Fault-tolerant control circuit, system and equipment

Abstract

The invention relates to a fault-tolerant control circuit, a fault-tolerant control system and fault-tolerant control equipment. A power module detection unit detects a main power module in a power bridge arm and outputs a module detection signal corresponding to the main power module to a fault diagnosis unit; therefore, the fault diagnosis unit performs fault diagnosis according to the module detection signal and the reference signal provided by the preset reference signal end, so that the fault self-diagnosis is realized by adopting pure hardware, the fault loudness speed is improved, and the fault diagnosis signal is output through the fault diagnosis unit. The fault-tolerant switching unit controls the first branch circuit to be disconnected according to the fault diagnosis signal and controls the second branch circuit to be connected to the main loop, so that when the fault diagnosis signal is a hardware fault signal, the circuit path of the power bridge arm is switched from the first branch circuit to the second branch circuit; and when the main power module has an unrecoverable fault, the standby power module can be automatically switched, so that the reliability and the fault-tolerant operation capability of the system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronics, and in particular to a fault-tolerant control circuit, system and device. BACKGROUND

[0002] With the rapid development of power electronics technology, power converter systems are increasingly widely used. They mainly realize the conversion of the form of electric energy through power converters to meet the power requirements of different loads or systems. The damage of the power converter will cause the power converter system to work in an abnormal state. If it is not diagnosed and eliminated in time, it will cause secondary faults to occur, and eventually lead to system downtime. However, the existing high-power converter systems usually use microprocessors such as micro control units (MCU), digital signal processors (DSP) for fault diagnosis, and their diagnosis logic completely depends on software running. When the microprocessor has software program runaway, crash, or the system is subjected to strong electromagnetic interference, the software diagnosis function is easily disabled, which cannot identify faults in time, so it cannot protect the equipment in time, resulting in equipment damage or system paralysis. SUMMARY

[0003] The present application provides a fault-tolerant control circuit, system and device to solve the problems of low system reliability and delayed response in the prior art that rely on software running to realize fault diagnosis of power converter systems.

[0004] In a first aspect, the present application provides a fault-tolerant control circuit, comprising: a power conversion unit, a power module detection unit, a fault diagnosis unit and a fault-tolerant switching unit; Each of the power bridge arms includes a main power module and a standby power module connected in parallel with the main power module. The power module detection unit is configured to detect the main power module and output a module detection signal corresponding to the main power module. The fault diagnosis unit is configured to perform fault diagnosis based on the module detection signal and a reference signal provided by a preset reference signal terminal, and output a fault diagnosis signal corresponding to the main power module. The fault-tolerant switching unit is configured to control a first branch to be disconnected and a second branch to be connected to a main loop based on the fault diagnosis signal, so as to switch a circuit path of the power bridge arm from the first branch to the second branch when the fault diagnosis signal is a hardware fault signal. The first branch is a control branch formed by the main power module, and the second branch is a control branch formed by the standby power module.

[0005] Optionally, the module detection signal comprises: a temperature monitoring signal, a voltage monitoring signal and a current monitoring signal; The reference signal comprises: an over-temperature reference signal, an over-current reference signal and an over-voltage reference signal; The fault diagnosis unit comprises: a first comparison module, a second comparison module, a third comparison module and an OR gate judgment module; The first comparison module is configured to compare the temperature monitoring signal with the over-temperature reference signal and output a first comparison signal; The second comparison module is configured to compare the current monitoring signal with the over-current reference signal and output a second comparison signal; The third comparison module is configured to compare the voltage monitoring signal with the over-voltage reference signal and output a second comparison signal; The OR gate judgment module is configured to perform fault judgment according to the first comparison signal, the second comparison signal and the third comparison signal and output the fault diagnosis signal.

[0006] Optionally, the first comparison module comprises an over-temperature diagnosis comparator, the second comparison module comprises an over-current comparator, the third comparison module comprises a desaturation comparator, and the OR gate judgment module comprises an OR gate array; The preset reference signal end comprises a first reference signal end, a second reference signal end and a third reference signal end, the first reference signal end is configured to provide the over-temperature reference signal, the second reference signal end is configured to provide the over-current reference signal, and the third reference signal end is configured to provide the over-voltage reference signal; The first end of the over-temperature diagnosis comparator is electrically connected with the temperature detection output end of the power module detection unit, the second end of the over-temperature diagnosis comparator is electrically connected with the first reference signal end, the output end of the over-temperature diagnosis comparator is electrically connected with the first input end of the OR gate judgment module, the temperature detection output end of the power module detection unit is configured to output the temperature monitoring signal, and the output end of the over-temperature diagnosis comparator is configured to output the first comparison signal; The first end of the over-temperature diagnosis comparator is electrically connected with the temperature detection output end of the power module detection unit, the second end of the over-temperature diagnosis comparator is electrically connected with the first reference signal end, the output end of the over-temperature diagnosis comparator is electrically connected with the first input end of the OR gate judgment module, the temperature detection output end of the power module detection unit is configured to output the temperature monitoring signal, and the output end of the over-temperature diagnosis comparator is configured to output the first comparison signal; The first end of the desaturation comparator is electrically connected with a voltage detection output end of the power module detection unit, the second end of the desaturation comparator is electrically connected with the third reference signal end, and the output end of the desaturation comparator is electrically connected with the third input end of the OR gate judgment module; the voltage detection output end of the power module detection unit is used for outputting the voltage monitoring signal, and the output end of the desaturation comparator is used for outputting the third comparison signal. The first input end of the OR gate array is electrically connected with the output end of the over-temperature diagnosis comparator, the second input end of the OR gate array is electrically connected with the output end of the over-current comparator, the third input end of the OR gate array is electrically connected with the output end of the third comparison, and the output end of the OR gate array is electrically connected with the input end of the fault-tolerant switching unit.

[0007] Optionally, the fault-tolerant switching unit comprises a redundancy switching module and a driving circuit module. The redundancy switching module is configured to output a switching signal when the fault diagnosis signal is the hardware fault signal. The driving circuit module is configured to control a first branch to be disconnected to block the first branch and control a second branch to be connected to the main loop to switch the circuit path from the first branch to the second branch according to the switching signal.

[0008] Optionally, the redundancy switching module comprises a bistable flip-flop. The input end of the bistable flip-flop is electrically connected with the output end of the fault diagnosis unit as the input end of the redundancy switching module, and the output end of the bistable flip-flop is electrically connected with the driving control end of the driving circuit module as the output end of the redundancy switching module. The input end of the redundancy switching module is configured to receive the fault diagnosis signal. The output end of the redundancy switching module is configured to output the switching signal.

[0009] Optionally, the driving circuit module comprises a relay driving submodule, and the driving control end of the relay driving submodule is electrically connected with the output end of the redundancy switching module. The relay driving submodule comprises a first relay and a second relay, the main power module is connected with the main loop through the first relay, and the standby power module is connected with the main loop through the second relay. The relay driving submodule is configured to control the first relay to be disconnected to block the first branch and control the second relay to be closed to connect the second branch to the main loop through the closed second relay according to the switching signal.

[0010] Optionally, the drive circuit module further comprises a hardware drive chip. The first input end of the hardware drive chip is electrically connected with the output end of the redundancy switching module, the second input end of the hardware drive chip is used for a power control signal, and the output end of the hardware drive chip is electrically connected with the control end of the backup power module. The hardware drive chip is specifically configured to output, based on the switching signal, a power switch signal corresponding to the power switch control signal to the backup power module.

[0011] Optionally, the fault-tolerant control circuit further comprises a self-repairing DC bus capacitor group, the self-repairing DC bus capacitor group comprising at least two capacitors connected in parallel and a recoverable fuse connected in series with each of the capacitors. The main circuit comprises a first DC bus and a second DC bus. The first end of each of the capacitors is electrically connected with the first DC bus, and the second end of each of the capacitors is electrically connected with the second DC bus through the recoverable fuse.

[0012] Optionally, the recoverable fuse is a high-molecular polymer positive coefficient temperature resistor, and the fault-tolerant control circuit further comprises a series diode connected in one-to-one correspondence with each of the capacitors. The second end of each of the capacitors is electrically connected with the second DC bus through the recoverable fuse, including: The second end of each of the capacitors is electrically connected with the first end of the high-molecular polymer positive coefficient temperature resistor, the second end of the high-molecular polymer positive coefficient temperature resistor is electrically connected with the first end of the series diode, and the second end of the series diode is electrically connected with the second DC bus; or, The second end of each of the capacitors is electrically connected with the first end of the series diode, the second end of the series diode is electrically connected with the first end of the high-molecular polymer positive coefficient temperature resistor, and the second end of the high-molecular polymer positive coefficient temperature resistor is electrically connected with the second DC bus.

[0013] In a second aspect, the present application provides a power converter system, the power converter system comprising the fault-tolerant control circuit according to any one of the first aspect of the present application.

[0014] In a third aspect, the present application provides an electrical appliance, the electrical appliance comprising the fault-tolerant control circuit according to any one of the first aspect of the present application.

[0015] The fault-tolerant control circuit, system and device provided by the embodiments of the present application can detect the main power module in the power bridge arm through the power module detection unit, output the module detection signal corresponding to the main power module to the fault diagnosis unit, so that the fault diagnosis unit can perform fault diagnosis according to the reference signal provided by the module detection signal and the preset reference signal terminal, to realize fault self-diagnosis by pure hardware, without relying on software operation, to improve the fault detection response speed, and then output the fault diagnosis signal corresponding to the main power module through the fault diagnosis unit, so that the fault-tolerant switching unit controls the first branch to be disconnected and controls the second branch to be connected to the main loop according to the fault diagnosis signal, to switch the circuit path of the power bridge arm from the first branch to the second branch when the fault diagnosis signal is a hardware fault signal, and then the power module can be automatically switched to the standby power module when the main power module has an unrecoverable fault, so that the reliability and anti-interference ability of the power converter system can be effectively improved, and the problems of low system reliability, response delay, complex redundant switching and poor fault-tolerant ability caused by the dependence of software operation to realize fault diagnosis of the power converter system in the prior art are solved. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without any creative labor under the premise of these drawings.

[0018] One or more embodiments are exemplarily illustrated by the pictures in the drawings corresponding thereto, and these exemplary illustrations do not constitute a limitation on the embodiments, and the elements with the same reference numerals in the drawings represent similar elements, unless otherwise specified, and the drawings do not constitute a proportional limitation.

[0019] Figure 1 A structural schematic diagram of a fault-tolerant control circuit provided by the embodiments of the present application; Figure 2 A circuit structural schematic diagram for diagnosing the main power module by the fault diagnosis unit provided by an example of the present application; Figure 3 A circuit schematic diagram of a fault-tolerant control circuit provided by an optional embodiment of the present application; Figure 4 A schematic diagram for redundant switching based on a hardware fault signal provided by an example of the present application; Figure 5A schematic diagram of a power converter system connected to a power grid is provided for embodiments of the present application; Figure 6 A schematic diagram of a self-healing DC bus capacitor bank connected to series diodes is provided for embodiments of the present application; Figure 7 A block diagram of a power converter system is provided for embodiments of the present application; Figure 8 A block diagram of a power converter system is provided for embodiments of the present application; Figure 9 A block diagram of an appliance system is provided for embodiments of the present application. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0021] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplification, the components and arrangements of specific examples are described in the following. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or arrangements discussed.

[0022] In the current field of power electronics, high-power converter systems usually use microprocessors for system state monitoring and fault diagnosis. However, there are inherent defects such as strong software dependency, response delay, complex redundant switching, and poor fault tolerance, which seriously restrict the system reliability and safety. Specifically, the existing power converter system relies on microprocessors for fault diagnosis. Once the software program runs away, crashes, or is subject to electromagnetic interference, the diagnostic function may fail, and the system may not be able to identify faults and trigger protection actions in time, which may cause catastrophic failures such as IGBT (Insulated Gate Bipolar Transistor) burnout, bus capacitor C burst, and other disasters. The system cannot protect the equipment in time, and there is a problem of insufficient reliability caused by strong software dependency. Moreover, the software sampling, calculation, and judgment process requires several or even tens of microseconds, which is not fast enough to respond to rapidly developing faults such as IGBT short circuits. The system may not be able to take protective action within a safe time (such as within 10 μs), which may easily cause irreversible damage to power devices. In addition, software-based redundant switching requires multiple CPU communications and voting, which not only increases the complexity and cost of the system architecture, but also relies on software logic during the redundant switching process, which cannot avoid software reliability problems.

[0023] Based on the above, the present application provides a fault-tolerant control circuit, system, and device to implement fault self-diagnosis using pure hardware, without relying on software operation, which can effectively improve the reliability and anti-interference ability of the power converter system, and solve the problems of low system reliability, response delay, complex redundant switching, and poor fault tolerance caused by relying on software operation to implement fault diagnosis of the power converter system in the prior art.

[0024] Figure 1 A structural diagram of a fault-tolerant control circuit 100 provided by an embodiment of the present application is shown in FIG. 1. As shown in FIG. 1, the fault-tolerant control circuit 100 includes a fault detection module 101, a fault diagnosis module 102, a fault protection module 103, and a fault recovery module 104. Figure 1As shown, the fault-tolerant control circuit 100 provided by the embodiment of the present application can include: a power conversion unit 110, a power module detection unit 120, a fault diagnosis unit 130 and a fault-tolerant switching unit 140; wherein the power conversion unit 110 includes power bridge arms 111, each of the power bridge arms 111 includes a main power module 112 and a backup power module 113 connected in parallel with the main power module 112. The power module detection unit 120 is configured to detect the main power module 112 and output a module detection signal corresponding to the main power module 112; the fault diagnosis unit 130 is configured to perform fault diagnosis according to the module detection signal and a reference signal provided by a preset reference signal terminal Vref, and output a fault diagnosis signal corresponding to the main power module 112, so that the fault-tolerant switching unit 140 can control a first branch 114 to be disconnected and a second branch 115 to be connected to a main loop according to the fault diagnosis signal, so as to switch a circuit path of the power bridge arm 111 from the first branch 114 to the second branch 115 when the fault diagnosis signal is a hardware fault signal, wherein the first branch 114 is a control branch formed by using the main power module 112, and the second branch 115 is a control branch formed by using the backup power module 113.

[0025] Specifically, the fault diagnosis signal in the embodiment of the present application is a signal generated by the fault diagnosis unit 130 according to the module detection signal corresponding to the main power module 112, and can be specifically used to determine whether the main power module 112 has an unrecoverable fault. For example, when the fault diagnosis signal is a pre-set hardware fault signal, it can be considered that the main power module 112 has an unrecoverable fault; and when the fault diagnosis signal is not the pre-set hardware fault signal, for example, when the fault diagnosis signal is a circuit normal signal, it can be considered that the main power module 112 is normal and has no circuit fault; wherein the hardware fault signal is used to indicate that the main power module 112 has an unrecoverable fault; and the circuit normal signal is used to indicate that the circuit is working normally.

[0026] The fault-tolerant switching unit 140 in the embodiment of the present application can be specifically used to control the first branch 114 to be disconnected and the second branch 115 to be connected to the main loop according to the fault diagnosis signal, so as to switch the circuit path of the power bridge arm 111 from the first branch 114 to the second branch 115 when the fault diagnosis signal is a hardware fault signal, so that the backup power module 113 on the second branch 115 can replace the main power module 112, and then when the main power module 112 has an unrecoverable fault, the backup power module 113 can be automatically switched to, so as to realize seamless redundant switching and improve system availability.

[0027] In summary, the fault-tolerant control circuit 100 provided by the embodiment of the present application comprises a power conversion unit 110, a power module detection unit 120, a fault diagnosis unit 130, and a fault-tolerant switching unit 140. The main power module 112 of the power bridge arm 111 is detected by the power module detection unit 120, and the module detection signal corresponding to the main power module 112 is output to the fault diagnosis unit 130, so that the fault diagnosis unit 130 can perform fault diagnosis according to the module detection signal corresponding to the main power module 112 and the reference signal provided by the preset reference signal terminal Vref, generate the fault diagnosis signal corresponding to the main power module 112, and then output the fault diagnosis signal to the fault-tolerant switching unit 140. The fault-tolerant switching unit 140 can determine whether the main power module 112 has an unrecoverable fault by judging whether the fault diagnosis signal is a pre-set hardware fault signal. When the fault diagnosis signal is the hardware fault signal, it is considered that the main power module 112 has an unrecoverable fault. At this time, the first branch 114 corresponding to the main power module 112 can be disconnected by the fault-tolerant switching unit 140 according to the fault diagnosis signal, so as to block the first branch 114, so that the first branch 114 enters an open circuit state, and the second branch 115 corresponding to the backup power module 113 is connected to the main loop, so that the second branch 115 enters a circuit connection state, so as to replace the main power module 112 with the backup power module 113, so that the circuit path of the power bridge arm is switched from the first branch 114 to the second branch 115, that is, when the main power module 112 has an unrecoverable fault, the backup power module 113 is automatically switched to, seamless redundancy switching is realized, and system availability is improved.

[0028] Specifically, the power bridge arm 111 in the embodiment of the present application can be provided with a main power module 112 and a backup power module 113 connected in parallel as a core device for power control. The main power module 112 can be a power module currently connected to the main loop 150 of the power bridge arm 111, that is, the main power module 112 is connected to the main loop 150 to form the first branch 114 of the power bridge arm 111. The backup power module 113 connected in parallel with the main power module 112 can be used to form another branch of the power bridge arm 111 as the second branch 115 of the power bridge arm 111.

[0029] Optionally, the power bridge arm 111 in the embodiment of the present application can be provided with at least two power modules connected in parallel, and any one of the at least two power modules connected in parallel can be determined as the main power module 112 of the power bridge arm 111, and the other power modules connected in parallel with the main power module 112 in the power bridge arm 111 can be determined as the standby power module 113. For example, when two power modules are provided in the same power bridge arm 111 and connected in parallel, any one of the two power modules can be determined as the main power module 112, and the other power module can be determined as the standby power module 113. The embodiment of the present application does not limit this.

[0030] In an example embodiment of the present application, each power module in the power bridge arm 111 can be detected by the power module detection unit 120, a module detection signal corresponding to each power module can be generated, and the module detection signal corresponding to each power module can be output to the fault diagnosis unit 130, so that the fault diagnosis unit 130 can perform fault diagnosis according to the module detection signal corresponding to each power module, to determine a fault diagnosis signal corresponding to each power module. For example, when the fault diagnosis unit 130 receives the module detection signal corresponding to the main power module 112, the fault diagnosis unit 130 can perform fault diagnosis according to the module detection signal corresponding to the main power module 112, to determine the fault diagnosis signal corresponding to the main power module 112, and the fault diagnosis signal corresponding to the main power module 112 can be output to the fault-tolerant switching unit 140, so that the fault-tolerant switching unit 140 can determine whether the main power module 112 has an unrecoverable fault according to the fault diagnosis signal corresponding to the main power module 112, to automatically switch to the standby power module 113 when the main power module 112 has an unrecoverable fault, to realize seamless redundancy switching.

[0031] Optionally, an input terminal of the fault diagnosis unit 130 is electrically connected with an output terminal of the power module detection unit 120, and an output terminal of the fault diagnosis unit 130 is electrically connected with an input terminal of the fault-tolerant switching unit 140, so that the fault diagnosis unit 130 can perform fault diagnosis according to the module detection signal and a reference signal provided by the preset reference signal terminal Vref, and output a fault diagnosis signal corresponding to the main power module 112 to the fault-tolerant switching unit 140. The control output terminal of the fault-tolerant switching unit 140 is electrically connected with the control terminal of the first branch 114 and the control terminal of the second branch 115 respectively, so that the fault-tolerant switching unit 140 can output branch control signals to the first branch 114 and the second branch 115 respectively through the control output terminal according to the fault diagnosis signal, so as to control the circuit state of the first branch 114 and the second branch 115 through the branch control signals. For example, when the fault diagnosis signal is a circuit normal signal, the first branch 114 is controlled to be connected to the main loop 150 through the first branch 114 control signal, so that the circuit state of the first branch 114 is a circuit connection state, and the second branch 115 is controlled to be disconnected, so as to block the second branch 115, so that the circuit state of the second branch 115 is a circuit open state, and then the circuit path of the power bridge arm is the transmission path of the first branch 114, and the main power module 112 in the first branch 114 is driven and controlled, so as to realize the power control function of the power bridge arm 111. When the fault diagnosis signal is a hardware fault signal, the first branch 114 is controlled to be disconnected through the second branch 115 control signal, so as to block the first branch 114, so that the circuit state of the first branch 114 is a circuit open state, and the second branch 115 is controlled to be connected to the main loop 150, so that the circuit state of the second branch 115 is a circuit connection state, and then the circuit path of the power bridge arm is switched from the first branch 114 to the second branch 115, that is, the circuit path of the power bridge arm is the transmission path of the first branch 114, and the standby power module 113 in the second branch 115 is driven and controlled, so as to realize the power control function of the power bridge arm 111.

[0032] The preset reference signal terminal Vref can be a reference signal terminal preset according to fault detection requirements and circuit protection requirements. The reference signal provided by the reference signal terminal can be used to determine whether the power module has an unrecoverable fault. Specifically, the reference signal provided by the preset reference signal terminal Vref can include but is not limited to an over-temperature reference signal set according to an over-temperature threshold, an over-voltage reference signal set according to an over-voltage threshold, an over-current reference signal set according to an over-current threshold, and the like. The embodiments of the present application are not limited in this regard.

[0033] The power module in the power bridge arm as the monitored object can be implemented by an IGBT, and the embodiments of the present application limit this. For example, in the case of implementing the power module by an IGBT, the IGBT power module can contain an IGBT die and an anti-parallel freewheeling diode.

[0034] Further, in order to accurately determine the health status of the power module, the embodiments of the present application can perform multi-dimensional monitoring on each power module in the power bridge arm 111 through the power module detection unit 120. For example, the power module detection unit 120 can monitor the voltage, current, and temperature of each power module, and the monitored temperature monitoring signal, voltage monitoring signal, and current monitoring signal can be used as the module detection signal corresponding to the power module, and transmitted to the fault diagnosis unit 130. The fault diagnosis unit 130 can perform fault diagnosis according to the "three-dimensional" module detection signal, thereby more comprehensively and accurately determining the health status of the power module, and solving the fault misjudgment problem in the prior art due to relying on a single dimension to determine the state of the power module.

[0035] For example, in the case of an IGBT module, if only the current overcurrent is used to determine the health status of the power module, it may be misreported due to load mutation, but in combination with the abnormality of the "desaturation" voltage, it can be 100% confirmed that it is a short circuit fault, and misoperation is avoided.

[0036] Optionally, the module detection signal in the embodiments of the present application can specifically include a temperature monitoring signal, a voltage monitoring signal, and a current monitoring signal, so as to subsequently accurately determine whether the main power module 112 fails according to the temperature monitoring signal, the voltage monitoring signal, and the current monitoring signal. The temperature monitoring signal represents the real-time temperature of the main power module 112 currently monitored; the current monitoring signal represents the real-time current of the power module currently monitored; and the voltage monitoring signal represents the voltage of the power module currently monitored.

[0037] Optionally, to achieve real-time multi-dimensional status monitoring of the power module, the power module detection unit 120 in this embodiment includes a voltage acquisition module 121, a current acquisition module 123, and a temperature acquisition module 122. These modules form a three-dimensional monitoring module, which acquires the voltage, current, and temperature of the power module in real time. Based on the acquired voltage, current, and temperature, the module outputs corresponding voltage monitoring signals, current monitoring signals, and temperature monitoring signals. Specifically, the voltage acquisition module 121 acquires the voltage of the power module to obtain a voltage monitoring signal; the current acquisition module 123 acquires the current of the power module to obtain a current monitoring signal; and the temperature acquisition module 122 acquires the temperature of the power module to obtain a temperature monitoring signal.

[0038] In an optional embodiment of this application, the voltage acquisition module 121, current acquisition module 123, and temperature acquisition module 122 in the power module detection unit 120 can be integrated into each power module of the power bridge arm to perform multi-dimensional detection of the power module through the voltage acquisition module 121, current acquisition module 123, and temperature acquisition module 122, construct a three-dimensional monitoring matrix, so that the fault diagnosis unit 130 can perform fault diagnosis based on the voltage monitoring signal, current monitoring signal, and temperature monitoring signal.

[0039] For example, such as Figure 2 As shown, the voltage acquisition module 121, current acquisition module 123, and temperature acquisition module 122 in the power module detection unit 120 can be integrated into the main power bridge arm 112. This allows for multi-dimensional detection of the main power bridge arm 112 through the voltage acquisition module 121, current acquisition module 123, and temperature acquisition module 122, constructing a three-dimensional monitoring matrix. This enables the fault diagnosis unit 130 to diagnose faults based on the voltage monitoring signal, current monitoring signal, and temperature monitoring signal, and output the fault diagnosis signal corresponding to the main power module 112.

[0040] In specific implementations, the voltage acquisition module 121, the current acquisition module 123, and the temperature acquisition module 122 can all be implemented using sensing elements. For example, the voltage acquisition module 121 can be implemented using a voltage sensor, the current acquisition module 123 can be implemented using a current sensor, and the temperature acquisition module 122 can be implemented using a temperature sensor. This application embodiment does not impose specific limitations on this.

[0041] In an optional embodiment of the present application, the voltage sensor can be a high-voltage differential voltage sensor, which can include a voltage dividing resistor and an isolated operational amplifier. In a specific implementation, the high-voltage differential voltage sensor can sample the C-E voltage of the IGBT in real time through a voltage dividing circuit composed of a voltage dividing resistor; when the IGBT is normally turned on, the C-E voltage is a low saturation voltage drop (such as a low saturation voltage drop Vce sat between 2-3V); when a short circuit occurs, the current rises sharply, the IGBT quickly exits the saturation region, and the C-E voltage will instantaneously rise to close to the DC bus voltage (such as 700V). The high-voltage differential voltage sensor safely converts this high-voltage signal into a low-voltage analog signal (such as a low-voltage analog signal of 0-5V), and then outputs a corresponding voltage monitoring signal to the fault diagnosis unit 130 through the isolated operational amplifier, so that the fault diagnosis unit 130 can perform fault detection according to the voltage monitoring signal.

[0042] In a specific implementation, the current sensor can be a Hall sensor installed on the emitter of the IGBT or the DC bus, which is used to monitor the real-time current. Specifically, the Hall sensor can output a voltage signal proportional to the main current as a current monitoring signal to the fault diagnosis unit 130 through the detection of the magnetic field generated by the current, realizing real-time acquisition of the current, so that the fault diagnosis unit 130 can perform fault detection according to the current monitoring signal.

[0043] In addition, the temperature sensor can include a thermistor, which can monitor the operating temperature of the IGBT module by closely installing a negative temperature coefficient (NTC) or positive temperature coefficient (PTC) thermistor on the substrate or heat sink of the IGBT module. For example, the resistance of the NTC thermistor decreases as the temperature of the IGBT module rises, and the temperature acquisition module 122 can convert the resistance change into a voltage change through a simple voltage dividing circuit to output a temperature detection signal for representing the real-time temperature to the fault diagnosis unit 130 based on the voltage change, realizing temperature monitoring, so that the fault diagnosis unit 130 can perform fault diagnosis according to the temperature monitoring signal, and thus can more comprehensively and accurately determine whether the power module has a fault, improving the accuracy of fault identification.

[0044] As an example of the present application, in the case of using an IGBT power module as the main power module 112 in the power bridge arm, as shown in FIG. 1, the main power module 112 can include a temperature acquisition module 122, a voltage sensor 124, a current sensor 126, and a fault diagnosis unit 130. Figure 2As shown, in order to accurately identify whether the main power module 112 fails, three sensors of high-voltage differential voltage sensor, current sensor and temperature sensor can be integrated and installed on the IGBT power module, to build a three-dimensional monitoring matrix through the high-voltage differential voltage sensor, the current sensor and the temperature sensor, so that the fault diagnosis unit 130 can more comprehensively and accurately judge whether the power module fails according to the voltage monitoring signal, the current monitoring signal and the temperature monitoring signal, and improve the fault identification accuracy.

[0045] Among them, the high-voltage differential voltage sensor is connected in parallel between the collector (C) and the emitter (E) of the IGBT, that is, the high-voltage differential voltage sensor is connected in parallel between the collector-emitter (C-E) of each IGBT module, so as to take the high-voltage differential voltage sensor as the voltage acquisition module 121, monitor the C-E voltage of the IGBT through the high-voltage differential voltage sensor, and output an analog voltage signal proportional to the C-E voltage as a voltage monitoring signal, to realize real-time acquisition of voltage. Specifically, the high-voltage differential voltage sensor can be used to monitor the desaturation voltage. When the IGBT is normally turned on, the C-E voltage is a saturation voltage drop; when the IGBT is short-circuited, the IGBT current rises sharply, the IGBT exits the saturation region, and the C-E voltage rapidly rises to the DC bus voltage. The high-voltage differential voltage sensor can safely convert this high-voltage signal into a low-voltage analog signal as a voltage monitoring signal, and transmit it to the fault diagnosis unit 130, so that the fault diagnosis unit 130 can perform fault diagnosis according to the voltage monitoring signal.

[0046] The current sensor can be a Hall current sensor installed on the emitter of the IGBT or the DC bus. Specifically, a fast-response Hall current sensor can be installed at the emitter of the IGBT or the DC bus, to take the fast-response Hall current sensor as the current acquisition module 123, so that the current flowing through the IGBT can be monitored through the fast-response Hall current sensor, and an analog voltage signal proportional to the current is output as a current monitoring signal and transmitted to the fault diagnosis unit 130, to realize real-time acquisition of current.

[0047] In addition, the temperature sensor can be provided with a thermistor, which is a variable resistor whose resistance changes with temperature. In order to be recognized by the subsequent hardware comparator, the resistance change of the thermistor can be converted into a voltage change through a simple resistance voltage dividing circuit. The resistance voltage dividing circuit can be composed of a fixed resistance pull-up resistor and an NTC thermistor connected in series. One end of the resistance voltage dividing circuit is connected to a stable reference voltage source V_ref, and the other end is connected to the ground (GND). The connection point between the NTC thermistor and the pull-up resistor is the voltage output point. The voltage signal at the voltage output point can be output as a temperature monitoring signal to the fault diagnosis unit 130, so that the fault diagnosis unit 130 can perform fault diagnosis according to the temperature monitoring signal.

[0048] For example, according to the series voltage dividing principle, the voltage value of the constant temperature monitoring signal V_temp is determined according to the preset output voltage calculation formula V_temp = V_ref x (R_ntc / (R_pull-up + R_ntc)). When the IGBT temperature is low, the resistance R_ntc of the NTC thermistor is high. At this time, the resistance R_ntc of the NTC thermistor accounts for a large proportion in the voltage dividing circuit, and the resistance R_pull-up of the pull-up resistor accounts for a small proportion in the voltage dividing circuit. Therefore, the voltage value of the temperature monitoring signal V_temp is high. When the IGBT temperature rises, the resistance R_ntc of the NTC thermistor decreases. At this time, the resistance R_pull-up of the pull-up resistor accounts for a large proportion in the voltage dividing circuit. Therefore, the voltage value of the temperature monitoring signal V_temp decreases.

[0049] In an optional embodiment of the present application, the NTC thermistor can be installed on the grid (G) end of the IGBT substrate to monitor the substrate temperature of the IGBT module through the NTC thermistor, and output an analog voltage signal that decreases with the increase of temperature. After being converted by the voltage dividing circuit, the analog voltage signal can be output through the output end of the temperature sensor as a temperature detection signal for representing the real-time temperature, and the temperature detection signal can be transmitted to the fault diagnosis unit 130, so that the fault diagnosis unit 130 can perform fault diagnosis according to the temperature monitoring signal.

[0050] Of course, in addition to the negative temperature coefficient NTC thermistor, the temperature acquisition module 122 in the embodiment of the present application can also use a positive temperature coefficient (PTC) thermistor to realize real-time temperature monitoring. The type of thermistor is not limited in the embodiment of the present application.

[0051] In an optional embodiment of the present application, in order to quickly determine whether the main power module 112 fails, after receiving the voltage monitoring signal, the current monitoring signal and the temperature monitoring signal output by the power module detection unit, the fault diagnosis unit 130 can quickly determine by using independent high-speed comparators for the voltage monitoring signal, the current monitoring signal and the temperature monitoring signal, so as to quickly determine whether the power module has an unrecoverable fault such as short circuit, overcurrent, overtemperature and the like by using the hardware comparators, and to achieve millisecond-level response to the short circuit, overcurrent, overtemperature and the like.

[0052] Optionally, the fault diagnosis unit 130 in the embodiment of the present application can include a first comparison module 131, a second comparison module 132, a third comparison module 133 and an OR gate judgment module 134. The input end of the OR gate judgment module 134 is electrically connected with the output end of the first comparison module 131, the output end of the second comparison module 132 and the output end of the third comparison module 133, so that the OR gate judgment module 134 can perform fault judgment according to the first comparison signal, the second comparison signal and the third comparison signal, and output a fault diagnosis signal. The first comparison module 131 is used for comparing the temperature monitoring signal with the overtemperature reference signal and outputting a first comparison signal; the second comparison module 132 is used for comparing the current monitoring signal with the overcurrent reference signal and outputting a second comparison signal; the third comparison module 133 is used for comparing the voltage monitoring signal with the overvoltage reference signal and outputting a third comparison signal; and the OR gate judgment module 134 is used for performing fault judgment according to the first comparison signal, the second comparison signal and the third comparison signal, and outputting the fault diagnosis signal.

[0053] For example, the OR gate judgment module 134 can use an OR gate array 1340 to collect the first comparison signal output by the first comparison module 131, the second comparison signal output by the second comparison module 132 and the third comparison signal output by the third comparison module 133, so as to perform OR operation based on the first comparison signal, the second comparison signal and the third comparison signal, generate a digital level signal without delay, and use the digital level signal as a total hardware fault signal Hardware_Fault. Subsequently, the hardware fault signal Hardware_Fault can be transmitted as a fault diagnosis signal to the fault-tolerant switching unit 140, so that the fault-tolerant switching unit 140 can perform redundancy switching according to the fault diagnosis signal.

[0054] Optionally, to avoid misjudgments or missed judgments caused by program crashes, system freezes, or electromagnetic interference, embodiments of this application may employ hardware comparators to implement the first comparison module 131, the second comparison module 132, and the third comparison module 133. For example, as Figure 2 As shown, the first comparison module 131 includes an over-temperature diagnostic comparator COMP1, the second comparison module 132 includes an overcurrent comparator COMP2, and the third comparison module 133 includes a desaturation comparator COMP3. These three comparators, along with the over-temperature diagnostic comparator COMP1, overcurrent comparator COMP2, and desaturation comparator COMP3, form a high-speed comparator network in the fault diagnosis unit 130. This network allows the temperature monitoring signal, voltage monitoring signal, and current monitoring signal to be compared with the over-temperature parameter provided by the preset reference signal terminal Vref, based on the over-temperature diagnostic comparator COMP1, overcurrent comparator COMP2, and desaturation comparator COMP3. The reference signal, overvoltage reference signal, and overcurrent reference signal are compared to generate a first comparison signal, a second comparison signal, and a third comparison signal. These signals are then transmitted to an OR gate judgment module 134 for judgment. The OR gate judgment module 134 outputs a fault diagnosis signal to the fault-tolerant switching unit 140, enabling the fault-tolerant switching unit 140 to perform redundancy switching based on the fault diagnosis signal. In the event of an unrecoverable fault in the main power module 112, the fault-tolerant switching unit 140 can switch the circuit path of the power bridge arm from the first branch 114 to the second branch 115, achieving automatic switching between the main power module 112 and the backup power module 113 without software intervention, ensuring continuous system operation even when the main power module 112 fails.

[0055] Among them, the over-temperature diagnostic comparator COMP1, the over-current comparator COMP2, and the desaturation comparator COMP3 can all be implemented using independent high-speed comparators. These high-speed comparators can be voltage comparators, and this application embodiment does not limit this.

[0056] Optionally, the preset reference signal end Vref in the embodiment of the application can include a first reference signal end, a second reference signal end and a third reference signal end; wherein the first reference signal end is used to provide an over-temperature reference signal, which can be set according to temperature detection requirements, for example, the voltage value of the over-temperature reference signal can be set to 2.0V according to a pre-set over-temperature threshold, so that when the temperature of the main power module 112 exceeds the over-temperature threshold, the over-temperature diagnosis comparator COMP1 in the first comparison module 131 generates an over-temperature fault signal according to the voltage value of the over-temperature reference signal and the voltage value of the temperature monitoring signal corresponding to the main power module 112, and transmits the over-temperature fault signal as a first comparison signal to the OR gate judgment module 134; the second reference signal end is used to provide the over-current reference signal, which can be set according to over-current detection requirements, for example, the voltage value of the over-current reference signal can be set to 3.0V according to a pre-set over-current threshold, so that when the current of the main power module 112 exceeds the over-current threshold, the over-current comparator COMP2 in the second comparison module 132 generates an over-current fault signal according to the over-current reference signal and the current monitoring signal corresponding to the main power module 112, and transmits the over-current fault signal as a second comparison signal to the OR gate judgment module 134; and the third reference signal end is used to provide the over-voltage reference signal, which can be set according to over-voltage detection requirements, for example, the voltage value of the over-voltage reference signal can be set to 0.15V according to a pre-set desaturation voltage threshold 0.15V, so that when the desaturation voltage of the main power module 112 exceeds the desaturation voltage threshold, the desaturation comparator COMP3 in the third comparison module 133 generates a desaturation fault signal according to the over-voltage reference signal and the voltage monitoring signal corresponding to the main power module 112, and transmits the desaturation fault signal as a third comparison signal to the OR gate judgment module 134.

[0057] Optionally, the first reference signal end, the second reference signal end and the third reference signal end in the embodiment of the application can all be output ends of a potentiometer, so as to output the over-temperature reference signal, the over-voltage reference signal and the over-current reference signal through the potentiometer, which is not limited in the embodiment of the application.

[0058] In an optional embodiment of the present application, the first end of the over-temperature diagnosis comparator COMP1 can be electrically connected to the temperature detection output end of the power module detection unit as the first input end of the first comparison module 131; the second end of the over-temperature diagnosis comparator COMP1 can be electrically connected to the first reference signal end as the second input end of the first comparison module 131; and the output end of the over-temperature diagnosis comparator COMP1 can be electrically connected to the first input end of the OR gate judgment module 134 as the output end of the first comparison module 131, so that the over-temperature diagnosis comparator COMP1 can compare the temperature monitoring signal output by the temperature detection output end of the power module detection unit with the over-temperature reference signal provided by the first reference signal end, and output a first comparison signal to the OR gate judgment module 134 for fault judgment. The temperature detection output end of the power module detection unit is configured to output the temperature monitoring signal, which can be used to represent the real-time temperature of the main power module 112 currently monitored; and the output end of the over-temperature diagnosis comparator COMP1 is configured to output the first comparison signal, which can be used to represent whether the temperature of the main power module 112 exceeds the preset over-temperature threshold, so as to determine whether the main power module 112 has an over-temperature fault.

[0059] As an example of the present application, in the case where the temperature sensor adopts an NTC thermistor to detect the temperature of the main power module 112, the voltage value of the temperature monitoring signal V_temp output by the temperature sensor decreases with the increase of temperature. If the output end of the temperature sensor is connected to the inverting input end of the over-temperature diagnosis comparator COMP1, the temperature monitoring signal V_temp can be compared with the over-temperature reference signal V_th_ot of the non-inverting input end of the over-temperature diagnosis comparator COMP1, and then when the temperature exceeds the standard, i.e., when the temperature is too high, the over-temperature diagnosis comparator COMP1 can be triggered to output a high-level signal as an over-temperature fault signal Fault_OT, i.e., Fault_OT=1, and the over-temperature fault signal Fault_OT can be transmitted to the OR gate judgment module 134 as the first comparison signal output by the over-temperature diagnosis comparator COMP1, to determine whether an over-temperature fault occurs. Wherein, the digital "1" represents a high-level signal in a digital signal, which is used to represent that the temperature of the main power module 112 exceeds the preset over-temperature threshold, so that the OR gate judgment module 134 can determine whether the over-temperature fault signal Fault_OT is "1" to determine whether the main power module 112 has an over-temperature fault.

[0060] For example, in the case that the over-temperature threshold is set to 150 °C according to the maximum allowed junction temperature of the IGBT, and a separate high-speed comparator is used as the over-temperature diagnosis comparator COMP1, the inverting input terminal of the high-speed comparator can be used as the first terminal of the over-temperature diagnosis comparator COMP1 for receiving the temperature monitoring signal V_temp output by the NTC thermistor or the integrated temperature sensor; the non-inverting input terminal of the high-speed comparator can be used as the first terminal of the over-temperature diagnosis comparator COMP1 for accessing the over-temperature reference signal V_th_ot corresponding to the over-temperature threshold of 150 °C, the voltage value V_ref_th of the over-temperature reference signal V_th_ot being the voltage threshold 2.0 V corresponding to the over-temperature threshold of 150 °C, and the temperature judgment logic of the over-temperature diagnosis comparator COMP1 being: when the temperature T is less than 150 °C, i.e., at normal temperature, the voltage value of the temperature monitoring signal V_temp is greater than the voltage threshold 2.0 V, i.e., the voltage value of the temperature monitoring signal V_temp is greater than the voltage value V_ref_th of the over-temperature reference signal, at this time the over-temperature diagnosis comparator COMP1 outputs a low-level signal as the over-temperature fault signal Fault_OT, i.e., Fault_OT = 0, wherein the digital "0" represents a low-level signal in a digital signal; and when the temperature T is greater than 150 °C, i.e., at an excessively high temperature, the voltage value of the temperature monitoring signal V_temp is less than the voltage threshold 2.0 V, i.e., the voltage value of the temperature monitoring signal V_temp is less than the voltage value V_ref_th of the over-temperature reference signal, at this time the voltage of the inverting input terminal of the over-temperature diagnosis comparator COMP1 is lower than the voltage of the non-inverting input terminal, the over-temperature diagnosis comparator COMP1 flips, i.e., the over-temperature diagnosis comparator COMP1 outputs a high-level signal as the over-temperature fault signal Fault_OT, i.e., Fault_OT = 1.

[0061] As can be seen, in the examples of the present application, when the temperature is normal, the over-temperature diagnosis comparator COMP1 can judge that V_temp > V_ref_th, at this time the over-temperature diagnosis comparator COMP1 outputs a low-level signal as the over-temperature fault signal Fault_OT, i.e., Fault_OT = 1; and when an over-temperature fault occurs, i.e., when the excessively high temperature causes V_temp < V_ref_th, the over-temperature diagnosis comparator COMP1 can output a high-level signal as the over-temperature fault signal Fault_OT, i.e., Fault_OT = 1, so that the subsequent or gate judgment module 134 can determine whether an over-temperature fault occurs by judging whether the over-temperature fault signal Fault_OT is "1"; when the over-temperature fault signal Fault_OT is "1", it is considered that an over-temperature fault occurs; and when the over-temperature fault signal Fault_OT is "0", it is considered that the temperature is normal and no over-temperature fault occurs.

[0062] Optionally, the first end of the overcurrent comparator COMP2 in the embodiment of the present application can be electrically connected to the first input end of the second comparison module 132 and the current detection output end of the power module detection unit; the second end of the overcurrent comparator COMP2 can be electrically connected to the second input end of the second comparison module 132 and the second reference signal end; and the output end of the overcurrent comparator COMP2 can be electrically connected to the second input end of the OR gate judgment module 134 as the second output end of the second comparison module 132, so that the overcurrent comparator COMP2 can compare the current monitoring signal output by the current detection output end of the power module detection unit with the overcurrent reference signal provided by the second reference signal end, and output the second comparison signal to the OR gate judgment module 134 for fault judgment. The current detection output end of the power module detection unit is configured to output the current monitoring signal, which can be used to represent the real-time current of the main power module 112 monitored at present; and the output end of the overcurrent comparator COMP2 is configured to output the second comparison signal, which can be used to represent whether the current of the main power module 112 exceeds the pre-set overcurrent threshold, so as to determine whether the main power module 112 has an overcurrent fault.

[0063] As an example of the present application, when the pre-set overcurrent threshold is 1.5 times of the rated current of the main power module 112, the current monitoring signal is converted and input into the overcurrent comparator COMP2 to compare with the pre-set overcurrent reference signal corresponding to 1.5 times of the rated current, so that the overcurrent comparator COMP2 can output the overcurrent fault signal Fault_OC as the second comparison signal according to the voltage comparison result of the current monitoring signal and the overcurrent reference signal, and transmit the overcurrent fault signal Fault_OC to the OR gate judgment module 134, so that the OR gate judgment module 134 can determine whether the main power module 112 has an overcurrent fault according to the overcurrent fault signal Fault_OC.

[0064] For example, in the case that the first end of the over-current comparator COMP2 is the in-phase input end of the high-speed comparator, and the second end of the over-current comparator COMP2 is the inverse-phase input end of the high-speed comparator, when the current of the main power module 112 exceeds 1.5 times of the rated current, i.e., in the case that the voltage value of the current monitoring signal V_i is greater than the voltage value of the over-current reference signal V_th_oc, the over-current comparator COMP2 can output a high-level signal as the over-current fault signal Fault_OC, i.e., Fault_OC=1; and when the current of the main power module 112 does not exceed 1.5 times of the rated current, i.e., in the case that the voltage value of the current monitoring signal V_i is less than the voltage value of the over-current reference signal V_th_oc, the over-current comparator COMP2 outputs a low-level signal as the over-current fault signal Fault_OC, i.e., Fault_OC=0, so that the judging module 134 can determine whether the over-current fault occurs by judging whether the over-current fault signal Fault_OC is “1”, and then can consider that the over-current fault occurs when the over-current fault signal Fault_OC is “1”, and consider that the current is normal and no over-current fault occurs when the over-current fault signal Fault_OC is “0”.

[0065] In addition, the first end of the desaturation comparator COMP3 in the embodiment of the present application can be electrically connected with the voltage detection output end of the power module detection unit as the first input end of the third comparison module 133; the second end of the desaturation comparator COMP3 can be electrically connected with the third reference signal end as the second input end of the third comparison module 133; and the output end of the desaturation comparator COMP3 can be electrically connected with the third input end of the or gate judging module 134 as the output end of the third comparison module 133, so that the desaturation comparator COMP3 can compare the voltage monitoring signal output by the voltage detection output end of the power module detection unit with the over-voltage reference signal provided by the third reference signal end, and output a third comparison signal to the or gate judging module 134 for fault judgment. The voltage detection output end of the power module detection unit is used to output the voltage monitoring signal, which can be used to represent the desaturation voltage of the main power module 112; and the output end of the desaturation comparator COMP3 is used to output the third comparison signal, and the third comparison signal can be used to represent whether the desaturation voltage of the main power module 112 exceeds the pre-set desaturation voltage threshold, so as to determine whether the main power module 112 has a desaturation fault.

[0066] For example, in the case that the preset desaturation voltage threshold is "15V", after the voltage monitoring signal V ce is input into the desaturation comparator COMP3, the voltage monitoring signal V ce is compared with the preset overvoltage reference signal V th_desat corresponding to the "15V" desaturation voltage threshold, so that the desaturation comparator COMP3 can output a desaturation fault signal Fault_Desat according to the voltage comparison result of the voltage monitoring signal V ce and the overvoltage reference signal V th_desat as the third comparison signal output by the desaturation comparator COMP3, and transmit the desaturation fault signal Fault_Desat to the OR gate judgment module 134, so that the OR gate judgment module 134 can determine whether the over-desaturation fault flow fault occurs in the main power module 112 according to the desaturation fault signal Fault_Desat.

[0067] For example, in the case that the first end of the desaturation comparator COMP3 is the non-inverting input end of the high-speed comparator, and the second end of the desaturation comparator COMP3 is the inverting input end of the high-speed comparator, when the desaturation voltage of the main power module 112 exceeds 15V, that is, in the case that the voltage value of the voltage monitoring signal V ce is greater than the voltage value of the overvoltage reference signal V th_desat, the desaturation comparator COMP3 can output a high-level signal as the desaturation fault signal Fault_Desat, and the desaturation fault signal Fault_Desat is Fault_Desat=1. When the desaturation voltage of the main power module 112 does not exceed 15V, for example, in the case that the voltage value of the voltage monitoring signal V ce is less than the voltage value of the overvoltage reference signal V th_desat, the desaturation comparator COMP3 outputs a low-level signal as the desaturation fault signal Fault_Desat, that is, Fault_Desat=0, so that the judgment module 134 can determine whether the over-current fault signal Fault_Desat is "1" to determine whether the desaturation fault occurs, and then it can be considered that the desaturation fault occurs when the desaturation fault signal Fault_Desat is "1", and it can be considered that the desaturation voltage is normal and no desaturation fault occurs when the desaturation fault signal Fault_Desat is "0".

[0068] It can be seen that the over-temperature diagnosis comparator COMP1, the over-current comparator COMP2 and the overvoltage comparator in the embodiment of the present application can all be implemented by using independent high-speed voltage comparators, and the specific types of the over-temperature diagnosis comparator COMP1, the over-current comparator COMP2 and the overvoltage comparator are not limited in the embodiment of the present application.

[0069] Optionally, the OR gate judgment module 134 in the embodiment of the present application can use an OR gate array 1340 to realize the function of the OR gate judgment module 134. For example, as shown in FIG. 13, the OR gate array 1340 can be used to realize the function of the OR gate judgment module 134. Figure 2As shown, the or gate judgment module 134 comprises an or gate array 1340; a first input end of the or gate array 1340 can be electrically connected with an output end of the over-temperature diagnostic comparator COMP1 as a first input end of the or gate judgment module 134; a second input end of the or gate array 1340 can be electrically connected with an output end of the over-current comparator COMP2 as a second input end of the or gate judgment module 134; a third input end of the or gate array 1340 can be electrically connected with an output end of the desaturation comparator COMP3 as a third input end of the or gate judgment module 134, and an output end of the or gate array 1340 is electrically connected with an input end of the fault-tolerant switching unit 140 as an output end of the or gate judgment module 134, so that after the first comparison signal output by the first comparison module 131, the second comparison signal output by the second comparison module 132 and the third comparison signal output by the third comparison module 133 are collected by the or gate array 1340, a corresponding fault diagnosis signal is output, so that the fault-tolerant switching unit 140 can perform redundancy switching according to the fault diagnosis signal.

[0070] In a specific implementation, the or gate array 1340 can be a network "decision center" in the fault-tolerant switching unit 140, and can be implemented by using an or gate logic chip. The or gate array 1340 is responsible for combining multiple fault signals into a total hardware fault signal Hardware Fault as a fault diagnosis signal, so that the fault-tolerant switching unit 140 can perform redundancy switching according to the hardware fault signal, so as to automatically switch to the standby power module 113 when the main power module 112 occurs an unrecoverable fault, realize seamless redundancy switching, and improve system availability.

[0071] As an example of the present application, in the case that the input signals of the OR gate array 1340 contain the desaturation fault signal Fault_Desat output by the desaturation comparator COMP3, the overcurrent fault signal Fault_OC output by the overcurrent comparator COMP2, and the over-temperature fault signal Fault_OT output by the over-temperature diagnostic comparator COMP1, the desaturation fault signal Fault_Desat, the overcurrent fault signal Fault_OC, and the over-temperature fault signal Fault_OT can be ORed according to the logical formula of the OR gate array 1340: Hardware Fault = Fault_Desat OR Fault_OC OR Fault_OT, so as to aggregate the desaturation fault signal Fault_Desat output by the desaturation comparator COMP3, the overcurrent fault signal Fault_OC output by the overcurrent comparator COMP2, and the over-temperature fault signal Fault_OT output by the over-temperature diagnostic comparator COMP1 through the OR gate array 1340, and thus the total output hardware fault signal Hardware Fault can immediately become a high-level signal, i.e., Hardware Fault Signal = 1, when any one of the over-temperature diagnostic comparator COMP1, the overcurrent comparator COMP2, and the desaturation comparator COMP3 outputs a high-level signal, so as to output a high-level "hardware fault signal" through the OR gate array 1340 to represent that the main power module 112 has an automatically unrecoverable hardware fault.

[0072] For example, in the case that the voltage of the overcurrent reference signal V_th_oc is 3V, when the voltage value of the current monitoring signal V_i exceeds 3V, the overcurrent comparator COMP2 outputs a high-level signal as the overcurrent fault signal Fault_OC based on the received current monitoring signal V_i, so that the hardware fault signal Hardware Fault output by the OR gate array 1340 immediately becomes a high-level signal, i.e., Hardware Fault Signal = 1, and thus the fault-tolerant switching unit 140 can be triggered by the high-level hardware fault signal to perform redundancy switching.

[0073] For another example, in the case that the IGBT exits the saturation region due to excessive current, the voltage of the voltage monitoring signal V_ce output by the voltage detection output terminal instantaneously rises from 2-3V to the bus voltage, at which time the desaturation comparator COMP3 outputs a high-level signal as the desaturation fault signal Fault_Desat, so that the hardware fault signal Hardware Fault output by the OR gate array 1340 immediately becomes a high-level signal, and thus the fault-tolerant switching unit 140 can be triggered by the high-level hardware fault signal to perform redundancy switching.

[0074] In summary, the example of the present application can adopt three high-speed voltage comparators, three precise adjustable reference sources, and one OR logic chip to realize the fault diagnosis function of the fault diagnosis unit 130, so as to realize the fault self-diagnosis in pure hardware and not rely on software running, that is, the real-time state of the IGBT module is monitored through the hardware circuit elements such as voltage comparator and logic OR gate, so as to avoid the misjudgment or omission problem caused by program runaway, dead machine or electromagnetic interference, and improve the reliability and anti-interference ability of the system.

[0075] In some optional embodiments of the present application, as shown in Figure 3 The fault diagnosis unit 130 can be connected to the input end of the fault tolerance switching unit 140, and the output end of the fault diagnosis unit 130 can be connected to the input end of the fault tolerance switching unit 140, so that the fault diagnosis unit 130 can output the fault diagnosis signal to the fault tolerance switching unit 140. The fault tolerance switching unit 140 can include a redundancy switching module 141 and a drive circuit module 142. The input end of the redundancy switching module 141 is electrically connected to the output end of the fault diagnosis unit 130, and the output end of the redundancy switching module 141 is electrically connected to the drive control end of the drive circuit module 142, so that the drive circuit module 142 can control the first branch 114 to be disconnected according to the switching signal output by the redundancy switching module 141, so as to block the first branch 114, and control the second branch 115 to be connected to the main loop 150 according to the switching signal, so as to switch the circuit path from the first branch 114 to the second branch 115. Wherein, the redundancy switching module 141 is used for outputting the switching signal when the fault diagnosis signal is the hardware fault signal; and the drive circuit module 142 is used for controlling the first branch 114 to be disconnected according to the switching signal, so as to block the first branch 114, and controlling the second branch 115 to be connected to the main loop 150, so as to switch the circuit path from the first branch 114 to the second branch 115.

[0076] In a specific implementation, the switching module can be implemented by using a bistable flip-flop or a complex programmable logic device (CPLD), and the embodiments of the present application do not limit this. When the fault tolerance switching unit 140 receives the valid hardware fault signal Hardware_Fault as the fault diagnosis signal, the switching signal can be output to the drive circuit module 142 through the bistable flip-flop or the CPLD, so that the drive circuit module 142 can be controlled to start the double-channel action through the switching signal: one is to control the first branch 114 to be disconnected through the drive circuit module 142, so as to block the first branch 114 and realize the isolation of the main power module 112; the other is to control the second branch 115 to be connected to the main loop 150, so as to connect the standby power module 113 to the main loop 150, so that the circuit path of the power bridge arm is switched from the first branch 114 to the second branch 115, and then the seamless switching of the main power module 112 and the standby power module 113 is realized.

[0077] In an optional embodiment of the present application, the redundancy switching module 141 comprises a bistable flip-flop; an input end of the bistable flip-flop is electrically connected to an output end of the fault diagnosis unit 130 as an input end of the redundancy switching module 141, and an output end of the bistable flip-flop is electrically connected to a drive control end of the drive circuit module 142 as an output end of the redundancy switching module 141, so that the bistable flip-flop outputs a switching signal to the drive circuit module 142 according to a hardware fault signal when the received fault diagnosis signal is the hardware fault signal. Wherein, the input end of the redundancy switching module 141 is used for receiving the fault diagnosis signal; and the output end of the redundancy switching module 141 is used for outputting the switching signal. Wherein, the bistable flip-flop can comprise but is not limited to a set (S) / reset (R) flip-flop and an SR latch.

[0078] For example, in the case of the bistable flip-flop being an SR latch, an input end of the SR latch is electrically connected to an output end of the fault diagnosis unit 130 as an input end of the redundancy switching module 141, and an output end of the SR latch is electrically connected to a drive control end of the drive circuit module 142 as an output end of the redundancy switching module 141, so that the SR latch outputs a switching signal to the drive circuit module 142 according to a hardware fault signal when the received fault diagnosis signal is the hardware fault signal, to trigger the drive circuit module 142 to directly drive two channels; one of the channels is a shutdown channel, such as the drive circuit module 142 can block the drive optocoupler or chip of the main IGBT module by a hardware drive chip, so as to hard-shut it, to block the first branch 114, so as to achieve the purpose of controlling the first branch 114 to be disconnected according to the switching signal; the other channel is a switching channel, that is, to control the second branch 115 to access the main loop 150, such as to drive a relay drive circuit to attract the relay of the standby module path and to disconnect the relay of the fault module path, so as to switch the circuit path of the power bridge arm from the first branch 114 to the second branch 115.

[0079] In another optional embodiment of the present application, the redundancy switching module 141 comprises a complex programmable logic device (CPLD); an input end of the CPLD is electrically connected with an output end of the fault diagnosis unit 130 as an input end of the redundancy switching module 141; an output end of the CPLD is electrically connected with a driving control end of the driving circuit module 142 as an output end of the redundancy switching module 141, so that the CPLD outputs a switching signal to the driving circuit module 142 according to a hardware fault signal received by the CPLD. The input end of the redundancy switching module 141 is configured to receive the fault diagnosis signal, and the output end of the redundancy switching module 141 is configured to output the switching signal.

[0080] Optionally, the driving circuit module 142 in the embodiment of the present application comprises a relay driving submodule, a driving control end of the relay driving submodule is electrically connected with the output end of the redundancy switching module 141; the relay driving submodule comprises a first relay and a second relay, the main power module 112 is connected with the main circuit 150 through the first relay, and the standby power module 113 is connected with the main circuit 150 through the second relay; the relay driving submodule is configured to control the first relay to be disconnected according to the switching signal, so as to block the first branch 114, and control the second relay to be closed according to the switching signal, so as to connect the second branch 115 to the main circuit 150 through the closed second relay.

[0081] The first relay is a relay of a main power module path, which can be used to control whether the main power module 112 is connected to the main circuit 150. For example, when the first relay is in a closed conduction state, the main power module 112 can be connected to the main circuit 150 through the first relay in the closed conduction state, so that the first branch 114 is in a circuit connection state; when the first relay is in an open circuit state, the main power module path is disconnected, so that the first branch 114 is in a circuit disconnection state, and the main power module 112 is not connected to the main circuit 150.

[0082] The second relay is a relay of a standby power module path, which can be used to control whether the standby power module 113 is connected to the main circuit 150. For example, when the second relay is in a closed conduction state, the standby power module 113 can be connected to the main circuit 150 through the second relay in the closed conduction state, so that the second branch 115 is in a circuit connection state; when the second relay is in an open circuit state, the standby power module path is disconnected, so that the second branch 115 is in a circuit disconnection state, and the standby power module 113 is not connected to the main circuit 150.

[0083] Of course, the drive circuit module 142 in the embodiment of the application can contain a relay drive submodule, and can also contain other circuit devices, such as a hardware drive chip, and the embodiment of the application does not make specific limitations.

[0084] Optionally, the drive circuit module 142 contains a relay drive submodule and a hardware drive chip; wherein the first input end of the hardware drive chip is electrically connected with the output end of the redundant switching module 141, the second input end of the hardware drive chip is used for a power control signal, and the output end of the hardware drive chip is electrically connected with the control end of the backup power module 113, so that the hardware drive chip can output a power switch signal corresponding to the power switch control signal to the backup power module 113 based on the switching signal, to realize the power control function of the main power module 112 through the backup power module 113.

[0085] It can be seen that the hardware drive chip in the embodiment of the application can be specifically used for outputting a power switch signal corresponding to the power switch control signal to the backup power module 113 based on the switching signal. The relay drive submodule can be used as a relay drive circuit, so that the drive circuit module 142 can attract the second relay of the backup power module path and disconnect the first relay of the main power module path through the drive relay drive circuit after receiving the switching signal, to realize the switching of the main power module 112 and the backup power module 113.

[0086] For example, as shown in FIG. 2, a redundant switching mechanism based on hardware logic can be used to equip each power bridge arm in the power converter with a backup IGBT module identical to the main IGBT module, and the automatic switching of the main IGBT module and the backup IGBT module can be realized through SR latch or CPLD hardware logic device, without the participation of software, to ensure that the power converter system can still run continuously when the main IGBT module fails. Figure 4

[0087] Specifically, the SR latch or the programmable logic device CPLD is the core of the fault-tolerant switching unit 140. When receiving the hardware fault signal output by the fault diagnosis unit 130, the SR latch or the programmable logic device CPLD is immediately set, so that the output end of the SR latch or the output end of the programmable logic device CPLD outputs the switching signal, to directly drive the following two channels through the switching signal: One is the shutdown channel: through the switching signal, the hardware drive chip immediately triggers the drive optocoupler or chip of the main IGBT module to be blocked, so that the main IGBT module is hard-shut off through the hardware drive chip blocking the drive optocoupler or chip of the main IGBT module. ​

[0088] Another is the switching channel: through the switching signal, drive a relay drive circuit, attract the relay of the standby IGBT module path, disconnect the relay of the main IGBT module path; At the same time, the "enable" signal can be sent to the standby IGBT drive circuit, so that the standby IGBT drive circuit outputs the power switch signal to the standby IGBT module through the hardware drive chip according to the power switch control signal, to realize the power control function by using the standby IGBT module s output power control signal CE.

[0089] Optionally, the hardware switching logic circuit of the fault-tolerant switching unit 140 can have a manual reset button, so that maintenance personnel can perform manual reset operation through the manual reset button after troubleshooting and system power failure, so that the SR trigger can restore the initial state based on the reset operation, prepare for the next action, and thus effectively prevent secondary failure problems caused by automatic reset of the system when the fault is not eliminated.

[0090] Optionally, in order to further improve the fault-tolerant operation capability of the circuit system, the fault-tolerant control circuit provided by the embodiment of the application further includes: a self-repairing DC bus capacitor group 160, as shown in Figure 5 The self-repairing DC bus capacitor group 160 includes at least two capacitors C connected in parallel and a recoverable fuse 151 connected one-to-one with the capacitors C; the main circuit 150 includes a first DC bus 171 and a second DC bus 172; the first end of each capacitor C is electrically connected to the first DC bus 171 through the recoverable fuse 151, and the second end of each capacitor C is electrically connected to the second DC bus 172.

[0091] The recoverable fuse 151 is specifically used to block the circuit path of the fault capacitor when the fault capacitor occurs a short circuit fault, and the recoverable fuse 151 can be a polyer positive temperature coefficient (PPTC) element, and the embodiment of the application does not limit this. The fault capacitor refers to the capacitor C connected in series with the recoverable fuse 151 and occurring a short circuit fault.

[0092] Optionally, the capacitor C in the self-repairing DC bus capacitor group 160 can be implemented by an electrolytic capacitor, and the embodiment of the application does not specifically limit this.

[0093] Optionally, in order to quickly locate the capacitor fault, the fault-tolerant control circuit provided by the embodiment of the application further comprises a series diode D connected in series with the capacitor C, wherein the series diode D refers to a light emitting diode (LED) connected in series with the capacitor C; the series diode D is used to indicate the circuit working state of the target capacitor, and the target capacitor is the capacitor C connected in series with the series diode D.

[0094] In a specific implementation, the circuit working state of the target capacitor can be divided into a circuit normal working state and a circuit abnormal working state; the circuit normal working state is used to represent that the target capacitor can work normally, that is, the target capacitor has no fault; and the circuit abnormal working state is used to represent that the target capacitor has a fault, such as a short circuit fault of the target capacitor.

[0095] In an optional embodiment of the application, the series diode D can indicate the short circuit fault of the target capacitor by emitting light. Specifically, the second end of each capacitor C is electrically connected to the second DC bus 172 through the recoverable fuse 151, and can specifically include any one of the following connection modes: The first connection mode: the second end of each capacitor C is electrically connected to the first end of the high-molecular polymer positive coefficient temperature resistor, the second end of the high-molecular polymer positive coefficient temperature resistor is electrically connected to the first end of the series diode D, and the second end of the series diode D is electrically connected to the second DC bus 172.

[0096] For example, in the case where the second DC bus 172 is connected to the reference ground of the main circuit 150, the first end of the series diode D is the positive end, and the second end of the series diode D is the negative end, that is, the second end of each capacitor C is electrically connected to the first end of the high-molecular polymer positive coefficient temperature resistor, the second end of the high-molecular polymer positive coefficient temperature resistor is electrically connected to the positive end of the series diode D, and the negative end of the series diode D is electrically connected to the second DC bus 172, and one end of each capacitor C is electrically connected to the first DC bus 171. Thus, when a short circuit fault occurs in any one capacitor C, a short circuit current generated by the short circuit of the capacitor C can trigger the series diode D connected in series with the fault capacitor to emit light, thereby achieving quick positioning of the capacitor fault, and the high-molecular polymer positive coefficient temperature resistor connected in series with the fault capacitor can isolate the fault capacitor, thereby achieving the circuit protection function.

[0097] For example, in the case where the first DC bus 171 is connected to the reference ground of the main circuit 150, the first end of the series diode D is the negative end, and the second end of the series diode D is the positive end, i.e., the second end of each capacitor C is electrically connected to the first end of the high-molecular polymer positive coefficient temperature resistor, the second end of the high-molecular polymer positive coefficient temperature resistor is electrically connected to the negative end of the series diode D, the positive end of the series diode D is electrically connected to the second DC bus 172, and one end of each capacitor C is electrically connected to the first DC bus 171. Thus, when a short circuit fault occurs in any one capacitor C, the short circuit current generated by the short circuit of the capacitor C can trigger the series diode D connected in series corresponding to the fault capacitor to emit light, thereby realizing rapid positioning of the capacitor fault, and the high-molecular polymer positive coefficient temperature resistor connected in series corresponding to the fault capacitor can isolate the fault capacitor, thereby realizing the circuit protection function.

[0098] The second connection mode: the second end of each capacitor C is electrically connected to the first end of the series diode D, the second end of the series diode D is electrically connected to the first end of the high-molecular polymer positive coefficient temperature resistor, and the second end of the high-molecular polymer positive coefficient temperature resistor is electrically connected to the second DC bus 172. For example, in the case where the second DC bus 172 is connected to the reference ground of the main circuit 150, the first end of the series diode D is the positive end, and the second end of the series diode D is the negative end, i.e., the second end of each capacitor C is electrically connected to the positive end of the series diode D, the negative end of the series diode D is electrically connected to the first end of the high-molecular polymer positive coefficient temperature resistor, and the second end of the high-molecular polymer positive coefficient temperature resistor is electrically connected to the second DC bus 172. Thus, when a short circuit fault occurs in any one capacitor C, the short circuit current generated by the short circuit of the capacitor C can trigger the series diode D connected in series corresponding to the fault capacitor to emit light, thereby realizing rapid positioning of the capacitor fault, and the high-molecular polymer positive coefficient temperature resistor connected in series corresponding to the fault capacitor can isolate the fault capacitor, thereby realizing the circuit protection function.

[0099] As an example of the present application, as Figure 6As shown, in the case of using electrolytic capacitors as the capacitors C in the self-repairing DC bus capacitor bank 160, when a certain electrolytic capacitor in the self-repairing DC bus capacitor bank 160 short-circuits due to aging or overheating, the short-circuit current causes the PPTC element in series to heat up in milliseconds and the resistance to increase dramatically, isolating the faulty capacitor with high resistance; the remaining healthy capacitors in the self-repairing DC bus capacitor bank 160 automatically share the current and filtering tasks except for the faulty capacitor, ensuring that the total capacity of the capacitor bank decreases slightly but still maintains circuit operation, allowing the circuit system to continue to operate in a reduced capacity state, thereby reserving a time window for subsequent planned maintenance, while the series diode D corresponding to the faulty capacitor emits light, providing a visual fault indication to facilitate quick fault location, reduce maintenance difficulty and time, and thereby improve circuit maintenance convenience.

[0100] To sum up, the fault-tolerant control circuit 100 provided by the embodiment of the present application detects the main power module 112 in the power bridge arm 110 in the power conversion unit 110 through the power module detection unit 120, outputs the module detection signal corresponding to the main power module 112 to the fault diagnosis unit 130, so that the fault diagnosis unit 130 can perform fault diagnosis according to the module detection signal and the reference signal provided by the preset reference signal terminal Vref, and output the fault diagnosis signal corresponding to the main power module 112, so that the fault-tolerant switching unit 140 controls the first branch 114 to be disconnected and controls the second branch 115 to be connected to the main loop when the fault diagnosis signal is a hardware fault signal, so as to switch the circuit path of the power bridge arm 111 from the first branch 114 to the second branch 115, thereby automatically switching to the standby power module 113 when the main power module 112 has an unrecoverable fault, and improving system availability.

[0101] Further, the embodiment of the present application uses pure hardware circuit to realize fault diagnosis and switching, so that the time required from detection of the fault signal to output of the fault signal is only microseconds, for example, the time required from detection of the fault signal to output of the fault signal is less than 10 μs. Compared with the existing fault detection scheme using software algorithm, the embodiment of the present application uses pure hardware circuit to realize fault diagnosis and switching, has ultra-fast response speed, provides fault detection response speed, can effectively suppress short-circuit current, and protects the power module. Furthermore, the fault-tolerant control circuit 100 provided by the embodiment of the present application further comprises a self-repairing DC bus capacitor bank 160, which comprises at least two capacitors C connected in parallel and a recoverable fuse 151 connected one-to-one with the capacitors C. In the case of single capacitor failure, the fault-tolerant control circuit can still keep the system running based on other capacitors C in the self-repairing DC bus capacitor bank 160, reduce downtime, and improve mean time between failures and fault-tolerant operation capability.

[0102] In addition, the fault-tolerant control circuit 100 provided by the embodiment of the present application further comprises a series diode D, which is connected in one-to-one correspondence with the capacitor C in the self-repairing DC bus capacitor group 160, so that the visual fault indication can be provided through the series diode D, the capacitor fault point can be quickly located, the maintenance difficulty and time are reduced, and the maintenance convenience is improved.

[0103] In a specific implementation, the fault-tolerant control circuit 100 provided by the embodiment of the present application can be used as a fault-tolerant control circuit of a power converter, and applied to the power converter system 700, so that the power converter system 700 can realize fault diagnosis through the fault-tolerant control circuit 100, and automatically switch to the standby power module 113 in the power bridge arm when detecting that the main power module 112 in the power bridge arm has an unrecoverable fault, thereby improving system availability and system operation reliability.

[0104] As shown in Figure 7 The power converter system 700 provided by the embodiment of the present application comprises the fault-tolerant control circuit 100, which can be the fault-tolerant control circuit 100 described in any of the above embodiments of the present application, so that the fault diagnosis can be realized through the fault-tolerant control circuit 100 to realize the fault self-diagnosis by pure hardware, without relying on software running, avoiding the misjudgment or omission caused by program runaway, dead machine or electromagnetic interference, and automatically switching to the standby power module 113 in the power bridge arm when detecting that the main power module 112 in the power bridge arm has an unrecoverable fault, thereby improving the reliability and anti-interference ability of the system.

[0105] For the convenience of understanding the embodiments of the present application, the IGBT module is taken as the power module in the power bridge arm as an example, and further explanation and description are made in combination with the drawings and specific examples, but the example embodiments do not constitute a limitation on the embodiments of the present application.

[0106] In an example embodiment of the present application, in order to avoid the misjudgment or omission caused by program runaway, dead machine or electromagnetic interference, the power converter system 700 can integrate voltage, current and temperature sensors on the IGBT module to realize real-time state monitoring of the IGBT module through IGBT three-dimensional monitoring and hardware comparator circuit, and realize fault self-diagnosis based on the monitored temperature monitoring signal, voltage monitoring signal and current monitoring signal, without relying on software running, which can quickly judge whether the currently monitored IGBT module has an unrecoverable fault, realize millisecond-level response to short circuit, overcurrent and overtemperature faults, so that the fault response time is less than 10 microseconds, and the fault response processing speed can be effectively improved.

[0107] Specifically, the IGBT module multi-dimensional monitoring layer of the power converter system 700 can be implemented by the power module detection unit 120 in the fault-tolerant control circuit 100, as shown in Figure 8 For example, the system can synchronously monitor the key operating parameters of the main IGBT module through the IGBT module multi-dimensional monitoring layer, such as connecting a high-voltage differential voltage sensor in parallel at the C-E end of the IGBT module to collect the desaturation voltage in real time; installing a fast-response Hall current sensor at the emitter or DC bus to monitor the real-time current; and attaching an NTC / PTC thermistor to the IGBT substrate / heat sink to collect the operating temperature, so as to form real-time state data in three dimensions of voltage, current and temperature. Among them, the real-time state data of the IGBT module can be represented by the signals output by the sensors, such as the real-time voltage data of the IGBT module represented by the voltage monitoring signal output by the voltage sensor, the real-time current data of the IGBT module represented by the current monitoring signal output by the current sensor, and the real-time temperature data of the IGBT module represented by the temperature monitoring signal output by the temperature sensor.

[0108] After detecting the module detection signals corresponding to the IGBT modules of each power bridge arm through the voltage sensor, the current sensor and the temperature sensor, the application embodiment can perform fault diagnosis through the hardware comparator diagnosis layer, so as to quickly judge the temperature monitoring signal, the voltage monitoring signal and the current monitoring signal corresponding to each IGBT module through the hardware comparator in the hardware comparator diagnosis layer, thereby achieving millisecond-level response to faults such as short circuit, overcurrent and overtemperature, such as a response time less than 10 microseconds.

[0109] Specifically, the embodiment of the present application can implement the hardware comparator diagnostic circuit in the hardware comparator diagnostic layer by using the fault diagnosis unit 130 in the fault-tolerant control circuit 100, so as to set an independent high-speed voltage comparator for each monitoring dimension through the hardware comparator diagnostic circuit. The high-speed voltage comparator can specifically include a temperature diagnosis comparator COMP1, an overcurrent comparator COMP2, and a desaturation comparator COMP3. For example, for overcurrent / short circuit diagnosis, the current monitoring signal output by the current sensor can be connected to the overcurrent comparator COMP2, and compared with the overcurrent reference signal provided by the second reference signal end, so as to compare the current value represented by the current monitoring signal with the overcurrent threshold of "1.5 times rated current", and output a first comparison signal; at the same time, the voltage monitoring signal output by the voltage sensor can be connected to the desaturation comparator COMP3, and compared with the overpressure reference signal provided by the third reference signal, so as to compare the voltage value of the voltage monitoring signal with the desaturation voltage threshold of "15V", and output a second comparison signal; the temperature monitoring signal output by the temperature sensor is converted and connected to the overtemperature diagnosis and comparator, and compared with the overtemperature reference signal provided by the first reference signal end, so as to compare the temperature value of the temperature monitoring signal with the overtemperature threshold of "corresponding to 150°C", and output a third comparison signal. In the case of using high-level signal "1" to represent the fault signal, the first comparison signal and the second comparison signal are output through the "or gate" judgment, and any signal is high-level signal "1", that is, the "or gate" can generate high-level signal "1" to represent the overcurrent / short circuit fault signal through the high-level signal "1"; if the third comparison signal is high-level signal "1", an overtemperature fault signal can be generated. All fault signals are finally collected through the "or gate" array to generate a digital level signal without delay, which is directly transmitted to the redundant switching logic drive circuit in the redundant switching logic layer as a fault diagnosis signal.

[0110] As can be seen, in the hardware comparator diagnostic layer in the power converter system 700, the monitored multi-dimensional data can be respectively connected to the independent high-speed voltage comparator for judgment, so that whether the current monitored IGBT module has an unrecoverable fault can be quickly judged, and fault diagnosis can be realized.

[0111] In addition, the embodiment of the present application can implement the redundant switching logic drive circuit in the hardware comparator diagnostic layer by using the fault-tolerant switching unit 140 in the fault-tolerant control circuit 100, so as to realize redundant bridge arm switching through the redundant switching logic drive circuit. Specifically, the redundant switching logic circuit can include an SR flip-flop, a relay drive circuit, and a master and standby IGBT module. The SR flip-flop, as the core of the redundant switching logic circuit, can be used to drive the redundant bridge arm switching. The master and standby IGBT module includes a master IGBT module and a standby IGBT module of the same power bridge arm.

[0112] For example, each power bridge arm (such as the upper bridge arm of phase A) in the power converter is equipped with a standby IGBT module identical to the main IGBT module. The outputs of the main IGBT module and the standby IGBT module can be connected to a common output point through a large-current, high-reliability mechanical relay (or contactor). When the SR flip-flop in the redundancy switching logic circuit receives a fault diagnosis signal as a hardware fault signal Hardware_Fault, the SR flip-flop can be immediately set by the hardware fault signal Hardware_Fault and the dual-channel action is started: first, the driving optocoupler / chip of the main IGBT is blocked through the hardware driving chip to achieve hard shutdown of the main IGBT module; second, the relay driving circuit is driven to attract the relay in the standby IGBT module path and open the relay in the main IGBT module path, and at the same time, an "enable" signal is sent to the standby IGBT module driving circuit to complete the uninterrupted switching of the main and standby modules. After the fault is eliminated and the system is powered off, the maintenance personnel reset the SR flip-flop through the manual reset button, and the system returns to the initial state, avoiding secondary faults caused by main IGBT module failure and improving system reliability. In addition, the power converter system in the embodiment of the present application can also realize fault self-isolation and derating operation of the DC bus capacitor bank through the self-repairing DC bus capacitor bank 160. Specifically, while ensuring the normal work of the IGBT loop through redundancy switching, the power converter system can realize self-repairing of the DC bus capacitor bank through the "PPTC + multiple capacitor C parallel" structure: when a certain electrolytic capacitor in the DC bus capacitor bank short-circuits due to aging or overheating, the short-circuit current causes the PPTC element in series to heat up in milliseconds and the resistance to increase dramatically, isolating the faulty capacitor with high resistance; the remaining healthy capacitors automatically share the current and filtering tasks, ensuring that the total capacity of the capacitor bank decreases slightly but still maintains work, and the converter continues to operate in a derated state, reserving a time window for subsequent planned maintenance, while the LED indicating circuit beside the faulty capacitor is lit to realize fault positioning.

[0113] Wherein, the DC bus capacitor group is a capacitor group on the DC bus side, which can be a capacitor group composed of N electrolytic capacitors in parallel. N is an integer greater than 1. Specifically, the embodiment of the application can be based on the fault isolation mechanism, and a PPTC element is connected in series on the positive or negative lead of each electrolytic capacitor. When an internal short circuit fault occurs in a certain electrolytic capacitor due to aging, overheating, etc., the PPTC element connected in series with the electrolytic capacitor will rapidly heat up, and its resistance value will increase sharply (jump) within milliseconds, thereby isolating the faulty capacitor from the circuit with high resistance. The total capacity of the capacitor group will decrease slightly, but the remaining (N-1) healthy capacitors will automatically share the entire working current and filtering task, ensuring that the power converter continues to operate in a reduced capacity but not stopped state, providing a time window for planned maintenance. In addition, a normally closed indicator circuit (such as an LED in series with a resistor) can be connected in parallel with each PPTC. When the PPTC is fused and in a high resistance state, current flows through the indicator circuit, and the LED lights up, providing visual fault location.

[0114] In summary, the power converter system provided by the embodiment of the application is based on a fault-tolerant control circuit, and realizes high-reliability operation and self-repair of the power conversion unit through a full-link logic of real-time multi-dimensional monitoring → hardware fault diagnosis → redundant module switching → fault capacitor isolation, thereby improving the reliability and fault-tolerant operation capability of system operation. In a specific implementation, the power converter system provided by the embodiment of the application can be integrated in an electrical appliance, so that the electrical appliance can realize fault diagnosis through the fault-tolerant control circuit 100, and can automatically switch to the standby power module 113 in the power bridge arm when detecting that the main power module 112 in the power bridge arm has an unrecoverable fault, thereby realizing seamless switching.

[0115] As shown in Figure 9 The embodiment of the application also provides an electrical appliance 900, which includes the fault-tolerant control circuit 100 described in any of the above embodiments of the application, so that the electrical appliance 900 can perform fault-tolerant control based on the fault-tolerant control circuit 100, to realize high-reliability operation and self-repair of the power conversion unit based on fault-tolerant control, and improve the reliability and fault-tolerant operation capability of the device system operation.

[0116] In a specific implementation, the electrical appliance in the embodiment of the application can include but is not limited to an air conditioner, a refrigerator, and can also include other types of electrical appliances using a power converter, such as a transformer device, etc., and the embodiment of the application does not specifically limit this.

[0117] The system and device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0118] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0119] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A fault-tolerant control circuit, characterized in that, include: Power conversion unit, power module detection unit, fault diagnosis unit, and fault-tolerant switching unit; The power conversion unit includes a power bridge arm, and each power bridge arm includes a main power module and a backup power module connected in parallel with the main power module. The power module detection unit is used to detect the main power module and output the module detection signal corresponding to the main power module. The fault diagnosis unit is used to perform fault diagnosis based on the module detection signal and the reference signal provided by the preset reference signal terminal, and output the fault diagnosis signal corresponding to the main power module. The fault-tolerant switching unit is used to control the first branch to disconnect and control the second branch to connect to the main circuit according to the fault diagnosis signal, so that when the fault diagnosis signal is a hardware fault signal, the circuit path of the power bridge arm is switched from the first branch to the second branch. The first branch is a control branch formed by the main power module and the second branch is a control branch formed by the reserve rate module.

2. The fault-tolerant control circuit according to claim 1, characterized in that, The module detects signals including: temperature monitoring signal, voltage monitoring signal, and current monitoring signal; The reference signals include: over-temperature reference signal, over-current reference signal, and over-voltage reference signal; The fault diagnosis unit includes: a first comparison module, a second comparison module, a third comparison module, and an OR gate judgment module; The first comparison module is used to compare the temperature monitoring signal with the over-temperature reference signal and output a first comparison signal; The second comparison module is used to compare the current monitoring signal with the overcurrent reference signal and output a second comparison signal; The third comparison module is used to compare the voltage monitoring signal with the overvoltage reference signal and output a second comparison signal; The OR gate judgment module is used to judge the fault based on the first comparison signal, the second comparison signal and the third comparison signal, and output the fault diagnosis signal.

3. The fault-tolerant control circuit according to claim 2, characterized in that, The first comparison module includes an over-temperature diagnostic comparator, the second comparison module includes an over-current comparator, the third comparison module includes a desaturation comparator, and the OR gate judgment module includes an OR gate array; The preset reference signal terminal includes a first reference signal terminal, a second reference signal terminal, and a third reference signal terminal. The first reference signal terminal is used to provide the over-temperature reference signal, the second reference signal terminal is used to provide the over-current reference signal, and the third reference signal terminal is used to provide the over-voltage reference signal. Wherein, the first terminal of the over-temperature diagnostic comparator is electrically connected to the temperature detection output terminal of the power module detection unit, the second terminal of the over-temperature diagnostic comparator is electrically connected to the first reference signal terminal, the output terminal of the over-temperature diagnostic comparator is electrically connected to the first input terminal of the OR gate judgment module, the temperature detection output terminal of the power module detection unit is used to output the temperature monitoring signal, and the output terminal of the over-temperature diagnostic comparator is used to output the first comparison signal. The first terminal of the overcurrent comparator is electrically connected to the current detection output terminal of the power module detection unit, the second terminal of the overcurrent comparator is electrically connected to the second reference signal terminal, the output terminal of the overcurrent comparator is electrically connected to the second input terminal of the OR gate judgment module, the current detection output terminal of the power module detection unit is used to output the current monitoring signal, and the output terminal of the overcurrent comparator is used to output the second comparison signal. The first terminal of the desaturation comparator is electrically connected to the voltage detection output terminal of the power module detection unit, the second terminal of the desaturation comparator is electrically connected to the third reference signal terminal, the output terminal of the desaturation comparator is electrically connected to the third input terminal of the OR gate judgment module, the voltage detection output terminal of the power module detection unit is used to output the voltage monitoring signal, and the output terminal of the desaturation comparator is used to output the third comparison signal. The first input terminal of the OR gate array is electrically connected to the output terminal of the over-temperature diagnostic comparator, the second input terminal of the OR gate array is electrically connected to the output terminal of the overcurrent comparator, the third input terminal of the OR gate array is electrically connected to the output terminal of the third comparator, and the output terminal of the OR gate array is electrically connected to the input terminal of the fault-tolerant switching unit.

4. The fault-tolerant control circuit according to claim 1, characterized in that, The fault-tolerant switching unit includes: a redundancy switching module and a drive circuit module; The redundancy switching module is used to output a switching signal when the fault diagnosis signal is the hardware fault signal; The drive circuit module is used to control the first branch to disconnect according to the switching signal, so as to block the first branch, and control the second branch to connect to the main circuit, so as to switch the circuit path from the first branch to the second branch.

5. The fault-tolerant control circuit according to claim 4, characterized in that, The redundancy switching module includes a bistable trigger. The input terminal of the bistable trigger serves as the input terminal of the redundancy switching module and is electrically connected to the output terminal of the fault diagnosis unit. The output terminal of the bistable trigger serves as the output terminal of the redundancy switching module and is electrically connected to the drive control terminal of the drive circuit module. The input terminal of the redundancy switching module is used to receive the fault diagnosis signal; The output of the redundancy switching module is used to output the switching signal.

6. The fault-tolerant control circuit according to claim 1, characterized in that, The drive circuit module includes a relay drive submodule, wherein the drive control terminal of the relay drive submodule is electrically connected to the output terminal of the redundancy switching module. The relay drive submodule includes a first relay and a second relay. The main power module is connected to the main circuit through the first relay, and the standby power module is connected to the main circuit through the second relay. The relay driving submodule is used to control the first relay to open according to the switching signal to block the first branch, and to control the second relay to close according to the switching signal to connect the second branch to the main circuit through the closed second relay.

7. The fault-tolerant control circuit according to claim 6, characterized in that, The driving circuit module further includes: a hardware driving chip; The first input terminal of the hardware driver chip is electrically connected to the output terminal of the redundancy switching module, the second input terminal of the hardware driver chip is used for power control signals, and the output terminal of the hardware driver chip is electrically connected to the control terminal of the backup power module. The hardware driver chip is specifically used to output a power switch signal corresponding to the power switch control signal to the backup power module based on the switching signal.

8. The fault-tolerant control circuit according to any one of claims 1 to 7, characterized in that, The fault-tolerant control circuit also includes: a self-healing DC bus capacitor bank, wherein the self-healing DC bus capacitor bank comprises at least two capacitors connected in parallel and a resettable fuse connected in series with each of the capacitors; The main circuit includes a first DC bus and a second DC bus; The first terminal of each capacitor is electrically connected to the first DC bus, and the second terminal of each capacitor is electrically connected to the second DC bus through the resettable fuse.

9. The fault-tolerant control circuit according to claim 8, characterized in that, The resettable fuse is a polymer positive coefficient temperature resistor, and the fault-tolerant control circuit further includes: series diodes connected in a one-to-one correspondence with the capacitors; Wherein, the second terminal of each of the capacitors is electrically connected to the second DC bus via the resettable fuse, including: The second terminal of each capacitor is electrically connected to the first terminal of the polymer positive coefficient temperature resistor, the second terminal of the polymer positive coefficient temperature resistor is electrically connected to the first terminal of the series diode, and the second terminal of the series diode is electrically connected to the second DC bus; or... The second terminal of each capacitor is electrically connected to the first terminal of the series diode, the second terminal of the series diode is electrically connected to the first terminal of the polymer positive coefficient temperature resistor, and the second terminal of the polymer positive coefficient temperature resistor is electrically connected to the second DC bus.

10. A power converter system, characterized in that, The power converter system includes the fault-tolerant control circuit as described in any one of claims 1 to 9.

11. An electrical appliance, characterized in that, The electrical device includes a fault-tolerant control circuit as described in any one of claims 1 to 9.

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