Method, device and non-transitory storage medium for scheduling an energy storage system

Abstract

The application discloses a kind of scheduling method, device and nonvolatile storage medium of energy storage system.Therein, the method includes: obtaining total active power target and the state of charge of connected battery cluster;Based on the state of charge of connected battery cluster, the average state of charge of three-phase and system average state of charge are calculated and the phase internal deviation value of multiple H bridge power unit and the phase-to-phase deviation value of three-phase are determined;Based on phase internal deviation value, determine additional voltage amount;Based on phase-to-phase deviation value, determine zero sequence voltage signal;Based on total active power target, according to phase internal deviation value and phase-to-phase deviation value, determine the active power target of multiple H bridge power unit;Based on zero sequence voltage signal, additional voltage amount and active power target, generate voltage control signal.The application solves the current for cascaded energy storage system scheduling is influenced by battery itself factor, the state of charge of battery cluster can appear discrete phenomenon, leading to partial battery cluster overcharge, overdischarge, shorten the technical problem of battery service life.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and more specifically, to a scheduling method, apparatus, and non-volatile storage medium for an energy storage system. Background Technology

[0002] Currently, in actual operation, 10kV high-voltage cascaded energy storage systems experience a gradual dispersion in the state of charge (SOC) of each battery cluster due to factors such as differences in battery manufacturing processes, varying charge-discharge cycle counts, uneven ambient temperature distribution, and differences in H-bridge power unit losses. This dispersion is mainly categorized into intra-phase SOC imbalance and inter-phase SOC imbalance, and this issue has become a key bottleneck restricting system performance improvement. If the SOC imbalance persists for a long time, it can lead to overcharging and over-discharging of some battery clusters, shortening battery life, reducing system usable capacity, and even causing safety hazards.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This invention provides a scheduling method, apparatus, and non-volatile storage medium for an energy storage system, which at least solves the current technical problem that the scheduling of cascaded energy storage systems is affected by factors related to the batteries themselves, resulting in discrete states of charge of battery clusters, leading to overcharging and over-discharging of some battery clusters and shortening battery life.

[0005] According to one aspect of the present invention, a scheduling method for an energy storage system is provided, comprising: acquiring a total active power target corresponding to the energy storage system and the state of charge (SOC) of the battery clusters connected to each of the multiple H-bridge power units corresponding to each of the three phases in the energy storage system, wherein the energy storage system is a three-phase three-wire cascaded H-bridge topology, and each phase includes multiple H-bridge power units; calculating the average SOC of each of the three phases and the average SOC of the energy storage system based on the SOC of the battery clusters connected to each of the multiple H-bridge power units corresponding to each of the three phases; determining the intra-phase deviation value and the inter-phase deviation value corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the average SOC of each of the three phases and the average SOC of the energy storage system; and determining the intra-phase deviation value and the inter-phase deviation value corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the SOC of each of the multiple H-bridge power units corresponding to each of the three phases. Based on the phase-to-phase deviation values ​​of each of the multiple H-bridge power units, the additional voltage of each of the three phases corresponding to the multiple H-bridge power units is determined, wherein the sum of the additional voltages of each of the three phases corresponding to the multiple H-bridge power units is zero; based on the phase-to-phase deviation values ​​of each of the three phases, the zero-sequence voltage signal is determined; based on the total active power target, the active power target of each of the multiple H-bridge power units corresponding to the multiple phases is determined according to the phase-to-phase deviation values ​​and the phase-to-phase deviation values ​​of each of the three phases corresponding to the multiple H-bridge power units; based on the zero-sequence voltage signal, the additional voltage of each of the multiple H-bridge power units corresponding to the multiple phases corresponding to the multiple H-bridge power units, and the active power target, the voltage control signal of each of the multiple H-bridge power units corresponding to the multiple phases is generated.

[0006] Optionally, based on the phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, the following steps are used to determine the additional voltage amount corresponding to each of the multiple H-bridge power units corresponding to each of the three phases, wherein the target phase is any one of the three phases, including: generating the initial voltage amount corresponding to each of the multiple H-bridge power units corresponding to the target in proportion to the phase deviation values ​​of the multiple H-bridge power units corresponding to the target, wherein the sign of the initial voltage amount matches the sign of the phase deviation values; correcting the initial voltage amount corresponding to each of the multiple H-bridge power units corresponding to the target to obtain the additional voltage amount corresponding to each of the multiple H-bridge power units corresponding to the target.

[0007] Optionally, the zero-sequence voltage signal is determined based on the phase-to-phase deviation values ​​of the three phases, including: acquiring the three-phase AC current corresponding to the energy storage system; determining the maximum phase-to-phase deviation value based on the phase-to-phase deviation values ​​of the three phases; generating an initial voltage signal based on the maximum phase-to-phase deviation value and a preset grid fundamental frequency; and adjusting the initial voltage signal based on the three-phase AC current to obtain the zero-sequence voltage signal.

[0008] Optionally, based on the total active power target, and according to the phase-to-phase deviation values ​​and phase-to-phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases is determined, including: allocating the total active power according to the phase-to-phase deviation values ​​of each of the three phases to determine the active power target corresponding to each of the three phases; and determining the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the phase-to-phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases.

[0009] Optionally, based on the zero-sequence voltage signal, the additional voltage amount corresponding to each of the three-phase H-bridge power units, and the active power target, voltage control signals corresponding to each of the three-phase H-bridge power units are generated, including: determining the reference voltage command corresponding to each of the three-phase H-bridge power units based on the total active power target and the active power target corresponding to each of the three-phase H-bridge power units; adjusting the reference voltage command corresponding to each of the three-phase H-bridge power units based on the additional voltage amount corresponding to each of the three-phase H-bridge power units to determine the modified voltage command corresponding to each of the three-phase H-bridge power units; and superimposing the zero-sequence voltage signal onto the modified voltage command corresponding to each of the three-phase H-bridge power units to determine the voltage control signal corresponding to each of the three-phase H-bridge power units.

[0010] Optionally, the multiple H-bridge power units corresponding to each of the three phases are controlled based on their respective voltage control signals; the state of charge of the multiple H-bridge power units and their respective connected battery clusters is continuously monitored, and the intra-phase deviation value and inter-phase deviation value of the multiple H-bridge power units corresponding to each of the three phases are determined; when the intra-phase deviation value of the multiple H-bridge power units corresponding to each of the three phases is less than a first safety threshold and the inter-phase deviation value of the multiple H-bridge power units corresponding to each of the three phases is less than a second safety threshold, the multiple H-bridge power units corresponding to each of the three phases are controlled based on their respective reference voltage commands.

[0011] According to another aspect of the present invention, a scheduling device for an energy storage system is also provided, comprising: an acquisition module, configured to acquire a total active power target corresponding to the energy storage system and the state of charge (SOC) of the battery clusters connected to each of the multiple H-bridge power units corresponding to each of the three phases in the energy storage system, wherein the energy storage system is a three-phase three-wire cascaded H-bridge topology, and each phase includes multiple H-bridge power units; a calculation module, configured to calculate the average SOC of each of the three phases and the average SOC of the energy storage system based on the SOC of the battery clusters connected to each of the multiple H-bridge power units corresponding to each of the three phases; a first determination module, configured to determine the intra-phase deviation value and the inter-phase deviation value corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the average SOC of each of the three phases and the average SOC of the energy storage system; and a second ... SOC of each of the three phases based on the average SOC of each of the three phases and the average SOC of the energy storage system; and a second determination module, configured to determine the SOC of each of the three phases based on the average SOC of each of the three phases and the average SOC of the energy storage system. The three-phase power units are divided into several modules: a first module determines the phase-to-phase deviation value of each H-bridge power unit, and a second module determines the additional voltage of each H-bridge power unit. The sum of the additional voltages of each H-bridge power unit is zero. The third module determines the zero-sequence voltage signal based on the phase-to-phase deviation value of each phase. The fourth module determines the active power target of each H-bridge power unit based on the total active power target, the phase-to-phase deviation value of each H-bridge power unit, and the phase-to-phase deviation value of each phase. The fifth module generates the voltage control signal of each H-bridge power unit based on the zero-sequence voltage signal, the additional voltage of each H-bridge power unit, and the active power target.

[0012] According to another aspect of the present invention, a non-volatile storage medium is also provided, the non-volatile storage medium including a stored program, wherein, when the program is running, it controls the device where the non-volatile storage medium is located to execute any of the above-described energy storage system scheduling methods.

[0013] According to another aspect of the present invention, a computer device is also provided, the computer device including a processor, the processor being configured to run a program, wherein the program executes any of the above-described energy storage system scheduling methods during runtime.

[0014] According to another aspect of the present invention, a computer program product is also provided, including a computer program that, when executed by a processor, implements the scheduling method of any of the above-described energy storage systems.

[0015] In this embodiment of the invention, an energy storage system scheduling method is adopted. This involves obtaining the total active power target of the energy storage system and the state of charge (SOC) of the battery clusters connected to each of the multiple H-bridge power units in each of the three phases of the energy storage system. The energy storage system is a three-phase, three-wire cascaded H-bridge topology, with each phase including multiple H-bridge power units. Based on the SOC of the battery clusters connected to each of the multiple H-bridge power units in each of the three phases, the average SOC of each of the three phases and the average SOC of the energy storage system are calculated. Based on the average SOC of each of the three phases and the average SOC of the energy storage system, the intra-phase deviation value and inter-phase deviation value of each of the multiple H-bridge power units in each of the three phases are determined. Based on the intra-phase deviation value of each of the multiple H-bridge power units in each of the three phases, the additional voltage of each of the multiple H-bridge power units in each of the three phases is determined. The sum of the corresponding additional voltages is zero; the zero-sequence voltage signal is determined based on the phase-to-phase deviation values ​​of the three phases; based on the total active power target, the active power target of each of the multiple H-bridge power units corresponding to the three phases is determined according to the phase-to-phase deviation values ​​of the multiple H-bridge power units corresponding to the three phases and the phase-to-phase deviation values ​​of the three phases; based on the zero-sequence voltage signal, the additional voltages of the multiple H-bridge power units corresponding to the three phases, and the active power target, the voltage control signals of the multiple H-bridge power units corresponding to the three phases are generated, achieving the purpose of energy storage system scheduling based on phase-to-phase deviation and phase-to-phase deviation, thereby realizing the technical effect of improving battery life and energy utilization efficiency of energy storage system, and thus solving the technical problem that the scheduling of cascaded energy storage systems is affected by the battery itself, and the state of charge of the battery cluster will be discrete, resulting in overcharging and over-discharging of some battery clusters and shortening the battery life. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0017] Figure 1 A hardware block diagram of a computer terminal for implementing a scheduling method for an energy storage system is shown.

[0018] Figure 2 This is a flowchart illustrating the scheduling method for an energy storage system provided according to an embodiment of the present invention;

[0019] Figure 3 This is a structural block diagram of a scheduling device for an energy storage system provided according to an embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] According to an embodiment of the present invention, a method embodiment of a scheduling method for an energy storage system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0023] The method embodiment provided in Embodiment 1 of this application can be executed on a mobile terminal, computer terminal, or similar computing device. Figure 1 A hardware block diagram of a computer terminal for implementing a scheduling method for an energy storage system is shown. Figure 1 As shown, the computer terminal 10 may include one or more processors (shown as 102a, 102b, ..., 102n in the figure) (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0024] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be embodied, in whole or in part, in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be integrated, in whole or in part, into any other element within the computer terminal 10. As involved in the embodiments of this application, the data processing circuits serve as a processor control mechanism (e.g., selection of a variable resistor termination path connected to an interface).

[0025] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the energy storage system scheduling method in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the energy storage system scheduling method of the aforementioned application. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0026] The display can be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10.

[0027] Figure 2 This is a flowchart illustrating the scheduling method for an energy storage system provided according to an embodiment of the present invention, as shown below. Figure 2 As shown, the method includes the following steps:

[0028] Step S202: Obtain the total active power target corresponding to the energy storage system and the state of charge of the battery clusters connected to the multiple H-bridge power units corresponding to each of the three phases in the energy storage system. The energy storage system is a three-phase three-wire cascaded H-bridge topology, and each phase includes multiple H-bridge power units.

[0029] In this step, the energy storage system can be a 10kV high-voltage cascaded energy storage system, with a star-connected three-phase three-wire system. Each phase consists of at least 10 H-bridge power units connected in series. The number of units can be adjusted according to the actual capacity requirements. Each H-bridge power unit has a corresponding independent battery cluster connected to its DC side.

[0030] The total active power target is issued in real time by the power grid dispatch center or distribution network energy management system (EMS) through a communication interface to respond to the operational needs of the power system, such as frequency regulation, voltage regulation, peak shaving and valley filling, or renewable energy smoothing. This target is the total power value that the system should output or absorb within the current control cycle, in kW or MW, and can be a positive value (discharge mode), a negative value (charging mode), or a dynamically changing power curve.

[0031] The state of charge (SOC) of each battery cluster is collected in real time by the battery management system (BMS) configured in the system. The BMS samples each battery cluster through high-precision voltage and current sensors and temperature monitoring modules to determine the real-time SOC value of each battery cluster. The sampling frequency is no less than 100Hz and the accuracy is better than ±0.5%. Each H-bridge power unit corresponds to an independent battery cluster. Therefore, the system can acquire the individual SOC data of 30 battery clusters in three phases (taking 10 units per phase as an example).

[0032] Step S204: Based on the state of charge of the battery clusters connected to the multiple H-bridge power units corresponding to each of the three phases, calculate the average state of charge of each of the three phases and the average state of charge of the energy storage system.

[0033] In this step, the arithmetic mean of the SOC values ​​of the battery clusters corresponding to all H-bridge power units within each phase can be calculated. The average state of charge (SOC) of phases A, B, and C is calculated separately. The average SOC of a single phase, i.e., the average value of the battery cluster SOC, is denoted as... The corresponding calculation formula is as follows:

[0034] ,

[0035] Where n is the number of H-bridge power units in a single phase (i.e., the number of battery clusters in that phase). Let SOC be the SOC value of the battery cluster corresponding to the i-th H-bridge power unit (i=1,2,...,n), with a value range of 0~100%.

[0036] Subsequently, the total average state of charge (SOC) of the energy storage system can be further calculated based on the three-phase average SOC value. The average SOC of each of the three battery clusters is collected in real time. , , ), calculate the average total SOC of the system ( The calculation formula is as follows:

[0037] ,

[0038] in, , , The values ​​are the average SOC values ​​of the battery clusters in phases A, B, and C, respectively, ranging from 0% to 100%. The calculation method is the same as the formula for calculating the average SOC value within a phase (i.e., the arithmetic mean of the SOC values ​​of each battery cluster within each phase).

[0039] The overall average value reflects the overall energy storage level of the system and is a key benchmark for judging whether there is a systemic imbalance among the three phases. The phase-average SOC is used to assess the equilibrium state of each unit within a phase, while the overall average SOC is used to measure the relative advantages and disadvantages among the three phases. Together, they form the basis for calculating the SOC deviation within and between phases.

[0040] Step S206: Based on the average state of charge of each of the three phases and the average state of charge of the energy storage system, determine the intra-phase deviation value and the inter-phase deviation value of each of the multiple H-bridge power units corresponding to each of the three phases.

[0041] In this step, the intra-phase deviation value is used to characterize the difference between each H-bridge power unit within the same phase and the average state of charge (SOC) of its phase. For each H-bridge power unit in each phase, the real-time SOC of the connected battery cluster can be compared with the average SOC of that phase to obtain the relative degree of excess or deficiency for each unit. If a unit's SOC is higher than the phase average, its intra-phase deviation is positive, indicating that the unit has excess energy and should be discharged preferentially; if it is lower than the phase average, the deviation is negative, indicating that the unit has insufficient energy and should be charged appropriately or discharged less. In this way, the system obtains the intra-phase deviation value for each H-bridge power unit within each phase, which guides the energy redistribution within that phase.

[0042] Specifically, the SOC deviation of each H-bridge power unit corresponding to the battery cluster is calculated. The calculation formula is as follows:

[0043] ,

[0044] in, Let be the intra-phase SOC deviation corresponding to the i-th H-bridge power unit, when At that time, the SOC of the battery cluster was too high; when At that time, the SOC of the battery cluster was low; when At that time, the SOC of the battery cluster was consistent with the average value within the phase.

[0045] The phase-to-phase deviation value reflects the degree of imbalance in the overall energy storage level among the three phases. The controller compares the average state of charge (SOC) of each phase with the overall average SOC of the system to obtain the relative state of each phase with respect to the system as a whole. If the average SOC of a certain phase is higher than the overall average of the system, it indicates that the phase has excess energy and the potential to transfer energy to other phases; if it is lower than the overall average of the system, it indicates that the phase has insufficient energy and needs to receive more energy. Thus, the system obtains the phase-to-phase deviation values ​​for each of the three phases A, B, and C, which are used to determine which phase should increase power output and which should decrease it, thereby achieving power redistribution among the three phases.

[0046] Specifically, the deviation between the three-phase SOC average value and the system's overall average value is calculated using the following formula:

[0047] ,

[0048] in, , , These are the SOC deviations for phases A, B, and C, respectively. When the deviation is positive, the corresponding phase SOC is higher; when the deviation is negative, the corresponding phase SOC is lower; when the deviation is zero, the corresponding phase SOC is consistent with the overall average value of the system.

[0049] The aforementioned intra-phase and inter-phase deviation values ​​are relative quantities used to reflect the relative state differences between units or phases. They do not depend on the absolute SOC value, exhibiting good robustness and adaptability, and can effectively cope with non-ideal operating conditions in actual operation, such as battery aging and uneven temperature distribution. Both types of deviation values ​​are updated in real time by the controller, serving as the direct basis for subsequently generating the voltage additive component and zero-sequence voltage signal, ensuring that the equalization strategy is always dynamically matched with the current battery state.

[0050] Step S208: Based on the phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, determine the additional voltage of each of the multiple H-bridge power units corresponding to each of the three phases, wherein the sum of the additional voltage of each of the multiple H-bridge power units corresponding to each of the three phases is zero.

[0051] In this step, after obtaining the phase deviation value of each H-bridge power unit within each phase, an additional voltage quantity matching its state can be generated for each unit based on the sign and magnitude of the deviation. The function of this additional voltage quantity is to fine-tune the output power of the unit, thereby pushing its state of charge (SOC) closer to the average value of the phase. For units with a high SOC within the phase, a positive additional voltage quantity can be generated, causing them to absorb more active power when current flows, thus accelerating the discharge rate and reducing their SOC. For units with a low SOC within the phase, a negative additional voltage quantity is generated, reducing their active power output or enhancing their charging capacity, thereby slowing down the SOC decline or promoting its recovery. The polarity of the additional voltage quantity is strictly consistent with the sign of the phase deviation value, ensuring that the power adjustment direction is completely consistent with the balance target.

[0052] To ensure that this operation does not affect the total output power of the phase, an automatic overall calibration is performed after generating the additional voltage of all units: by adjusting the amplitude distribution of the additional voltage of each unit, the algebraic sum of all additional voltages within the phase is precisely returned to zero. In other words, the total power increase of all units due to balancing is equal to the total power decrease of all units due to balancing, thereby achieving "energy transfer within the phase, but the total phase power remains unchanged".

[0053] Because the current within the same phase in a cascaded H-bridge topology is completely consistent, the additional voltage only affects active power distribution and does not disrupt the stability of the grid-connected power. Each phase executes this process independently; phases A, B, and C each generate and zero-correct the additional voltage for all units within their respective phases without interference. This step achieves precise and disturbance-free active balancing of battery clusters within a phase without altering the grid dispatch power command.

[0054] Step S210: Determine the zero-sequence voltage signal based on the phase-to-phase deviation values ​​of each of the three phases.

[0055] In this step, after obtaining the phase-to-phase deviation values ​​for phases A, B, and C, the differences in energy distribution among the three phases can be further analyzed to determine which phase has a higher overall state of charge and which phase has a lower overall state of charge, thereby determining whether power redistribution among the three phases is necessary. To achieve this goal, a zero-sequence voltage signal with the same frequency as the grid fundamental frequency is injected to realize the dynamic redistribution of active power among the three phases without changing the total output power of the energy storage system.

[0056] The amplitude of the zero-sequence voltage signal is determined by the maximum phase-to-phase deviation among the three phases. A larger deviation indicates a greater difference between the zero-sequence voltage and the overall system level, necessitating stronger power regulation. Therefore, the zero-sequence voltage amplitude is correspondingly increased to enhance power suppression of the high-SOC phase and power support for the low-SOC phase. Simultaneously, the phase of this voltage signal is dynamically adjusted based on the real-time phase of the three-phase AC current, ensuring that the injected power direction precisely matches the balancing requirements: providing negative additional power to the phase with a high SOC, such as reducing discharge or enhancing charging; and providing positive additional power to the phase with a low SOC, such as increasing discharge or reducing charging.

[0057] Because the energy storage system adopts a star-connected three-phase three-wire topology, the sum of the three-phase currents is always zero. Therefore, the zero-sequence voltage signal does not generate net power injection in the system; it only achieves internal power transfer between the three phases. This characteristic ensures that the total system power is completely unaffected, enabling continuous and accurate response to dispatch commands issued by the grid, while simultaneously achieving coordinated control of inter-phase SOC.

[0058] Step S212: Based on the total active power target, determine the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases according to the intra-phase deviation value and the inter-phase deviation value of each of the three phases.

[0059] In this step, after the system receives the total active power target from the power grid, the controller does not directly distribute it equally to each H-bridge power unit. Instead, it combines the current phase-to-phase equilibrium state of the three phases with the unit-level imbalance state within each phase to perform hierarchical and coordinated power target reconstruction, ensuring that the execution of energy dispatch instructions and the battery state equilibrium target are achieved synchronously.

[0060] First, the controller determines the relative surplus or shortage of energy in each phase based on the phase-to-phase deviation values. For phases with positive phase-to-phase deviations, i.e., a high overall State of Charge (SOC), the system appropriately reduces the power output it should bear (or increases its absorbed power) when allocating the total active power target to suppress further charging or accelerate its discharging. For phases with negative phase-to-phase deviations, i.e., a low overall SOC, the system appropriately increases its power output (or reduces its absorbed power) to compensate for its energy deficit and promote its SOC recovery. Through this priority adjustment based on phase-to-phase status, the system prioritizes allocating resources to the more energy-starved phases while meeting the total power command.

[0061] Subsequently, within each phase, the controller performs a refined redistribution of the power target already allocated to that phase based on the phase-specific deviation values ​​of each H-bridge power unit. For units with a high State of Charge (SOC) within the phase, the system assigns them a higher discharge priority, meaning that within the total power range of that phase, more discharge power or less charging power is allocated to them, causing their SOC to decrease rapidly. For units with a low SOC within the phase, their discharge power is reduced or their charging capacity is increased, allowing their SOC to recover slowly. This process ensures that the direction of power allocation is always consistent with the balance target.

[0062] Ultimately, through the aforementioned two-layer collaborative allocation, the first layer adjusts the power share among the three phases based on inter-phase deviation, while the second layer adjusts the unit-level power within each phase based on intra-phase deviation. This allows for the generation of a dedicated active power target for each H-bridge power unit. The determination of this power target does not require setting a separate balancing period or pausing scheduling tasks; all calculations are completed synchronously within the control cycle, ensuring that the system maintains high availability and high operating efficiency throughout dynamic operation.

[0063] Step S214: Based on the zero-sequence voltage signal, the additional voltage and active power target of each of the three phases' corresponding H-bridge power units, generate the voltage control signals corresponding to each of the three phases' corresponding H-bridge power units.

[0064] In this step, after generating the additional voltage within the phase, determining the zero-sequence voltage signal, and allocating the active power target for each H-bridge power unit, the controller enters the final voltage command synthesis stage, generating a precise voltage control signal for each H-bridge power unit as the direct basis for driving its power output.

[0065] First, based on the active power target of each unit and combined with the current grid voltage and current conditions of the system, the controller reverse-engineers the reference voltage command that the unit should output. This command represents the voltage level required to meet the power target without any balancing intervention. This reference voltage command is the starting point for all control actions, ensuring that the system always prioritizes responding to grid dispatch commands.

[0066] Subsequently, the controller adds the previously generated intra-phase additional voltage to the reference voltage command of that unit. This addition operation is completed independently within each phase, and its function is to fine-tune the output voltage of each unit to ensure that its power characteristics are consistent with the SOC balance target within the phase: high SOC units have increased discharge capacity due to the addition of positive voltage, while low SOC units have reduced discharge or enhanced charging due to the addition of negative voltage. Since this additional amount has already been zeroed out within the phase, the addition does not change the total power of the phase, but only achieves the redistribution of internal energy.

[0067] Based on this, the controller synchronously superimposes the previously determined zero-sequence voltage signal onto the voltage command of each H-bridge power unit in the three phases. This zero-sequence voltage is a common component with the same frequency as the grid fundamental wave. Its function is to cause a consistent shift in the voltage reference points between the three phases without changing the total system power, thereby guiding the redistribution of the three-phase current and realizing the directional transfer of power between phases, that is, the high SOC phase receives negative power compensation, and the low SOC phase receives positive power compensation.

[0068] Finally, by first superimposing the intra-phase equalization component and then the inter-phase equalization component, the voltage control signal for each H-bridge power unit is precisely generated. This voltage control signal is converted into a pulse width modulation (PWM) signal by the drive circuit, directly controlling the switching state of the IGBT devices in each H-bridge power unit, thereby achieving precise regulation of the charging and discharging power of the battery cluster. The entire generation process is completed in real time within the control cycle, with a response delay of less than 2ms, ensuring that the system maintains fast response and stable operation in a dynamic power grid environment.

[0069] As an optional embodiment, based on the phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, the following steps are used to determine the additional voltage amount corresponding to each of the multiple H-bridge power units corresponding to each of the three phases, wherein the target phase is any one of the three phases, including: generating the initial voltage amount corresponding to each of the multiple H-bridge power units corresponding to the target in proportion to the phase deviation values ​​of the multiple H-bridge power units corresponding to the target, wherein the sign of the initial voltage amount matches the sign of the phase deviation values; correcting the initial voltage amount corresponding to each of the multiple H-bridge power units corresponding to the target to obtain the additional voltage amount corresponding to each of the multiple H-bridge power units corresponding to the target.

[0070] Optionally, after determining the intra-phase deviation value of each H-bridge power unit in each phase of the three phases, the controller independently performs the process of generating the intra-phase equalization voltage for each phase. This process takes any one phase as the processing object, called the "target phase," and its processing method is completely consistent in phases A, B, and C.

[0071] First, the controller generates a set of initial voltage values ​​based on the phase deviation of each H-bridge power unit within the target phase, according to a uniform proportional relationship. This proportional relationship uses a preset fixed gain to ensure that the larger the deviation, the larger the corresponding initial voltage amplitude. The polarity of the initial voltage value strictly matches the sign of the phase deviation value: when the SOC of a unit is higher than the average value of the phase, its initial voltage value is positive, indicating that the discharge capability of that unit should be enhanced; when the SOC of a unit is lower than the average value of the phase, its initial voltage value is negative, indicating that its discharge power should be reduced or its charging capability should be increased. This step achieves a direct mapping from the deviation state to the voltage regulation intention, ensuring that the voltage response direction of each unit perfectly matches its energy state requirement.

[0072] Subsequently, the controller performs an overall correction on this set of initial voltage values. The core objective of the correction is to ensure that the sum of the initial voltage values ​​generated by all H-bridge power units within the target phase is zero. Since the amplitude and sign of the initial voltage values ​​of each unit are determined only by their own deviations, their sum is usually not zero. Therefore, the controller fine-tunes the voltage amplitude of each unit so that the sum of the power increase from all positive voltage values ​​is exactly offset by the sum of the power decrease from all negative voltage values. This process does not change the relative magnitude and polarity of the voltage values ​​of each unit; it only performs smooth adjustments while satisfying the constraint that the sum is zero, thereby ensuring that the total output power of the target phase is not affected in any way.

[0073] The voltage generated after correction is the additional voltage corresponding to each H-bridge power unit in that phase. This additional voltage is a direct control signal for achieving disturbance-free equalization within the phase. Its function is only to "transfer energy" within the phase—allowing energy to flow from surplus units to deficient units, without outputting or absorbing any net power externally.

[0074] Specifically, it generates a balanced additional component, or additional voltage amount, of the AC side output voltage of each H-bridge power unit. The phase of this additional component is completely consistent with the phase of the output current on the AC side of the main phase, ensuring that the additional component only generates active power and reactive power disturbances. amplitude and Linear correlation, calculated using the following formula:

[0075] ,

[0076] in, The phase equalization ratio coefficient has a value range of 0.8 to 2.5V / %, which can be determined based on the rated voltage of the H-bridge power unit and the battery capacity in the actual system. An additional voltage equalization component (in V) is added to the i-th H-bridge power unit, and its polarity is the same as... Maintain consistency.

[0077] To ensure that the sum of the voltage additional components of all H-bridge power units within the same phase is zero, and to achieve disturbance-free intra-phase SOC balance without affecting the total power output of a phase, the following constraints apply:

[0078] ,

[0079] Calibrate each under this constraint. The amplitude should be adjusted to avoid fluctuations in total phase power due to superimposed voltage.

[0080] As an optional embodiment, the zero-sequence voltage signal is determined based on the phase-to-phase deviation values ​​of the three phases, including: acquiring the three-phase AC current corresponding to the energy storage system; determining the maximum phase-to-phase deviation value based on the phase-to-phase deviation values ​​of the three phases; generating an initial voltage signal based on the maximum phase-to-phase deviation value and a preset grid fundamental frequency; and adjusting the initial voltage signal based on the three-phase AC current to obtain the zero-sequence voltage signal.

[0081] Optionally, after determining the phase-to-phase deviation values ​​of phases A, B, and C, the controller enters the phase-to-phase equalization signal generation stage. The goal is to achieve directional energy transfer between the three phases without changing the total power of the system by injecting a zero-sequence voltage signal with the same frequency as the grid fundamental wave.

[0082] First, the controller acquires the current signals from the three-phase AC side of the energy storage system in real time, obtaining the instantaneous current waveforms of phases A, B, and C. This current information reflects the current power flow direction and amplitude characteristics between the system and the grid, serving as the basis for subsequent precise control of power distribution.

[0083] Subsequently, the controller analyzes the phase-to-phase deviation values ​​of the three phases and identifies the one with the largest absolute value as the "maximum phase-to-phase deviation value." This value represents the phase with the most uneven energy distribution in the current system and is a key indicator determining the strength of the balance. The larger the maximum phase-to-phase deviation value, the more significantly the overall energy of a certain phase deviates from the system average level, requiring stronger power regulation to achieve balance.

[0084] Based on the maximum phase-to-phase deviation value, the controller generates an initial voltage signal. The amplitude of this signal is proportional to the maximum phase-to-phase deviation value—the larger the deviation, the higher the amplitude of the initial voltage signal, thereby enhancing the suppression of energy-rich phases and the compensation for energy-deficient phases. The frequency of this initial voltage signal is strictly locked to the fundamental frequency of the 10kV power grid to ensure synchronization with the system operating frequency and avoid introducing any non-fundamental frequency harmonic components.

[0085] After obtaining the initial voltage signal, the controller dynamically adjusts the phase of the signal in conjunction with the previously acquired three-phase AC current signal. Specifically, the controller determines whether the system is in a discharging or charging state, and the flow trend of each phase current, based on the real-time phase relationship of the three-phase currents. Based on this, the controller shifts the phase of the initial voltage signal to an optimal angle, ensuring that the injected zero-sequence voltage precisely generates a negative power effect (reducing discharge or enhancing charging) in the phase with higher energy, while simultaneously generating a positive power effect (enhancing discharge or suppressing charging) in the phase with lower energy, thereby achieving directional energy flow.

[0086] The voltage signal after phase adjustment is the final zero-sequence voltage signal. This signal, as a common component, will be synchronously superimposed on the three-phase voltage reference command. It does not change the total system power, but only realizes the redistribution of power among the three phases, so that the phase with a high SOC naturally decreases and the phase with a low SOC steadily recovers.

[0087] Specifically, generating the zero-sequence voltage of the injection system , The frequency is exactly the same as the fundamental frequency of the 10kV power grid, and the expression is:

[0088] ,

[0089] in, Zero-sequence voltage amplitude (unit: V). The fundamental angular frequency (unit: rad / s). , The fundamental frequency of the 10kV power grid (usually 50Hz); Zero-sequence voltage phase angle (unit: °); Time (unit: seconds).

[0090] Then confirm The amplitude and phase angle are adjusted to ensure that the additional power distribution meets the SOC equalization requirements:

[0091] Amplitude It is positively correlated with the maximum deviation of the three-phase SOC, and the calculation formula is as follows:

[0092] ,

[0093] in, This is the phase-to-phase equalization ratio coefficient, with a value ranging from 1.5 to 4V / %, which can be calibrated and determined according to the system voltage level and power requirements. The absolute maximum value of the three-phase SOC deviation (unit: %).

[0094] Phase angle Based on the polarity of the three-phase SOC deviation and the phase of the grid-connected current, dynamic adjustment is achieved by changing... Controlling the distribution of additional power across phases ensures that the additional active power is positive (power increases, SOC decreases) for phases with higher SOC, and negative (power decreases, SOC increases) for phases with lower SOC. The calculation formula is as follows:

[0095] ,

[0096] in, The fundamental phase of the grid-connected current (unit: °) can be detected in real time by the data acquisition module; This is the phase angle correction factor (unit: °), with a value range of -10° to 10°. It is dynamically calibrated based on the polarity of the three-phase SOC deviation to ensure that the direction of the additional power is consistent with the SOC balance requirement.

[0097] This method achieves precise, adaptive, and harmonic-free intervention for phase imbalances, completely avoiding the power quality issues caused by fixed amplitude or non-fundamental frequency injection in traditional methods.

[0098] As an optional embodiment, based on the total active power target, the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases is determined according to the phase-to-phase deviation value and the phase-to-phase deviation value of each of the three phases. This includes: allocating the total active power according to the phase-to-phase deviation value of each of the three phases to determine the active power target corresponding to each of the three phases; and determining the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the phase-to-phase deviation value of each of the multiple H-bridge power units corresponding to each of the three phases.

[0099] Optionally, after the system receives the total active power target from the grid, the controller does not simply distribute the power equally to each H-bridge power unit. Instead, based on the differences in energy distribution between the three phases in the current energy storage system and the differences in the state of the battery clusters within each phase, it adopts a hierarchical and coordinated approach to determine the active power target that each H-bridge power unit should ultimately undertake.

[0100] First, the controller determines which phase is in an energy surplus state and which is in an energy shortage state based on the phase-to-phase deviation values ​​of each of the three phases. For phases with positive phase-to-phase deviations, meaning their average state of charge (SOC) is higher than the overall system level, the controller appropriately reduces their share of power output when allocating total active power to suppress further discharge and reduce their SOC. For phases with negative phase-to-phase deviations, meaning their SOC is lower than the overall system level, the controller appropriately increases their power output share to support energy replenishment and promote SOC recovery. Through this priority adjustment based on phase-to-phase status, the system achieves intelligent tilting of power resources among the three phases without violating the grid's total power command, prioritizing support for phases that "need more energy."

[0101] After completing the initial power allocation among the three phases, the controller enters the second-level fine-tuning stage: within each phase, based on the phase deviation value of each H-bridge power unit within that phase, the total power target already allocated to that phase is redistributed. For units with a high State of Charge (SOC) within a phase, the controller assigns them a higher discharge priority, allowing them to bear more discharge power within their phase power quota, thereby accelerating their energy release; for units with a low SOC, their discharge power is reduced accordingly or their charging capacity is moderately increased, allowing them to slowly recover their energy level. This process ensures that the energy transfer direction within each phase is always consistent with the equilibrium target.

[0102] Specifically, it receives power dispatch instructions (such as charging and discharging power, frequency regulation instructions, etc.) issued by the 10kV grid side in real time, and collects operating parameters such as the total output power of the system's grid connection point, the voltage and current of each phase, and the SOC of all battery clusters.

[0103] Determine the target total output power of the system based on the total available capacity of the system's battery clusters. Power is preferentially allocated to phases with high SOC balance and within a reasonable SOC range (20%~80%), synchronously matching the inter-phase SOC balance requirements. The three-phase power allocation calculation formula is as follows:

[0104] ,

[0105] in, , , The power distribution (in W) for phases A, B, and C is respectively, and satisfies the following conditions: ; This is a power distribution correction factor, with a value ranging from 0.01 to 0.05, used to adjust the degree of influence of SOC deviation on power distribution.

[0106] When allocating phase power to each H-bridge power unit, the SOC balancing demand within the phase is simultaneously matched, prioritizing the allocation of more discharge power (or less charging power) to units with higher SOC, so that the power allocation is consistent with the SOC balancing direction. The power allocation calculation formula for each H-bridge power unit within a single phase is as follows:

[0107] ,

[0108] in, The power allocated to the i-th H-bridge power unit (in W). Total power allocated to this phase (unit: W). This is the intra-phase power distribution correction factor, with a value ranging from 0.02 to 0.08. This represents the number of H-bridge power units within this phase.

[0109] When power grid dispatching instructions change (such as power adjustment or frequency regulation), the intra-phase and inter-phase equalization control parameters are adjusted synchronously. , , (etc.) to ensure that the balance control and energy dispatch operate in coordination without affecting the grid dispatch response speed.

[0110] Overmodulation suppression and battery protection logic are incorporated. When the modulation ratio exceeds 0.95 after voltage superposition, the amplitude of the equalization additional component and zero-sequence voltage is automatically limited to ensure grid-connected power quality. When the SOC of the battery cluster exceeds the reasonable range, its charging and discharging power is limited to avoid overcharging and over-discharging. The system safety is improved by referring to multi-dimensional monitoring fire early warning and battery thermal runaway protection schemes.

[0111] Through the two coordinated steps described above, the system ultimately generates a unique active power target for each H-bridge power unit. This target not only fully responds to the total active power command issued by the grid but also proactively guides each battery cluster towards a balanced state, truly achieving "scheduling without interfering with balancing, and balancing without violating scheduling." The entire process does not require interrupting grid scheduling tasks or setting independent balancing periods. All calculations and adjustments are completed synchronously within the control cycle, resulting in rapid response and dynamic adaptation, effectively avoiding capacity waste and battery life loss caused by balancing lag.

[0112] As an optional embodiment, based on the zero-sequence voltage signal, the additional voltage amount corresponding to each of the three-phase H-bridge power units, and the active power target, a voltage control signal corresponding to each of the three-phase H-bridge power units is generated. This includes: determining the reference voltage command corresponding to each of the three-phase H-bridge power units based on the total active power target and the active power target corresponding to each of the three-phase H-bridge power units; adjusting the reference voltage command corresponding to each of the three-phase H-bridge power units based on the additional voltage amount corresponding to each of the three-phase H-bridge power units to determine the modified voltage command corresponding to each of the three-phase H-bridge power units; and superimposing the zero-sequence voltage signal onto the modified voltage command corresponding to each of the three-phase H-bridge power units to determine the voltage control signal corresponding to each of the three-phase H-bridge power units.

[0113] Optionally, based on the total active power target received by the system and the specific active power target determined for each H-bridge power unit in the previous step, the reference voltage command to be output by each unit is derived in reverse. This reference voltage command reflects the voltage level required for each unit to output under ideal conditions, where only power allocation needs are met and no equalization corrections are considered. This command ensures that the system as a whole always faithfully responds to grid dispatch commands and serves as the basis for all subsequent adjustments.

[0114] The additional voltage generated in the previous stage is then applied, one by one, to the reference voltage command of each H-bridge power unit. For units with a high SOC in the phase, the additional voltage is positive, and the controller adds it to the reference voltage, increasing the output voltage amplitude of the unit and enabling it to release more active power under the same current, thereby accelerating the SOC decline. For units with a low SOC in the phase, the additional voltage is negative, and the controller correspondingly reduces its voltage command, decreasing its discharge capacity or increasing its charging capacity, promoting SOC recovery. This adjustment process is completed independently within each phase, changing only the voltage reference point of each unit without changing the total power of the phase, thus achieving "internal flow" of energy within the phase.

[0115] After completing the intra-phase adjustment, the controller synchronously superimposes the zero-sequence voltage signal generated in the previous step onto the modified voltage command of each H-bridge power unit in the three phases. This zero-sequence voltage signal is a common voltage component with the same frequency as the grid fundamental wave, amplitude matching the inter-phase deviation, and phase synchronized with the system current. Its function is to shift the three-phase voltage reference points in the same way, thereby guiding the redistribution of the three-phase current without changing the total system power—the energy-surplus phases naturally reduce their net power output due to the superimposed voltage, while the energy-deficient phases receive additional power support, achieving a precise rebalancing of energy among the three phases.

[0116] Specifically, the zero-sequence voltage The actual three-phase output phase voltage command is obtained by synchronously superimposing it onto the reference phase voltage of the three phases. The calculation formula is as follows:

[0117]

[0118] in, , , These are the reference phase voltages (unit: V) for phases A, B, and C, respectively, determined by the system power dispatch command; , , These are the actual output phase voltage commands for phases A, B, and C (unit: V).

[0119] Each H-bridge power unit is arranged according to Execute pulse width modulation (PWM) output; battery clusters with high SOC correspond to... A positive SOC indicates positive additional active power, increased discharge power, and decreased SOC; battery clusters with lower SOC correspond to... A negative value indicates a negative additional active power, a decrease in discharge power (or an increase in charging power), and an increase in SOC. Specifically, the additional active power of the i-th H-bridge power unit... The calculation formula is as follows:

[0120] ,

[0121] in, This is the common current (unit: A) of the H-bridge power units within a single phase. Since the in-phase current of the cascaded H-bridges is consistent, this current is the same for all H-bridge power units within the same phase.

[0122] Added voltage The reference output voltage superimposed on the corresponding H-bridge power unit The actual output voltage command is obtained from the above. The calculation formula is as follows:

[0123] ,

[0124] in, The reference output voltage (in V) of the i-th H-bridge power unit is determined by the system power dispatch command; This is the actual output voltage command of the i-th H-bridge power unit, which is the voltage control signal (unit: V) corresponding to each of the multiple H-bridge power units in each of the three phases.

[0125] The voltage control signal is converted into a pulse width modulation signal by the drive circuit, directly controlling the on / off state of the IGBT devices in each H-bridge power unit, achieving millisecond-level precise control of the battery cluster's charging and discharging power. The entire generation process is completed within a single control cycle, exhibiting rapid response and high stability. Furthermore, because the zero-sequence voltage is in sync with the fundamental frequency and the additional voltage only acts on the active power channel, the total harmonic distortion rate of the grid-connected current is ensured to be less than 3%, fully meeting the 10kV grid access standard.

[0126] After the above triple superposition, the reference voltage is first generated by the power target, then the voltage is modified by the intra-phase equalization adjustment, and finally the zero-sequence signal is superimposed by the inter-phase equalization. The final voltage control signal of each H-bridge power unit is then accurately generated. This signal integrates the three control objectives of grid dispatching intent, intra-phase equalization requirements, and inter-phase equalization requirements. It is the final execution instruction for the system to achieve "dispatch priority, balanced coordination, and disturbance-free operation".

[0127] In actual system operation, the controller does not directly superimpose the three-phase total voltage. Instead, it incorporates this intention of three-phase power redistribution when setting the base voltage command for each power unit. That is to say, the base voltage value of each power unit is not simply obtained by equal distribution, but is automatically adjusted according to the state of charge (SRC) of the phase to which it belongs—the base voltage of each unit in the phase with a higher SRC will be relatively higher, and the base voltage of the units in the phase with a lower SRC will be relatively lower.

[0128] In actual operation, the controller does not apply this zero-sequence voltage signal to the three phases as a whole, but rather integrates it evenly and synchronously into the base voltage command of each power unit within each phase. That is, when a phase has a high state of charge and requires more discharge, the controller adds a positive adjustment from the zero-sequence voltage to the base command of all units in that phase; conversely, when a phase has a low state of charge and requires less discharge, a negative adjustment is added to the base command of all units in that phase. This adjustment occurs simultaneously and is consistent across all units within each phase.

[0129] Ultimately, each power unit receives only one complete voltage command that has undergone dual adjustments: the first adjustment comes from the overall balancing requirements of its phase, and the second adjustment comes from its own individual state. This command directly drives the power switching devices of that unit, precisely controlling the charging and discharging behavior of the battery.

[0130] The entire process involves no physical superposition of the three-phase total voltage, nor does it transmit additional control signals to each unit individually. All balancing intentions are naturally woven into the basic instructions of each unit, then superimposed with local corrections, ultimately forming a unique and explicit control command. This approach ensures automatic energy balance between the three phases, achieves fine-tuning within each unit, and does not affect the stability of the system's external output power, nor does it require any additional hardware.

[0131] As an optional embodiment, the multiple H-bridge power units corresponding to each of the three phases are controlled based on their respective voltage control signals; the state of charge of the multiple H-bridge power units and their respective connected battery clusters is continuously monitored, and the intra-phase deviation value and inter-phase deviation value of the multiple H-bridge power units corresponding to each of the three phases are determined; when the intra-phase deviation value of the multiple H-bridge power units corresponding to each of the three phases is less than a first safety threshold and the inter-phase deviation value of the multiple H-bridge power units corresponding to each of the three phases is less than a second safety threshold, the multiple H-bridge power units corresponding to each of the three phases are controlled based on their respective reference voltage commands.

[0132] Optionally, based on the final voltage control command corresponding to each power unit, each independent power unit in the three phases is precisely driven, so that each unit adjusts its output power according to the command, thereby realizing the charging and discharging control of the connected battery cluster.

[0133] The controller continuously collects the operating status of each power unit and its connected battery cluster in the three phases, and judges the difference between the current state of charge of each battery cluster and the average value in its phase in real time, forming the phase deviation of each power unit; at the same time, it also calculates the difference between the average state of charge of each of the three phases and the overall average value of the system, forming the phase deviation between the three phases.

[0134] When the intra-phase deviation of all power units is within a small allowable range, and the inter-phase deviation between the three phases does not exceed the set safety range, it indicates that the state of charge of each battery cluster has become balanced, and the system is operating stably. At this time, the controller will stop performing additional equalization adjustments on the power units, and will only generate a base voltage command for each power unit based on the power dispatch command issued by the power grid, and continue to control the operation of each unit based on this command to ensure that the system accurately responds to external dispatch requirements.

[0135] If any intra-phase or inter-phase deviation exceeds the safe range, the controller will immediately activate the equalization control strategy. By adjusting the voltage command of each power unit, the unit with a high state of charge will discharge more appropriately, and the unit with a low state of charge will discharge less appropriately or charge more, gradually eliminating the deviation until the equalization state is restored.

[0136] The entire control process does not require interruption of power grid dispatching commands, nor does it rely on any external balancing circuits. Through continuous monitoring and dynamic response, it achieves seamless coordination of energy distribution and state balancing, ensuring the long-term efficient, safe, and stable operation of the system.

[0137] Specifically, the SOC equalization status within a phase is monitored in real time. When the difference between the SOC and SOC_avg_ph of all battery clusters within a phase is less than the preset equalization threshold (1% to 3%), the phase SOC equalization control is exited. The equalization threshold judgment conditions are as follows:

[0138] ,

[0139] in, The in-phase SOC equalization threshold ranges from 1% to 3% and can be adjusted according to the system's accuracy requirements.

[0140] Real-time monitoring of inter-phase SOC balance status. When the difference between the average SOC values ​​of any two phases is less than the preset balance threshold (1%~3%), zero-sequence voltage injection is stopped, and inter-phase SOC balance control is exited. The judgment conditions are as follows:

[0141] ,

[0142] in, This is the interphase SOC equalization threshold, which is consistent with the intraphase equalization threshold, and its value ranges from 1% to 3%.

[0143] Through the above steps, precise SOC balancing within and between phases is achieved: Utilizing the inherent characteristics of cascaded H-bridge topology and star-connected three-phase three-wire systems, a pure software control strategy is employed, eliminating the need for additional hardware balancing circuits. Combined with precise calculation formulas, the SOC imbalance problem of battery clusters within and between phases is resolved, ensuring power disturbance-free balancing. Furthermore, SOC balancing is deeply coupled with system energy dispatch, completing SOC balancing simultaneously with 10kV grid power dispatch commands, improving system energy utilization efficiency and avoiding capacity waste. Interphase balancing is also achieved using fundamental frequency zero-sequence voltage injection, combined with precise calculation formulas for zero-sequence voltage amplitude and phase angle, avoiding harmonic pollution, ensuring the system meets 10kV grid connection standards, improving system operational reliability, and achieving high-efficiency and high-stability operation.

[0144] Specifically, to achieve the above method, an optional device can also be provided, applied to a 10kV star-connected three-phase three-wire cascaded H-bridge energy storage system, including the following core modules, each connected via optical fiber communication, adapted to high-voltage isolation requirements:

[0145] 1. BMS module: includes SOC acquisition unit, voltage acquisition unit, current acquisition unit, and protection module: integrates battery overcharge and over-discharge protection, overcurrent protection, overvoltage protection, and cell fault bypass protection. When a fault is detected, the protection action is triggered immediately.

[0146] 2. PCS Main Controller: As the core control unit, it receives the collected data, calculates key parameters such as SOC average value and deviation, voltage additional component, zero-sequence voltage amplitude and phase angle through the above calculation formula, determines the equalization start-up conditions, issues control commands to each functional module, coordinates the collaborative operation of each module, and has fault diagnosis and protection functions.

[0147] 3. Equalization control module: Communicates with the main controller and the slave controllers of each H-bridge power unit, executes the intra-phase SOC equalization strategy, calculates the voltage equalization additional component of each H-bridge power unit through the relevant calculation formula of intra-phase equalization, and generates the superimposed voltage command; executes the inter-phase SOC equalization strategy, calculates the amplitude and phase angle of the zero-sequence voltage through the relevant calculation formula of inter-phase equalization, and generates the zero-sequence voltage injection command.

[0148] 4. Power Dispatch Module: Receives power dispatch instructions from the power grid, combines the SOC balance status, and uses the power allocation calculation formula to complete the step-by-step allocation of the total system power to the three phases and each H-bridge power unit, generating power closed-loop control instructions;

[0149] 5. Drive and Pulse Width Modulation Module: Receives voltage commands from each module, converts them into PWM drive signals, and drives the IGBT switching devices of each H-bridge power unit to achieve precise voltage and power control, ensuring the execution effect of the calculation formula;

[0150] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0151] Through the above description of the embodiments, those skilled in the art can clearly understand that the scheduling method of the energy storage system according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0152] According to embodiments of the present invention, a scheduling apparatus for an energy storage system for implementing the above-described scheduling method for an energy storage system is also provided. Figure 3 This is a structural block diagram of a scheduling device for an energy storage system according to an embodiment of the present invention, such as... Figure 3 As shown, the scheduling device of the energy storage system includes: an acquisition module 302, a calculation module 304, a first determination module 306, a second determination module 308, a third determination module 310, a fourth determination module 312, and a generation module 314. The scheduling device of the energy storage system will be described below.

[0153] The acquisition module 302 is used to acquire the total active power target corresponding to the energy storage system and the state of charge of the battery clusters connected to the multiple H-bridge power units corresponding to each of the three phases in the energy storage system. The energy storage system is a three-phase three-wire cascaded H-bridge topology, and each phase includes multiple H-bridge power units.

[0154] The calculation module 304, connected to the acquisition module 302, is used to calculate the average state of charge of each of the three phases and the average state of charge of the energy storage system based on the state of charge of the battery clusters connected to the multiple H-bridge power units of each phase.

[0155] The first determining module 306, connected to the calculation module 304, is used to determine the intra-phase deviation value and inter-phase deviation value of each of the multiple H-bridge power units corresponding to the three phases, based on the average state of charge of each of the three phases and the average state of charge of the energy storage system.

[0156] The second determining module 308, connected to the first determining module 306, is used to determine the additional voltage of each of the multiple H-bridge power units corresponding to each of the three phases based on the phase deviation values ​​of each of the multiple H-bridge power units corresponding to each of the three phases, wherein the sum of the additional voltage of each of the multiple H-bridge power units corresponding to each of the three phases is zero.

[0157] The third determining module 310, connected to the second determining module 308, is used to determine the zero-sequence voltage signal based on the phase-to-phase deviation values ​​of the three phases.

[0158] The fourth determining module 312, connected to the third determining module 310, is used to determine the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the total active power target, according to the phase deviation value and the phase-to-phase deviation value of each of the multiple H-bridge power units corresponding to each of the three phases.

[0159] The generation module 314, connected to the fourth determination module 312, is used to generate voltage control signals corresponding to the multiple H-bridge power units corresponding to each of the three phases based on the zero-sequence voltage signal, the additional voltage and active power target corresponding to the multiple H-bridge power units corresponding to each of the three phases.

[0160] It should be noted that the acquisition module 302, calculation module 304, first determination module 306, second determination module 308, third determination module 310, fourth determination module 312, and generation module 314 mentioned above correspond to steps S202 to S214 in the embodiments. Multiple modules and their corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in the above embodiments. It should also be noted that the above modules, as part of the device, can run on the computer terminal 10 provided in the embodiments.

[0161] Embodiments of the present invention may provide a computer device. Optionally, in this embodiment, the computer device may be located in at least one of a plurality of network devices in a computer network. The computer device includes a memory and a processor.

[0162] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the energy storage system scheduling method and device in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby realizing the aforementioned energy storage system scheduling method. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to a computer terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0163] The processor can access the information and application programs stored in the memory via the transmission device to execute any of the above-mentioned energy storage system scheduling methods.

[0164] This invention provides a scheduling method for an energy storage system. The method involves obtaining the total active power target of the energy storage system and the state of charge (SOC) of the battery clusters connected to each of the multiple H-bridge power units in each of the three phases of the energy storage system. The energy storage system is a three-phase, three-wire cascaded H-bridge topology, with each phase including multiple H-bridge power units. Based on the SOC of the battery clusters connected to each of the multiple H-bridge power units in each phase, the average SOC of each of the three phases and the average SOC of the energy storage system are calculated. Based on the average SOC of each of the three phases and the average SOC of the energy storage system, the intra-phase deviation value and inter-phase deviation value of each of the multiple H-bridge power units in each phase are determined. Based on the intra-phase deviation value of each of the multiple H-bridge power units in each phase, the additional voltage of each of the multiple H-bridge power units in each phase is determined. The sum of the additional voltages corresponding to each element is zero; based on the phase-to-phase deviation values ​​of each of the three phases, the zero-sequence voltage signal is determined; based on the total active power target, according to the phase-to-phase deviation values ​​of each of the multiple H-bridge power units corresponding to each of the three phases and the phase-to-phase deviation values ​​of each of the three phases, the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases is determined; based on the zero-sequence voltage signal, the additional voltages corresponding to each of the multiple H-bridge power units corresponding to each of the three phases and the active power target, the voltage control signals corresponding to each of the multiple H-bridge power units corresponding to each of the three phases are generated, thus achieving the purpose of energy storage system scheduling based on phase-to-phase deviation and phase-to-phase deviation, thereby realizing the technical effect of improving battery life and energy utilization efficiency of energy storage system, and further solving the technical problem that the scheduling of cascaded energy storage systems is affected by the battery itself, and the state of charge of battery clusters will be discrete, resulting in overcharging and over-discharging of some battery clusters and shortening battery life.

[0165] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a non-volatile storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0166] Embodiments of the present invention also provide a non-volatile storage medium. Optionally, in this embodiment, the aforementioned non-volatile storage medium can be used to store the program code executed by the scheduling method of the energy storage system provided in the above embodiments.

[0167] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0168] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing any energy storage system scheduling method.

[0169] Embodiments of the present invention also provide a computer program product, including a computer program. Optionally, in this embodiment, when the computer program is executed by a processor, it can implement any of the above-mentioned energy storage system scheduling methods.

[0170] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0171] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0172] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0173] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0174] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0175] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0176] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A scheduling method for an energy storage system, characterized in that, include: The total active power target corresponding to the energy storage system and the state of charge of the battery clusters connected to the multiple H-bridge power units corresponding to each of the three phases in the energy storage system are obtained. The energy storage system is a three-phase three-wire cascaded H-bridge topology, and each of the three phases includes multiple H-bridge power units. Based on the state of charge of the battery clusters connected to the multiple H-bridge power units corresponding to each of the three phases, calculate the average state of charge of each of the three phases and the average state of charge of the energy storage system. Based on the average state of charge of the three phases and the average state of charge of the energy storage system, the intra-phase deviation value and the inter-phase deviation value of the multiple H-bridge power units corresponding to the three phases are determined. Based on the phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, the additional voltage of each of the multiple H-bridge power units corresponding to each of the three phases is determined, wherein the sum of the additional voltage of each of the multiple H-bridge power units corresponding to each of the three phases is zero. The zero-sequence voltage signal is determined based on the phase-to-phase deviation values ​​of the three phases. Based on the total active power target, the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases is determined according to the phase deviation value and the phase-to-phase deviation value of each of the three phases. Based on the zero-sequence voltage signal, the additional voltage and active power target of each of the multiple H-bridge power units corresponding to the three phases, the voltage control signal corresponding to each of the multiple H-bridge power units corresponding to the three phases is generated. Specifically, based on the total active power target, and according to the phase-to-phase deviation values ​​and phase-to-phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases is determined, including: Based on a preset formula, the total active power target is allocated according to the phase deviation values ​​of the three phases, thereby determining the active power target for each of the three phases. The preset formula is as follows: ； in, , , The active power targets for each of the three phases are as follows: The total active power target is given, and satisfies the following conditions: , This is a preset power distribution correction factor used to adjust the degree of influence of intra-phase deviation on power distribution. , , These are the phase deviation values ​​corresponding to each of the three phases; Based on the phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, the active power targets corresponding to the multiple H-bridge power units corresponding to each of the three phases are determined respectively for the active power targets corresponding to each of the three phases. The step of generating voltage control signals for each of the multiple H-bridge power units corresponding to each of the three phases based on the zero-sequence voltage signal, the additional voltage and active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases, includes: Based on the total active power target and the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases, determine the reference voltage command corresponding to each of the multiple H-bridge power units corresponding to each of the three phases. Based on the additional voltage of each of the multiple H-bridge power units corresponding to the three phases, the reference voltage command of each of the multiple H-bridge power units corresponding to the three phases is adjusted, and the modified voltage command of each of the multiple H-bridge power units corresponding to the three phases is determined. The zero-sequence voltage signal is superimposed on the modified voltage command corresponding to each of the multiple H-bridge power units corresponding to each of the three phases to determine the voltage control signal corresponding to each of the multiple H-bridge power units corresponding to each of the three phases.

2. The method according to claim 1, characterized in that, Based on the phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases, the additional voltage corresponding to each of the multiple H-bridge power units corresponding to each of the three phases is determined by the following steps, wherein the target phase is any one of the three phases, including: Based on the phase deviation values ​​of each of the multiple H-bridge power units corresponding to the target, the initial voltage values ​​of each of the multiple H-bridge power units corresponding to the target are generated proportionally, wherein the sign of the initial voltage values ​​matches the sign of the phase deviation values. The initial voltage of each of the multiple H-bridge power units corresponding to the target is corrected to obtain the additional voltage of each of the multiple H-bridge power units corresponding to the target.

3. The method according to claim 1, characterized in that, The determination of the zero-sequence voltage signal based on the phase-to-phase deviation values ​​of the three phases includes: Obtain the three-phase AC current corresponding to the energy storage system; Based on the phase-to-phase deviation values ​​corresponding to the three phases, the maximum phase-to-phase deviation value is determined; Based on the maximum phase-to-phase deviation value and the preset grid fundamental frequency, an initial voltage signal is generated; Based on the three-phase alternating current, the initial voltage signal is adjusted to obtain the zero-sequence voltage signal.

4. The method according to claim 1, characterized in that, Also includes: Based on the voltage control signals corresponding to the multiple H-bridge power units corresponding to each of the three phases, the multiple H-bridge power units corresponding to each of the three phases are controlled. The state of charge of each of the three phases and the battery clusters connected to them is continuously monitored, and the intra-phase deviation value of each of the three phases and the inter-phase deviation value of each of the three phases are determined. When the intra-phase deviation values ​​of the multiple H-bridge power units corresponding to each of the three phases are all less than the first safety threshold and the inter-phase deviation values ​​of the three phases are all less than the second safety threshold, the multiple H-bridge power units corresponding to each of the three phases are controlled based on the reference voltage command corresponding to each of the multiple H-bridge power units corresponding to each of the three phases.

5. A dispatching device for an energy storage system, characterized in that, include: The acquisition module is used to acquire the total active power target corresponding to the energy storage system and the state of charge of the battery clusters connected to the multiple H-bridge power units corresponding to each of the three phases in the energy storage system. The energy storage system is a three-phase three-wire cascaded H-bridge topology, and each of the three phases includes multiple H-bridge power units. The calculation module is used to calculate the average state of charge of each of the three phases and the average state of charge of the energy storage system based on the state of charge of the battery clusters connected to the multiple H-bridge power units corresponding to each of the three phases. The first determining module is used to determine the intra-phase deviation value and the inter-phase deviation value of each of the multiple H-bridge power units corresponding to the three phases, based on the average state of charge of the three phases and the average state of charge of the energy storage system. The second determining module is used to determine the additional voltage amount corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the phase deviation value corresponding to each of the multiple H-bridge power units corresponding to each of the three phases, wherein the sum of the additional voltage amounts corresponding to each of the multiple H-bridge power units corresponding to each of the three phases is zero. The third determining module is used to determine the zero-sequence voltage signal based on the phase-to-phase deviation values ​​corresponding to the three phases. The fourth determining module is used to determine the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the total active power target, according to the phase deviation value corresponding to each of the multiple H-bridge power units corresponding to each of the three phases and the phase deviation value corresponding to each of the three phases. The generation module is used to generate voltage control signals for each of the multiple H-bridge power units corresponding to the three phases based on the zero-sequence voltage signal, the additional voltage and active power target corresponding to each of the multiple H-bridge power units corresponding to the three phases. The fourth determining module is used to allocate the total active power target based on a preset formula and according to the phase deviation values ​​of the three phases, thereby determining the active power target for each of the three phases. The preset formula is as follows: ； in, , , The active power targets for each of the three phases are as follows: The total active power target is given, and satisfies the following conditions: , This is a preset power distribution correction factor used to adjust the degree of influence of intra-phase deviation on power distribution. , , The phase-to-phase deviation values ​​for each of the three phases are defined; based on the phase-to-phase deviation values ​​for each of the multiple H-bridge power units corresponding to each of the three phases, the active power targets for each of the multiple H-bridge power units corresponding to each of the three phases are determined respectively. The generation module is further configured to: determine the reference voltage command corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the total active power target and the active power target corresponding to each of the multiple H-bridge power units corresponding to each of the three phases; adjust the reference voltage command corresponding to each of the multiple H-bridge power units corresponding to each of the three phases based on the additional voltage amount corresponding to each of the multiple H-bridge power units corresponding to each of the three phases, and determine the modified voltage command corresponding to each of the multiple H-bridge power units corresponding to each of the three phases; and superimpose the zero-sequence voltage signal onto the modified voltage command corresponding to each of the multiple H-bridge power units corresponding to each of the three phases, and determine the voltage control signal corresponding to each of the multiple H-bridge power units corresponding to each of the three phases.

6. A non-volatile storage medium, characterized in that, The non-volatile storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the non-volatile storage medium to perform the scheduling method of the energy storage system according to any one of claims 1 to 4.

7. A computer device, characterized in that, include: Memory and processor The memory stores computer programs; The processor is configured to execute a computer program stored in the memory, wherein when the computer program is executed, the processor performs the scheduling method of the energy storage system according to any one of claims 1 to 4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the scheduling method of the energy storage system according to any one of claims 1 to 4.

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