices 10 in the above-mentioned switching structure fail due to a short circuit, such that the total withstand voltage value of the remaining turn-off semiconductor devices is less than the operating voltage of the voltage clamping circuit, and the series-connected turn-off semiconductor devices 10 are in the turn-off transient, the voltage clamping circuit 13 will be triggered to break down all the remaining turn-off semiconductor devices, rendering them ineffective.

[0032] Through the above embodiments, at least two turn-off semiconductor devices in the switch structure are connected in series, the turn-off semiconductor devices are respectively connected to drivers, the drivers send heartbeat signals regularly, and when a driver does not receive the heartbeat signal of other drivers within a predetermined period, the turn-off semiconductor device corresponding to the driver is controlled to remain in the conducting state. The voltage clamping circuit is connected in parallel at both ends of the series branch of the turn-off semiconductor devices. When the withstand voltage value of the non-failed turn-off semiconductor device in the series branch is less than the operating voltage of the voltage clamping circuit and the voltage across the voltage clamping circuit is greater than the operating voltage, the voltage clamping circuit will break down and fail all the non-failed turn-off semiconductor devices. In this application, the drivers of the turn-off semiconductor devices in the series circuit send heartbeat signals regularly. When a heartbeat signal is not received, it is considered that the turn-off semiconductor device corresponding to the driver that did not send the heartbeat signal has failed. At this time, the driver of the non-failed turn-off semiconductor device controls the turn-off semiconductor device to remain in the conducting state, thereby reducing the voltage across the voltage clamping circuit and making it lower than the operating voltage, avoiding the problem that in a series circuit of turn-off semiconductor devices sharing a voltage clamping circuit, the breakdown of non-failed devices is triggered by the failure of some devices, preventing the further expansion of the failure range, and solving the problem of high loss cost of turn-off semiconductor devices.

[0033] Through the heartbeat signal mechanism, this application can timely lock the corresponding turn-off semiconductor device in the conducting state when a failure occurs in the turn-off semiconductor device, avoiding the problem that the failure of some turn-off semiconductor devices leads to the failure of all turn-off semiconductor devices in the entire switch structure. This is particularly important for application scenarios such as high-voltage direct current transmission and high-power motor drive, and can significantly reduce the loss cost of the system.

[0034] In this application, the above-mentioned driver is used to control the corresponding turn-off semiconductor device to remain in the conducting state when the above-mentioned driver does not receive the above-mentioned heartbeat signal of the above-mentioned other drivers within a predetermined period, the above-mentioned turn-off semiconductor device is in the above-mentioned conducting state, and a turn-off instruction is received.

[0035] According to some alternative embodiments of the present application, each of the above-mentioned drivers is configured to send the above-mentioned heartbeat signal to all the other above-mentioned drivers in the above-mentioned switching structure, and is further configured to determine the number of the above-mentioned heartbeat signals not received within the above-mentioned predetermined period. When the number is greater than or equal to a predetermined threshold, the corresponding turn-off semiconductor device is in the on state and a turn-off instruction is received, the driver controls the corresponding turn-off semiconductor device to maintain the on state, and the turn-off instruction is used to indicate turning off the turn-off semiconductor device. In this embodiment, one driver in the switching structure interacts with all other drivers for heartbeat signals. When each turn-off semiconductor device is operating normally, the above-mentioned driver can receive heartbeat signals from all other drivers. Whenever a turn-off semiconductor device fails due to a short circuit, the above-mentioned driver will receive one less heartbeat signal within the predetermined period. Therefore, the above-mentioned number refers to the number of turn-off semiconductor devices that have failed due to short circuits in the switching structure. When this number is greater than or equal to the predetermined threshold, it indicates that there is a risk that the withstand voltage value of the remaining turn-off semiconductor devices is less than the operating voltage. At this time, in order to prevent the trigger voltage clamping circuit from breaking down the remaining turn-off semiconductor devices, the driver controls the corresponding turn-off semiconductor device connected thereto to remain conducting when receiving the turn-off instruction, so as to avoid the actual voltage across the turn-off transient voltage clamping circuit being greater than its operating voltage, thereby effectively preventing the problem of further expansion of the device failure range caused by the breakdown of non-failed devices.

[0036] The comprehensive monitoring mechanism of the heartbeat signal in the above-mentioned embodiment can more accurately judge the short-circuit failure state of the turn-off semiconductor device, avoiding the influence of the short-circuit failure of some turn-off semiconductor devices on other normal turn-off semiconductor devices in the entire switching structure, and is particularly suitable for industrial control and power systems that require high reliability, such as wind power and photovoltaic inverters, ensuring the continuity and safety of power conversion.

[0037] Specifically, the above-mentioned driver 11 and all the other above-mentioned drivers 11 constitute all the drivers in the above-mentioned switching structure. For example, when the above-mentioned switching structure includes two drivers, driver A and driver B, driver A is the driver 11, and driver B is all the other drivers 11; when the above-mentioned switching structure includes three drivers, driver A, driver B, and driver C, driver A is the above-mentioned driver 11, and driver B and driver C constitute all the other above-mentioned drivers 11.

[0038] Moreover, when the number is greater than or equal to the predetermined threshold, the corresponding turn-off semiconductor device is in the on state and a turn-off instruction is received, each driver corresponding to a normal turn-off semiconductor device in the switching structure performs the action of maintaining the on state of the turn-off semiconductor device.

[0039] In some other embodiments, the number of the above-mentioned turn-off semiconductor devices and the above-mentioned drivers is even. In the above-mentioned switching structure, the above-mentioned heartbeat signals are periodically transmitted between every two of the above-mentioned drivers. The above-mentioned drivers are further configured to control the corresponding turn-off semiconductor device to remain in the on state when the above-mentioned heartbeat signal is not received within the above-mentioned predetermined period, the corresponding turn-off semiconductor device is in the on state, and a turn-off instruction is received. The above-mentioned turn-off instruction is used to indicate turning off the above-mentioned turn-off semiconductor device. By adopting an even-numbered configuration of drivers and turn-off semiconductor devices, through the interaction mode of pairwise heartbeat signals, when one turn-off semiconductor device fails, the driver of another normal turn-off semiconductor device can act quickly, reducing the risk of breakdown of the normal turn-off semiconductor device. It is particularly suitable for occasions that require high parallel processing capabilities, enhancing the overall robustness of the system.

[0040] In the above-mentioned switching structure of the present application, any two of the above-mentioned drivers interact the above-mentioned heartbeat signals through an isolated communication path. The design of the isolated communication path effectively prevents electrical interference between drivers, ensuring the accurate transmission of heartbeat signals, which is crucial for occasions with a complex electromagnetic environment, and can significantly improve the signal stability and the anti-interference ability of the device.

[0041] Optionally, the above-mentioned isolated communication path includes one of the following: an optocoupler isolation path, a magnetic coupler isolation path, a capacitive coupler isolation path, a transformer isolation path, or a digital isolation path.

[0042] Those skilled in the art can adopt various isolated communication paths to achieve communication interaction between drivers, and can flexibly select the most suitable communication method according to the specific application environment and requirements. For example, in a high-voltage and high-current power conversion system, an optocoupler isolation path can provide better electrical isolation, while in occasions that require high-speed data transmission, such as a power electronic control unit, a digital isolation path is more applicable.

[0043] In some other exemplary solutions, as Figure 3 shown, the above-mentioned switching structure further includes: a network switch 12, which communicates with all the above-mentioned drivers 11 in the above-mentioned switching structure, and the above-mentioned drivers 11 interact the above-mentioned heartbeat signals with other above-mentioned drivers 11 through the above-mentioned network switch 12. The drivers 11 interact heartbeat signals with other drivers through the network switch, that is, all the drivers in the switching structure communicate and interact through the network switch. The introduction of the network switch not only simplifies the communication connection between drivers, reduces the system complexity, but also enables the efficient distribution and collection of heartbeat signals, which is particularly suitable for large-scale power device arrays, greatly improving the system scalability and management efficiency.

[0044] In some alternative embodiments, the above-mentioned voltage clamping circuit includes one of the following:

[0045] A lightning arrester (such as Figure 2 and Figure 3 shown), one end is electrically connected to the input end of the turn-off semiconductor device of the series head, and the other end is electrically connected to the output end of the turn-off semiconductor device of the series tail;

[0046] A Zener diode, the cathode of the Zener diode is electrically connected to the input end of the turn-off semiconductor device of the series head, and the anode of the Zener diode is electrically connected to the output end of the turn-off semiconductor device of the series tail;

[0047] A transient diode, the cathode of the transient diode is electrically connected to the input end of the turn-off semiconductor device of the series head, and the anode of the transient diode is electrically connected to the output end of the turn-off semiconductor device of the series tail;

[0048] A gate clamping circuit, one end is electrically connected to the input end of the turn-off semiconductor device of the series head, and the other end is electrically connected to the output end of the turn-off semiconductor device of the series tail.

[0049] In the above embodiments, the setting of the voltage clamping circuit can effectively prevent the turn-off transient overvoltage from damaging the thyristor, and can significantly improve the stability of the system and the service life of the thyristor.

[0050] Specifically, the lightning arrester has characteristics such as high energy absorption, fast response, and simple structure, and can be an ideal choice for voltage clamping, especially having irreplaceable advantages in the field of high voltage and high power. The Zener diode has advantages such as high voltage clamping accuracy, fast response speed, and cost overlap, and can be an ideal choice for medium and small power applications. The transient diode has advantages such as fast response speed, high surge absorption capacity, precise clamping voltage, and two-way protection, and can simplify the circuit structure design. The above gate clamping circuit has strong compatibility, can stabilize the signal level, and reduce false triggering caused by noise coupling.

[0051] In some exemplary embodiments, the above lightning arrester can be one or several of a metal oxide lightning arrester, a tube type lightning arrester, a valve type lightning arrester, and a zinc oxide lightning arrester.

[0052] In some other embodiments, the above gate clamping circuit may specifically include: a diode, a capacitor, and a resistor. The diode is the core component of the circuit, used to control the current direction and achieve voltage clamping, such as ordinary diodes, Schottky diodes, etc. Schottky diodes have the characteristics of low forward conduction voltage and fast switching speed, and are often used in clamping circuits with high requirements for speed and power consumption; the capacitor plays a role in storing charge and maintaining voltage stability, and its capacitance value will affect the clamping effect and the circuit response speed; the resistor cooperates with the capacitor to determine the charging and discharging time constants of the capacitor, and at the same time can also limit the current in the circuit to protect other components.

[0053] In addition, some clamping circuits may also include a power supply to provide a specific level reference for clamping.

[0054] According to some other embodiments of the present application, as Figure 2 and Figure 3 shown, the above switch structure further includes: a plurality of first voltage equalizing circuits 15, corresponding to the above turn-off semiconductor devices 10 one by one. The first voltage equalizing circuit 15 includes a first resistor 16 and an energy storage device 17. The first end of the first resistor 16 is electrically connected to the input end of the turn-off semiconductor device 10, the second end of the first resistor 16 is electrically connected to the first end of the energy storage device 17, and the second end of the energy storage device 17 is electrically connected to the output end of the turn-off semiconductor device 10; a plurality of second voltage equalizing circuits, corresponding to the above turn-off semiconductor devices 10 one by one. The second voltage equalizing circuit includes a second resistor 18. The first end of the second resistor 18 is electrically connected to the input end of the turn-off semiconductor device 10, and the second end of the second resistor 18 is electrically connected to the output end of the turn-off semiconductor device 10. In the above embodiments, the first voltage equalizing circuit and the second voltage equalizing circuit are used in combination, which can not only achieve the equal distribution of voltage, but also provide necessary energy buffering when the thyristor conducts or turns off, and is particularly suitable for occasions that require frequent switching operations, such as power electronic converters, which can significantly improve the efficiency and life of the device and reduce energy loss.

[0055] Specifically, the above-mentioned first voltage equalizing circuit 15 serves as the dynamic voltage equalizing circuit of the turn-off semiconductor device 10. The dynamic voltage equalizing circuit is used to slow down the change rate of the voltage across the turn-off semiconductor device 10 during the turn-on and turn-off transients, thereby reducing the dynamic voltage difference between multiple turn-off semiconductor devices 10. When the turn-off semiconductor device 10 is in the turn-off transient state, the voltage across it rises and charges the energy storage device 17 through the first resistor 16. The dynamic voltage equalizing circuit provides an additional current path for the turn-off semiconductor device 10, reducing the equivalent input impedance across the turn-off semiconductor device 10 and the rising rate of the voltage across it. When the turn-off semiconductor device 10 is in the turn-on transient state, the voltage across it drops and discharges the energy storage device 17 through the first resistor 16. The dynamic voltage equalizing circuit provides an additional current source for the turn-off semiconductor device 10, reducing the equivalent output impedance across the turn-off semiconductor device 10 and the dropping rate of the voltage across it. The above-mentioned second voltage equalizing circuit serves as the static voltage equalizing circuit of the turn-off semiconductor device 10. The resistance value of the static voltage equalizing circuit is much smaller than the equivalent impedance of the turn-off semiconductor device 10 in the blocking state, and can balance the leakage current of the turn-off semiconductor device 10 in the blocking state, thereby reducing the static voltage difference between multiple turn-off semiconductor devices 10.

[0056] In addition, those skilled in the art can optimize the parameters of the first resistor and the energy storage device in the dynamic voltage equalizing circuit according to the characteristics of IGCT and other turn-off semiconductor devices, so as to better adapt to the rapidly changing switching state, reduce the dynamic voltage difference between turn-off semiconductor devices, and reduce the energy loss of the dynamic voltage equalizing circuit during the turn-on and turn-off transients.

[0057] Those skilled in the art can choose any suitable device as the above-mentioned energy storage device 17. For example, as Figure 2 and Figure 3 shown, a capacitor is selected as the above-mentioned energy storage device 17; or, an inductor is selected as the above-mentioned energy storage device 17. In addition, the above-mentioned first resistor 16 can include only one resistor element, or can include multiple resistor elements connected in series and parallel. Similarly, the above-mentioned second resistor 18 can include only one resistor element, or can include multiple resistor elements connected in series and parallel.

[0058] Optionally, the above-mentioned turn-off semiconductor device includes at least one of the following: IGBT (Insulated Gate Bipolar Transistor), HEMT (High Electron Mobility Transistor), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), and turn-off thyristor. The above-mentioned turn-off thyristor includes at least one of the following: IGCT (Integrated Gate-Commutated Thyristor), GTO (Gate Turn-Off Thyristor), SGTO (Super Gate Turn-Off Thyristor), ETO (Emitter Turn-Off Thyristor), and IETO (Integrated Emitter Turn-Off Thyristor). In actual application, the voltage clamping circuit is divided into two types: passive clamping and active clamping. Among them, the passive clamping voltage clamping circuit is a voltage-controlled variable resistor device, such as a lightning arrester, a Zener diode, and a transient suppression diode, etc.; the active clamping voltage clamping circuit converts the voltage across the turn-off semiconductor device into a gate compensation current, and converts the turn-off semiconductor device into a voltage-controlled variable resistor device during the voltage equalization process. The equivalent impedance of the voltage clamping circuit decreases as the voltage across the switch structure increases, and is used to limit the further rise of the voltage across the turn-off semiconductor device that limits overvoltage during the turn-off transient, forcing other turn-off semiconductor devices in the switch structure to bear the voltage, so that the voltages across each turn-off semiconductor device in the switch structure tend to be consistent, thereby realizing the voltage clamping function.

[0059] The withstand voltage of multiple series-connected turn-off semiconductor devices in the switch structure determines the operating voltage of the voltage clamping circuit. When the number of failed devices in the series increases and causes the operating voltage to be greater than the total withstand voltage of the remaining normal devices, during the turn-off transient, when the voltage across the voltage clamping circuit is greater than the operating voltage, it will cause all devices to break down due to overvoltage, resulting in a further expansion of the fault range. The failure mode of the turn-off semiconductor device is short circuit. Therefore, the driver of the failed device cannot obtain energy from the main circuit and thus cannot execute the preset logic normally. Among them, the above-mentioned operating voltage is generally set to be less than the total withstand voltage value of all turn-off semiconductor devices in the switch structure when they are not failed.

[0060] ​

[0061] Taking the example that the switching structure of the present application includes two turn-off semiconductor devices and both turn-off semiconductor devices are IGCTs, the working principle of the semiconductor power device of the present application will be explained. As Figure 2 shown, in the switching structure of the present application, there are two turn-off semiconductor devices 10, namely the first turn-off semiconductor device 101 and the second turn-off semiconductor device 102. The cathode of the first turn-off semiconductor device 101 is electrically connected to the anode of the second turn-off semiconductor device 102; correspondingly, there are also two drivers 11, namely the first driver 111 and the second driver 112. The first end of the first driver 111 is electrically connected to the gate of the first turn-off semiconductor device 101, the second end of the first driver 111 is electrically connected to the cathode of the first turn-off semiconductor device 101, the first end of the second driver 112 is electrically connected to the gate of the second turn-off semiconductor device 102, and the second end of the second driver 112 is electrically connected to the cathode of the second turn-off semiconductor device 102; one end of the voltage clamping circuit 13 is electrically connected to the anode of the first turn-off semiconductor device 101, and the other end is electrically connected to the cathode of the second turn-off semiconductor device 102. That is to say, the two turn-off semiconductor devices 10 share one voltage clamping circuit 13; the first driver 111 and the second driver 112 send heartbeat signals to each other through the isolation communication bus. The heartbeat signal can specifically be high and low pulses or communication packets, etc.; after the first driver 111 receives the heartbeat signal of the second driver 112, it considers that the second turn-off semiconductor device 102 is normal and executes the turn-off instruction when the turn-off instruction arrives; otherwise, the first driver 111 considers that the second turn-off semiconductor device 102 fails and refuses to execute the turn-off instruction when the turn-off instruction arrives, and keeps the first turn-off semiconductor device 101 turned on, thereby reducing the series voltage to below the operating voltage of the voltage clamping circuit 13 and effectively preventing the further expansion of the fault range.

[0062] When there are multiple series-connected switching structures, the communication connection complexity between the drivers increases exponentially. Therefore, as Figure 3 shown, a network switch is used to realize the aggregation and distribution of the heartbeat signals between the drivers, reducing the system complexity.

[0063] In addition to the heartbeat signal communication between the drivers, the present application can further integrate a fault detection function, such as real-time monitoring of the current and voltage of the turn-off semiconductor device. Once an abnormality is detected, a fault isolation strategy is immediately started to quickly reduce the impact of the fault on the entire system.

[0064] In a series circuit, considering the uncertainty of the device parameters changing with time and temperature, the operating voltage of the voltage clamping circuit can be dynamically adjusted through an intelligent algorithm to make it more adaptable to the current system state and working conditions, improving the robustness and reliability of the system.

[0065] In addition to achieving indirect communication through a network switch, a distributed control strategy can also be adopted to endow each driver with a certain degree of autonomous decision-making ability. For example, each driver can also decide whether to execute the turn-off instruction on its own according to the locally monitored voltage and communication status, and how to adjust its drive signal, so as to improve the overall response speed and reliability of the system.

[0066] Considering the large amount of energy release that may be caused by overvoltage breakdown, an efficient thermal management mechanism can also be integrated in the semiconductor power device of the present application, such as heat sinks, liquid cooling systems, and thermal protection circuits, to timely remove excess heat and prevent secondary failures caused by overheating.

[0067] In a specific embodiment, the driver is further configured to collect and analyze the state parameters of the connected turn-off semiconductor device in real time through a monitoring unit, including but not limited to the temperature, voltage, current, and conduction time of the device. These monitoring units can be sensors integrated in the driver, such as temperature sensors, voltage-current transformers, and time timers. They transmit heartbeat signals carrying these state parameters to other drivers through an isolated communication bus for further data processing and analysis.

[0068] The driver is also configured to process the state parameters using a pre-designed intelligent algorithm. The algorithm may be based on one of the following several technologies: Machine learning: By training models (such as support vector machines, neural networks, or decision trees, etc.) to learn the laws of device parameters changing with time and temperature, predict future states, and adjust the operating voltage of the voltage clamping circuit accordingly; Adaptive control: Design an adaptive controller that can automatically adjust the parameters of the control algorithm according to the real-time monitored parameter changes to optimize the operating voltage of the voltage clamping circuit; Fuzzy logic control: Use a fuzzy logic system to process uncertain parameters, such as the impact of temperature changes on device performance, and dynamically adjust the operating voltage of the voltage clamping circuit by setting a series of fuzzy rules.

[0069] After that, the driver adjusts the operating voltage by controlling the impedance characteristics of the voltage-controlled variable resistor devices (such as lightning arresters, Zener diodes, etc.) in the voltage clamping circuit. This can be achieved through the following methods: Using an adjustable resistor: Integrate an adjustable resistor in the voltage clamping circuit, and adjust its resistance value in real time through the control signal output by the intelligent algorithm, so as to change the impedance of the entire circuit and achieve the purpose of adjusting the operating voltage; Integrating a digitally controlled voltage source: Add a digitally adjustable voltage source controlled by an intelligent algorithm to the circuit. When the algorithm detects that the operating voltage needs to be adjusted, dynamically adjust the output voltage of the voltage source, thereby indirectly changing the behavior of the voltage clamping circuit; Combination of intelligent algorithm and electronic switch: Use an electronic switch (such as MOSFET or IGBT) in parallel with multiple fixed-resistance resistors. The intelligent algorithm selects different resistance values of resistors to be connected to the circuit by controlling the on and off of the electronic switch according to the monitored parameters, so as to achieve dynamic adjustment of the operating voltage.

[0070] In this way, the intelligent dynamic adjustment of the operating voltage of the voltage clamping circuit can significantly improve the adaptability and stability of the power electronic system in the face of device parameter uncertainties and environmental changes, and effectively avoid system failures and safety risks caused by overvoltage breakdown. This method is not only applicable to IGCT, but also can be applied to the series circuit design of other turn-off semiconductor devices, such as GTO, SGTO, ETO, and IETO, etc.

[0071] In some embodiments, the above-mentioned driver may include a first turn-on circuit and a second turn-on circuit that are redundant to each other. The first ends of the first turn-on circuit and the second turn-on circuit are respectively electrically connected to the control end of the turn-off semiconductor device, and the second ends of the first turn-on circuit and the second turn-on circuit are respectively electrically connected to the output end of the turn-off semiconductor device. When the voltage difference between the input end and the output end of the turn-off semiconductor device is not greater than a preset voltage threshold, and when the voltage difference between the input end and the control end of the turn-off semiconductor device is not greater than a preset voltage threshold, one of the first turn-on circuit and the second turn-on circuit is in a charging state (subsequently referred to as the turn-on circuit in the charging state), and the other is not in a charging state (subsequently referred to as the turn-on circuit not in the charging state), and neither of them operates; When the voltage difference between the input end and the output end of the turn-off semiconductor device is greater than a preset voltage threshold, or when the voltage difference between the input end and the control end of the turn-off semiconductor device is greater than a preset voltage threshold, the turn-on circuit in the charging state starts to discharge and charges the turn-on circuit not in the charging state, so that the turn-on circuit not in the charging state can quickly operate and control the turn-off semiconductor device to conduct.

[0072] In some other alternative embodiments, there is a driver with the highest priority among multiple drivers. This driver is used to receive the operating states of turn-off semiconductor devices fed back by other drivers, and is also used to obtain the operating states of the corresponding turn-off semiconductor devices and the overall environmental conditions of the semiconductor power devices, and intelligently adjust the sending interval of the heartbeat signal. In high-risk situations such as high load of the turn-off semiconductor device or large change in ambient temperature, the above driver shortens the heartbeat interval, and packs the shortened heartbeat interval information and the heartbeat signal before the shortening action and sends them to other drivers, so that other drivers operate according to the shortened heartbeat interval information; in low-risk situations such as low load of the turn-off semiconductor device or small change in ambient temperature, the above driver increases the heartbeat interval, and packs the increased heartbeat interval information and the heartbeat signal before the increasing action and sends them to other drivers, so that other drivers operate according to the increased heartbeat interval information, in order to improve the real-time monitoring and response capabilities of the system.

[0073] An embodiment of the present application further provides a converter, including: a plurality of bridge arms, and each of the above bridge arms includes a plurality of any of the above semiconductor power devices connected in series.

[0074] Through the above embodiments, each bridge arm includes a plurality of the above semiconductor power devices connected in series. In the series circuit of the semiconductor power devices, the drivers of the turn-off semiconductor devices regularly send heartbeat signals. When a heartbeat signal is not received, it is considered that the turn-off semiconductor device corresponding to the driver that did not send the heartbeat signal has failed. At this time, the driver of the turn-off semiconductor device that has not failed controls the turn-off semiconductor device to remain in the conducting state, thereby reducing the voltage across the voltage clamping circuit and making it lower than the operating voltage, avoiding the problem that in the series circuit of turn-off semiconductor devices sharing a voltage clamping circuit, the breakdown of some devices triggers the breakdown of the non-failed devices, preventing the further expansion of the failure range, and solving the problems of high loss cost and high maintenance cost of the converter.

[0075] Applying the semiconductor power device of the present application in a converter can not only achieve high-precision voltage control. Since the semiconductor power device fully considers the fault detection and protection mechanism in design, through the sending and receiving of heartbeat signals, the state of the turn-off semiconductor device can be effectively monitored by the driver, ensuring that when the turn-off semiconductor device fails, other turn-off semiconductor devices on the series branch remain in the conducting state when receiving the turn-off instruction, avoiding the problem of being broken down, which is of great significance for the design and maintenance of the power electronic system.

[0076] Specifically, the plurality of turn-off semiconductor devices in the above bridge arm can form a half-bridge inverter circuit or a full-bridge inverter circuit.

[0077] Obviously, those skilled in the art should understand that the various modules or steps of the present invention described above can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. They can be implemented by program codes executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described herein can be executed in a different order, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation. In this way, the present invention is not limited to any specific combination of hardware and software.

[0078] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0079] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0080] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0081] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the functions in the processFigure 1 one or more processes and / or blocks Figure 1 steps of functions specified in one or more blocks

[0082] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0083] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

[0084] Computer-readable media includes permanent and non-permanent, removable and non-removable media and can be implemented by any method or technology for information storage. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0085] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0086] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0087] For the semiconductor power device of the present application, at least two turn-off semiconductor devices are connected in series in the switching structure. The turn-off semiconductor devices are connected to drivers one by one, and the drivers send heartbeat signals regularly. When a driver does not receive the heartbeat signal from other drivers within a predetermined period, it controls the turn-off semiconductor device connected to it to remain in the conducting state. The voltage clamping circuit is connected in parallel across both ends of the series branch of the turn-off semiconductor devices. When the breakdown voltage of the non-failed turn-off semiconductor devices in the series branch is less than the operating voltage of the voltage clamping circuit and the voltage across the voltage clamping circuit is greater than the operating voltage, the voltage clamping circuit will break down all the non-failed turn-off semiconductor devices. In the present application, the drivers of the turn-off semiconductor devices in the series circuit send heartbeat signals regularly. When a heartbeat signal is not received, it is considered that the turn-off semiconductor device corresponding to the driver that did not send the heartbeat signal has failed. At this time, the driver of the non-failed turn-off semiconductor device controls the turn-off semiconductor device to remain in the conducting state, thereby reducing the voltage across the voltage clamping circuit and making it lower than the operating voltage, avoiding the problem that in a series circuit of turn-off semiconductor devices sharing a voltage clamping circuit, the breakdown of non-failed devices is triggered by the failure of some devices, preventing the further expansion of the failure range, and solving the problem of high loss cost of turn-off semiconductor devices.

[0088] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A semiconductor power device, characterized in that: include: A switch structure, comprising at least two turn-off semiconductor devices and at least two drivers, wherein at least two of the turn-off semiconductor devices are connected in series, a first end of the driver is electrically connected to a control end of the turn-off semiconductor device in a one-to-one correspondence, a second end of the driver is electrically connected to an output end of the turn-off semiconductor device in a one-to-one correspondence, the driver is used to periodically send a heartbeat signal to at least one other driver in the switch structure, and the driver is also used to control the corresponding turn-off semiconductor device to remain in a conducting state when the heartbeat signal of the other driver is not received within at least a predetermined period; A voltage clamping circuit is connected in parallel at both ends of at least two of the turn-off semiconductor devices. When the withstand voltage of the remaining turn-off semiconductor devices is less than the action voltage of the voltage clamping circuit and the voltage across the voltage clamping circuit is greater than the action voltage, the voltage clamping circuit breaks down all the remaining turn-off semiconductor devices in the switch structure. The remaining turn-off semiconductor devices are the turn-off semiconductor devices in the switch structure that have not failed due to short circuit.

2. The semiconductor power device according to claim 1, characterized in that: Each of the drivers is used to send the heartbeat signal to all other drivers in the switch structure, and is also used to determine the number of the heartbeat signals that have not been received within the predetermined period. When the number is greater than or equal to a predetermined threshold and the corresponding turn-off semiconductor device is in the on-state and receives a shutdown instruction, the corresponding turn-off semiconductor device is controlled to maintain the on-state, and the shutdown instruction is used to instruct to shut down the turn-off semiconductor device.

3. The semiconductor power device according to claim 1, characterized in that: The number of the turnable semiconductor devices and the drivers is an even number, and every two drivers in the switch structure send the heartbeat signal to each other at a regular interval. The driver is also used to control the corresponding turnable semiconductor device to remain in the on state when the heartbeat signal is not received within the predetermined period and the corresponding turnable semiconductor device is in the on state and a shutdown instruction is received, and the shutdown instruction is used to instruct to shut down the turnable semiconductor device.

4. The semiconductor power device according to claim 1, characterized in that: In the switch structure, any two of the drivers exchange the heartbeat signal through an isolated communication path.

5. The semiconductor power device according to claim 4, characterized in that: The isolated communication path includes one of the following: an optical coupling isolation path, a magnetic coupling isolation path, a capacitive coupling isolation path, a transformer isolation path or a digital isolation path.

6. The semiconductor power device according to claim 1, characterized in that: The switch structure further includes: A network switch communicates with all the drivers in the switch structure, and the driver exchanges the heartbeat signal with the other drivers through the network switch.

7. The semiconductor power device according to claim 1, characterized in that: The voltage clamping circuit includes one of the following: A lightning arrester, one end of which is electrically connected to the input end of the turn-off semiconductor device at the head of the series connection, and the other end of which is electrically connected to the output end of the turn-off semiconductor device at the tail of the series connection; a Zener diode, wherein a cathode of the Zener diode is electrically connected to an input terminal of the semiconductor device that can be turned off at a head of the series connection, and an anode of the Zener diode is electrically connected to an output terminal of the semiconductor device that can be turned off at a tail of the series connection; A transient diode, wherein a cathode of the transient diode is electrically connected to the input terminal of the turn-off semiconductor device at the head of the series connection, and an anode of the transient diode is electrically connected to the output terminal of the turn-off semiconductor device at the tail of the series connection; The gate clamp circuit has one end electrically connected to the input end of the turn-off semiconductor device at the head of the series connection, and the other end electrically connected to the output end of the turn-off semiconductor device at the tail of the series connection.

8. The semiconductor power device according to claim 1, characterized in that: The switch structure further includes: A plurality of first voltage balancing circuits, corresponding one to one with the semiconductor devices that can be turned off, wherein the first voltage balancing circuits include a first resistor and an energy storage device, wherein a first end of the first resistor is electrically connected to an input end of the semiconductor device that can be turned off, a second end of the first resistor is electrically connected to a first end of the energy storage device, and a second end of the energy storage device is electrically connected to an output end of the semiconductor device that can be turned off; A plurality of second voltage-equalizing circuits correspond one-to-one to the turnable semiconductor devices, wherein the second voltage-equalizing circuits include a second resistor, wherein a first end of the second resistor is electrically connected to an input end of the turnable semiconductor device, and a second end of the second resistor is electrically connected to an output end of the turnable semiconductor device, and a resistance value of the second resistor is less than an equivalent resistance of the turnable semiconductor device when the turnable semiconductor device is in a blocking state.

9. The semiconductor power device according to claim 1, characterized in that: The turn-off semiconductor device includes at least one of the following: IGBT, HEMT, MOSFET and turn-off thyristor, and the turn-off thyristor includes at least one of the following: IGCT, GTO, SGTO, ETO and IETO.

10. A converter, characterized in that: include: A plurality of bridge arms, each of the bridge arms comprising a plurality of semiconductor power devices according to any one of claims 1 to 9 connected in series.

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