A method, device and medium for configuring the capacity of an energy storage system based on loss calculation

Abstract

The present invention provides a method, device and medium for configuring the capacity of an energy storage system based on loss calculation. The method includes the following steps: S1. Considering the ohmic resistance brought by the diaphragm resistance, electrode material, electrolyte and fluid, and the connection of the tab in the battery, as well as the polarization resistance generated instantaneously when the current is loaded, an energy storage battery charge-discharge loss index is established; S2. Considering the DC cable loss, low, medium and high voltage cable losses, PCS loss and transformer station loss of the energy storage system, an energy storage system loss index is established; S3. Considering the internal power supply of the auxiliary system, based on the power consumption of the cooling system, PCS, BMS and video monitoring system, an energy storage auxiliary loss index is established; S4. According to the grid connection point power, discharge duration of the photovoltaic energy storage power station, whether the power supply of the auxiliary system is provided by the energy storage system, and whether there is a constant power discharge requirement, the configured capacity of the energy storage system is confirmed. The present invention quantifies the charge-discharge loss of the energy storage device itself and establishes a more accurate energy storage system loss model.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage on the power generation side, and relates to a method for configuring the capacity of a new energy power generation side energy storage system, in particular to a method, device and medium for configuring the capacity of an energy storage system based on loss calculation. Background Art

[0002] Energy storage systems are currently a hot topic in the development of new energy projects at home and abroad. With the world's consensus on global carbon reduction, building an energy supply system dominated by clean energy such as wind power and photovoltaic power has become an important goal of the world's energy transformation. To promote the vigorous development of the new energy power generation field, the power grid needs to have strong new energy power transmission and consumption capabilities, and the installation of a large-scale energy storage system on the new energy power generation side is significantly helpful for new energy power stations to access the power system, the consumption of renewable energy, and frequency modulation and peak shaving on the grid side.

[0003] At present, many provinces in China have introduced a number of policies stipulating that in order to improve the consumption capacity of newly built wind power and photovoltaic power generation projects, it is necessary to reasonably plan and build an appropriate scale of new energy storage facilities. The installed capacity of the energy storage system usually needs to be configured at least according to 10% - 20% of the installed capacity of the power station according to the requirements of different provinces and cities, and there are also certain requirements for the continuous duration of the energy storage device.

[0004] At the same time, the configuration of overseas energy storage systems usually considers their economic benefits and the power requirements of the grid connection point. By clarifying the construction purpose, business model, installed capacity of the new energy power station, etc., the initial power and discharge duration of the energy storage system are selected.

[0005] The existing energy storage capacity configuration methods usually configure the installed capacity of the energy storage system by applying its capacity annual attenuation (SOH) curve based on the initial power and discharge duration of the energy storage system. However, the system loss and auxiliary power consumption loss of the energy storage facility are not considered in detail, resulting in the power of the energy storage system reaching the grid connection point not meeting the system requirements after long-term operation. Summary of the Invention

[0006] The first object of the present invention is to provide a method for configuring the capacity of an energy storage system based on loss calculation in view of how to consider the charge and discharge efficiency, system loss and auxiliary power consumption loss of the energy storage facility, so as to ensure that the power at its grid connection point can meet the overall requirements of the system.

[0007] To this end, the above object of the present invention is achieved by the following technical solutions:

[0008] A method for configuring the capacity of an energy storage system based on loss calculation, characterized in that: the method is applied to a large-scale energy storage system on the power generation side, and includes the following steps:

[0009] S1. Consider the ohmic resistance brought by parts such as diaphragm resistance, electrode materials, electrolytes and fluids, and the connection of tabs inside the battery, as well as the polarization resistance generated instantaneously when the current is loaded, and establish the charge and discharge loss index P of the energy storage battery. cha and P dis ;

[0010] The charge and discharge loss P of the energy storage battery cha and P dis are respectively:

[0011]

[0012]

[0013] Among them: P dis is the power loss during the charging process of the energy storage system; P cha is the power loss during the discharging process of the energy storage system; is the rated ampere-hour of a single cell; is the rated operating voltage of a single cell; is the maximum energy capacity of the energy storage system; r is the internal resistance of a single cell; k is the polarization resistance of a single battery unit; E is the electrical energy stored in the energy storage system; P bat is the power of the energy storage system;

[0014] S2. Consider the DC cable loss, low, medium and high voltage cable losses, PCS loss and transformer substation loss of the energy storage system, and establish the loss index P sys ;

[0015] P sys = P cab + P pcs + P sts (0.11)

[0016]

[0017] P pcs = (1 - α)P P (0.13)

[0018] P sts = (1 - β)P s (0.14)

[0019] Among them: P cab is the line loss from the energy storage system to the grid connection point; I DC is the current flowing through the DC cable; R DC is the line resistance of the DC cable; I LVAC is the current flowing through the single-phase low-voltage AC cable; R LVAC is the line resistance of the single-phase low-voltage AC cable; I MVACis the current flowing through the single-phase medium-voltage AC cable; R MVAC is the line resistance of the single-phase medium-voltage AC cable; I HVAC is the current flowing through the single-phase high-voltage AC cable; R HVAC is the line resistance of the single-phase high-voltage AC cable; P pcs is the power loss on the PCS; P P is the power input to the DC side of the PCS; α is the conversion efficiency of the PCS, and α is a constant; P sts is the power loss on the box-type transformer; P s is the power input to the low-voltage side of the box-type transformer; β is the conversion efficiency of the box-type transformer, and β is a constant;

[0020] S3. Considering the internal power supply of the auxiliary system, based on the power consumption of the cooling system, PCS, BMS, and video monitoring system, establish the energy storage auxiliary loss index P aux ;

[0021]

[0022] Among them: P aux is the power consumption of the energy storage auxiliary system; P b is the output power of the energy storage container; is the power consumption coefficient of the energy storage container temperature control system; ξ is the power consumption coefficient of the PCS device; ε is the power consumption coefficient of the energy storage container BMS system; μ is the power consumption coefficient of the energy storage container video monitoring system;

[0023] S4. According to the grid connection point power, discharge duration, whether the auxiliary system power supply is provided by the energy storage system, and whether constant power discharge is required in the photovoltaic and energy storage power station, confirm the configuration capacity of the energy storage system;

[0024] Considering the static loss of the battery during transportation, the loss during installation and commissioning, and the heat loss caused by environmental factors, set a redundancy coefficient to cover the battery capacity consumption brought by the above losses. Therefore, the final capacity configuration of the energy storage system is:

[0025]

[0026] Among them: E bat is the capacity of the energy storage system to be configured; P bat is the power of the energy storage system; P poc is the grid connection point power requirement; h is the energy storage system discharge duration requirement; λ is the redundancy coefficient.

[0027] The second object of the present invention is to provide an electronic device.

[0028] To this end, the above object of the present invention is achieved by the following technical solutions:

[0029] An electronic device includes a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that: when the processor executes the computer program, the steps of the energy storage system capacity configuration method based on loss calculation as described above are implemented.

[0030] Another object of the present invention is to provide a non-transitory computer-readable storage medium.

[0031] To achieve this, the above object of the present invention is realized through the following technical solutions:

[0032] A non-transitory computer-readable storage medium stores a computer program thereon, characterized in that: when the computer program is executed by a processor, the steps of the energy storage system capacity configuration method based on loss calculation as described above are implemented.

[0033] The present invention provides a method, device, and medium for configuring the capacity of an energy storage system based on loss calculation. Aiming at the problems that the existing energy storage capacity configuration scheme does not consider the charge and discharge losses of energy storage devices perfectly and the calculation of system losses and auxiliary power consumption losses is inaccurate, etc., the present invention improves the expression of its charge and discharge losses based on the ohmic resistance and polarization resistance inside the energy storage device; at the same time, considering the charge and discharge losses, line losses, PCS losses, box transformer losses, auxiliary power consumption, etc. of the energy storage system, an energy storage system loss model is established; finally, considering the requirements of the grid connection point power, discharge duration, and constant power discharge of the energy storage power station, a method for configuring the capacity of the energy storage system based on loss calculation is proposed. Compared with the traditional energy storage system capacity configuration scheme, this scheme quantifies the charge and discharge losses of the energy storage device itself, establishes a more accurate energy storage system loss model, comprehensively considers the DC cable losses, PCS losses, low-voltage AC cable losses, box transformer losses, medium-voltage AC cable losses, main transformer losses, high-voltage AC cable losses, auxiliary power consumption losses (including air conditioners, battery management systems, and video monitoring systems) of the entire energy storage system, improves the loss model that needs to be considered in the energy storage system capacity configuration process, and enables the configured capacity of the energy storage system to more accurately meet the requirements. The present invention can respond to grid requirements more precisely, and on the premise of ensuring its power supply reliability and grid stability, avoid the phenomenon of under-allocation or over-allocation of energy storage capacity. Description of the Drawings

[0034] Figure 1 It is the main wiring diagram of the energy storage system.

[0035] Figure 2 It is the flowchart of the method for configuring the capacity of the energy storage system based on loss calculation provided by the present invention. Detailed Embodiments

[0036] The present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

[0037] AsFigure 1 As shown in the figure, the main wiring diagram of the energy storage system includes an energy storage device 1, a DC cable 2, a PCS device 3, a low-voltage AC cable 4, a box transformer system 5, a medium-voltage AC cable 6, a main transformer 7, and a high-voltage AC cable 8.

[0038] A method for configuring the energy storage capacity considering system losses includes the following steps:

[0039] S1. Considering the ohmic resistance brought by parts such as the diaphragm resistance, electrode material, electrolyte and fluid, and connection of the tab in the battery, and the polarization resistance generated instantaneously when the current is loaded, establish the charge and discharge loss index P of the energy storage battery cha 、P dis ;

[0040] S2. Considering the DC cable loss, low, medium, and high-voltage cable losses, PCS loss, and box transformer loss of the energy storage system, establish the energy storage system loss index P sys ;

[0041] S3. Considering the internal power supply of the auxiliary system, based on the power consumption of the cooling system, PCS, BMS, and video monitoring system, establish the energy storage auxiliary loss index P aux ;

[0042] S4. According to the grid connection point power of the photovoltaic energy storage power station, discharge duration, whether the power supply of the auxiliary system is provided by the energy storage system, and whether the constant power discharge requirement is met, confirm the configured capacity of the energy storage system;

[0043] In the present invention, the energy storage system is a lithium-ion battery. The losses caused by connection or cell inconsistency during the energy storage integration process are not considered, and the DOD of the energy storage system is considered according to 100%.

[0044] Specifically, the above method for configuring the energy storage capacity considering system losses is implemented in the following manner:

[0045] In step S1, the charging loss P of the energy storage battery cha and the discharging loss P dis :

[0046]

[0047]

[0048] In the formula: P dis is the power loss of the energy storage battery during the charging process; P cha is the power loss of the energy storage battery during the discharging process; is the rated ampere-hour number of one cell; is the rated operating voltage of one cell; is the maximum energy capacity of the energy storage system; r is the internal resistance of a single cell; k is the polarization resistance of a single battery unit; E is the electrical energy stored in the energy storage system; P bat is the power of the energy storage system.

[0049] In step S2, the system losses of the energy storage include cable losses, PCS losses, and transformer losses:

[0050] P sys = P cab + P pcs + P sts

[0051]

[0052] P pcs = (1 - α)P P

[0053] P sts = (1 - β)P s

[0054] Among them: P cab is the line loss from the energy storage system to the grid connection point; I DC is the current flowing through the DC cable; R DC is the line resistance of the DC cable; I LVAC is the current flowing through the single-phase low-voltage AC cable; R LVAC is the line resistance of the single-phase low-voltage AC cable; I MVAC is the current flowing through the single-phase medium-voltage AC cable; R MVAC is the line resistance of the single-phase medium-voltage AC cable; I HVAC is the current flowing through the single-phase high-voltage AC cable; R HVAC is the line resistance of the single-phase high-voltage AC cable; P pcs is the power loss on the PCS; P P is the power input on the DC side of the PCS; α is the conversion efficiency of the PCS, and α is a constant; P sts is the power loss on the box transformer; P s is the power input on the low-voltage side of the box transformer; β is the conversion efficiency of the box transformer, and β is a constant.

[0055] In step S3, the auxiliary loss P aux of the energy storage system includes cooling system loss, battery monitoring system loss, and video monitoring system loss:

[0056]

[0057] Among them: P aux is the power consumption of the energy storage auxiliary system; P b is the output power of the energy storage container; Let η be the power consumption coefficient of the energy storage container temperature control system; ξ be the power consumption coefficient of the PCS device; ε be the power consumption coefficient of the energy storage container BMS system; μ be the power consumption coefficient of the energy storage container video monitoring system.

[0058] In step S4, considering the static loss of the battery during transportation, the loss during installation and commissioning, and the heat loss caused by environmental factors, a redundancy coefficient is set to cover the battery capacity consumption brought by the above losses. Therefore, the final capacity configuration of the energy storage system is:

[0059]

[0060] Where: P bat is the power of the energy storage system; E bat is the capacity of the energy storage system to be configured; P poc is the power requirement at the grid connection point; h is the required discharge duration of the energy storage system; λ is the redundancy coefficient.

[0061] The present invention considers the internal resistance and polarization resistance of the energy storage device, and proposes an expression for the charge and discharge loss of the energy storage device based on its electrochemical characteristics. At the same time, it considers the overall loss of the energy storage system, including line loss, PCS loss, transformer loss, auxiliary power consumption loss, etc. Based on the above losses, considering the power requirement at the grid connection point of the energy storage power station, the discharge duration of the energy storage, and whether the energy storage system discharges at a constant power, etc., a method for configuring the capacity of the energy storage system based on loss calculation is proposed. Compared with the traditional energy storage system capacity configuration scheme, this scheme quantifies the charge and discharge loss of the energy storage battery itself and details the overall loss link of the energy storage system, can accurately respond to the grid requirements, effectively configure the capacity of the energy storage system in the energy storage and the energy storage system in the photovoltaic energy storage power station, and ensure its power supply reliability and grid stability.

[0062] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for configuring the capacity of the energy storage system based on loss calculation as described above.

[0063] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the method for configuring the capacity of the energy storage system based on loss calculation as described above.

[0064] The above computer-readable storage medium can be any available medium or data storage device that can be accessed by the processor in the electronic device, including but not limited to magnetic memories such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc., optical memories such as CDs, DVDs, BDs, HVDs, etc., and semiconductor memories such as ROM, EPROM, EEPROM, non-volatile memories (NANDFLASH), solid-state drives (SSD), etc.

[0065] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices produce a means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0066] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including an instruction means that implements the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0067] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0068] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0069] The above specific embodiments are used to explain the present invention, which are only the preferred embodiments of the present invention and do not limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and scope of the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A method for configuring the capacity of an energy storage system based on loss calculation, characterized in that: The method is applied to a large-scale energy storage system on the power generation side and includes the following steps: S1. Considering the ohmic resistance caused by the diaphragm resistance, electrode materials, electrolyte and fluid, and the connection of the tab in the battery, as well as the polarization resistance generated instantaneously when the current is applied, establish the charge and discharge loss index P of the energy storage battery cha 、P dis ; Charge and discharge loss P of energy storage battery cha , P dis Are respectively Where: P dis is the power loss of the energy storage system during charging; P cha is the power loss of the energy storage system during discharging; is the rated ampere-hour of a single cell; is the rated operating voltage of a single cell; is the maximum energy capacity of the energy storage system; r is the internal resistance of a single cell; k is the polarization resistance of a battery unit; E is the electrical energy stored in the energy storage system; P bat is the power of the energy storage system; S2. Considering the DC cable losses, low, medium and high voltage cable losses, PCS losses and transformer losses of the energy storage system, establish the energy storage system loss index P sys ; P sys = P cab + P pcs + P sts (0.3) P pcs = (1 - α)P P (0.5) P sts = (1 - β)P s (0.6) Among them: P cab is the line loss from the energy storage system to the grid connection point; I DC is the current flowing through the DC cable; R DC is the line resistance of the DC cable; I LVAC is the current flowing through the single-phase low-voltage AC cable; R LVAC is the line resistance of the single-phase low-voltage AC cable; I MVAC is the current flowing through the single-phase medium-voltage AC cable; R MVAC is the line resistance of the single-phase medium-voltage AC cable; I HVAC is the current flowing through the single-phase high-voltage AC cable; R HVAC is the line resistance of the single-phase high-voltage AC cable; P pcs is the power loss on the PCS; P P is the power input on the DC side of the PCS; α is the conversion efficiency of the PCS, and α is a constant; P sts is the power loss on the transformer substation; P s is the power input on the low-voltage side of the transformer substation; β is the conversion efficiency of the transformer substation, and β is a constant; S3. Consider the internal power supply of the auxiliary system, and establish the energy storage auxiliary loss index P based on the power consumption of the cooling system, PCS, BMS, and video monitoring system aux ; Where: P aux is the power consumption of the energy storage auxiliary system; P b is the output power of the energy storage container; is the power consumption coefficient of the energy storage container temperature control system; ξ is the power consumption coefficient of the PCS device; ε is the power consumption coefficient of the energy storage container BMS system; μ is the power consumption coefficient of the energy storage container video monitoring system; S4. Confirm the configured capacity of the energy storage system according to the grid connection point power of the photovoltaic energy storage power station, the discharge duration, whether the auxiliary system power supply is provided by the energy storage system, and the requirement of constant power discharge; Considering the static loss of the battery during transportation, the loss during installation and commissioning, and the heat loss caused by environmental factors, a redundancy factor is set to cover the battery capacity consumption caused by the above losses. Therefore, the final capacity configuration of the energy storage system is: Where: E bat is the energy storage system capacity to be configured; P bat is the power of the energy storage system; P poc is the power requirement at the grid connection point; h is the required discharge duration of the energy storage system; λ is the redundancy factor.

2. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the steps of the method for configuring the capacity of the energy storage system based on loss calculation as described in claim 1.

3. 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 method for configuring the capacity of the energy storage system based on loss calculation as described in claim 1.

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