A method and device for coordinated control of multiple parallel energy storage systems

Abstract

The embodiment of the application provides a kind of multi-parallel energy storage system coordination control method and device, by setting the equalization factor of dynamic change, each energy storage unit can be according to the state of charge value, capacity adaptively adjusts the size of output current, realizes the state of charge fast equalization of all energy storage units in network under the premise of guaranteeing that each energy storage unit output current is not over limit in equalization process, simultaneously makes that output voltage average estimation converges to rated value to improve common bus voltage quality, the present application is based on distributed communication architecture, can reduce communication pressure, improve system reliability, simultaneously meet the demand of energy storage unit plug and play.

Description

Technical Field

[0001] The present invention relates to the field of energy management technology for energy storage systems, and in particular to a coordinated control method and apparatus for multiple parallel energy storage systems. Background Technology

[0002] The dwindling reserves of fossil fuels and the increasing prominence of global carbon emissions and pollution have made the upgrading and large-scale replacement of energy sources imperative. Renewable energy sources, represented by photovoltaics and wind power, have become important ways to alleviate energy problems. my country has consistently adhered to its sustainable energy development strategy, and with the introduction of the "dual carbon" target, the development of new energy sources has been further accelerated. On the one hand, new energy sources possess cleanliness and renewability that traditional fossil fuels cannot match; on the other hand, the uncertainty and volatility of their output have always been the dominant factors limiting their further penetration rate in the power grid.

[0003] The coordinated operation of new energy sources with energy storage is an effective means to address the uncertainty and fluctuations in new energy output. Since the capacity of a single energy storage unit is limited, the parallel operation of multiple energy storage units can effectively increase system capacity. IU droop control technology is widely used to coordinate power distribution among multiple energy storage units. However, droop control achieves voltage stability and load power distribution at the expense of the output voltage's adherence to the rated voltage, resulting in a certain degree of voltage deviation. This affects the normal operation of voltage-sensitive loads under heavy load conditions. Furthermore, inconsistent line resistance in actual lines makes precise current distribution to the load difficult. In addition, in practical applications, energy storage units vary in capacity, initial state of charge (SOC), and power limits. Traditional droop control methods do not specifically consider the SOC information of each energy storage unit, making some units prone to overcharging and over-discharging during operation, and causing them to prematurely shut down. This poses a significant threat to the normal operation of the new energy distribution and storage system. Summary of the Invention

[0004] This invention provides a coordinated control method and device for a multi-parallel energy storage system. It adaptively adjusts the balancing current based on its own state of charge (SOC) information and the SOC average estimate considering global information, achieving rapid SOC balancing control and precise load current distribution. Furthermore, it obtains a secondary compensation amount for the output voltage based on dynamic voltage averaging, improving load voltage quality and alleviating the contradiction between load current balancing and voltage repair.

[0005] In a first aspect, embodiments of the present invention provide a coordinated control method for a multi-parallel energy storage system, wherein the multi-parallel energy storage system includes a photovoltaic power source and a plurality of energy storage units, the photovoltaic power source and the plurality of energy storage units being connected in parallel to a common bus, and the method includes:

[0006] Based on the local information of each energy storage unit and the information received from adjacent energy storage units, the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate are determined.

[0007] Step S2: The comparison value between the local average voltage estimate and the reference value of the common bus rated voltage is passed through a voltage compensator to obtain the secondary voltage correction amount;

[0008] Step S3: Determine the equalization voltage correction amount based on the local virtual current average estimate and local virtual current information;

[0009] Step S4: Determine the comprehensive voltage correction amount based on the secondary voltage correction amount and the balanced voltage correction amount, and superimpose the comprehensive voltage correction amount with the voltage reference command of the primary control as the outer loop control command of the DC / DC converter voltage.

[0010] Preferably, the energy storage unit includes a battery and a DC / DC converter.

[0011] Preferably, step S1 specifically includes:

[0012] Determine and the first i The adjacent energy storage units that communicate with each other are determined, and the first energy storage unit is identified. i Local information of the first energy storage unit, and information related to the second energy storage unit. i Average estimated information of neighboring energy storage units that communicate and interact with each other;

[0013] The local average voltage estimate, local virtual current estimate, and local state of charge estimate are obtained based on the dynamic average consensus algorithm. In the above formula, For the first i Average local voltage estimate for each energy storage unit For the first i Local virtual current average estimate of each energy storage unit For the first i Average estimate of the local state of charge of each energy storage unit; N i In order to be with the first i A set of adjacent energy storage units that communicate and interact with each other. N i | represents the number of elements in the set; voi Indicates the first i The output voltage of the DC / DC converter of each energy storage unit i viri Indicates the first i The virtual current of each energy storage unit, SOC i Indicates the first i Local state of charge (S&C) of each energy storage unit; α i , β i , γ i The first i Consistency control gain of local output voltage, virtual current, and state of charge of each energy storage unit.

[0014] Preferably, in step S2, the secondary voltage correction amount is: In the above formula, This indicates the secondary voltage correction amount; For the first i Average local voltage estimate for each energy storage unit v ref This is the reference value for the rated voltage of the common bus. k P_a This represents the proportional coefficient of the voltage secondary controller. k I_a This represents the integral coefficient of the voltage secondary controller. s This represents the Laplace operator.

[0015] Preferably, in step S3, the equalization voltage correction amount is: In the above formula, δv viri This indicates the amount of voltage equalization correction. For the first i Local virtual current average estimate of each energy storage unit i viri Indicates the first i The virtual current of each energy storage unit k P_vir This represents the proportional coefficient of the current balancing controller. k I_vir This represents the integral coefficient of the current balancing controller. s This represents the Laplace operator.

[0016] Preferably, step S1 further includes:

[0017] The equilibrium factor is calculated based on the measured local state of charge and the average estimated value of the local state of charge. In the above formula, l < ψi < h ;express For the first i Average estimated local state of charge (SOC) of each energy storage unit i Indicates the first i Local state of charge of each energy storage unit; k This is the charging / discharging mode switching coefficient. When the output power of the photovoltaic power source is less than the power consumption of the load, k =1; When the output power of the photovoltaic power source is greater than the power consumption of the load. k =-1; l , h These are the upper and lower limits of the equilibrium factor, respectively.

[0018] The virtual current of the energy storage unit is determined based on its capacity, balancing factor, and actual output current. In the above formula, i viri Indicates the first i The virtual current of each energy storage unit C ri For the first i The relative capacity factor of each energy storage unit i pi For the first i Each energy storage unit outputs current.

[0019] Preferably, in step S4, the comprehensive voltage correction amount is: In the above formula, δv bi This indicates the overall voltage correction amount. δv viri This indicates the amount of voltage equalization correction. δv ai This indicates the secondary voltage correction amount.

[0020] Secondly, embodiments of the present invention provide a coordinated control system for a multi-parallel energy storage system. The multi-parallel energy storage system includes a photovoltaic power source and a plurality of energy storage units. The photovoltaic power source and the plurality of energy storage units are connected in parallel to a common bus. The device includes:

[0021] The local calculation module determines the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate based on the local information of each energy storage unit and the information received from adjacent energy storage units.

[0022] The secondary voltage correction module compares the local average voltage estimate with the reference value of the common bus rated voltage and then passes the comparison with the voltage compensator to obtain the secondary voltage correction amount.

[0023] The equalization voltage correction module determines the equalization voltage correction amount based on the local virtual current average estimate and local virtual current information;

[0024] The coordination control module determines the comprehensive voltage correction amount based on the secondary voltage correction amount and the balanced voltage correction amount, and superimposes the comprehensive voltage correction amount with the voltage reference command of the primary control as the outer loop control command of the DC / DC converter voltage.

[0025] Thirdly, embodiments of the present invention provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of the coordinated control method for a multi-parallel energy storage system as described in the first aspect of the present invention.

[0026] Fourthly, embodiments of the present invention provide a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the coordinated control method for multiple parallel energy storage systems as described in the first aspect of the present invention.

[0027] This invention provides a coordinated control method and device for a multi-parallel energy storage system. By setting a dynamically changing balancing factor, each energy storage unit can adaptively adjust the magnitude of its output current according to its own state of charge (SOC) value and capacity. Under the premise of ensuring that the output current of each energy storage unit does not exceed the limit during the balancing process, the SOC of all energy storage units in the network is quickly balanced. At the same time, the average estimated value of the output voltage converges to the rated value, thereby improving the voltage quality of the common bus. This invention is based on a distributed communication architecture, which can reduce communication pressure, improve system reliability, and meet the plug-and-play requirements of energy storage units. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart of a coordinated control method for multiple parallel energy storage systems according to an embodiment of the present invention;

[0030] Figure 2 This is a topology diagram of a DC microgrid according to an embodiment of the present invention;

[0031] Figure 3 The output current waveforms of each energy storage unit are shown in the diagram below when the coordinated control method for a multi-parallel energy storage system according to an embodiment of the present invention is applied.

[0032] Figure 4 This is a diagram showing the change in the state of charge of each energy storage unit under the application of the coordinated control method for multi-parallel energy storage systems according to an embodiment of the present invention.

[0033] Figure 5 The local output voltage waveform diagram is shown in the embodiment of the present invention when the coordinated control method for multi-parallel energy storage systems is applied.

[0034] Figure 6 The waveform diagram of the common bus voltage is shown in the embodiment of the present invention for the coordinated control method of multi-parallel energy storage systems.

[0035] Figure 7 This is a schematic diagram of the physical structure according to an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0038] The terms "first" and "second" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a system, product, or device that includes a series of components or units is not limited to the listed components or units, but may optionally include unlisted components or units, or may optionally include other components or units inherent to such products or devices. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] Traditional droop control methods do not specifically consider the state of charge information of each energy storage unit, which makes some energy storage units prone to overcharging and over-discharging during operation, causing the corresponding energy storage units to shut down prematurely. This poses a great threat to the normal operation of the energy storage system.

[0041] Therefore, embodiments of the present invention provide a coordinated control method and apparatus for a multi-parallel energy storage system. By setting a dynamically changing balancing factor, each energy storage unit can adaptively adjust the magnitude of its output current according to its own state of charge (SOC) value and capacity. This achieves rapid SOC balance of all energy storage units within the grid while ensuring that the output current of each energy storage unit does not exceed limits during the balancing process. Simultaneously, it causes the average estimated value of the output voltage to converge to the rated value, thereby improving the stability of the common bus voltage. The following will elaborate and describe this through several embodiments.

[0042] Figure 1 This invention provides a coordinated control method for a multi-parallel energy storage system, which establishes a system such as... Figure 2 The DC microgrid shown includes one photovoltaic power source and n energy storage units (ESUs). i and n resistive loads; the energy storage unit includes a battery, a DC / DC converter, and no load is connected to the common bus of the DC microgrid, while the photovoltaic power supply is generating electricity normally. At this time, each energy storage unit will be charged. The method includes:

[0043] Step S1: Based on the local information of each energy storage unit and the information received from adjacent energy storage units, determine the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate.

[0044] In this step, based on the known local state information of each energy storage unit and the average estimated state quantities received from neighboring energy storage units, the average estimated values ​​of local voltage, local virtual current, and local state of charge are obtained, specifically including:

[0045] Determine and the first i The adjacent energy storage units that communicate with each other are determined, and the first energy storage unit is identified. i The local state of charge information of the first energy storage unit, and the information related to the second energy storage unit. iThe average estimate of the local state of charge of neighboring energy storage units that communicate with each other.

[0046] The local average voltage estimate, local virtual current estimate, and local state of charge estimate are obtained based on the dynamic average consensus algorithm. In the above formula, For the first i Average local voltage estimate for each energy storage unit For the first i Local virtual current average estimate of each energy storage unit For the first i Average estimate of the local state of charge of each energy storage unit; N i In order to be with the first i A set of adjacent energy storage units that communicate and interact with each other. N i | represents the number of elements in the set; v oi Indicates the first i The output voltage of the DC / DC converter of each energy storage unit i viri Indicates the first i The virtual current of each energy storage unit, SOC i Indicates the first i Local state of charge of each energy storage unit; α i , β i , γ i The first i Consistency control gain of local output voltage, virtual current, and state of charge of each energy storage unit.

[0047] In this embodiment, the equilibrium factor is also calculated based on the measured local state of charge and the average estimated value of the local state of charge: In the above formula, l < ψ i < h ;express For the first i Average estimated local state of charge (SOC) of each energy storage unit i Indicates the first i Local state of charge of each energy storage unit; k This is the charging / discharging mode switching coefficient. When the output power of the photovoltaic power source is less than the power consumption of the load, k =1; When the output power of the photovoltaic power source is greater than the power consumption of the load. k =-1; l , hThese are the upper and lower limits of the balancing factor, respectively; they can be determined by the maximum operating capacity of each energy storage unit in the microgrid under rated load conditions. Since the state of charge of each energy storage unit is constantly changing during charging and discharging, the balancing factor is also a dynamically changing quantity.

[0048] The virtual current of the energy storage unit is determined based on its capacity, balancing factor, and actual output current. In the above formula, i viri Indicates the first i The virtual current of each energy storage unit C ri For the first i The relative capacity factor of each energy storage unit i pi For the first i The output current of each energy storage unit. The ratio between the virtual current and the actual output current of the battery is related to the product of the relative capacity coefficient and the balancing factor. The relative capacity coefficient is determined by the actual capacity of the battery, and its value is determined after the equipment selection is completed.

[0049] Step S2: The comparison value between the local average voltage estimate and the reference value of the common bus rated voltage is passed through a voltage compensator to obtain the secondary voltage correction amount;

[0050] The secondary voltage correction amount is: In the above formula, δv ai This indicates the secondary voltage correction amount; For the first i Average local voltage estimate for each energy storage unit v ref This is the reference value for the rated voltage of the common bus. k P_a This represents the proportional coefficient of the voltage secondary controller. k I_a This represents the integral coefficient of the voltage secondary controller. s This represents the Laplace operator.

[0051] Step S3: Determine the equalization voltage correction amount based on the local state of charge average estimate and local state of charge information;

[0052] The equalization voltage correction amount is: In the above formula, δv viri This indicates the amount of voltage equalization correction. For the first i Local virtual current average estimate of each energy storage unit i viri Indicates the first i The virtual current of each energy storage unitk P_vir This represents the proportional coefficient of the current balancing controller. k I_vir This represents the integral coefficient of the current balancing controller. s This represents the Laplace operator.

[0053] Step S4: Determine the comprehensive voltage correction amount based on the secondary correction amount and the balanced voltage correction amount. Superimpose the comprehensive voltage correction amount with the voltage reference command from the primary control to obtain the DC / DC converter. The comprehensive voltage correction amount is: In the above formula, δv bi This indicates the overall voltage correction amount. δv viri This indicates the amount of voltage equalization correction. δv ai This indicates the secondary voltage correction amount.

[0054] Figure 3 The image shows the charging current waveform of the energy storage units. Taking three energy storage units as an example, it can be seen that in the first half of the simulation (0s~5s), the charging current of the third energy storage unit is close to 0, which is less than the charging current of the other two energy storage units. The charging current of the second energy storage unit is the largest. Figure 4 As shown in the diagram of state of charge (SBC) changes, the third energy storage unit has the largest initial SBC, while the second energy storage unit has the smallest. Applying the method provided in this embodiment, the charging current of each energy storage unit can be actively adjusted based on its initial SBC information, ensuring that the unit with the largest initial SBC has the smallest charging current, and vice versa, thereby effectively accelerating the SBC equalization rate. During the simulation phase from t=5s to 9s, as the difference between each SBC and the average estimated SBC decreases, the equalization factor of the energy storage unit leaves the limiting region and enters the adaptive change phase. Figure 3 As can be seen, the output current of each energy storage unit gradually changes towards a more even distribution of the load current. After t=9s, the state of charge of each energy storage unit becomes nearly uniform, at which point the output current of each energy storage unit is precisely distributed according to the battery capacity.

[0055] To mitigate the voltage drop on the common bus of the DC microgrid, secondary voltage control was initiated at t=5s. Figure 5 It can be seen that before t=5s, the output voltage of all DC / DC converters is higher than 100V. Because each energy storage unit is in a charging state, the bus voltage must also be higher than 100V. Figure 6 As shown. After the secondary voltage control is activated, the output voltage of each DC / DC converter is distributed around 100V, and its average voltage is equal to 100V. From Figure 6It can be seen that the deviation between the common bus voltage and the rated voltage has been significantly improved.

[0056] This invention provides a coordinated control method for a multi-parallel energy storage system. By setting a dynamically changing balancing factor, each energy storage unit can adaptively adjust its output current based on its own state of charge (SOC) value and capacity. This achieves rapid SOC balancing of all energy storage units in the network while ensuring that the output current of each energy storage unit does not exceed the limit during the balancing process. At the same time, it makes the average estimated value of the output voltage converge to the rated value, thereby improving the stability of the common bus voltage. Based on a distributed communication architecture, it can reduce communication pressure, improve communication reliability, and meet the plug-and-play requirements of energy storage units.

[0057] This invention also provides a coordinated control device for a multi-parallel energy storage system, based on the coordinated control methods for multi-parallel energy storage systems described in the above embodiments. The multi-parallel energy storage system includes a photovoltaic power source and several energy storage units, wherein the photovoltaic power source and the several energy storage units are connected in parallel to a common bus. The device includes:

[0058] The local calculation module determines the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate based on the local information of each energy storage unit and the information received from adjacent energy storage units.

[0059] The secondary voltage correction module compares the local average voltage estimate with the reference value of the common bus rated voltage and then passes the comparison with the voltage compensator to obtain the secondary voltage correction amount.

[0060] The equalization voltage correction module determines the equalization voltage correction amount based on the local virtual current average estimate and local virtual current information;

[0061] The coordination control module determines the comprehensive voltage correction amount based on the secondary voltage correction amount and the balanced voltage correction amount, and superimposes the comprehensive voltage correction amount with the voltage reference command of the primary control as the outer loop control command of the DC / DC converter voltage.

[0062] Based on the same concept, this invention also provides a schematic diagram of a physical structure, such as... Figure 7 As shown, the server may include a processor 810, a communications interface 820, a memory 830, and a communication bus 840. The processor 810, communications interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions stored in the memory 830 to execute the steps of the multi-parallel energy storage system coordinated control method described in the above embodiments. For example, this includes:

[0063] Step S1: Based on the local information of each energy storage unit and the information received from adjacent energy storage units, determine the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate.

[0064] Step S2: The comparison value between the local average voltage estimate and the reference value of the common bus rated voltage is passed through a voltage compensator to obtain the secondary voltage correction amount;

[0065] Step S3: Determine the equalization voltage correction amount based on the local virtual current average estimate and local virtual current information;

[0066] Step S4: Determine the comprehensive voltage correction amount based on the secondary voltage correction amount and the balanced voltage correction amount, and superimpose the comprehensive voltage correction amount with the voltage reference command of the primary control as the outer loop control command of the DC / DC converter voltage.

[0067] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a 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, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0068] Based on the same concept, embodiments of the present invention also provide a non-transitory computer-readable storage medium storing a computer program. This computer program includes at least one piece of code that can be executed by a master control device to control the master control device to implement the steps of the coordinated control method for multi-parallel energy storage systems as described in the above embodiments. For example, it includes:

[0069] Step S1: Based on the local information of each energy storage unit and the information received from adjacent energy storage units, determine the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate.

[0070] Step S2: The comparison value between the local average voltage estimate and the reference value of the common bus rated voltage is passed through a voltage compensator to obtain the secondary voltage correction amount;

[0071] Step S3: Determine the equalization voltage correction amount based on the local virtual current average estimate and local virtual current information;

[0072] Step S4: Determine the comprehensive voltage correction amount based on the secondary voltage correction amount and the balanced voltage correction amount, and superimpose the comprehensive voltage correction amount with the voltage reference command of the primary control as the outer loop control command of the DC / DC converter voltage.

[0073] Based on the same technical concept, this application also provides a computer program, which, when executed by a main control device, is used to implement the above-described method embodiments.

[0074] The program may be stored, in whole or in part, on a storage medium packaged with the processor, or in part or in whole on a memory not packaged with the processor.

[0075] Based on the same technical concept, this application also provides a processor for implementing the above-described method embodiments. The processor can be a chip.

[0076] The various embodiments of the present invention can be combined arbitrarily to achieve different technical effects.

[0077] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive).

[0078] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coordinated control method for a multi-parallel energy storage system, wherein the multi-parallel energy storage system includes a photovoltaic power source and a plurality of energy storage units, wherein the photovoltaic power source and the plurality of energy storage units are connected in parallel to a common bus, characterized in that, The method includes: Step S1: Based on the local information of each energy storage unit and the information received from adjacent energy storage units, determine the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate. Step S2: The comparison value between the local average voltage estimate and the reference value of the common bus rated voltage is passed through a voltage compensator to obtain the secondary voltage correction amount; Step S3: Determine the equalization voltage correction amount based on the local virtual current average estimate and local virtual current information; Step S4: Determine the comprehensive voltage correction amount based on the secondary voltage correction amount and the balanced voltage correction amount, and superimpose the comprehensive voltage correction amount with the voltage reference command of the primary control as the outer loop control command of the DC / DC converter voltage. Specifically, step S1 includes: Determine and the first i The adjacent energy storage units that communicate with each other are determined, and the first energy storage unit is identified. i Local information of the first energy storage unit, and information related to the second energy storage unit. i Average estimated information of neighboring energy storage units that communicate and interact with each other; The local average voltage estimate, local virtual current estimate, and local state of charge estimate are obtained based on the dynamic average consensus algorithm. In the above formula, For the first i Average local voltage estimate for each energy storage unit For the first i Local virtual current average estimate of each energy storage unit For the first i Average estimate of the local state of charge of each energy storage unit; In order to be with the first i A collection of adjacent energy storage units that communicate and interact with each other. The number of elements in the set; Indicates the first i The output voltage of the DC / DC converter of each energy storage unit Indicates the first i The virtual current of each energy storage unit Indicates the first i Local state of charge of each energy storage unit; The first i The consistency control gain of local output voltage, virtual current, and state of charge (SOC) of each energy storage unit; the equalization factor is calculated based on the measured local SOC and the average estimate of the local SOC. In the above formula, ; Represented as the first i Average estimate of the local state of charge of each energy storage unit, SoC i Indicates the first i Local state of charge of each energy storage unit; k This is the charging / discharging mode switching coefficient. When the output power of the photovoltaic power source is less than the power consumption of the load, k =1; When the output power of the photovoltaic power source is greater than the power consumption of the load. k =-1; l , h These are the lower and upper limits of the balancing factor, respectively; the virtual current of the energy storage unit is determined based on the relative capacity coefficient, balancing factor, and actual output current of the energy storage unit. In the above formula, i viri Indicates the first i The virtual current of each energy storage unit C ri For the first i The relative capacity factor of each energy storage unit i pi For the first i The actual output current of each energy storage unit.

2. The coordinated control method for multiple parallel energy storage systems according to claim 1, characterized in that, The energy storage unit includes a battery and a DC / DC converter.

3. The coordinated control method for multiple parallel energy storage systems according to claim 1, characterized in that, In step S2, the secondary voltage correction amount is: In the above formula, This indicates the secondary voltage correction amount; Let be the average estimated local voltage value of the i-th energy storage unit. This is the reference value for the rated voltage of the common bus. This represents the proportional coefficient of the voltage secondary controller. This represents the integral coefficient of the voltage secondary controller. This represents the Laplace operator.

4. The coordinated control method for multiple parallel energy storage systems according to claim 1, characterized in that, In step S3, the equalization voltage correction amount is: In the above formula, This indicates the amount of voltage equalization correction. For the first i Local virtual current average estimate of each energy storage unit Indicates the first i The virtual current of each energy storage unit This represents the proportional gain of the current balancing controller. This represents the integral coefficient of the current balancing controller. This represents the Laplace operator.

5. The coordinated control method for multiple parallel energy storage systems according to claim 1, characterized in that, In step S4, the comprehensive voltage correction amount is: In the above formula, This indicates the overall voltage correction amount. This indicates the amount of voltage equalization correction. This indicates the secondary voltage correction amount.

6. A coordinated control device for a multi-parallel energy storage system, the multi-parallel energy storage system comprising a photovoltaic power source and a plurality of energy storage units, wherein the photovoltaic power source and the plurality of energy storage units are connected in parallel to a common bus, the device comprising: The local calculation module determines the local average voltage estimate, the local average state of charge estimate, and the local average virtual current estimate based on the local information of each energy storage unit and the information received from adjacent energy storage units. The secondary voltage correction module compares the local average voltage estimate with the reference value of the common bus rated voltage and then passes the comparison with the voltage compensator to obtain the secondary voltage correction amount. The equalization voltage correction module determines the equalization voltage correction amount based on the local virtual current average estimate and local virtual current information; The coordination control module determines the comprehensive voltage correction amount based on the secondary voltage correction amount and the balanced voltage correction amount, and superimposes the comprehensive voltage correction amount with the voltage reference command of the primary control as the outer loop control command of the DC / DC converter voltage. Specifically, the operations performed by the local computing module include: Determine and the first i The adjacent energy storage units that communicate with each other are determined, and the first energy storage unit is identified. i Local information of the first energy storage unit, and information related to the second energy storage unit. i Average estimated information of neighboring energy storage units that communicate and interact with each other; The local average voltage estimate, local virtual current estimate, and local state of charge estimate are obtained based on the dynamic average consensus algorithm. In the above formula, For the first i Average local voltage estimate for each energy storage unit For the first i Local virtual current average estimate of each energy storage unit For the first i Average estimate of the local state of charge of each energy storage unit; In order to be with the first i A collection of adjacent energy storage units that communicate and interact with each other. The number of elements in the set; Indicates the first i The output voltage of the DC / DC converter of each energy storage unit Indicates the first i The virtual current of each energy storage unit Indicates the first i Local state of charge of each energy storage unit; The first i The consistency control gain of local output voltage, virtual current, and state of charge (SOC) of each energy storage unit; the equalization factor is calculated based on the measured local SOC and the average estimate of the local SOC. In the above formula, ; Represented as the first i Average estimate of the local state of charge of each energy storage unit Indicates the first i Local state of charge of each energy storage unit; k This is the charging / discharging mode switching coefficient. When the output power of the photovoltaic power source is less than the power consumption of the load, k =1; When the output power of the photovoltaic power source is greater than the power consumption of the load. k =-1; l , h These are the lower and upper limits of the equilibrium factor, respectively. The virtual current of the energy storage unit is determined based on its relative capacity factor, equalization factor, and actual output current. In the above formula, Indicates the first i The virtual current of each energy storage unit For the first i The relative capacity factor of each energy storage unit For the first i The actual output current of each energy storage unit.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the coordinated control method for multiple parallel energy storage systems as described in any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the coordinated control method for multiple parallel energy storage systems as described in any one of claims 1 to 5.

Images