Fault-tolerant control method, system, device and medium based on asymmetric balance regulation

Abstract

The application discloses a fault-tolerant control method, system, device and medium based on asymmetric balance adjustment, and relates to the technical field of energy storage system control. The method comprises the following steps: acquiring state information representing the states of all energy storage units in an energy storage system; in the case that the state information represents that at least one energy storage unit has failed, shutting down all energy storage units; acquiring the number of normal units in each phase circuit; comparing the number of normal units in each phase to obtain a comparison result; and in the case that the comparison result represents that the number of normal units in any two phases is not equal, performing asymmetric balance adjustment. Through asymmetric balance adjustment, fault-tolerant adjustment can be performed in the case that the energy storage units in different phases are different, the fault-tolerant capability of the energy storage system is improved, the system has high reliability, the shutdown rate is reduced, the system utilization rate is high, and the system can be widely applied to the technical field of energy storage system control.

Description

Technical Field

[0001] This invention relates to the field of energy storage system control technology, and in particular to a fault-tolerant control method, system, device and medium based on asymmetric balance regulation. Background Technology

[0002] In current high-voltage energy storage systems, high-voltage energy storage technology is typically used to achieve high voltage and large capacity, requiring the cascading of corresponding power units and battery modules. However, as the number of cascaded units increases, the number of power switching devices also increases, and each unit has a potential failure point, increasing the probability of system failure and affecting the stable operation of the system.

[0003] Therefore, it is of great significance to ensure the effective output of the energy storage system by adopting fault-tolerant control while ensuring that the system does not shut down. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a fault-tolerant control method, system, device and medium based on asymmetric balance regulation, which can reduce downtime caused by energy storage system failures and improve the reliability of energy storage systems.

[0005] In a first aspect, embodiments of the present invention provide a fault-tolerant control method based on asymmetric balance adjustment, comprising the following steps:

[0006] Obtain the status information representing the state of all energy storage units in the energy storage system;

[0007] If the status information indicates that at least one of the energy storage units has failed, all of the energy storage units shall be shut down.

[0008] Obtain the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not experienced a fault;

[0009] The comparison results are obtained by comparing the number of normal units in each phase;

[0010] When the comparison results indicate that the number of normal units in any two phases is not equal, asymmetric balance adjustment is performed.

[0011] Optionally, the asymmetric balance adjustment includes:

[0012] The fundamental phase angle is calculated based on the number of normal units in each phase and a preset first calculation rule, wherein the fundamental phase angle represents the fundamental phase angle between every two phase voltages;

[0013] Obtain the operating voltage of each phase, where the operating voltage represents the phase voltage during normal operation;

[0014] Obtain the DC voltage of a normal unit, wherein the normal unit represents the energy storage unit that has not experienced a fault;

[0015] The adjustment coefficient of the normal unit is determined based on the operating voltage, the fundamental phase angle, the DC voltage, and the second calculation rule, wherein the adjustment coefficient of all the normal units is the same;

[0016] Inject the third harmonic into the phase circuit of each phase;

[0017] The corrected adjustment coefficient is obtained by correcting the adjustment coefficient based on the third harmonic;

[0018] The regulating voltage for each phase is calculated based on the modified regulation coefficient and the third calculation rule;

[0019] The phase voltage of each phase is adjusted to the corresponding adjustment voltage.

[0020] Optionally, obtaining the corrected adjustment coefficient based on the third harmonic correction includes:

[0021] The third harmonic is superimposed on the DC voltage to obtain the corrected DC voltage;

[0022] The modified regulation coefficient is obtained by modifying the regulation coefficient according to the modified DC voltage.

[0023] Optionally, obtaining the fault tolerance information of the energy storage system specifically includes:

[0024] Obtain the fault-tolerant voltage and the number of fault-tolerant units for each phase;

[0025] The number of normal units in each phase is obtained based on the status information;

[0026] Obtain the energy storage unit voltage for each phase, wherein the energy storage unit voltage represents the energy storage unit voltage when no fault occurs;

[0027] If the first ratio of the fault-tolerant voltage to the number of fault-tolerant units is greater than the second ratio of the energy storage unit voltage to the number of normal units, then the energy storage system has fault-tolerant conditions.

[0028] If the first ratio of the fault-tolerant voltage to the number of fault-tolerant units is less than the second ratio of the energy storage unit voltage to the number of normal units, then the energy storage system does not have fault-tolerant conditions.

[0029] Optionally, the method further includes:

[0030] When the recovery response information of the faulty unit is detected, it is determined whether the reconnection conditions are met. The faulty unit represents the energy storage unit that has failed.

[0031] If the conditions are not met, the system will enter a waiting mode until the reconnection conditions are met.

[0032] If the reconnection conditions are met, then all operating energy storage units will be shut down.

[0033] The number of normal units in each phase after access recovery is determined based on the faulty units after access recovery.

[0034] Fault tolerance adjustment is performed based on the number of normal units in each phase after access, and the fault tolerance adjustment includes the asymmetric balance adjustment.

[0035] After the fault-tolerant adjustment is completed, the recovered faulty unit is connected to the energy storage system.

[0036] Optionally, if the comparison results indicate that the number of normal units in each phase is equal, a symmetry adjustment is performed, the symmetry adjustment including:

[0037] Obtain the preset modulation ratio of the energy storage system, wherein the preset modulation ratio represents the modulation ratio when all energy storage units of the energy storage system are without faults;

[0038] The symmetric modulation ratio is determined based on the number of energy storage units in each phase, the number of normal units in each phase, and the preset modulation ratio.

[0039] The phase voltage of each phase is adjusted according to the symmetrical modulation ratio.

[0040] Optionally, before obtaining the number of normal units in each phase circuit, the method further includes:

[0041] Obtain the fault tolerance information of the energy storage system;

[0042] When the fault-tolerant information indicates that the energy storage system has fault-tolerant conditions, the location information of the faulty unit is obtained, wherein the faulty unit represents the energy storage unit that has failed.

[0043] Isolate the faulty unit based on the location information and generate isolation response information;

[0044] Fault-tolerant adjustment is initiated based on the isolation response information, wherein the fault-tolerant adjustment represents the symmetric adjustment and the asymmetric balance adjustment.

[0045] Secondly, embodiments of the present invention provide a fault-tolerant control system based on asymmetric balance adjustment, comprising:

[0046] The first module is used to obtain state information that characterizes the state of all energy storage units in the energy storage system;

[0047] The second module is used to shut down all the energy storage units when the status information indicates that at least one of the energy storage units has failed.

[0048] The third module is used to obtain the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not experienced a fault.

[0049] The fourth module is used to compare the number of normal units in each phase to obtain the comparison result;

[0050] The fifth module is used to perform asymmetric balance adjustment when the comparison results indicate that the number of normal units in any two phases is not equal.

[0051] Thirdly, embodiments of the present invention provide a computer device, the computer device including a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, it implements the steps of the above-described method.

[0052] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to perform the method described above.

[0053] Implementing the embodiments of the present invention provides the following beneficial effects: The embodiments of the present invention provide a fault-tolerant control method based on asymmetric balance adjustment, comprising: acquiring state information representing the state of all energy storage units in the energy storage system; shutting down all energy storage units when the state information indicates that at least one of the energy storage units has failed; acquiring the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not failed; comparing the number of normal units in each phase to obtain a comparison result; and performing asymmetric balance adjustment when the comparison result indicates that the number of normal units in any two phases is unequal. Through asymmetric balance adjustment, fault-tolerant adjustment can be performed when the number of energy storage units in each phase is different, improving the fault tolerance capability of the energy storage system, resulting in high system reliability, reduced downtime, and high system utilization. Attached Figure Description

[0054] Figure 1 This is a flowchart illustrating the steps of a fault-tolerant control method based on asymmetric balance adjustment provided in an embodiment of the present invention.

[0055] Figure 2 This is a schematic block diagram of the energy storage system provided in an embodiment of the present invention;

[0056] Figure 3This is a schematic block diagram of a fault-tolerant control system based on asymmetric balance adjustment provided in an embodiment of the present invention;

[0057] Figure 4 This is a schematic block diagram of the structure of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0058] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0059] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0060] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0061] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0062] like Figure 1 As shown, in a first aspect, embodiments of the present invention provide a fault-tolerant control method based on asymmetric balance adjustment, which includes the following steps.

[0063] S101. Obtain the status information representing the status of all energy storage units in the energy storage system.

[0064] Specifically, refer to Figure 2In some specific embodiments, the main controller in the energy storage system acquires real-time signals such as temperature, voltage, and fault status of each energy storage unit, monitors the energy storage units in real time, issues parameters and control commands, and generates pulse-width modulation signals through energy storage unit algorithm decoding to perform optical signal encoding and decoding control. The energy storage system includes three-phase voltages (A, B, and C), with the same number of energy storage units connected to each phase. The specific number of energy storage units and phases can be set according to requirements and is not limited here. The main controller acquires the status information of each energy storage unit in the three phases (A, B, and C) in real time. The status information includes operating status, voltage value, current value, temperature and humidity values, etc., and is not specifically limited. Specifically, the status information of each energy storage unit can be acquired through voltage sensors, current sensors, temperature and humidity sensors, etc.

[0065] S102. If the status information indicates that at least one of the energy storage units has failed, shut down all of the energy storage units.

[0066] Specifically, by acquiring the status information of each energy storage unit, it is determined whether a fault has occurred in the energy storage unit. The specific determination method can be based on the voltage, current, and temperature values ​​of the energy storage unit. That is, unit fault information can be due to excessive voltage, excessive current, excessive temperature, etc., without being limited here. Based on the received energy storage unit fault information, a blocking message is generated. This blocking message is used to block pulses, thereby locking all energy storage units, stopping all input and / or output, and prohibiting charging and discharging. This facilitates the control of faulty units and prevents them from affecting the entire energy storage system.

[0067] S103. Obtain the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not experienced a fault.

[0068] Specifically, the number of normal units in each phase circuit is obtained based on the number of energy storage units that have failed in each phase and the number of energy storage units that were originally working normally in each phase.

[0069] S104. Compare the number of normal units in each phase to obtain the comparison result.

[0070] Specifically, after obtaining the number of normal units in each phase, the number of normal units in each phase is compared pairwise, which means comparing the number of normal units in every two phases.

[0071] In some optional embodiments, before obtaining the number of normal units in each phase circuit, the method further includes: obtaining fault tolerance information of the energy storage system; if the fault tolerance information indicates that the energy storage system has fault tolerance conditions, obtaining the location information of the faulty unit, wherein the faulty unit represents the energy storage unit that has failed; isolating the faulty unit according to the location information and generating isolation response information; and initiating fault tolerance adjustment according to the isolation response information, wherein the fault tolerance adjustment represents the symmetrical adjustment and the asymmetrical balance adjustment.

[0072] Specifically, after obtaining the location information of the faulty unit, the system quickly locates the faulty unit and sends corresponding control signals to it. The control signals control the opening and closing of the fault-tolerant switch of the faulty unit and generate isolation response information. Based on this isolation response information, the fault-tolerant adjustment program is initiated. This disconnects the faulty unit from the energy storage system, quickly preventing it from affecting the operation of the entire system. When the energy storage system has fault-tolerant conditions, it rapidly locates the faulty unit, closes its fault-tolerant switch K, short-circuiting the AC output of the faulty unit. When a successful closure signal is detected from the fault-tolerant switch K, the current fault state of the faulty unit is latched, the unit exits operation, and the connection with the energy storage system is disconnected. The corresponding automatic fault-tolerant adjustment program is then activated to maintain the stable operation of the energy storage system. When the energy storage system does not have fault-tolerant conditions, or when the fault-tolerant switch K fails to close, the system activates a safety protection strategy, stopping the operation of the entire system.

[0073] S105. When the comparison results indicate that the number of normal units in any two phases is not equal, perform asymmetric balance adjustment.

[0074] Specifically, when the number of normal units in any two or more phases is unequal, the energy storage system is subjected to asymmetric balance adjustment.

[0075] In some optional embodiments, the energy storage system consists of N1 energy storage units connected in series to form phase A, N2 energy storage units connected in series to form phase B, and N3 energy storage units connected in series to form phase C. The three phases A, B, and C are connected in a star configuration and connected in parallel to the high-voltage power grid. In some optional embodiments, N1 = N2 = N3 = N, meaning that the number of energy storage units in each phase is the same, N. The energy storage units can integrate battery systems with lower rated voltage levels into a single system to obtain a large-capacity battery energy system. The energy storage system controls the operating state of the energy storage units through pulse width modulation (PWM) technology, thereby indirectly controlling the bidirectional energy exchange between the grid and the battery. When the energy storage units operate in inverter mode, the battery discharges, and the energy storage units provide energy to the grid; while when the energy storage units operate in rectifier mode, the battery charges, absorbing energy from the grid. However, due to factors such as the capacity, internal resistance, and aging of energy storage units, as well as the increase in the number of power switches and energy storage units and potential failure points caused by the increase in the number of cascaded units, the number of energy storage units in the three phases of the energy storage system may be inconsistent, resulting in a three-phase asymmetrical balance state in the energy storage system, which in turn affects the stable operation of the system.

[0076] In some optional embodiments, the asymmetric balance adjustment includes: calculating the fundamental phase angle based on the number of normal units in each phase and a preset first calculation rule, wherein the fundamental phase angle represents the fundamental phase angle between every two phase voltages; obtaining the operating voltage of each phase, wherein the operating voltage represents the phase voltage during normal operation; obtaining the DC voltage of the normal unit, wherein the normal unit represents the energy storage unit that has not experienced a fault; determining the adjustment coefficient of the normal unit based on the operating voltage, the fundamental phase angle, the DC voltage, and a second calculation rule, wherein the adjustment coefficient of all normal units is the same; injecting a third harmonic into the phase circuit of each phase; correcting the adjustment coefficient based on the third harmonic to obtain a corrected adjustment coefficient; calculating the adjustment voltage of each phase based on the corrected adjustment coefficient and a third calculation rule; and adjusting the phase voltage of each phase to the corresponding adjustment voltage.

[0077] Specifically, when the number of normal units in at least one phase is inconsistent with that in other phases, asymmetric regulation is initiated. The fundamental phase angle is calculated, and a fault regulation coefficient is obtained based on the acquired pre-fault voltage, thereby regulating the voltage of each phase after the fault. In some embodiments, the energy storage system has a large number of energy storage units, each with a potential fault point. The number and distribution of faulty units are highly random, and the number of units in phases A, B, and C may be inconsistent after a fault, resulting in asymmetric phase unit existence. Let n A n B n CThese represent the number of non-faulty units in phases A, B, and C after a unit failure. By changing the position of the system neutral point, the phase angles of each unit are readjusted, thus adjusting the phase angles between the three-phase voltages. After adjustment, the fundamental phase angle is θ. AB θ BC θ CA The following relationship should be satisfied between the three-phase voltages and the fundamental phase angles of the phase voltages:

[0078]

[0079] The asymmetric balance regulation method changes the modulation fundamental phase angle of each phase, causing the neutral point of the unit to move away from its original position, and the three-phase line voltages to rebalance, thereby maintaining the stable operation of the entire energy storage system under fault conditions.

[0080] After adjusting the fundamental phase angle, the three-phase output line voltages are balanced, but the three-phase line voltage values ​​still do not reach the line voltage values ​​under normal operating conditions. To ensure normal system operation, it is necessary to appropriately increase the modulation ratio of the energy storage units to fully restore the system to the line voltage under normal operating conditions. Based on the modulation waves of each phase unit, a certain proportion is simultaneously increased. Let this proportion be the adjustment coefficient k. The corresponding phase voltage and line voltage should also be increased by a factor of k. The output voltages of all energy storage units are multiplied by the adjustment coefficient k simultaneously, so that the adjusted line voltage reaches the line voltage under normal operating conditions. Let the output three-phase phase voltage of the energy storage system be U. A U B U C The following relationship should be satisfied:

[0081]

[0082] Among them, U DC The DC voltage of the normal unit is used. Asymmetric regulation makes the regulation ratio of all energy storage units consistent and synchronizes all energy storage units, so that the three-phase output line voltage of the energy storage system reaches the level under normal operating conditions. Asymmetric balance regulation avoids over-modulation caused by directly increasing the modulation ratio of the energy storage unit. All three-phase units have the same regulation coefficient k.

[0083] Asymmetric balance regulation distributes the voltage increment of a faulty cell evenly across all three-phase non-faulty cells, avoiding overmodulation caused by directly increasing the cell modulation ratio. By introducing a fault regulation coefficient, the output voltage of all non-faulty cells is simultaneously multiplied by coefficient k, restoring the total output line voltage to the level under normal operating conditions. Asymmetric balance regulation ensures that the regulation ratios of all non-faulty cells (i.e., normal cells) are consistent, and the SOC (State of Charge) of the batteries in non-faulty cells is balanced. This allows the battery modules of all non-faulty cells to share the task of SOC balancing, enhancing the reliability of system operation and fully utilizing the energy efficiency of the remaining non-faulty cells.

[0084] In some optional embodiments, the step of obtaining the corrected adjustment coefficient based on the third harmonic includes: superimposing the third harmonic onto the DC voltage to obtain a corrected DC voltage; and correcting the adjustment coefficient based on the corrected DC voltage to obtain the corrected adjustment coefficient.

[0085] Specifically, to further reduce the regulation coefficient and avoid over-modulation of the energy storage unit's modulation ratio, a third harmonic is injected into the DC bus voltage of the energy storage unit. A third harmonic with the same amplitude and phase is superimposed on the fundamental frequency of the three-phase phase voltages. These harmonics cancel each other out in the line voltage, and the zero-sequence component does not generate harmonic current, thus not changing the fundamental frequency components of the three-phase output current and voltage. The third harmonic injection method can improve the limitation of over-modulation of the energy storage unit's modulation ratio, increase the DC voltage utilization rate of the energy storage unit, and reduce the probability of over-modulation. Further analysis is conducted on the methods for calculating the amplitude and phase angle of the third harmonic injection to maximize the energy utilization rate of the energy storage system's battery. Let the amplitude of the third harmonic be U3, and the initial phase angle be θ0. The expression for the third harmonic is:

[0086] U thi =U3·cos(3ωt+θ0)

[0087] Among them, U thi ω is the voltage value of the third harmonic, and 3ω is the angular frequency of the third harmonic.

[0088] The output voltage of the third harmonic generator is superimposed on the DC voltage of the energy storage unit to form a new DC bus voltage for the energy storage unit, which must satisfy the following relationship:

[0089] U′ DC =U DC +U thi

[0090] Among them, U′ DC The new DC bus voltage of the energy storage unit, after being injected with the third harmonic, is evenly distributed among the energy storage units in each phase. The new DC bus voltage of the energy storage unit is then transmitted to the three-phase output of the energy storage system. The injection of the third harmonic can reduce the peak value of the composite vector of the energy storage units, which can reduce the peak value of the phase voltage to a certain extent, thereby reducing the peak value of the output voltage of each energy storage unit. The total three-phase output voltage after the injection of the third harmonic satisfies the following relationship:

[0091]

[0092] Where k′ is the correction adjustment coefficient, the third harmonic injection method further improves the DC bus voltage utilization rate of the energy storage unit. The third harmonic injection can reduce the peak value of the synthesized vector of the energy storage unit, and the fault adjustment coefficient is k′. Asymmetric balance adjustment ensures that the adjustment ratio of all energy storage units remains consistent. After the third harmonic is injected, it is evenly distributed to each phase of the energy storage unit, avoiding problems such as insufficient compensation margin, over-adjustment of the modulation wave of the working energy storage unit, and excessively high output voltage, which can cause significant damage to the power devices of the energy storage unit. After the above three-phase asymmetric balance adjustment control, the energy storage system achieves a better regulation effect.

[0093] In some optional embodiments, obtaining the fault tolerance information of the energy storage system specifically includes: obtaining the fault tolerance voltage and the number of fault tolerance units for each phase; obtaining the number of normal units for each phase based on the status information; obtaining the energy storage unit voltage for each phase, wherein the energy storage unit voltage represents the energy storage unit voltage when no fault occurs; if a first ratio of the fault tolerance voltage to the number of fault tolerance units is greater than a second ratio of the energy storage unit voltage to the number of normal units, then the energy storage system has fault tolerance conditions; if the first ratio of the fault tolerance voltage to the number of fault tolerance units is less than the second ratio of the energy storage unit voltage to the number of normal units, then the energy storage system does not have fault tolerance conditions.

[0094] Specifically, the fault-tolerant voltage represents the voltage value at which fault-tolerant conditions are met, and the number of fault-tolerant units represents the number of energy storage units that operate normally when fault-tolerant conditions are met. The ratio of the fault-tolerant voltage to the first number of fault-tolerant units is used as the fault tolerance ratio. If the ratio is greater than the first ratio, it indicates that the energy storage system does not meet the fault-tolerant conditions. Specifically, the number of faulty units in each phase can be obtained based on the unit fault information. Then, the number of normal units in each phase can be obtained by subtracting the number of faulty units in each phase from the preset number of energy storage units in each phase. Then, the phase voltage of each phase when no fault occurs can be obtained, which is the energy storage unit voltage of each phase. The second ratio of each phase can be obtained based on the energy storage unit voltage of each phase and the number of normal units in each phase. If the second ratio is less than the first ratio, it indicates that the fault tolerance condition is met. Specifically, the fault tolerance condition of each phase can be obtained. If all phases meet the fault tolerance condition, the entire energy storage system meets the fault tolerance condition. If none phases meet the fault tolerance condition, the entire energy storage system does not meet the fault tolerance condition. If at least one phase meets the fault tolerance condition, the total number of normal units in each phase and the total energy storage unit voltage value can be obtained. The total number of normal units is the sum of the number of normal units in each phase, and the total energy storage unit voltage value is the sum of the energy storage unit voltage values ​​in each phase. Furthermore, the fault tolerance of the entire energy storage system is determined by the relationship between the third ratio of the total energy storage unit voltage to the total number of normal units and the first ratio. If the third ratio is less than the first ratio, the energy storage system has fault tolerance. Conversely, if the first ratio of the fault-tolerant voltage to the number of fault-tolerant units is less than the third ratio of the total energy storage unit voltage to the total number of normal units, the energy storage system does not have fault tolerance.

[0095] In some optional embodiments, when the comparison result indicates that the number of normal units in each phase is equal, symmetrical adjustment is performed, the symmetrical adjustment including: obtaining a preset modulation ratio of the energy storage system, the preset modulation ratio indicating that all energy storage units of the energy storage system are without faults; determining a symmetrical modulation ratio based on the number of energy storage units in each phase, the number of normal units in each phase, and the preset modulation ratio; and adjusting the phase voltage of each phase based on the symmetrical modulation ratio.

[0096] Specifically, assuming each phase has n fault units, the symmetrical adjustment modulation ratio of all units in phases A, B, and C is:

[0097]

[0098] Where M is the preset modulation ratio when all units are functioning normally, and D... SV This refers to the symmetrical modulation ratio when energy storage units in phases A, B, and C fail, where each phase has n units failing, and N represents the total number of energy storage units in each phase. The symmetrical modulation ratio for all non-faulty units in phases A, B, and C is increased to N / (Nn) times the preset modulation ratio when all units are functioning normally; U i Let U be the voltage of the i-th phase.ij U is the voltage of the j-th energy storage unit in the i-th phase; S Peak phase voltage on the grid side, U B This refers to the battery voltage of the energy storage unit.

[0099] When all units are functioning normally, the AC output voltage U of the j-th energy storage unit in phase i is... ij Peak phase voltage U of the i-th phase AC side i The relationship between them (modulation ratio) is as follows:

[0100]

[0101] By symmetrically increasing the modulation ratio of the non-faulty unit, the phase voltage output of the three-phase AC side can still be restored to the pre-fault level after a fault, enabling the system to operate normally under fault conditions and improving the system's energy utilization rate after a fault.

[0102] In some optional embodiments, the method further includes: when a recovery response information of a faulty unit is detected, determining whether a reconnection condition is met, wherein the faulty unit represents the energy storage unit that has failed; if not, entering a waiting mode until the reconnection condition is met; if the reconnection condition is met, shutting down all operating energy storage units; determining the number of normal units in each phase after reconnection based on the recovered faulty units; performing fault-tolerant adjustment based on the number of normal units in each phase after reconnection, wherein the fault-tolerant adjustment includes the asymmetric balance adjustment; and connecting the recovered faulty units to the energy storage system after the fault-tolerant adjustment is completed.

[0103] Specifically, fault-tolerant regulation includes asymmetric balance regulation and symmetric regulation. After a faulty unit recovers, it sends a recovery response message. Upon receiving the response message, the system master controller determines whether the energy storage system meets the reconnection conditions. That is, when a fault recovery of an energy storage unit is detected, the system determines whether the reconnection conditions are met based on the current battery unit voltage. If the reconnection conditions are not met, the system enters a waiting state until the next charge / discharge cycle of the energy storage system, at which point the reconnection conditions are met. When the reconnection conditions are met, the system immediately blocks pulses, shuts down all operating energy storage units, and stops all inputs and / or outputs, prohibiting charging and discharging. After shutting down all energy storage units, a judgment is made to determine whether other units in the system have failed. If so, the fault-tolerant regulation procedure needs to be entered again, and fault-tolerant regulation is performed again based on the current unit fault status. Otherwise, the normal operation regulation procedure is entered. When a recovered faulty unit is connected, the fault-tolerant switch K of the recovered faulty unit is disconnected, the fault latch state of the current faulty unit is cleared, the energy storage system starts pulse output, and the energy storage system continues to operate.

[0104] The implementation of this invention provides the following beneficial effects: This invention provides a fault-tolerant control method based on asymmetric balance adjustment, comprising: acquiring state information representing the state of all energy storage units in the energy storage system; shutting down all energy storage units when the state information indicates that at least one energy storage unit has failed; acquiring the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not failed; comparing the number of normal units in each phase to obtain a comparison result; and performing asymmetric balance adjustment when the comparison result indicates that the number of normal units in any two phases is unequal. Through asymmetric balance adjustment, fault-tolerant adjustment can be performed when the number of energy storage units in each phase is different, improving the fault tolerance of the energy storage system. Only the failed units are taken out of operation, resulting in high system reliability, reduced downtime, and high system utilization. By injecting a third harmonic to obtain a corrected adjustment coefficient, the energy storage units in each phase are evenly distributed, avoiding insufficient compensation margin, over-modulation of the modulation wave of the operating energy storage units, and excessively high output voltage, which can cause significant damage to the power devices of the energy storage units.

[0105] like Figure 3 As shown, in a second aspect, embodiments of the present invention also provide a fault-tolerant control system based on asymmetric balance adjustment, comprising:

[0106] The first module is used to obtain state information that characterizes the state of all energy storage units in the energy storage system;

[0107] The second module is used to shut down all the energy storage units when the status information indicates that at least one of the energy storage units has failed.

[0108] The third module is used to obtain the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not experienced a fault.

[0109] The fourth module is used to compare the number of normal units in each phase to obtain the comparison result;

[0110] The fifth module is used to perform asymmetric balance adjustment when the comparison results indicate that the number of normal units in any two phases is not equal.

[0111] It is evident that the content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0112] like Figure 4As shown, in a third aspect, embodiments of the present invention also provide a computer device, which can be a terminal. The computer device includes a processor, a memory, and a network interface connected via a system bus. The memory may include a non-volatile storage medium and internal memory. The non-volatile storage medium may store an operating system and a computer program. The computer program includes program instructions, which, when executed, cause the processor to execute any industrial equipment visualization management method. The processor provides computing and control capabilities to support the operation of the entire computer device. The internal memory provides an environment for the execution of the computer program in the non-volatile storage medium; when executed by the processor, the computer program causes the processor to execute any industrial equipment visualization management method. The network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present disclosure and does not constitute a limitation on the computer equipment to which the present disclosure is applied. Specific computer equipment may include, for example, [the following is a list of possible additional structures]. Figure 4 The components shown may be more or fewer, or some components may be combined, or there may be different component arrangements. It should be understood that the processor may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor. In one embodiment, the processor is used to run a computer program stored in memory to perform the following steps: acquiring status information characterizing the state of all energy storage units in the energy storage system; shutting down all energy storage units if the status information indicates that at least one energy storage unit has failed; acquiring the number of normal units in each phase circuit, wherein the number of normal units characterizes the number of energy storage units that have not failed; comparing the number of normal units in each phase to obtain a comparison result; and performing asymmetric balance adjustment if the comparison result indicates that the number of normal units in any two phases is unequal.

[0113] It is evident that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented in this device embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0114] Furthermore, this application also discloses a computer program product or computer program stored in a computer-readable storage medium. A processor of a computer device can read the computer program from the computer-readable storage medium, and the processor executes the computer program, causing the computer device to perform the described method. Similarly, the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0115] It is understood that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital information processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data information such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0116] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A fault-tolerant control method based on asymmetric balance adjustment, characterized in that, Applied to energy storage systems, the method includes: Obtain the status information representing the state of all energy storage units in the energy storage system; If the status information indicates that at least one of the energy storage units has failed, all of the energy storage units shall be shut down. Obtain the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not experienced a fault; The comparison results are obtained by comparing the number of normal units in each phase; When the comparison results indicate that the number of normal units in any two phases is unequal, asymmetric balance adjustment is performed. Specifically, this includes: calculating the fundamental phase angle based on the number of normal units in each phase, where the fundamental phase angle represents the fundamental phase angle between any two phase voltages; obtaining the operating voltage of each phase, where the operating voltage represents the phase voltage during normal operation; obtaining the DC voltage of the normal unit, where the normal unit represents the energy storage unit that has not experienced a fault; determining the adjustment coefficient of the normal unit based on the operating voltage, the fundamental phase angle, and the DC voltage, where the adjustment coefficient of all normal units is the same; injecting a third harmonic into the phase circuit of each phase; correcting the adjustment coefficient based on the third harmonic to obtain a corrected adjustment coefficient; calculating the adjusted voltage of each phase based on the corrected adjustment coefficient; and adjusting the phase voltage of each phase to the corresponding adjusted voltage. When the comparison results indicate that the number of normal units in each phase is equal, a symmetry adjustment is performed, which includes: Obtain the preset modulation ratio of the energy storage system, wherein the preset modulation ratio represents the modulation ratio when all energy storage units of the energy storage system are without faults; The symmetric modulation ratio is determined based on the number of energy storage units in each phase, the number of normal units in each phase, and the preset modulation ratio. The phase voltage of each phase is adjusted according to the symmetrical modulation ratio.

2. The method according to claim 1, characterized in that, The asymmetric balance adjustment includes: The fundamental phase angle is calculated based on the number of normal units in each phase and a preset first calculation rule; the specific calculation formula is as follows: in, , , These represent the number of normal units in phases A, B, and C after a unit failure; , , The fundamental phase angle between every two phase voltages; The adjustment coefficient of the normal unit is determined based on the operating voltage, the fundamental phase angle, the DC voltage, and the second calculation rule; the specific calculation formula is as follows: in, , , The operating voltage of each phase, For adjustment coefficients, This is the DC voltage of a normal unit; The regulating voltage for each phase is calculated based on the aforementioned correction adjustment coefficient and the third calculation rule; the specific calculation formula is as follows: in, To correct the adjustment coefficient, The amplitude of the third harmonic. The third harmonic angular frequency, This is the initial phase angle of the third harmonic.

3. The method according to claim 2, characterized in that, The step of obtaining the corrected adjustment coefficient based on the third harmonic correction includes: The third harmonic is superimposed on the DC voltage to obtain the corrected DC voltage; The modified adjustment coefficient is obtained by modifying the adjustment coefficient according to the modified DC voltage.

4. The method according to claim 1, characterized in that, The method further includes: When the recovery response information of the faulty unit is detected, it is determined whether the reconnection conditions are met. The faulty unit represents the energy storage unit that has failed. If the conditions are not met, the system will enter a waiting mode until the reconnection conditions are met. If the reconnection conditions are met, then all operating energy storage units will be shut down. The number of normal units in each phase after access recovery is determined based on the faulty units after access recovery. Fault tolerance adjustment is performed based on the number of normal units in each phase after access, and the fault tolerance adjustment includes the asymmetric balance adjustment. After the fault-tolerant adjustment is completed, the recovered faulty unit is connected to the energy storage system.

5. The method according to claim 1, characterized in that, Before obtaining the number of normal units in each phase circuit, the method further includes: Obtain the fault tolerance information of the energy storage system; When the fault-tolerant information indicates that the energy storage system has fault-tolerant conditions, the location information of the faulty unit is obtained, wherein the faulty unit represents the energy storage unit that has failed. Isolate the faulty unit based on the location information and generate isolation response information; Fault-tolerant adjustment is initiated based on the isolation response information, wherein the fault-tolerant adjustment represents the symmetric adjustment and the asymmetric balance adjustment.

6. The method according to claim 5, characterized in that, The acquisition of the fault tolerance information of the energy storage system specifically includes: Obtain the fault-tolerant voltage and the number of fault-tolerant units for each phase; The number of normal units in each phase is obtained based on the status information; Obtain the energy storage unit voltage for each phase, wherein the energy storage unit voltage represents the energy storage unit voltage when no fault occurs; If the first ratio of the fault-tolerant voltage to the number of fault-tolerant units is greater than the second ratio of the energy storage unit voltage to the number of normal units, then the energy storage system has fault-tolerant conditions. If the first ratio of the fault-tolerant voltage to the number of fault-tolerant units is less than the second ratio of the energy storage unit voltage to the number of normal units, then the energy storage system does not have fault-tolerant conditions.

7. A fault-tolerant control system based on asymmetric balance adjustment, characterized in that, include: The first module is used to obtain state information that characterizes the state of all energy storage units in the energy storage system. The second module is used to shut down all the energy storage units when the status information indicates that at least one of the energy storage units has failed. The third module is used to obtain the number of normal units in each phase circuit, wherein the number of normal units represents the number of energy storage units that have not experienced a fault. The fourth module is used to compare the number of normal units in each phase to obtain the comparison result; The fifth module is used to perform asymmetric balance adjustment when the comparison result indicates that the number of normal units in any two phases is unequal. Specifically, it includes: calculating the fundamental phase angle based on the number of normal units in each phase, where the fundamental phase angle represents the fundamental phase angle between any two phase voltages; obtaining the operating voltage of each phase, where the operating voltage represents the phase voltage during normal operation; obtaining the DC voltage of the normal unit, where the normal unit represents the energy storage unit that has not experienced a fault; determining the adjustment coefficient of the normal unit based on the operating voltage, the fundamental phase angle, and the DC voltage, where the adjustment coefficient of all normal units is the same; injecting a third harmonic into the phase circuit of each phase; correcting the adjustment coefficient based on the third harmonic to obtain a corrected adjustment coefficient; calculating the adjusted voltage of each phase based on the corrected adjustment coefficient; and adjusting the phase voltage of each phase to the corresponding adjusted voltage. When the comparison result indicates that the number of normal units in each phase is equal, symmetrical adjustment is performed. The symmetrical adjustment includes: obtaining a preset modulation ratio of the energy storage system, which indicates the modulation ratio when all energy storage units of the energy storage system are without faults; determining a symmetrical modulation ratio based on the number of energy storage units in each phase, the number of normal units in each phase, and the preset modulation ratio; and adjusting the phase voltage of each phase based on the symmetrical modulation ratio.

8. A computer device, wherein, The computer device includes a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, it implements the steps of the method as described in any one of claims 1-6.

9. A computer-readable storage medium storing a processor-executable program, characterized in that, The processor-executable program, when executed by the processor, is used to perform the method as described in any one of claims 1-6.

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