Fault-tolerant control signal generation method, control method, generation device and equipment

Abstract

The invention provides a fault-tolerant control signal generation method, a control method, a generation device and equipment, and solves the technical problem that an existing rectifier fault-tolerant control method is not stable enough. By arranging the protective tubes at the P position, the O position and the N position of the rectifier and cutting off the faulty switch tube by fusing the protective tubes after the switch tube breaks down, the embodiment of the invention can isolate the faulty position in time and avoid further expansion of the fault. When the fuse is detected to be fused, the implementation mode can automatically select different fault-tolerant control strategies according to the position of the fault switch tube, so that other normally working switch tubes can still run continuously. According to the mode, plate explosion or system shutdown caused by faults of individual switch tubes is effectively avoided, and stable operation of the rectifier system is ensured. Meanwhile, a control signal is generated based on a space vector pulse width modulation algorithm, the system after the fault can be accurately controlled, and the stability of the output voltage is maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of rectifiers, and in particular to a method for generating a fault-tolerant control signal, a control method, a generating device and equipment. Background Art

[0002] The T-type three-level rectifier is a power electronic device and a topology of a multi-level converter. Compared with the traditional two-level rectifier, the T-type three-level rectifier increases the midpoint potential (point O) and adds additional switching devices on each phase, so that the output voltage can provide three levels (positive voltage, midpoint voltage and negative voltage), thereby reducing voltage stress, harmonic distortion and improving power quality.

[0003] In the related art, there is a technical problem of insufficient stability in the fault-tolerant control strategy of the rectifier. Summary of the invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a method for generating a fault-tolerant control signal, a control method, a generating device and equipment to solve the technical problem that the fault-tolerant control strategy for the rectifier in the related art is not stable enough.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for generating a fault-tolerant control signal, wherein the fault-tolerant control signal is used to control the operation of a rectifier, wherein fuses are provided at three positions P, O, and N of at least one phase of the rectifier, and wherein the fuses are used to passively fuse to cut off the faulty switch tube after a switch tube at a corresponding position fails; the method comprises: After detecting that the fuse is blown, determine the location of the faulty switch tube; Based on the position of the faulty switch tube, determining a target fault-tolerant control strategy from a preset fault-tolerant control strategy set; wherein the fault-tolerant control strategies corresponding to the positions of different faulty switch tubes are at least partially different; The target fault-tolerant control strategy and a preset space vector pulse width modulation algorithm are used to generate a control signal for fault-tolerant control.

[0006] In a second aspect, the present invention provides a fault-tolerant control method for a rectifier, the method comprising: Using the above-mentioned method for generating a fault-tolerant control signal, a control signal for fault-tolerant control is generated; The control signal for fault-tolerant control is sent to a driving chip to drive the rectifier to operate in the event of a fault.

[0007] In a third aspect, the present invention provides a device for generating a fault-tolerant control signal, wherein the fault-tolerant control signal is used to control the operation of a rectifier, wherein fuses are provided at three positions P, O, and N of at least one phase of the rectifier, and wherein the fuses are used to passively fuse to cut off the faulty switch tube after a switch tube at a corresponding position fails; the device comprises: A first determination module, which is used to determine the position of the faulty switch tube after detecting that the fuse tube is blown; A second determination module is used to determine a target fault-tolerant control strategy from a preset fault-tolerant control strategy set based on the position of the faulty switch tube; wherein the fault-tolerant control strategies corresponding to the positions of different faulty switch tubes are at least partially different; A generating module is used to generate a control signal for fault-tolerant control by using the target fault-tolerant control strategy and a preset space vector pulse width modulation algorithm.

[0008] In a fourth aspect, the present invention provides an electronic device comprising: a memory, and one or more processors communicatively connected to the memory; the memory stores instructions executable by the one or more processors, and the instructions are executed by the one or more processors so that the one or more processors implement the above-mentioned method.

[0009] Beneficial effects: The present invention solves the technical problem of instability in the existing rectifier fault-tolerant control method. By setting fuses at the P, O, and N positions of the rectifier, and cutting off the faulty switch tube by fusing the fuse after the switch tube fails, this embodiment can isolate the fault location in time to prevent the fault from further expanding. When it is detected that the fuse is blown, the embodiment can automatically select different fault-tolerant control strategies according to the position of the faulty switch tube, so that the remaining normally working switches can continue to operate. This method effectively avoids the explosion of the board or system shutdown caused by the failure of individual switch tubes, and ensures the stable operation of the rectifier system. At the same time, by generating control signals based on the space vector pulse width modulation algorithm, the system after the fault can be accurately controlled to maintain the stability of the output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a topological diagram of a fault-tolerant control circuit of a T-type three-level rectifier provided by an embodiment of the present invention; Figure 2 It is a flow chart of a method for generating a fault-tolerant control signal provided by an embodiment of the present invention; Figure 3 is a schematic diagram of a buzzer circuit provided by an embodiment of the present invention; Figure 4 It is a FA1 fuse space vector diagram provided by an embodiment of the present invention; Figure 5 It is a two-level lower vector diagram of FA1 or FA3 fuse equivalent provided by an embodiment of the present invention; Figure 6 It is a FA3 fuse space vector diagram provided by an embodiment of the present invention; Figure 7 It is a FA2 fuse space vector diagram provided by an embodiment of the present invention; Figure 8 It is a FA2 fuse sector division vector diagram provided by an embodiment of the present invention; Fig. 9 is a block diagram of a device for generating a fault-tolerant control signal provided by an embodiment of the present invention; Fig.10 It is a block diagram of an electronic device used in an embodiment of the present invention. DETAILED DESCRIPTION

[0011] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0012] In the related technologies, the rapid development and popular application of power electronic devices have greatly increased the harmonic current in the power grid, and the power factor of the system has also decreased, which has had a serious adverse effect on the efficiency of electric energy utilization. For this reason, multi-level controllers have been rapidly developed. Multi-level has the advantages of increased output levels, better harmonic spectrum, and less voltage stress on the device. However, since the multi-level circuit uses a large number of switching devices, the reliability of the circuit is reduced accordingly. Any device failure may cause the entire circuit to stop working, and even affect the safety of other circuits, causing immeasurable economic losses. When the switching device of the traditional T-type three-level rectifier breaks down and shorts, if the original control is maintained, it will cause a short circuit between the live wires, and the instantaneous high current will cause the board to explode.

[0013] In some rectifier fuse control technologies, the handling of switch tube faults is usually not targeted, and the control strategy cannot be flexibly adjusted according to the location of the fault. This single control method may cause the system to be unable to continue to operate stably under different types of faults (for example, P, O, and N position faults). Especially in space vector pulse width modulation (SVPWM) control, when certain specific switch tubes fail, they cannot be effectively compensated by redundant vectors or synthesis methods, resulting in output voltage instability or output waveform distortion. This instability may further affect the overall reliability of the system, increase harmonic distortion, and even cause more serious faults. In addition, some fuse control strategies usually lack fault-tolerant control mechanisms for different fault point locations, and most of them rely on simple fault removal or shutdown, resulting in the system needing to be completely shut down under certain fault conditions. This not only reduces the system's work efficiency, but may also cause economic losses. For more complex scenarios, effective fault-tolerant operation cannot be achieved, the fault tolerance capacity is insufficient, and there is a lack of further derating operation mechanism to maintain the stable operation of the system.

[0014] Therefore, in the related art, there is a technical problem of insufficient stability in the fault-tolerant control strategy of the rectifier.

[0015] The present embodiment provides a method for generating a fault-tolerant control signal, wherein the fault-tolerant control signal is used to control the operation of a rectifier, wherein fuses are provided at the three positions P, O, and N of at least one phase of the rectifier, and wherein the fuses are used to passively fuse and cut off the faulty switch tube after a switch tube at a corresponding position fails.

[0016] In this embodiment, fuses may be provided at the three positions P, O, and N of each phase of the rectifier. The fuses are used to passively fuse and cut off the faulty switch tube after a switch tube at a corresponding position fails.

[0017] In this embodiment, the P position can be represented as the position in the rectifier circuit connected to the positive pole (point P) of the DC bus. When the upper switch tube of a phase is turned on, the voltage point of the phase will be connected to the positive pole P point of the DC bus. At this time, the voltage of the phase is equal to the voltage udc of the DC bus. The O position can be represented as the middle position in the rectifier circuit connected to the midpoint (point O) of the DC bus. When the switch tubes of a phase are turned on at the same time, the voltage point of the phase will be connected to the midpoint O of the DC bus. At this time, the voltage of the phase is half of the DC bus voltage, that is, udc / 2. The N position can be represented as the bottom position in the rectifier circuit connected to the negative pole (point N) of the DC bus. When the lower switch tube of a phase is turned on, the voltage point of the phase will be connected to the negative pole N point of the DC bus. At this time, the voltage of the phase is 0V.

[0018] In this embodiment, the three positions of P, O, and N are all provided with fuses, which can be expressed as providing a fuse before the switch tube of a certain phase, or as providing a fuse after the switch tube of a certain phase. Specifically, in some specific implementation schemes, the fuse can be provided upstream of the switch tube, for example, it can be located between the switch tube and the power supply. Its function is that when the switch tube fails (for example, the switch tube breaks down or shorts), the fuse first melts, thereby cutting off the connection between the faulty switch tube and the power supply, preventing the fault current from further expanding, and protecting other components in the rectifier. This can effectively prevent the propagation of the fault and ensure that other parts of the system can continue to work. In some specific implementation schemes, the fuse can also be provided downstream of the switch tube, between the switch tube and the load. When the switch tube fails, the fuse melts after the switch tube, cutting off the connection between the faulty switch tube and the load. This method can effectively prevent the fault current from flowing into the load and prevent damage to the load. At the same time, the fault-tolerant strategy can be used to maintain the derating operation of the system to ensure that the rectifier can still work partially normally in a fault state.

[0019] In a specific embodiment, Figure 1 As shown, the embodiment provides a T-type three-level rectifier fault-tolerant control circuit topology. The circuit is composed of an AC input module, a filter inductor, a rectifier bridge circuit, a DC bus capacitor, and a load, and fuses are set at different positions of each phase to achieve a protection function when a switch tube fails.

[0020] Specifically, in the AC input module, ua, ub, and uc represent the three-phase AC input voltage, which is connected to the rectifier bridge through inductors La, Lb, Lc and resistors Ra, Rb, and Rc. The combination of inductance and resistance plays a filtering role, eliminating high-frequency interference on the AC side and smoothing the input current. In the rectifier bridge circuit, the core part of the rectifier bridge is composed of IGBT switching tubes and diodes, which are used to rectify three-phase AC power into DC power. The rectifier bridge is divided into three phases. Phase A includes switching tubes SA1, SA2, SA3, and SA4, and diodes are connected in parallel to these switching tubes. Phase B includes switching tubes SB1, SB2, SB3, and SB4, and there are corresponding diodes. Phase C includes switching tubes SC1, SC2, SC3, and SC4, and there are also diodes.

[0021] The switch tube of each phase controls the connection between the phase and the DC bus. Specifically, SA1, SB1, and SC1 are connected to the positive pole (point P) of the DC bus. SA4, SB4, and SC4 are connected to the negative pole (point N) of the DC bus. SA2, SB2, and SC2, SA3, SB3, and SC3: are used to connect to the midpoint (point O) of the DC bus. When these two switch tubes are turned on at the same time, the voltage points of phases A, B, and C are connected to point O.

[0022] In order to protect the circuit when the switch fails, the fuse is installed in the P, O, and N positions, corresponding to the different positions of each phase: The fuses in the P position are: FA1 for phase A, FB1 for phase B, and FC1 for phase C.

[0023] The fuses in the O position are: FA2 for phase A, FB2 for phase B, and FC2 for phase C.

[0024] The N position fuses are: FA3 for phase A, FB3 for phase B, and FC3 for phase C.

[0025] When the switch tube fails (such as short circuit or breakdown), the fuse will passively blow, cutting off the fault current of that phase, protecting the rectifier from further damage, while maintaining the normal operation of other phases.

[0026] On the DC side, C1 and C2 are upper and lower capacitors, which store energy respectively and smooth the DC voltage output by rectification. The bus voltage udc is equal to the sum of the voltages on the two capacitors, where uc1=uc2=udc / 2, that is, the two capacitors divide the total bus voltage equally. The load is connected to the DC bus, and the voltage is the total bus voltage udc.

[0027] In normal operation, three-phase AC is converted into DC through a rectifier bridge and output to the load. When an IGBT switch of a phase fails, the corresponding fuse (such as the fuse at the P, O or N position) will fuse, cutting off the fault point of the phase and preventing the fault current from expanding.

[0028] like Figure 2 As shown, the method for generating a fault-tolerant control signal may be executed by a controller, and the method may include: Step S102: After detecting that the fuse is blown, determine the position of the faulty switch tube.

[0029] In this embodiment, the controller can detect whether the fuse is blown through a preset voltage detection circuit. For example, a voltage detection circuit can be set at both ends of the fuse, and the controller (for example, DSP) collects the voltage at both ends of the fuse in real time. If the fuse is blown, the voltage at both ends will change significantly (for example, the voltage is zero or drops significantly), so it can be determined whether the fuse is blown through voltage detection.

[0030] In this embodiment, the controller can determine the position of the faulty switch tube based on the identification information of the fuse tube that has blown. It can be understood that fuse tubes at different positions can correspond to different identification information to identify the position of the faulty switch tube.

[0031] In this embodiment, each fuse or switch position can also transmit a signal to the controller through an independent detection module to inform the controller which fuse is blown. The controller can directly determine the specific position of the faulty switch by receiving the blown signals from different positions.

[0032] In some embodiments, after detecting that the fuse is blown, the controller needs to identify which switch tube (i.e., P, O, N position) has failed. Specifically, when the fuse is blown, the preset sensor will detect the change in voltage or current at the corresponding position. The controller can determine which switch tube at which specific position (P, O, N) has failed by comparing the sensor data.

[0033] Step S104: Based on the position of the faulty switch tube, determine a target fault-tolerant control strategy from a preset fault-tolerant control strategy set; wherein the fault-tolerant control strategies corresponding to the positions of different faulty switch tubes are at least partially different.

[0034] In this embodiment, the position of the switch tube may include a switch tube at position P. Specifically, Figure 1 As shown, the switch tube at position P can be a switch tube connected to the positive pole (point P) of the DC bus, for example, SA1, SB1, SC1.

[0035] In this embodiment, the position of the switch tube may include a switch tube at position O. Specifically, Figure 1 As shown, the switch tube at position O can be a switch tube connected to the midpoint (point O) of the DC bus, for example, SA2, SA3, SB2, SB3, SC2, SC3.

[0036] In this implementation, the position of the switch tube may include a switch tube at position N. Specifically, Figure 1 As shown, the switch tube at the N position may be a switch tube connected to the negative pole of the DC bus (point N), for example, SA4, SB4, or SC4.

[0037] In this implementation, the preset fault-tolerant control strategy set may include a fault-tolerant control strategy for a P position, a fault-tolerant control strategy for an O position, and a fault-tolerant control strategy for an N position.

[0038] Specifically, when the switch tube is located at the P position (for example, SA1) and fails, the fault-tolerant control strategy of the P position can be triggered. It can be understood that in this case, the fault-tolerant control strategy of the P position is also the target fault-tolerant control strategy. The fault-tolerant control strategy of the P position can be: discard all vectors related to the P point (i.e., large vectors). A 7-segment SVPWM control strategy is adopted, which uses small vectors of the inner hexagon to synthesize the output voltage, maintain the stability of the system operation, reduce harmonic distortion, and ensure that the system does not completely shut down.

[0039] When the switch tube is located at the O position (for example, SA2 or SA3) and fails, the fault-tolerant control strategy of the O position can be triggered. It can be understood that in this case, the fault-tolerant control strategy of the O position is also the target fault-tolerant control strategy. The fault-tolerant control strategy of the O position can be: using adjacent small vectors for synthesis to ensure that the system can still synthesize the required output through adjacent voltage vectors when the middle vector is lost. The fault-tolerant control strategy of the O position can also be: using a 5-segment SVPWM control strategy, which is a modulation strategy suitable for O position faults, by reducing the number of switches, reducing losses, and maintaining the stability of the voltage output.

[0040] When the switch tube is located at position N (for example, SA4) and a fault occurs, the fault-tolerant control strategy of position N can be triggered. It can be understood that in this case, the fault-tolerant control strategy of the N position is also the target fault-tolerant control strategy. The fault-tolerant control strategy of the N position can be to abandon the low-voltage vector related to point N. The fault-tolerant control strategy of the N position can also be to use adjacent small vectors and medium vectors for synthesis to ensure the voltage output in the low-voltage range. The fault-tolerant control strategy of the N position can also adopt a 7-segment SVPWM control strategy, which ensures that the system can continue to operate after a fault and reduce the harmonic content through small vector synthesis.

[0041] In some implementations, the preset fault-tolerant control strategy set may also include: The three-stage fault-tolerant control strategy is specifically used when a serious fault occurs in the system, multiple switch tubes fail, and the system needs to continue to work at the lowest operating state. This strategy uses only the most basic vector combination to maintain minimal voltage fluctuations. This strategy can minimize the switching frequency and is suitable for the "emergency operation mode" in response to serious faults to ensure that the system can maintain the most basic power transmission and avoid complete shutdown.

[0042] In some embodiments, the preset fault-tolerant control strategy set may further include: a fault-tolerant derating control strategy. The fault-tolerant derating control strategy may reduce the bus voltage to a target value. The bus voltage of the target value may trigger an alarm circuit connected to the bus to perform an alarm. The target value may be eight-tenths of the bus voltage under normal circumstances. It may also be seven-tenths of the bus voltage under normal circumstances, and so on. The alarm circuit may be a buzzer circuit or other circuits capable of performing an alarm function. For example, the alarm circuit may also be an indicator light alarm circuit, a display screen alarm prompt circuit, or an audible and visual alarm circuit, and so on.

[0043] In a specific implementation scheme, when the fuse FA1 or FA2 is blown, the fault tolerance derating control strategy can also be started. Figure 3The circuit shown starts the buzzer for early warning, reminding the staff to repair the rectifier when a system failure occurs.

[0044] like Figure 3 As shown, the bus voltage sampling is added, and the voltage of the voltage divider resistor R2 is input to the positive input terminal of the comparator through the voltage divider R1 and R2. The R3 and R4 resistors set the reference voltage value to the negative input terminal of the comparator. When operating normally, the udc is high, and the comparator outputs a high level. R5 is a current limiting resistor, and S1 is an NPN transistor. When the input voltage is positive, the transistor is not turned on, and the buzzer is in a silent state. When a fuse is blown and derating control is performed, the bus voltage is reduced to the target value. At this time, the positive input terminal of the comparator is less than the negative input terminal. At this time, the comparator outputs a low voltage, the transistor is turned on, and the buzzer emits a buzzing sound.

[0045] Step S106: using the target fault-tolerant control strategy and a preset space vector pulse width modulation algorithm to generate a control signal for fault-tolerant control.

[0046] In this embodiment, after the target fault-tolerant control strategy is determined, the target fault-tolerant control strategy can be loaded to prepare for voltage vector calculation and pulse width modulation. The controller can calculate the target voltage vector that needs to be output currently according to the collected system state (for example, voltage, load requirements, etc.). This vector is a reference vector for generating a stable output voltage. The controller decomposes the target voltage vector into the basic voltage vector in space vector pulse width modulation (SVPWM). According to the fault location, the controller selects the available basic vectors (for example, small vectors, medium vectors), and determines which vectors to use for output according to the target fault-tolerant control strategy. For example, if the P position fails, the large vector related to P is discarded, and only the small vector or the medium vector is used for synthesis. The controller can calculate the conduction time of each basic vector according to the selected basic vector, combined with the size and angle of the target voltage vector. The controller generates a corresponding PWM signal according to the calculated basic vector conduction time, specifically including the on-off time of each switch tube. The controller generates a switch pulse signal for the switch of each switch tube to realize space vector modulation.

[0047] This implementation solves the technical problem of unstable operation in the existing rectifier fault-tolerant control method. By setting fuses at the P, O, and N positions of the rectifier, and cutting off the faulty switch tube by fusing the fuse after the switch tube fails, this implementation can isolate the fault location in time to prevent the fault from further expanding. When the fuse is detected to be blown, the implementation can automatically select different fault-tolerant control strategies according to the position of the faulty switch tube, so that the remaining normally working switches can continue to operate. This method effectively avoids the explosion of the board or system shutdown caused by the failure of individual switch tubes, and ensures the stable operation of the rectifier system. At the same time, by generating a control signal based on the space vector pulse width modulation algorithm, the system after the fault can be accurately controlled to maintain the stability of the output voltage.

[0048] In some cases, the rectifier control strategy in the related art has obvious deficiencies, especially in terms of flexibility and stability in dealing with faults. For example, in some technical solutions, a control strategy after a small vector fault is provided, but the processing of the medium vector and the large vector under fault conditions is not involved. This single fault handling method makes it impossible for the system to effectively achieve fault tolerance and stable operation when facing multiple fault modes. Specifically, when a small vector fails, some methods are to abandon the faulty small vector and replace it with a redundant small vector to achieve fault tolerance. However, this processing method is powerless when facing a medium vector or a large vector fault because there is a lack of corresponding strategies to handle these more complex fault conditions. As a result, the system may experience a higher harmonic content, resulting in a decrease in power quality and potential damage to the equipment. In addition, the operation relying on the medium vector and the large vector may cause the output voltage to be unstable under fault conditions, further affecting the overall performance and reliability of the system. Therefore, the limitation in the related art is the lack of flexible control strategies for different fault point locations, which cannot ensure that the rectifier can continue to operate stably after a fault occurs.

[0049] In view of the above technical problem, in some implementations, the step of determining a target fault-tolerant control strategy from a preset fault-tolerant control strategy set based on the position of the faulty switch tube includes: Step S1042: When the position of the faulty switch tube is the P position or the N position, the first fault-tolerant control strategy is determined as the target fault-tolerant control strategy; wherein the first fault-tolerant control strategy includes: using the small vectors of the inner hexagon in the space voltage vector diagram in the space vector pulse width modulation algorithm, and discarding the medium vectors and large vectors outside the inner hexagon to synthesize the output voltage vector, so that the output voltage vector of the rectifier can remain stable when the rectifier fails.

[0050] In a specific implementation scheme, when the P position of phase A fails, for example, phase A SA1 breaks down and short-circuits, blowing fuse FA1, phase A cannot output P state (switch tube SA1 is turned on, point A is connected to point P of the DC bus, and the voltage at point A is the bus voltage udc, and phase A is in P state; similarly, when SA4 is turned on, point A is connected to point N of the DC bus, and the voltage at point A is 0V, and phase A is in N state; when SA2 and SA3 are turned on at the same time, point A is connected to the midpoint O, and the voltage at point A is udc / 2, and phase A is in O state.) O and N states are output normally, and phases B and C can output P, ​​O, and N3 states normally. When the SVPWM algorithm is used for control, the P vector of phase A is missing due to the blowing of FA1, and the spatial vector distribution changes as shown in the following figure. Figure 4 As shown. The missing vectors include: large vectors PPN, PNN, PNP, medium vectors PON, PNO, small vectors PPO, POO, POP and zero vector PPP. According to the principle of space vector synthesis, all missing vectors can be synthesized by vectors OON, ONN, ONO and OOO. Phase A SA1 breaks down and short circuits, fuse FA1 is blown, analysis Figure 4 , the vector on the right is missing. According to the principle of symmetry, the rectifier circular rotating reference voltage vector Vref rotates within the circle in the figure, and the modulation ratio At this time, the system does not need to reduce the output.

[0051] like Figure 5 As shown, the hexagon is the equivalent two-level vector diagram of FA1 fuse. In order to minimize the switching loss, when the reference vector falls on the left side of the axis, the negative small vectors NON, NOO, and NNO are selected to complete the vector synthesis. In this case, the first fault-tolerant control strategy can include the FA1 fuse fault-tolerant control switch sequence as shown in the following table. When the voltage vector action sequence is determined, the vector action time, pulse distribution, etc. are the same as the two-level.

[0052] Table 1. FA1 Fuse Fault Tolerant Control Switch Sequence It can be understood that the space vector modulation diagram is divided into multiple sectors, and in each sector, the reference voltage vector will pass through different space vector points in a certain order. The table lists 6 sectors (I, II, III, IV, V, VI), corresponding to 6 different areas in the space vector diagram. In each sector, the controller realizes voltage output by switching different switch states in sequence. Specifically, in the first sector, the switch switching sequence is: NNN→ONN→OON→OOO→OON→ONN→NNN. This means that in the first sector, the rectifier is first in the "NNN" state, that is, all three phases are connected to the negative bus. Then it switches to the "ONN" state, indicating that phase A is connected to the midpoint, and phases B and C are still connected to the negative bus. Next, it switches to the "OON" state and then to the "OOO" state (all three phases are connected to the midpoint). After that, the rectifier switches in reverse and returns to the original state "NNN". The same understanding is made for the remaining sectors, which will not be repeated here.

[0053] In a specific implementation, when a fault occurs at the N position of phase A, for example, when SA4 of phase A breaks down and shorts, fuse FA3 is blown. At this time, phase A cannot output the N state, and the P and O states are output normally. Phases B and C can output the three states of P, O, and N normally. When the SVPWM algorithm is used for control, all vectors with N in phase A are missing due to the blown FA3, and the space vector distribution changes as follows: Figure 6 As shown. The missing vectors include: large vectors NPN, NPP, NNP, medium vectors NPO, NOP, small vectors NON, NOO, NNO, and zero vector NNN. All lost vectors can be synthesized by other vectors according to the principle of space vector synthesis.

[0054] like Figure 5 As shown, the hexagon is the FA3 fuse equivalent two-level lower vector diagram. Therefore, in this case, the first fault-tolerant control strategy may include the FA3 fuse fault-tolerant control switch sequence as shown in the following table.

[0055] Table 2, FA3 Fuse Fault Tolerant Control Switch Sequence In the above-mentioned embodiment, when the faulty switch tube is located at the P position or the N position, the output voltage vector is synthesized by using only the inner hexagonal small vector in the space vector pulse width modulation (SVPWM) algorithm, which can effectively reduce the fundamental content and total harmonic distortion. Specifically, the use of the inner hexagonal small vector enables the rectifier to avoid switching between the medium vector and the large vector when outputting voltage, thereby achieving a smoother voltage waveform. The core of this method is that the small vector in the inner hexagon can operate at a lower voltage amplitude, reducing the harmonic component under fault conditions, making the fundamental component relatively high, and thus significantly reducing the fundamental content. The reduction in fundamental content directly affects the total harmonic distortion of the rectifier output. The reduction in total harmonic distortion means that the rectifier has less harmonic pollution to the power grid, which helps to improve the quality of power. This is for extending the service life of electrical equipment, reducing the load on the power grid, and improving the overall stability of the system. In addition, through this control strategy, the rectifier can still maintain a stable voltage output when a fault occurs, avoiding voltage fluctuations and system instability caused by switch tube failure. All of this ensures that the rectifier can continue to operate safely and efficiently under relatively severe fault conditions.

[0056] In some cases, when the faulty switch tube is in the O position, especially when it comes to medium vectors and large vectors, the control methods in the related art often cannot effectively replace the voltage vector. This means that when the system cannot output the expected medium vector, the existing strategy does not have clear countermeasures, which may cause the voltage output of the entire system to be unstable and affect the normal operation of the rectifier. Specifically, the related art only focuses on the processing of small vector faults and lacks effective control solutions for medium vector and large vector faults. When the medium vector cannot be output, the system may completely lose its output capacity, causing a sudden drop in the output voltage, which will affect subsequent loads. When faced with large vector faults, the related technology also fails to provide a suitable alternative solution, and cannot use adjacent medium vectors or small vectors for synthesis, further increasing the instability and harmonic content of the system.

[0057] This lack of flexibility and adaptability in the control method may lead to severe power quality degradation in various fault conditions, increasing the risk of equipment damage. Therefore, a new and flexible control strategy is needed for fault handling at the O position to ensure that the rectifier can still operate stably and maintain good power quality under fault conditions.

[0058] In view of the above technical problem, in some implementations, the step of determining the target fault-tolerant control strategy from the preset fault-tolerant control strategy set further includes: Step S1044: When the position of the faulty switch tube is at position 0, the second fault-tolerant control strategy is determined as the target fault-tolerant control strategy; wherein the second fault-tolerant control strategy includes: when the voltage vector that cannot be output is a medium vector, the medium vector is synthesized using a small vector adjacent to the medium vector in the space voltage vector diagram; when the voltage vector that cannot be output is a large vector, the medium vector or small vector adjacent to the large vector in the space voltage vector diagram is synthesized, so that the output voltage vector of the rectifier can remain stable when the rectifier fails.

[0059] In a specific implementation, when a fault occurs at the O position of phase A, for example, when SA2 or SA3 of phase A breaks down and shorts, fuse FA2 blows. At this time, phase A cannot output the O state, and the P and N states are output normally. Both phases B and C can output the P, O, and N states normally. When the SVPWM algorithm is used for control, all vectors with O in phase A are missing due to the blowing of FA2, and the spatial vector distribution changes as shown in the following figure: Figure 7 As shown in Figure 1. The missing vectors include: middle vectors OPN, ONP, small vectors OPO, OPP, OOP, OON, ONN, ONO, and zero vector OOO. The lost zero vector and small vector can be replaced by their own redundant vectors, while the lost middle vector can be synthesized using two small vectors according to the principle of space vector synthesis.

[0060] The fuse FA2 of phase A is blown, and the small vector and zero vector can be replaced by redundant vectors. According to the principle of vector synthesis, the middle vector can be synthesized by adjacent small vectors, and the large vector is synthesized by adjacent middle vectors and small vectors. The state space voltage vector is divided into large sectors I to VI, and each large sector contains 1 to 6 small sectors. The specific division is as follows: Figure 8 Therefore, the second fault-tolerant control strategy may include: the FA2 fuse fault-tolerant control switch sequence as shown in the following table.

[0061] Table 3, FA2 Fuse Fault Tolerant Control Switch Sequence In this embodiment, when the faulty switch tube is located at the O position, by determining the second fault-tolerant control strategy, it is possible to effectively deal with the situation where the medium vector and the large vector cannot be directly output. The beneficial effect of this embodiment is that for the medium vector that cannot be output, the adjacent small vectors are used for synthesis to ensure the continuity and stability of the output voltage. At the same time, when the large vector cannot be output, a flexible alternative is provided by synthesizing the adjacent medium vector or small vector. This flexible control strategy solves the problem of imperfect O-position fault handling in the prior art, and avoids system instability and increase in harmonics caused by the inability to output the voltage vector. Through reasonable vector synthesis, the rectifier can continue to operate stably and maintain the quality of electric energy in the event of a fault, thereby effectively protecting the electrical equipment and extending its service life. At the same time, the method also enhances the reliability of the system and ensures that effective countermeasures can be taken in a variety of fault situations.

[0062] In some embodiments, the second fault-tolerant control strategy further includes: when the voltage vector that cannot be output is a large vector, and when the adjacent vectors of the large vector are a medium vector and a small vector, a medium vector and a small vector are used to synthesize the large vector, and when the adjacent vector of the large vector is a medium vector, two medium vectors are used to synthesize the large vector.

[0063] In this embodiment, the second fault-tolerant control strategy can significantly improve the voltage output stability of the rectifier under fault conditions. When the voltage vector that cannot be output is a large vector, the implementation strategy flexibly selects the synthesis method for the adjacent vectors: if the adjacent vectors include a medium vector and a small vector, a medium vector and a small vector are used for synthesis; if the adjacent vectors are all medium vectors, two medium vectors are used for synthesis. This flexible synthesis strategy effectively ensures that the system can still generate effective voltage output when the large vector fails, avoiding system instability caused by voltage loss. In addition, by rationally utilizing adjacent medium vectors and small vectors, the switching frequency of the switch tube is reduced, thereby reducing switching losses and improving the operating efficiency and power quality of the system. Overall, this implementation provides higher reliability and adaptability in fault handling, ensuring the normal operation of the rectifier under various fault conditions.

[0064] In some cases, the related art fails to effectively consider the combination of adjacent vectors to deal with situations where large vectors cannot be output. When a large vector fails, the controller may rely on a non-optimized vector synthesis strategy, resulting in frequent switching of the switch tube, increasing energy loss and system instability. Specifically, the related art lacks flexibility in the selection of adjacent vectors and fails to make effective comparisons based on the switching states of the switch tubes, often resulting in the need to change the states of multiple switch tubes in the event of a fault. This approach not only increases the frequency of switching, but may also cause greater harmonic content, reduce power quality, and thus affect the operating efficiency and reliability of the entire system. When faced with multiple adjacent vector combinations, there is no priority selection of the solution with the least number of switches, thereby failing to fully utilize the available redundant vector resources.

[0065] In some embodiments, the second fault-tolerant control strategy also includes: when the voltage vector that cannot be output is a large vector, based on the preferential selection rule of adjacent vectors, preferentially selecting an adjacent medium vector or a small vector synthesis that can minimize the number of switching times of the switch tube; wherein the preferential selection rule of adjacent vectors is expressed as comparing the switching states of the switch tubes corresponding to the adjacent vector combinations, and selecting the vector combination that only needs to change the states of the least number of switch tubes to reduce the frequency and loss of switching.

[0066] In this embodiment, the second fault-tolerant control strategy can effectively optimize the voltage output in the case of a large vector fault by using a preferential selection rule based on adjacent vectors. When the output voltage vector cannot be a large vector, the adjacent medium vector or small vector that can minimize the number of switch tube switching times is preferentially selected for synthesis. Specifically, when there are multiple adjacent vector combinations, the strategy compares the switch tube switching states corresponding to different combinations and selects a solution that only requires changing the states of the least number of switch tubes, thereby reducing the frequency and loss of switch switching. This optimization method not only ensures the effectiveness of achieving the target voltage output in the event of a fault, but also significantly reduces the energy loss of the switch tube, improves the operating efficiency of the rectifier and the overall system performance, and further enhances the reliability and stability of the system in a fault state.

[0067] In some cases, the rectifier modulation control strategy in the related art has certain limitations when dealing with switch tube faults at different positions. Specifically, a fixed modulation method is adopted, and it is not possible to flexibly adjust for different fault locations. For example, some methods use the same SVPWM modulation strategy in all fault conditions, and fail to distinguish the fault differences between the P position, N position and O position. This single modulation method often causes the system to generate a higher harmonic content after the fault, which in turn affects the power quality and the stability of the system operation. In particular, when the switch tube at the P position or N position fails, the fixed modulation method may not be able to fully optimize the output voltage of the system, resulting in an increase in harmonics and a decrease in system operating efficiency. In the case of an O position fault, due to the difference in system voltage characteristics, the failure to adopt a more appropriate modulation strategy may further increase the operating risk of the system, resulting in voltage instability and increased equipment losses.

[0068] Therefore, the related technology lacks a flexible fault modulation control strategy and cannot adopt optimized control methods for different fault locations (such as P, N, and O positions). This deficiency makes it impossible for the system to achieve the best operating effect under different fault conditions, and the harmonic content is high, which limits the reliability and efficiency of the rectifier.

[0069] In some embodiments, in the fault-tolerant control strategy set, when the position of the faulty switch tube is the P position or the N position, the corresponding target fault-tolerant control strategy is the 7-segment SVPWM fault-tolerant control strategy; when the position of the faulty switch tube is the O position, the corresponding target fault-tolerant control strategy is the 5-segment SVPWM fault-tolerant control strategy.

[0070] In this implementation, by adopting a 7-segment SVPWM fault-tolerant control strategy or a 5-segment SVPWM fault-tolerant control strategy for the position of the faulty switch tube in the fault-tolerant control strategy set, the modulation control capability of the rectifier under a fault state can be effectively improved. Specifically, when the faulty switch tube is located at the P position or the N position, the implementation of the 7-segment control strategy enables the system to maintain the stability of the voltage output at a lower harmonic content, thereby optimizing the power quality. In the event of a fault at the O position, the adoption of a 5-segment control strategy also ensures good output characteristics. Compared with a single SVPWM modulation method, this modulation control strategy combining 5-segment and 7-segment significantly reduces the harmonic content and improves the efficiency and stability of the system operation. Through this flexible control strategy, the rectifier can respond quickly under a variety of fault conditions to ensure the continuity and safety of the voltage output.

[0071] In some embodiments, the preset fault-tolerant control strategy set may further include: a fault-tolerant derating control strategy. The fault-tolerant derating control strategy may reduce the bus voltage to a target value. The bus voltage of the target value may trigger an alarm circuit connected to the bus to perform an alarm.

[0072] Specifically, when a switch fails, the controller can determine whether the fault has a significant impact on the bus voltage. Generally, if the fault is serious and may cause greater damage to the system, the controller can determine the fault-tolerant derating control strategy as the target fault-tolerant control strategy.

[0073] Based on this fault-tolerant derating control strategy, the controller will reduce the output voltage by adjusting the duty cycle in the space vector pulse width modulation algorithm under the premise of fault tolerance. For example, the on-time of the switch tube is controlled so that the synthesized output voltage corresponds to the target value after derating. Specifically, the controller will control the PWM signal of each switch tube to reduce the on-time, thereby reducing the output voltage amplitude. In this process, derating control is gradually achieved by adjusting the switching frequency of each switch tube.

[0074] The alarm circuit may include a voltage sampling circuit. The voltage sampling circuit monitors the changes in the bus voltage in real time. When the bus voltage drops to the target value (for example, 80% or 70%), the voltage sampling circuit inputs the divided signal to the positive input terminal of the comparator. The negative input terminal of the comparator sets the reference voltage through a resistor. During normal operation, the bus voltage is high, the positive input voltage is greater than the reference voltage, and the comparator outputs a high level. During derating operation, the bus voltage drops to the target value, the positive input voltage is lower than the reference voltage, and the comparator outputs a low level. When the comparator outputs a low level, the transistor is triggered to turn on, and the buzzer or other alarm modules are controlled to start, reminding the maintenance personnel that the system has entered a derating operation state.

[0075] In the above implementation, the fault-tolerant derating control strategy can not only reduce the bus voltage and reduce the system load when a fault occurs, but also trigger the alarm circuit connected to the bus by reducing the bus voltage to a preset target value. In this way, while the system is operating at a derating rate, it can promptly remind maintenance personnel of the existence of the fault through an alarm mechanism (such as a buzzer or indicator light), effectively preventing further damage caused by long-term fault operation, and ensuring the safety of the system and the timeliness of maintenance.

[0076] According to an embodiment of the present invention, a fault-tolerant control method for a rectifier is provided, the method comprising: Using the above-mentioned method for generating a fault-tolerant control signal, a control signal for fault-tolerant control is generated; The control signal for fault-tolerant control is sent to a driving chip to drive the rectifier to operate in the event of a fault.

[0077] According to an embodiment of the present invention, a device for generating a fault-tolerant control signal is provided. Fig. 9The fault-tolerant control signal is used to control the operation of the rectifier, and the three positions P, O, and N of at least one phase of the rectifier are all provided with fuses, and the fuses are used to passively fuse to cut off the faulty switch tube after the switch tube at the corresponding position fails; the device includes: A first determination module, which is used to determine the position of the faulty switch tube after detecting that the fuse tube is blown; A second determination module is used to determine a target fault-tolerant control strategy from a preset fault-tolerant control strategy set based on the position of the faulty switch tube; wherein the fault-tolerant control strategies corresponding to the positions of different faulty switch tubes are at least partially different; A generating module is used to generate a control signal for fault-tolerant control by using the target fault-tolerant control strategy and a preset space vector pulse width modulation algorithm.

[0078] According to an embodiment of the present invention, an electronic device is provided. Fig.10 The electronic device in this embodiment may include one or more of the following components: a processor, a network interface, a memory, a non-volatile memory, and one or more applications, wherein the one or more applications may be stored in the non-volatile memory and configured to be executed by one or more processors, and the one or more programs are configured to execute the method described in the aforementioned method embodiment.

[0079] According to an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a computer, the computer executes the method described in any of the above embodiments.

[0080] According to an embodiment of the present invention, a computer program product including instructions is also provided. When the instructions are executed by a computer, the computer executes a method in any one of the above embodiments.

[0081] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0082] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0083] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0084] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0085] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for generating a fault-tolerant control signal, characterized in that: The fault-tolerant control signal is used to control the operation of the rectifier, and fuses are provided at the three positions P, O, and N of at least one phase of the rectifier. The fuses are used to passively fuse to cut off the faulty switch tube after the switch tube at the corresponding position fails; the method comprises: After detecting that the fuse is blown, determine the location of the faulty switch tube; Based on the position of the faulty switch tube, determining a target fault-tolerant control strategy from a preset fault-tolerant control strategy set; wherein the fault-tolerant control strategies corresponding to the positions of different faulty switch tubes are at least partially different; The target fault-tolerant control strategy and a preset space vector pulse width modulation algorithm are used to generate a control signal for fault-tolerant control.

2. The method according to claim 1, characterized in that The step of determining a target fault-tolerant control strategy from a preset fault-tolerant control strategy set based on the position of the faulty switch tube comprises: When the position of the faulty switch tube is the P position or the N position, the first fault-tolerant control strategy is determined as the target fault-tolerant control strategy; wherein the first fault-tolerant control strategy includes: using the small vectors of the inner hexagon in the space voltage vector diagram in the space vector pulse width modulation algorithm, and discarding the medium vectors and large vectors outside the inner hexagon to synthesize the output voltage vector, so that the output voltage vector of the rectifier can remain stable when the rectifier fails.

3. The method according to claim 2, characterized in that The step of determining the target fault-tolerant control strategy from a preset fault-tolerant control strategy set based on the position of the faulty switch tube further includes: When the position of the faulty switch tube is at position O, the second fault-tolerant control strategy is determined as the target fault-tolerant control strategy; wherein, the second fault-tolerant control strategy includes: when the voltage vector that cannot be output is a medium vector, the medium vector is synthesized using a small vector adjacent to the medium vector in the space voltage vector diagram; when the voltage vector that cannot be output is a large vector, the medium vector or small vector adjacent to the large vector in the space voltage vector diagram is synthesized, so that the output voltage vector of the rectifier can remain stable when the rectifier fails.

4. The method according to claim 3, characterized in that The second fault-tolerant control strategy also includes: when the voltage vector that cannot be output is a large vector, and when the adjacent vectors of the large vector are a medium vector and a small vector, a medium vector and a small vector are used to synthesize the large vector, and when the adjacent vector of the large vector is a medium vector, two medium vectors are used to synthesize the large vector.

5. The method according to claim 3, characterized in that: The second fault-tolerant control strategy also includes: when the voltage vector that cannot be output is a large vector, based on the preferential selection rule of adjacent vectors, preferentially selecting an adjacent medium vector or a small vector synthesis that can minimize the number of switching times of the switch tube; wherein the preferential selection rule of the adjacent vectors is expressed as comparing the switching states of the switch tubes corresponding to the adjacent vector combinations, and selecting the vector combination that only needs to change the states of the least number of switch tubes, so as to reduce the frequency and loss of the switching.

6. The method according to claim 1, characterized in that In the fault-tolerant control strategy set, when the position of the faulty switch tube is the P position or the N position, the corresponding target fault-tolerant control strategy is the 7-segment SVPWM fault-tolerant control strategy; when the position of the faulty switch tube is the O position, the corresponding target fault-tolerant control strategy is the 5-segment SVPWM fault-tolerant control strategy.

7. The method according to claim 1, characterized in that The fault-tolerant control strategy set includes: a fault-tolerant derating control strategy, which is used to reduce the bus voltage to a target value; wherein the bus voltage of the target value can trigger an alarm circuit connected to the bus to execute an alarm.

8. A fault-tolerant control method for a rectifier, characterized in that: The method comprises: Using the method for generating a fault-tolerant control signal as described in any one of claims 1 to 7 to generate a control signal for fault-tolerant control; The control signal for fault-tolerant control is sent to a driving chip to drive the rectifier to operate in the event of a fault.

9. A device for generating a fault-tolerant control signal, characterized in that: The fault-tolerant control signal is used to control the operation of the rectifier, and fuses are provided at the three positions P, O, and N of at least one phase of the rectifier. The fuses are used to passively fuse to cut off the faulty switch tube after the switch tube at the corresponding position fails; the device includes: A first determination module, which is used to determine the position of the faulty switch tube after detecting that the fuse tube is blown; A second determination module is used to determine a target fault-tolerant control strategy from a preset fault-tolerant control strategy set based on the position of the faulty switch tube; wherein the fault-tolerant control strategies corresponding to the positions of different faulty switch tubes are at least partially different; A generating module is used to generate a control signal for fault-tolerant control by using the target fault-tolerant control strategy and a preset space vector pulse width modulation algorithm.

10. An electronic device, characterized in that: include: a memory, and one or more processors communicatively coupled to the memory; Instructions executable by the one or more processors are stored in the memory. The instructions are executed by the one or more processors to enable the one or more processors to implement the method according to any one of claims 1 to 8.

Images