An energy bidirectional flow-based power electronic transformer and a redundant control method thereof

Abstract

The application discloses an energy bidirectional flow-based power electronic transformer and a redundant control method thereof. The power electronic transformer comprises three-phase branches, each of which comprises a single-phase power module. The power electronic transformer further comprises a redundant power module used for connecting to a corresponding phase when a single-phase power module fails. The redundant power module and each single-phase power module comprise a DAB converter. The redundant control method is as follows: when each single-phase power module of each phase branch of the power electronic transformer normally works, the redundant power module is reversely fed with power to be in a hot standby state; when a single-phase power module of a certain phase branch fails, the driving signal of the single-phase power module is blocked, the single-phase power module is cut off from the branch, and the redundant power module is connected to the phase. The application can solve the technical problems of high cost, large size, large inrush current impact in the module replacement switching process, slow system recovery and complex control logic in the existing power electronic transformer redundant fault tolerance scheme, and can balance economy and high reliability.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology and relates to a power electronic transformer based on bidirectional energy flow and its redundancy control method. It includes a three-phase single-path redundant topology design for the power electronic transformer and a redundancy fault-tolerant smooth switching control strategy based on reverse feed of a bidirectional DC-DC converter. Background Technology

[0002] With the development of smart grids and AC / DC hybrid distribution networks, power electronic transformers have become core equipment in the energy internet due to their small size, light weight, ability to achieve bidirectional power flow, and various power quality management functions. However, compared with traditional transformers, power electronic transformer systems integrate a large number of semiconductor switches, filter inductors, DC support capacitors, and high-frequency transformers. The large number of components exposes them to more failure modes during operation (such as AC side open circuit, DC side open circuit, H-bridge module open circuit, and bidirectional DC-DC converter open circuit), posing a significant challenge to their power supply reliability.

[0003] For three-phase cascaded H-bridge power electronic transformer systems, redundancy and fault-tolerant control strategies are typically introduced to improve system reliability. Existing redundancy schemes mainly suffer from the following drawbacks:

[0004] (1) Complete redundancy (1+1 configuration) or three-phase three-way redundancy (3+3 configuration): Although the power supply continuity is good, a large number of additional backup modules are required, resulting in high system cost and large size. In the application scenario of large-capacity power electronic transformers, the number of additional redundant power modules is large, which leads to an increase in hardware cost and system size.

[0005] (2) No external redundancy or cold standby replacement method: The no-redundancy scheme will cause the remaining normal devices to be subjected to excessive voltage stress after a failure; while in the traditional "three-phase single-circuit redundancy" cold standby switching, since the initial voltage of the DC side capacitor of the redundant power module is zero, a huge capacitor charging surge current (inrush current) will be generated at the moment of connection, which is very easy to cause secondary system failure, and the system voltage drops significantly during the switching process, and the recovery time is long. In addition, the traditional method often requires recalculation and allocation of global carrier phase shift angle after switching, which has high control algorithm complexity and communication delay. Summary of the Invention

[0006] The purpose of this invention is to provide a power electronic transformer based on bidirectional energy flow and its redundancy control method, which can solve the key technical problems of high cost, large size, large surge current impact, slow system recovery and complex control logic in existing power electronic transformer redundancy fault-tolerant schemes, while taking into account both economy and high reliability.

[0007] To achieve the above objectives, the solution of the present invention is:

[0008] A power electronic transformer based on bidirectional energy flow includes a three-phase branch, each phase branch including an inductor and a single-phase power module connected sequentially from the input to the output; it also includes a redundant power module, which is used to connect to the corresponding phase when a single-phase power module fails; the redundant power module has the same structure as each single-phase power module, and each includes a rectifier H-bridge module and a DAB converter connected sequentially from the input to the output, wherein the DAB converter in the redundant power module is in a hot standby state when all single-phase power modules in each phase branch are working normally.

[0009] The DAB converter includes a pre-stage filter capacitor, a pre-stage full-bridge circuit, a transformer, a post-stage full-bridge circuit, and a post-stage filter capacitor. The pre-stage filter capacitor is connected in parallel to the input terminal of the pre-stage full-bridge circuit and serves as the input terminal of the DAB converter. The output terminal of the pre-stage full-bridge circuit is connected to the primary side of the transformer, and the secondary side of the transformer is connected to the input terminal of the post-stage full-bridge circuit. The output terminal of the post-stage full-bridge circuit is connected in parallel to the post-stage filter capacitor and serves as the output terminal of the DAB converter.

[0010] The redundancy control method for power electronic transformers based on bidirectional energy flow, as described above, includes:

[0011] When the single-phase power modules of each phase branch of the power electronic transformer are working normally, the redundant power modules are fed back in reverse to keep them in hot standby mode.

[0012] When a fault is detected in a single-phase power module of a certain phase branch, the drive signal of the single-phase power module is blocked and it is disconnected from the branch, and the redundant power module is connected to the phase.

[0013] This includes reverse power feeding of redundant power modules, including:

[0014] Using the output voltage value of the DAB converter in the single-phase power module under normal operating conditions or the ideal set value as the reference voltage, the DC voltage sampling value of the rectifier H-bridge module of the redundant power module is compared with the reference voltage, and the difference between the two is obtained by the PI regulator to obtain the reverse phase shift angle of the redundant power module.

[0015] When a single-phase power module in a certain phase branch fails, a redundant power module is connected to that phase, including:

[0016] The redundant power module inherits the modulation wave and carrier phase of the faulty single-phase power module. When the redundant power module is connected to the faulty phase, the DAB converter of the redundant power module smoothly transitions from the reverse-feed state to the normal operating state.

[0017] The redundant power module inherits the modulation wave and carrier phase of the faulty single-phase power module, including:

[0018] Before connecting the redundant power module to the faulty phase, the same carrier phase as the faulty single-phase power module is used, and the modulation wave of the faulty phase is assigned to the redundant power module.

[0019] Among them, determining a fault in a single-phase power module of a certain phase branch includes,

[0020] The negative sequence current imbalance of a certain phase is obtained based on the current of a certain phase of the power electronic transformer. When the negative sequence current imbalance is greater than a set threshold, it is determined that the phase is open circuit.

[0021] The output capacitor voltage of the DAB converter in each phase branch is collected in real time. When the conversion rate of the output capacitor voltage is higher than a preset value, the single-phase power module of that phase branch is determined to be faulty.

[0022] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor; the processor executes the computer program to implement the steps of the redundancy control method as described above.

[0023] A computer-readable storage medium storing a computer program; when executed by a processor, the computer program implements the steps of the redundancy control method as described above.

[0024] A computer program product that, when executed by a processor, implements the steps of the redundancy control method as described above.

[0025] By adopting the above scheme, this invention solves the problem of smooth switching and redundancy fault tolerance when internal modules of a power electronic transformer fail by configuring "three-phase single-path" (3+1) redundant power modules in the power electronic transformer and combining it with a control strategy of reverse feedforward from a bidirectional DC-DC converter. During normal system operation, this method utilizes the bidirectional energy flow capability of the bidirectional DC-DC converter to pre-charge the DC-side capacitors of the redundant power modules, putting them in a "hot standby" state. When a module fault is detected, the faulty power module is bypassed, and the redundant power module directly inherits the modulation wave and carrier phase of the faulty power module, achieving smooth switching. This invention adopts a three-phase shared single-path redundancy topology, significantly reducing redundancy costs and system size. Simultaneously, due to the introduction of the reverse feedforward strategy, it reduces the inrush current and voltage drop generated when traditional cold standby modules are switched in, achieving high reliability, low impact, and rapid recovery of the system under fault conditions.

[0026] This invention applies to a type of redundant control system for power electronic transformers, aiming to solve a series of technical problems currently faced by power electronic transformers in practical applications. Its implementation will bring the following beneficial effects:

[0027] (1) Cost saving and reduction of power electronic transformer size

[0028] The "3+1" redundant topology with three-phase shared single circuit is adopted, which significantly reduces the number of redundant devices compared to the "3+3" or whole-machine redundancy scheme, effectively saving hardware costs and floor space.

[0029] (2) Reduce surge impact and achieve smooth switching

[0030] By employing a reverse-feedback strategy, the DC capacitor voltage of the redundant power module reaches its rated value before it is switched on. This significantly reduces the surge current and voltage caused by capacitor voltage differences when switching on in traditional cold standby mode, thereby reducing device stress.

[0031] (3) Reduce control complexity and improve recovery speed

[0032] By directly inheriting the modulation wave and carrier phase sequence of the faulty power module, the global carrier phase shift angle does not need to be recalculated after a fault, reducing the burden on the controller. The system recovers from a fault state to normal operation at a significantly faster speed than traditional methods. Attached Figure Description

[0033] Figure 1 This is the redundancy mode diagram of the three-phase single-path redundant structure of the present invention;

[0034] Figure 2 This is a block diagram of the DAB reverse feed control strategy;

[0035] Figure 3 It is a flowchart of redundancy switching based on DAB reverse feed.

[0036] Figure 4 This is a simulation waveform diagram of the system before adding DAB reverse feed.

[0037] Where (a) is the voltage of the cascaded H-bridge in phase A, and (b) is the three-phase AC current;

[0038] Figure 5 This is a simulation waveform diagram of the system after adding DAB reverse feed.

[0039] Where (a) is the voltage of the cascaded H-bridge of phase A, and (b) is the three-phase AC current. Detailed Implementation

[0040] This invention provides a power electronic transformer based on bidirectional energy flow. The system topology adopts a "three-phase single-circuit redundancy (3+1)" configuration, meaning that the three phases of the power electronic transformer share one redundant power module. This redundant power module is connected between the high-voltage side output terminal and the neutral point of the three-phase system through a set of fully controlled redundant switches, used to replace the faulty path of any one phase. Here, the bidirectional DC-DC converter is illustrated using a DAB converter as an example.

[0041] During normal system operation, the redundant power modules are fed back via the DAB to maintain the DC-side capacitor voltage of their rectifier H-bridge near its rated value, and the redundant power modules are in hot standby mode. When a fault is detected in a single module, the drive signal of the faulty power module is blocked, and it is disconnected from the topology circuit through a fully controlled bypass switch. Subsequently, the redundant connection switch is closed to connect the redundant power module to the corresponding faulty phase. At this time, the redundant power module directly inherits the modulation wave and carrier phase of the faulty power module, and at the same time, the bidirectional DC-DC converter of the redundant power module smoothly transitions from the reverse-feed state to the normal operating state, taking over the output power of the faulty power module, so that the system can resume stable operation.

[0042] The present invention also provides a redundancy control method for the aforementioned power electronic transformer, comprising the following steps:

[0043] (1) During normal system operation, the DAB of the redundant power module is fed back in reverse. The output reference voltage of other normal working modules is used to apply a negative phase shift angle to the DAB of the redundant power module. The reverse power transmission capability of the DAB is used to charge the DC side capacitor of the rectifier H bridge of the redundant power module to compensate for standby loss and keep its voltage near the rated value (hot standby state).

[0044] (2) By collecting the AC side current of the system and the capacitor voltage of each submodule, and combining the electrical characteristics such as the negative sequence current imbalance and the capacitor voltage change rate, the submodule with the open circuit fault can be quickly detected and located.

[0045] (3) After locating a single module fault, the drive signal of the faulty power module is blocked, and it is disconnected from the topology circuit by a fully controlled bypass switch; then, the redundant connection switch is closed to connect the redundant power module to the corresponding faulty phase;

[0046] (4) The redundant power module directly inherits the modulation wave and carrier phase of the faulty power module, avoiding the redistribution of carrier phase shift. At the same time, it smoothly switches its DAB phase shift angle from the negative value of reverse feeding to the original positive phase shift angle of the faulty power module, taking over the output power of the faulty power module and restoring the system to stable operation.

[0047] The reverse power supply strategy specifically involves using the DAB output voltage value or ideal set value of the normally operating module as a reference voltage. The sampled DC voltage value of the cascaded H-bridge of the redundant power module is compared with the reference voltage. The difference is then controlled by a PI regulator to output the reverse phase shift angle of the redundant power module. This negative phase shift angle is applied to the DAB of the redundant power module to achieve reverse power transmission, compensate for the standby losses of the redundant power module, and keep the DC voltage of its cascaded H-bridge stable.

[0048] Specifically, the parameter inheritance strategy during the redundancy switching phase is as follows: to avoid reallocating the global carrier phase, before the redundant power module switches into the system, it directly adopts the same carrier phase as the target faulty power module and directly assigns the modulation wave of the faulty phase to the redundant power module; after the fault occurs, the bidirectional DC-DC converter of the redundant power module changes from its original reverse-feed state to the state when the faulty power module is working normally.

[0049] During the fault detection and location phase, for single-phase open-circuit faults on the AC side, the negative sequence current imbalance is calculated by extracting the three-phase current of the system. When the ratio of the effective value of the negative sequence current to the effective value of the positive sequence current (i.e., the negative sequence current imbalance) of a certain phase is greater than the set threshold, it is determined to be a single-phase open circuit. For transverse open-circuit faults such as transformer disconnection in bidirectional DC-DC converters, the judgment is made by detecting a significant increase in the rate of change of the output capacitor voltage.

[0050] The technical solution of a certain embodiment of the present invention will be described in detail and systematically below with the aid of relevant illustrations. It is worth noting that although this embodiment has been described in detail, it represents only one specific implementation of the present invention. In fact, the present invention covers a variety of possible embodiments, which may have various variations and optimizations. Based on the technical principles and methods disclosed herein, those skilled in the art can derive other implementation schemes without involving creative modifications, and these schemes should all be considered within the protection scope of the present invention.

[0051] Example:

[0052] This invention provides a power electronic transformer based on bidirectional energy flow. The system adopts a modular design, with each module's downstream stage consisting of a DAB (Dual Active Bridge) converter and an additional shared redundant power module. This redundant power module is connected to the three-phase main circuit through a set of fully controlled redundant switches, allowing it to flexibly connect to any faulty phase for replacement. A fully controlled switch connects the high-voltage side output terminal of the normal operating module to the neutral point, enabling the connection of the redundant power module when needed.

[0053] First, configure the DAB reverse feed-through control strategy for the redundant power module. During normal system operation, the redundant power module does not participate in main power transmission, but instead utilizes its internal DAB converter for reverse feed-through. By referencing the DC voltage of other normally operating modules, the PI controller adjusts the phase shift angle of the DAB to generate a reverse power flow, thereby precisely controlling the DC-side capacitor voltage of the cascaded H-bridge of the redundant power module, stabilizing it at or near the same rated value as the operating module in a "hot standby" state. This step ensures that the redundant power module is always in a pre-charged state for rapid and smooth switching.

[0054] Next, redundant fault-tolerant switching control logic is configured. When the system detects a fault in any power module of any operating phase, the control system responds quickly. First, the drive signal of the faulty power module is immediately blocked, and it is isolated from the circuit via a bypass switch. Subsequently, the DAB phase shift angle of the redundant power module switches from the reverse-feed state to the same normal operating state as the faulty power module, and the modulation wave and carrier phase information of the faulty power module are directly inherited and assigned to the redundant power module.

[0055] Finally, the redundant power modules are connected and the system is restored. After the control parameters are updated and ready, the system controls the redundant connection switch to seamlessly connect the pre-charged redundant power modules to the faulty phase, replacing the isolated faulty power modules. At this time, the redundant power modules will take over the power conversion task of the faulty phase, and the system returns to a stable operating state under extremely short transient impact. This process helps reduce the current surge and voltage drop during switching and ensures the continuity of system functions and power quality.

[0056] Specifically: The modal diagram of the designed three-phase single-path redundant topology is as follows: Figure 1 As shown. By controlling the input-side switching switch, neutral point reconfiguration switch, and output-side switching switch of the corresponding phase, the redundant power module replaces the faulty power module to establish an equivalent current path and voltage support path. Taking phase A as an example, when a fault occurs, the control system blocks the drive signal of the faulty power module and bypasses it. At this time, switches S2 and S3 are opened, and switch S1 is closed to connect the redundant power module to the high-voltage side of phase A. Simultaneously, switch S4 is opened and switches S5 and S6 are closed to establish a new neutral point. In addition, S8 and S9 are opened and S7 is closed to connect the redundant power module to the low-voltage side of phase A. In this way, the redundant power module completely replaces the faulty power module.

[0057] Under normal operating conditions, to avoid redundant power modules (let's call them numbered...) A surge current is generated at the moment of connection, which is pre-fed in reverse. The control structure is as follows: Figure 2As shown, the DC voltage sample value of the cascaded H-bridge of the redundant power modules is compared with the reference voltage of the normal module, and a negative phase shift angle is output by the PI controller. According to the DAB power transfer formula:

[0058]

[0059] in, These are the primary and secondary voltages of the transformer, respectively. For DAB switching frequency, The magnitude of the transformer leakage inductance. This is the phase shift duty cycle of DAB.

[0060] When the phase shift angle is negative, the system reverses the DC capacitor of the redundant power module to charge it, compensating for transformer iron loss and switching loss, and stabilizing the voltage of the redundant power module at the rated value.

[0061] like Figure 3 The flowchart shown is for a redundancy switching system based on DAB reverse feedforward. Assume a module in phase A fails. The system confirms the fault within a short time (e.g., 10ms). First, the normal switch connected to the faulty power module is disconnected, locking its drive. Second, the fully controlled switch is closed to connect the redundant power module to phase A. To avoid sudden current changes, the modulation wave and carrier phase of the redundant power module are directly determined by the following formula:

[0062]

[0063] in, The modulation wave for the redundant module, The modulated wave of the faulty module, For the carrier phase of the redundant module, The carrier phase of the faulty module.

[0064] Subsequently, the DAB phase shift angle of the redundant module transitions from the reverse-feed phase shift angle to the target normal operating phase shift angle according to the preset closed-loop tracking method, and is put into operation.

[0065] To verify the effectiveness of the control method described in this invention, a specific example is given. A simulation topology of a three-phase twelve-stage power electronic transformer with a three-phase single-path redundant power module is built on Simulink. The redundancy control strategy of this system incorporates DAB reverse feed. Its main parameters are shown in Table 1.

[0066] Table 1 Design Example Parameters

[0067]

[0068] Figure 4The waveforms shown are the voltage and current waveforms before the DAB reverse feed is applied. It can be seen from the waveforms that the voltage and current surges of the system are significant at the moment the redundant power module is switched on, and the system recovers from the fault state to the normal operating state in about 0.1 seconds. Figure 5 The waveforms shown are the voltage and current waveforms after the DAB reverse feed is added. It can be seen from the waveforms that, compared with the cold standby mode without the DAB reverse feed, the peak current on the AC side of the system and the peak voltage of the cascaded H-bridge are significantly reduced, and the time for the system to recover from the fault state to the normal working state is also significantly shortened.

[0069] This invention also provides another computer device, including a processor and a memory configured to store a computer program capable of running on the processor; wherein, when the processor is configured to run the computer program, it performs the method steps described in the foregoing embodiments.

[0070] In practical applications, the aforementioned processor includes a Field-Programmable Gate Array (FPGA), and the processor can be a Central Processing Unit (CPU) or a Digital Signal Processor (DSP). It is understood that for different devices, the electronic devices used to implement the above-mentioned processor functions can also be other types, and this embodiment of the invention does not impose specific limitations.

[0071] The aforementioned memory can be volatile memory, such as random-access memory (RAM); or non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); or a combination of the above types of memory, and provides instructions and data to the processor.

[0072] In an exemplary embodiment, the present invention also provides a computer-readable storage medium for storing a computer program.

[0073] Optionally, the computer-readable storage medium can be applied to any of the methods in the embodiments of the present invention, and the computer program causes the computer to execute the corresponding processes implemented by the processor in the various methods of the embodiments of the present invention. For the sake of brevity, these will not be described in detail here.

[0074] In an exemplary embodiment, the present invention also provides a computer program product for storing computer programs.

[0075] In the several embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0076] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0077] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A power electronic transformer based on bidirectional energy flow, comprising three-phase branches, each phase branch comprising a single-phase power module; characterized in that: It also includes a redundant power module, which is used to connect to the corresponding phase when a single-phase power module fails; the redundant power module has the same structure as each single-phase power module, and each includes a rectifier H-bridge module and a DAB converter connected in sequence from the input end to the output end. The DAB converter in the redundant power module is in a hot standby state when the single-phase power modules in each phase branch are working normally. The power electronic transformer based on bidirectional energy flow employs the following redundancy control method, including: When the single-phase power modules of each phase branch of the power electronic transformer are working normally, the redundant power modules are fed back in reverse to keep them in hot standby mode. When a fault is detected in a single-phase power module of a certain phase branch, the drive signal of the single-phase power module is blocked and it is disconnected from the branch, and the redundant power module is connected to the phase. When a single-phase power module in a certain phase branch fails, a redundant power module is connected to that phase, including: The redundant power module inherits the modulation wave and carrier phase of the faulty single-phase power module. When the redundant power module is connected to the faulty phase, the DAB converter of the redundant power module smoothly transitions from the reverse-feed state to the normal operating state. The redundant power module inherits the modulation wave and carrier phase of the faulty single-phase power module, including: Before connecting the redundant power module to the faulty phase, the same carrier phase as the faulty single-phase power module is used, and the modulation wave of the faulty phase is assigned to the redundant power module.

2. The power electronic transformer based on bidirectional energy flow as described in claim 1, characterized in that: The DAB converter includes a pre-stage filter capacitor, a pre-stage full-bridge circuit, a transformer, a post-stage full-bridge circuit, and a post-stage filter capacitor. The pre-stage filter capacitor is connected in parallel to the input terminal of the pre-stage full-bridge circuit and serves as the input terminal of the DAB converter. The output terminal of the pre-stage full-bridge circuit is connected to the primary side of the transformer, and the secondary side of the transformer is connected to the input terminal of the post-stage full-bridge circuit. The output terminal of the post-stage full-bridge circuit is connected in parallel to the post-stage filter capacitor and serves as the output terminal of the DAB converter.

3. The redundancy control method for power electronic transformers based on bidirectional energy flow as described in claim 1, characterized in that: include, When the single-phase power modules of each phase branch of the power electronic transformer are working normally, the redundant power modules are fed back in reverse to keep them in hot standby mode. When a fault is detected in a single-phase power module of a certain phase branch, the drive signal of the single-phase power module is blocked and it is disconnected from the branch, and the redundant power module is connected to the phase. When a single-phase power module in a certain phase branch fails, a redundant power module is connected to that phase, including: The redundant power module inherits the modulation wave and carrier phase of the faulty single-phase power module. When the redundant power module is connected to the faulty phase, the DAB converter of the redundant power module smoothly transitions from the reverse-feed state to the normal operating state. The redundant power module inherits the modulation wave and carrier phase of the faulty single-phase power module, including: Before connecting the redundant power module to the faulty phase, the same carrier phase as the faulty single-phase power module is used, and the modulation wave of the faulty phase is assigned to the redundant power module.

4. The redundancy control method as described in claim 3, characterized in that: Reverse power supply to redundant power modules includes, Using the output voltage value of the DAB converter in the single-phase power module under normal operating conditions or the ideal set value as the reference voltage, the DC voltage sampling value of the rectifier H-bridge module of the redundant power module is compared with the reference voltage, and the difference between the two is obtained by the PI regulator to obtain the reverse phase shift angle of the redundant power module.

5. The redundancy control method as described in claim 3, characterized in that: Determining a fault in a single-phase power module of a specific branch includes: The negative sequence current imbalance of a certain phase is obtained based on the current of a certain phase of the power electronic transformer. When the negative sequence current imbalance is greater than a set threshold, it is determined that the phase is open circuit. The output capacitor voltage of the DAB converter in each phase branch is collected in real time. When the conversion rate of the output capacitor voltage is higher than a preset value, the single-phase power module of that phase branch is determined to be faulty.

6. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: When the processor executes the computer program, it implements the steps of the redundancy control method as described in any one of claims 3 to 5.

7. A computer-readable storage medium storing a computer program; characterized in that: When the computer program is executed by the processor, it implements the steps of the redundancy control method as described in any one of claims 3 to 5.

8. A computer program product, characterized in that: When the computer program product is executed by a processor, it implements the steps of the redundancy control method as described in any one of claims 3 to 5.

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