Energy storage system enabling expansion of battery containers and operation thereof

Abstract

The present invention relates to an energy storage system enabling the expansion of battery containers and an operating method thereof. More specifically, the present invention provides: an energy storage system which is optimized by using a minimum number of PCSs and a required battery container capacity by differentiating the number of battery containers linked per PCS, and in which the expansion of additional battery containers is possible after a certain period of operation without an increase in grid connection capacity until an initial design reaches the end of life; and an energy storage system enabling the expansion of battery containers and an operating method thereof, wherein the energy storage system is operated optimally by reflecting the characteristics of the battery containers after expansion, thereby minimizing investment costs while enhancing the reliability and stability of the entire energy storage system through rearrangement of the battery containers rather than simple expansion, and providing a plan for managing the battery containers that are of different ages.

Description

Energy storage system capable of expanding battery containers and its operation

[0001] The present invention relates to an energy storage system capable of expanding battery containers and a method of operating the same. More specifically, it relates to an energy storage system capable of expanding additional battery containers after a certain period of operation without increasing grid connection capacity until the initial design reaches the end of its lifespan, by dualizing the number of battery containers connected per PCS to optimize the system using a minimum PCS and the required battery container capacity. It also relates to an energy storage system capable of expanding battery containers and a method of operating the same that is capable of minimizing investment costs by optimally operating the energy storage system by reflecting the characteristics of the battery containers after expansion, thereby increasing the reliability and stability of the entire energy storage system through the rearrangement of battery containers rather than simple expansion, and providing a management method for battery containers of different ages.

[0002] The use of fossil fuels emits large amounts of CO2, causing global warming. As this global warming leads to severe climate change, restrictions on the use of fossil energy are becoming increasingly severe. Consequently, major developed countries are strengthening regulations and support at the national level, and new markets and industries such as renewable energy, energy storage systems, and virtual power plants are being created, with energy storage systems (ESS) playing a particularly important role in this.

[0003] In other words, there is increasing interest in energy storage systems that can maximize the efficiency of energy use. An energy storage system is a system designed to reduce electricity costs and ensure efficient energy use by storing electricity in batteries, such as secondary batteries (lithium-ion, nickel-cadmium, nickel-hydrogen, nickel-zinc, etc.), which are supplied from commercial power sources or self-installed renewable energy sources (solar, wind, etc.) at companies, schools, homes, and factories during off-peak hours when prices are low, and then supplying it during periods of high power consumption on the load side.

[0004] An ESS is a system that improves power utilization efficiency by storing electricity and supplying it when needed. In other words, it brings innovation to demand management by storing electricity when rates are low and allowing it to be used during peak hours when rates are high. The use of an ESS stabilizes renewable energy outputs, such as solar and wind power, and increases the efficiency of energy utilization.

[0005] ESS is a comprehensive system that integrates various components, such as batteries, a Battery Management System (BMS), a Power Conversion System (PCS), and an Energy Management System (EMS), into a single system according to the purpose to provide integrated management, control, and control.

[0006] In other words, the battery stores electricity through the PCS and discharges it when needed, while the BMS provides information on the battery's charge status through an external interface and performs protection functions such as preventing overcharging. The PCS receives power from a power source and converts it into AC or DC to store it in the battery or release it into the grid. The EMS monitors the status of the battery and the PCS, and is a management system for monitoring and controlling the ESS from a control center or similar location.

[0007] Recently, Battery Energy Storage Systems (BESS) have been connected to the power grid, contributing to carbon neutrality and the expansion of renewable energy acceptance, and their importance is increasing even further.

[0008] The Power Conditioning System (PCS) connected to the power grid is a power device responsible for power conversion; it manages the connection capacity with the grid and serves as a standard for licensing and other requirements.

[0009] The BESS is connected to the battery system as a sub-stage of the PCS and plays the role of storing or discharging energy; although it is independent of the connection capacity, the discharge amount required during its lifespan is important.

[0010] When a BESS is connected to a power grid, capacity can be guaranteed through initial over-design to satisfy the conditions during its lifespan, which requires a preset discharge amount for 15 to 20 years; however, this has the disadvantage of high initial investment costs. In addition, to overcome this, only the batteries responsible for energy must be expanded to utilize it as a sustainable power source.

[0011] Previously, there were two ways to expand the battery.

[0012] The first method is to expand the entire ESS consisting of a PCS and a battery, and the second method is to add a battery container to the existing PCS.

[0013] In the case of the first method, since the capacity of the ESS connected to the existing grid is changed, it has the disadvantage of causing various problems such as the stability and reliability of the power grid.

[0014] In the case of the second method, since new equipment is added to the existing facilities, differences in the internal performance of the batteries can cause issues with system stability. Specifically, new batteries degrade rapidly, and as their internal resistance increases in an attempt to match the performance of the existing equipment, a problem arises where the required discharge amount cannot be met. In other words, this presents the same problem as replacing only a portion of the batteries with new ones when connecting them in parallel.

[0015] Therefore, against this backdrop, strategies for intermediate battery augmentation are becoming important, and it is predicted that this will become a key technology for energy storage devices in the future.

[0016] Korean registered patent [10-1936864] discloses a method of operating an energy storage system based on a profile.

[0017] Korean registered patent [10-2652000] discloses a power operation method and a power operation device that are operated in a power operation device for operating an energy storage system based on a power conversion system for linking heterogeneous batteries.

[0018] A battery system is disclosed in Korean registered patent [10-2706469].

[0019] Korean registered patent [10-2727557] discloses an ESS capacity calculation device and method that considers battery degradation.

[0020] Accordingly, the present invention has been devised to solve the problems described above. The objective of the present invention is to provide an energy storage system capable of expanding battery containers and a method of operation thereof, which is optimized by using a minimum number of PCS and required battery container capacity by dualizing the number of battery containers connected per PCS, and which allows for the expansion of additional battery containers after a certain period of operation without increasing grid connection capacity until the initial design reaches the end of its lifespan; and which is capable of minimizing investment costs by optimally operating the energy storage system by reflecting the characteristics of the battery containers after expansion, thereby increasing the reliability and stability of the entire energy storage system through the rearrangement of battery containers rather than simple expansion, and providing a management method for battery containers of different ages.

[0021] The purposes of the embodiments of the present invention are not limited to those mentioned above, and other unmentioned purposes will be clearly understood by those skilled in the art from the description below.

[0022] An energy storage system capable of expanding battery containers according to one embodiment of the present invention for achieving the above-mentioned purpose comprises: a plurality of battery containers (100) for providing charging power and discharging power; and a plurality of power conversion devices (PCS) (200) for performing AC-DC conversion of charging power and discharging power for the battery containers in conjunction with a preset number of battery containers, and is characterized by dividing the number of battery containers that can be connected to each power conversion device (PCS) into two types, and is characterized by setting the unit capacity of each battery container, the required capacity of the PCS, the unit capacity of the PCS, the total number of PCSs, and the number of two types of battery containers connected to each power conversion device, thereby setting the number of battery containers initially installed and the number of battery containers additionally expanded according to the battery replenishment plan.

[0023] In addition, an operation method of an energy storage system capable of expanding battery containers according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: an expandable design step (S10) of configuring the energy storage system according to the rated capacity, operating capacity, and unit capacity of the PCS, the unit capacity of each battery container, the number of initially installed battery containers, the number of additionally expanded battery containers according to a battery replenishment plan, a batch ratio according to the total number of PCSs, the number of blank slots, and the number of sectors; a first operation step (S20) of operating the energy storage system using the configuration of a plurality of battery containers and PCSs set in the expandable design step; and a first expansion step (S30) in which, after a first preset time, the remaining connectable battery containers connected to PCSs corresponding to a preset number of blank slots according to the battery replenishment plan are transferred, and a new battery container capable of being connected to the maximum number of empty PCSs is expanded. It includes a first adjustment step (S40) for calculating the PCS operating capacity of a sector that is changed by the battery replenishment plan, adjusting the charge / discharge rate (C-rate), and recalculating the PCS operating capacity of each sector; and a second operation step (S50) for operating the energy storage system according to the adjusted C-rate and the recalculated PCS operating capacity using the configuration of a plurality of battery containers and PCS set in the first expansion step.

[0024] In addition, according to one embodiment of the present invention, a computer-readable recording medium is provided that stores a program for implementing an operation method of an energy storage system capable of expanding the battery container.

[0025] In addition, according to one embodiment of the present invention, a program stored on a computer-readable recording medium is provided to implement a method of operating an energy storage system capable of expanding the battery container.

[0026] According to an energy storage system capable of expanding battery containers and a method of operating the same according to one embodiment of the present invention, the structure of the energy storage system can be optimized by dualizing the number of battery containers connected per PCS and utilizing the minimum PCS and the required capacity of the battery containers.

[0027] In addition, according to an energy storage system capable of expanding battery containers and a method of operating the same according to one embodiment of the present invention, an energy storage system capable of expanding additional battery containers after a certain period of operation without increasing grid connection capacity until the initial design reaches the end of its lifespan is provided, and there is an effect of being able to optimally operate the energy storage system by reflecting the characteristics of the battery containers after expansion.

[0028] In addition, according to an energy storage system capable of expanding battery containers and a method of operation thereof according to one embodiment of the present invention, it is possible to minimize investment costs while increasing the reliability and stability of the entire energy storage system through the rearrangement of battery containers rather than simple expansion, and to provide a management method for battery containers of different ages.

[0029] In addition, according to an energy storage system capable of expanding battery containers and a method of operation thereof according to one embodiment of the present invention, it is possible to optimize within the initial set capacity and at a minimum cost, and simultaneously achieve a guaranteed capacity by installing a minimum number of initial battery containers and replenishing additional battery containers within the lifespan.

[0030] In addition, according to an energy storage system capable of expanding a battery container and a method of operating the same, as per an embodiment of the present invention, the battery discharge amount can be guaranteed without additional capacity expansion from the grid's perspective, and when establishing a replenishment plan, there is an effect of being able to operate while lowering the C-rate to manage the battery's lifespan.

[0031] In addition, according to an energy storage system capable of expanding battery containers and a method of operating the same according to one embodiment of the present invention, space for battery containers to be replenished in the future can be secured through blank slot settings to establish a relocation plan, and battery life and characteristics can be clustered and managed and operated through sector settings.

[0032] FIG. 1 is a configuration diagram of an energy storage system capable of expanding a battery container according to one embodiment of the present invention.

[0033] FIG. 2 is a drawing for explaining the specifications of an energy storage system capable of expanding a battery container according to an embodiment of the present invention.

[0034] FIG. 3 is a drawing for explaining a battery replenishment plan for an energy storage system capable of expanding a battery container according to an embodiment of the present invention.

[0035] FIG. 4 is a diagram illustrating a change in sectors according to a battery replenishment plan of an energy storage system capable of expanding a battery container according to an embodiment of the present invention.

[0036] FIG. 5 is a flowchart of an exemplary embodiment of an operation method of an energy storage system capable of expanding battery containers according to the present invention.

[0037] FIG. 6 is a detailed flowchart of the first adjustment step (S40) of FIG. 5.

[0038] FIG. 7 is a detailed flowchart of the second adjustment step (S70) of FIG. 5.

[0039] FIGS. 8a to 8e are drawings for explaining sector-specific changes according to the operation method of an energy storage system capable of expanding battery containers according to the present invention.

[0040] FIG. 9 is a diagram illustrating the change in sector-specific charge / discharge rate (C-rate) over time in the operation method of an energy storage system capable of expanding battery containers according to the present invention.

[0041] *Detailed explanation of the main symbols in the drawing*

[0042] 10: Power System

[0043] 100: Battery container

[0044] 200: Power Conversion System (PCS)

[0045] 41: Sector 1 (Sector A)

[0046] 42: Second sector (F sector)

[0047] 43: Third sector (E sector)

[0048] 44: 4th sector (D sector)

[0049] 45: 5th sector (C sector)

[0050] 46: Sector 6 (Sector B)

[0051] S10: Design stage for expansion

[0052] S20: 1st Operational Phase

[0053] S30: 1st expansion phase

[0054] S40: 1st adjustment stage

[0055] S50: Second operational phase

[0056] S60: 2nd expansion phase

[0057] S70: Second adjustment stage

[0058] S80: Third Operational Phase

[0059] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0060] When it is stated that one component is "connected" or "joined" to another component, it should be understood that while it may be directly connected or joined to that other component, there may also be other components in between.

[0061] On the other hand, when it is stated that one component is "directly connected" or "directly coupled" to another component, it should be understood that there are no other components in between.

[0062] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, processes, operations, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, processes, operations, components, parts, or combinations thereof.

[0063] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0064] The present invention will be described in more detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Furthermore, unless otherwise defined, technical and scientific terms used shall have the meaning commonly understood by those skilled in the art to which this invention pertains. Descriptions of known functions and configurations that could unnecessarily obscure the essence of the present invention in the following description and attached drawings are omitted. The drawings presented below are provided as examples to ensure that the spirit of the present invention is sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Additionally, throughout the specification, the same reference numerals indicate the same components. It should be noted that the same components in the drawings are represented by the same reference numerals wherever possible.

[0065] The present invention reflects the characteristics of the battery and proposes a stable operation method to maintain the required discharge amount by replenishing the battery in the middle without changing from the initial design.

[0066] Batteries are typically in the form of containers with fixed energy capacity, and while the battery capacity is designed considering the required capacity and lifespan, the connection with PCS equipment is configured as an ESS system through a separate design.

[0067] In cases where the system is operated with a mix of initially installed batteries and batteries replenished after several years, we propose a method for replenishing batteries and a management plan for batteries of different ages to enhance operational reliability and stability, thereby mitigating the changes in characteristics associated with age.

[0068] The battery offers an optimal lifespan, but for optimal combination with the PCS, optimization of the linked system is required.

[0069] If not optimized, it requires increased costs and higher overall investment expenses, such as site costs; furthermore, since capacity per area is increasing due to battery research and development, this cannot be generalized.

[0070] The connected PCS is also the same, but since it must be designed in harmony with the combination of the two devices and the characteristics of the market requiring it, the ultimate goal is to optimize within the minimum cost and initial set capacity, while achieving guaranteed capacity through additional replenishment within the lifespan along with minimal initial battery installation.

[0071] When installing an ESS to maintain guaranteed capacity, the number of initial battery containers is defined, and the number of additional battery containers to be added after a certain period is defined. Since the facility is used for more than 20 years, the number of additions may be one or more.

[0072] The energy storage system capable of expanding batteries according to the present invention optimizes the minimum number of PCS units and the required battery container capacity by dualizing the number of battery containers that can be linked per PCS through a batch.

[0073] By setting up blank slots, a space for future battery connections can be secured to establish a relocation plan, and by setting up sectors, battery life or characteristics can be clustered for management and operation.

[0074] FIG. 1 is a configuration diagram of an energy storage system capable of expanding a battery container according to one embodiment of the present invention, and FIG. 2 is a drawing for explaining the specifications of an energy storage system capable of expanding a battery container according to one embodiment of the present invention.

[0075] As illustrated in FIG. 1, an energy storage system capable of expanding battery containers includes a plurality of battery containers (100) for providing charging power and discharging power, and a plurality of power conversion devices (PCS) (200) connected to a preset number of battery containers to perform AC-DC conversion of charging power and discharging power for the battery containers.

[0076] The number of battery containers that can be connected to each power conversion device (PCS) was classified into two categories.

[0077] The number of battery containers capable of being connected is divided into the maximum number of battery containers capable of being connected and the remaining number of battery containers capable of being connected, and the total number of PCS units is divided into a PCS equipped with the maximum number of battery containers capable of being connected and a PCS equipped with the remaining number of battery containers capable of being connected. Here, for example, it was divided into a PCS with a maximum of 6 connected units and a PCS with a remaining of 3 connected units.

[0078] According to the specifications of the energy storage system, the unit capacity of each battery container, the required capacity of the PCS, the unit capacity of the PCS, the total number of PCS units (quantity), and the number of two types of battery containers connected to each power conversion device are set, and the number of battery containers initially installed (quantity) and the number of additional battery containers added according to the battery replenishment plan are set.

[0079] As shown in Fig. 2, if the unit capacity of the battery container is 5.644 MWh and the number of battery containers initially installed is 474, the total is 2.675 GWh.

[0080] As an assumption, it is planned to replenish 30 battery containers in the 5th year and 10th year, for a total of 60, and it is defined that up to 6 battery containers can be connected with a unit capacity of 3.6 MW of PCS, the operating capacity is designed to be 275 MW, and up to 3 containers can be used as a remainder.

[0081] 1. Batch Settings

[0082] x is defined as the maximum number of battery containers that can be linked, and

[0083] Define y as the number of remaining connectable battery containers, (where x and y are natural numbers, x > y, and x ≠ y).

[0084] Total PCS_x is defined as a PCS algebra linked by x numbers, and

[0085] Total PCS_y is defined as a PCS algebra linked by y numbers, and

[0086] Total PCS is defined as the total number of the above PCS, and

[0087] If Total Batt. Container is defined as the number of the initial battery containers installed above,

[0088] The above batch ratio can be expressed as shown in [Mathematical Formula 1] below.

[0089] [Mathematical Formula 1]

[0090]

[0091]

[0092] By substituting x and y, and Total Batt. Container and Total PCS into the above [Equation 1], Total PCS_x and Total PCS_y can be expressed as shown in the following [Equation 2].

[0093] [Mathematical Formula 2]

[0094]

[0095] If we define Aug_BC_i as the number of battery containers replenished in the i-th step after a preset time, and define the sum of Aug_BC_i as the number of battery containers being expanded as z, and define zz as the total sum of the number of battery containers initially installed (Total Batt. Container) and the number of battery containers being expanded (z), then (where z is a natural number.)

[0096] The number of the first battery containers installed is set as a multiple of (xy), the total sum (zz) of the number of the first battery containers installed and the number of the expanded battery containers is set as a multiple of x, and the product of Total PCS_y and y, which is the number of PCS linked by y, must be equal to or greater than the number of the expanded battery containers (z).

[0097] At this time, y must be set to at least 1 / 2 times the total number of battery containers being expanded. This is because it is necessary to transfer to a block composed of less than the maximum linkage and expand new battery containers.

[0098] In other words, during the initial design phase, the layout is designed to satisfy the above conditions so that expansion is possible.

[0099] 2. Blank Slot Settings

[0100] A blank slot is the number of PCSs to link the battery container to be replenished with the PCS.

[0101] In the case of a plan for z expansions based on placement criteria of x and y, the number of blank slots should be allocated as z / x, and each blank slot can receive (xy) battery containers. Therefore, the number of blank slots is set as the product of y / (xy) and z / x. Here, z / x is a natural number, and the product of y / (xy) and z / x is also a natural number.

[0102] That is, a blank slot refers to the number of PCS units that are intentionally equipped with only remaining battery containers capable of connection for the purpose of expansion.

[0103] The following [Table 1] is a table to explain the method of setting blank slots.

[0104] xyzBlank slot636010656050

[0105] As shown in [Table 1], the blank slots vary depending on the values ​​of x and y. If x is 6 and y is 3, 10 PCS must be set as blank slots. On the other hand, if x is 6 and y is 5, 50 PCS must be set as blank slots.

[0106] [Table 2] below is a table to explain the number of blank slots for each expansion cycle, assuming that the expansion is performed identically when the number of expansions is 2.

[0107] xyz1z2Blank slot 1Blank slot 263303055

[0108] FIG. 3 is a diagram illustrating a battery replenishment plan for an energy storage system capable of expanding a battery container according to an embodiment of the present invention. As shown in FIG. 3, once the blank slot is set, the number of PCS units connected to the battery container changes during the initial, first, and second expansions according to the battery replenishment plan.

[0109] Initially, there were 68 and 22 units respectively, but after the first expansion, they were changed to 78 and 12 units, and after the second expansion, they were changed to 88 and 2 units.

[0110] The total number of initial battery containers was 474, but after the first expansion of 30, it became 504, and after the second expansion of 30, it became 534.

[0111] 3. Sector Setup

[0112] The sector is set up for the relocation of batteries to be replenished and is intended to distinguish battery containers connected to a power conversion device (PCS).

[0113] The total number of sectors above is composed of 2 + (2 xi), corresponding to the expansion order i. Here, i is a natural number.

[0114] Here, we will explain using the case where the number of expansions is 2 as an example.

[0115] If two expansions are considered, it consists of a total of 6 sectors.

[0116] Table 3 below is a table to explain the number of PCS units in each sector when the ratio of PCS units connected to 6 battery containers and PCS units connected to 3 battery containers is 68:22 for a total of 90 PCS units.

[0117] SectorABCDEFPCS Logarithm 6855552

[0118] Sector A: A sector equipped with six battery containers connected to each PCS, which remains unchanged throughout its lifespan.

[0119] Sector E: A sector equipped with three battery containers connected to PCSs of z1 / x (30 / 6=5), and a sector for supplementing the battery containers that are expanded in the first stage.

[0120] Sector C: A sector equipped with three battery containers connected to z2 / x (30 / 6=5) PCSs; it is a sector for supplementing the secondary expanded battery containers.

[0121] Sector D: A sector that receives the battery container used from the above Sector E, and the quantity is the product of y / (xy) and z / x.

[0122] Sector B: A sector that receives the used battery container from the above Sector C, and the quantity is the product of y / (xy) and z / x.

[0123] Sector F: The difference between the total number of PCS units and the sum of the number of PCS units from Sector A to Sector E, that is, a sector that operates unchanged throughout its lifespan without considering battery replenishment.

[0124] Meanwhile, when battery augmentation is performed, the following cases must be considered.

[0125] When transferring the remaining connected battery containers to the existing PCS, the PCS is changed to the maximum connected battery block.

[0126] The operating capacity of the location where the initial standard changes is increased due to the battery container increased by replenishment, but it must be made without change under the same connection as the existing one.

[0127] Therefore, if we denote the operating capacity of the changing location as 'a', we must subtract 'a' from the product of the unit capacity and the total number of operating units.

[0128] Next, adjust the charge / discharge rate (C-rate) based on each sector.

[0129] FIG. 4 is a diagram illustrating a change in sectors according to a battery replenishment plan of an energy storage system capable of expanding a battery container according to an embodiment of the present invention.

[0130] As shown in Fig. 4, the sector is divided into 6 types of sectors.

[0131] Sector A (Sector 1) (41) is a sector composed of a plurality of power conversion devices (PCS) (PCS #1 to PCS #68) having a maximum number of connectable battery containers x, and remains unchanged for the duration of its lifespan.

[0132] Sector F (second sector) (42) is a sector that is composed of a plurality of power conversion devices having a number y of remaining connectable battery containers and remains intact during the lifespan.

[0133] Sector E (third sector) (43) is a sector that is initially equipped with a number of battery containers y that can be connected in the remaining capacity, and is composed of a plurality of power conversion devices (PCS #79~PCS #83) corresponding to the number of battery containers that are expanded in the first stage, and is composed entirely of new battery containers after the first expansion.

[0134] Sector D (4th sector) (44) is initially equipped with a number of battery containers y that can be connected in the remaining capacity, and is composed of multiple power conversion devices (PCS #69~PCS #73) corresponding to the number of battery containers that are expanded in the first stage, and after the first expansion, it is a sector composed of battery containers that are all used by receiving the battery containers that are initially equipped in the 3rd sector (43).

[0135] Sector C (5th sector) (55) is a sector that is initially equipped with a number of remaining connectable battery containers y, and is composed of a number of power conversion devices (PCS #84~PCS #88) corresponding to the number of battery containers that are expanded in the second stage, and is composed entirely of new battery containers after the second stage expansion.

[0136] Sector B (Sector 6) (46) is initially equipped with a number of battery containers y that can be connected in the remaining capacity, and is composed of multiple power conversion devices (PCS #74~PCS #78) corresponding to the number of battery containers that are expanded in the second stage, and after the second stage expansion, it is a sector composed of battery containers that have been used by receiving the battery containers that are initially equipped in Sector 5 (45).

[0137] Above, the number of maximum connectable battery containers was set to 6 and the number of remaining connectable battery containers was set to 3, and an example of a battery replenishment plan was explained under assumed conditions, but the present invention is not limited thereto, and it is also possible to use other combinations and numbers.

[0138] FIG. 5 is a flowchart of an exemplary operation method of an energy storage system capable of expanding battery containers according to the present invention.

[0139] First, the number of battery containers that can be connected to each power conversion device (PCS) is classified into two types, and an energy storage system is configured according to the rated capacity, operating capacity, and unit capacity of the PCS, the unit capacity of each battery container, the number of battery containers initially installed, the number of battery containers additionally added according to the battery replenishment plan, the batch ratio according to the total number of PCSs, the number of blank slots, and the number of sectors (S10).

[0140] In the above expansionable design step (S10), the number of battery containers that can be connected is divided into the maximum number of battery containers that can be connected and the remaining number of battery containers that can be connected, and the total number of PCS is divided into a PCS that has the maximum number of battery containers that can be connected and a PCS that has the remaining number of battery containers that can be connected.

[0141] If x is defined as the maximum number of battery containers that can be connected, and y is defined as the remaining number of battery containers that can be connected (where x and y are natural numbers, x > y, and x ≠ y), Total PCS_x is defined as the number of PCS units connected by x, Total PCS_y is defined as the number of PCS units connected by y, Total PCS is defined as the total number of PCS units, and Total Batt. Container is defined as the number of battery containers initially installed, then the placement ratio is as shown in [Equation 1] below.

[0142] [Mathematical Formula 1]

[0143]

[0144]

[0145] In the above-mentioned expandable design step (S10), the method for setting blank slots and sectors is as described in FIGS. 1 to 4, so a detailed description is omitted.

[0146] Afterwards, the energy storage system is operated using the configuration of multiple battery containers and PCS set in the expansionable design stage (S20).

[0147] While proceeding to the first operation step (S20), after a first preset time (e.g., 5 years), the remaining battery containers that can be connected to the PCS corresponding to the preset blank slots according to the battery replenishment plan are transferred, and the maximum number of new battery containers that can be connected to the empty PCS is added (S30).

[0148] According to the first expansion step (S30) above, the PCS operating capacity of the sector that is changed by the battery replenishment plan is calculated, the charge / discharge rate (C-rate) is adjusted, and the PCS operating capacity of each sector is recalculated (first adjustment step (S40)).

[0149] Afterwards, the energy storage system is operated according to the C-rate adjusted in the first adjustment step (S40) and the recalculated PCS operating capacity using the configuration of multiple battery containers and PCS set in the first expansion step (S30) (S50).

[0150] Meanwhile, if the number of expansions in the above battery replenishment plan is 2, the process proceeds to the second operation stage (S50), and after a second preset time (e.g., 10 years), the remaining battery containers that can be connected to the PCS corresponding to the preset blank slots according to the second battery replenishment plan are transferred, and the maximum number of new battery containers that can be connected to the empty PCS is expanded (S60).

[0151] According to the second expansion step (S60) above, the PCS operating capacity of the sector that is changed by the second battery replenishment plan is calculated, the C-rate is adjusted, and the PCS operating capacity of each sector is recalculated (S70).

[0152] Afterwards, the energy storage system is operated according to the C-rate adjusted in the second adjustment step (S70) and the recalculated PCS operating capacity using the configuration of multiple battery containers and PCS set in the second expansion step (S60) (S80).

[0153] FIG. 6 is a detailed flowchart of the first adjustment step (S40) of FIG. 5.

[0154] In the first adjustment step (S40) above, first, the relocation of the battery container according to the first battery replenishment plan is performed (S610).

[0155] After the battery container is relocated according to the above first battery replenishment plan, it is determined whether the number of linked battery containers has changed from y to x (S620).

[0156] As a result of the judgment in the above judgment step (S620), the number of connected battery containers changes from y to x, and the operating capacity of x connected PCSs in the sector that changes according to the battery replenishment plan is calculated (S630).

[0157] It is calculated as the difference between the operating capacity of x connected unit PCS x number of configured PCS minus the change in the operating capacity of the changed sector before and after the change.

[0158] Meanwhile, as a result of the judgment in the above judgment step (S620), the number of connected battery containers does not change from y to x, so the operating capacity of y connected PCSs in the sector that changes according to the battery replenishment plan is calculated (S640).

[0159] It is calculated as the difference between the operating capacity of the PCS in the changed sector after the change and the operating capacity before the change, calculated as y connected unit PCS operating capacity x number of configured PCS units - the difference between the operating capacity of the PCS in the changed sector before the change.

[0160] Meanwhile, even if calculated according to step "S640" after the first battery replenishment plan, the operating capacity of the y connected PCSs in the sectors that are changed by the battery replenishment plan remains the same value without change.

[0161] Subsequently, the C-rate calculation of the sector changed by the above battery replenishment plan is updated (S650). It is calculated by dividing the PCS operating capacity by the battery capacity (PCS operating capacity / battery capacity).

[0162] Subsequently, the PCS operating capacity of each sector is recalculated (S660). This is calculated by multiplying the battery capacity by the updated C-rate. (Battery capacity x C-rate)

[0163] Figure 7 is a detailed flowchart of the second adjustment step (S70) of Figure 5.

[0164] In the second adjustment step (S70) above, first, the relocation of the battery container according to the secondary battery replenishment plan is performed (S710).

[0165] After the battery container is relocated according to the above second battery replenishment plan, it is determined whether the number of linked battery containers has changed from y to x (S720).

[0166] As a result of the judgment in the second judgment step (S720), the number of connected battery containers changes from y to x, and the operating capacity of x connected PCSs in the sector that changes according to the battery replenishment plan is calculated (S730).

[0167] It is calculated as the difference between the operating capacity of the PCS in the changed sector after the change and the operating capacity of the changed sector, excluding the first reallocated sector, x connected unit PCS operating capacity x number of configured PCS units.

[0168] Meanwhile, as a result of the judgment in the second judgment step (S720), the number of connected battery containers does not change from y to x, so the operating capacity of y connected PCSs in the sector that changes according to the battery replenishment plan is calculated (S740).

[0169] It is calculated as the difference between the operating capacity of the PCS in the changed sector after the change and the operating capacity of the PCS in the changed sector, excluding the first reallocated sector, multiplied by the operating capacity of the y connected unit PCS x the number of configured PCS units.

[0170] Subsequently, the C-rate calculation of the sector changed by the above battery replenishment plan is updated (S750). It is calculated by dividing the PCS operating capacity by the battery capacity (PCS operating capacity / battery capacity).

[0171] Subsequently, the PCS operating capacity of each sector is recalculated (S760). This is calculated by multiplying the battery capacity by the updated C-rate. (Battery capacity x C-rate)

[0172] FIGS. 8a to 8e are drawings illustrating sector-specific changes according to the operation method of an energy storage system capable of expanding battery containers according to the present invention.

[0173] As shown in Fig. 8a, the initial design was divided into 6 sectors, and the number of PCS in each sector, the number of battery containers connected to each PCS, the battery capacity, the PCS operating capacity, and the C-rate were indicated.

[0174] As shown in Fig. 8b, 30 battery containers were added in the first step to reallocate the number of PCS-linked batteries. The existing E sector batteries were transferred to the D sector.

[0175] Accordingly, the number of battery containers connected to each PCS in sectors D and E increased to 6, and the PCS operating capacity decreased.

[0176] As shown in Fig. 8c, the C-rate of sectors A and D was adjusted, and the PCS operating capacity of sectors A and D was recalculated according to the C-rate adjustment.

[0177] The C-rate of the E sector composed of new battery containers remains unchanged.

[0178] As shown in Fig. 8d, 30 battery containers were added in the second phase to reallocate the number of PCS-linked batteries. The existing C sector batteries were transferred to the B sector.

[0179] Accordingly, the number of battery containers connected to each PCS in sectors C and B increased to 6, and the C-rate decreased from 0.103 to 0.051.

[0180] As shown in Fig. 8e, after the second expansion, the C-rate of sectors A, B, C, and D was adjusted, and the PCS operating capacity of sectors A, B, C, and D was recalculated according to the adjustment of the C-rate.

[0181] FIG. 9 is a diagram illustrating the change in the sector-specific charge / discharge rate (C-rate) over time in the operation method of an energy storage system capable of expanding battery containers according to the present invention.

[0182] As shown in Fig. 9, initially, the C-rate of all sectors was the same at 0.103, and after the first expansion, the C-rate of sectors A and D was adjusted from 0.103 to 0.096. Subsequently, after the second expansion, the C-rate of sectors A, B, C, and D was adjusted from 0.096 to 0.090.

[0183] In conclusion, by operating at a C-rate adjusted according to the replenishment plan of battery containers for each sector, the energy storage system can be operated and managed more stably.

[0184] Stability can be ensured by applying the same approach based on the characteristics and operational history of reused batteries as well as new battery containers.

[0185] Although an operation method for an energy storage system capable of expanding a battery container according to one embodiment of the present invention has been described above, it is obvious that a computer-readable recording medium storing a program for implementing the operation method for an energy storage system capable of expanding a battery container, and a program stored on the computer-readable recording medium for implementing the operation method for an energy storage system capable of expanding a battery container, can also be implemented.

[0186] That is, those skilled in the art will readily understand that the method of operating an energy storage system capable of expanding the aforementioned battery container may be provided by being tangibly implemented as a program of instructions for implementing it, and included in a computer-readable recording medium. In other words, it may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc., either individually or in combination. The program instructions recorded on the computer-readable recording medium may be those specifically designed and configured for the present invention, or they may be those known and available to those skilled in computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and USB memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware device may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

[0187] The present invention is not limited to the embodiments described above, and its scope of application is diverse. Furthermore, it is understood that various modifications are possible without departing from the essence of the invention as claimed in the claims.

Claims

1. In an energy storage system capable of expanding battery containers, A plurality of battery containers (100) for providing charging power and discharging power; and A plurality of power conversion devices (PCS) (200) connected to a preset number of battery containers to perform AC-DC conversion of charging power and discharging power for the battery containers Includes, It is characterized by classifying the number of battery containers connectable to each power conversion device (PCS) into two categories, and As the unit capacity of each battery container, the required PCS capacity, and the PCS unit capacity, the total number of PCSs, and the number of two battery containers connected to each power converter are set, An energy storage system capable of expanding battery containers, characterized by setting the number of battery containers initially installed and the number of additional battery containers to be added according to a battery replenishment plan.

2. In Paragraph 1, The number of battery containers capable of being linked above is, It is characterized by being divided into the maximum number of connectable battery containers and the remaining number of connectable battery containers, and An energy storage system capable of expanding battery containers, characterized in that the total number of PCS units is divided into a PCS having the maximum connectable battery container and a PCS having the remaining connectable battery container.

3. In Paragraph 2, An energy storage system capable of expanding battery containers, characterized in that the rated capacity, operating capacity, and unit capacity of the above PCS, the unit capacity of each battery container, the number of battery containers initially installed, the number of battery containers additionally expanded according to the battery replenishment plan, the batch ratio according to the total number of PCS, the number of blank slots, and the number of sectors are determined.

4. In Paragraph 3, x is defined as the maximum number of battery containers that can be linked, and Define y as the number of the remaining connectable battery containers, (where x and y are natural numbers, x > y, and x ≠ y), Total PCS_x is defined as a PCS algebra linked by x numbers, and Total PCS_y is defined as a PCS algebra linked by y numbers, and Total PCS is defined as the total number of the above PCS, and If Total Batt. Container is defined as the number of the initial battery containers installed above, An energy storage system capable of expanding battery containers, characterized by the above-mentioned layout ratio satisfying the following [Mathematical Formula 1]. [Mathematical Formula 1] 5. In Paragraph 4, After a preset time, the number of battery containers replenished for the i-th time is defined as Aug_BC_i, and The sum of Aug_BC_i is the number of battery containers to be added, defined as z (where z is a natural number), If we define zz as the total sum of the number of initially installed battery containers (Total Batt. Container) and the number of expanded battery containers (z), The number of the first battery containers installed above is set as a multiple of (xy), and The total sum (zz) of the number of the first battery containers installed and the number of the expanded battery containers is set as a multiple of x, and The product of Total PCS_y, which is the number of PCS linked by y, and y must be equal to or greater than the number (z) of the battery containers being expanded, and The above blank slot is an algebra of PCS for linking the PCS with the replenishing battery container, and The number of blank slots mentioned above must be allocated as z / x, and Each blank slot can receive (xy) battery containers, and It is characterized by being set to the product of y / (xy) and z / x, and An energy storage system capable of expanding battery containers, characterized in that z / x is a natural number and the product of y / (xy) and z / x is also a natural number.

6. In Paragraph 4, The above sector is, It is characterized by being classified according to the configuration method of the battery container connected to the power conversion device (PCS), and A first sector (41) composed of a plurality of power conversion devices (PCS) having a maximum number of connectable battery containers x, and maintained as is during the lifetime; A second sector (42) composed of a plurality of power conversion devices having a number y of remaining connectable battery containers, and maintained as is during the lifespan; A third sector (43) having initially a number y of remaining connectable battery containers, composed of a plurality of power conversion devices corresponding to the number of battery containers expanded in the first stage, and composed entirely of new battery containers after the first stage expansion; and A fourth sector (44) that is initially provided with a number y of remaining connectable battery containers, is composed of a plurality of power conversion devices corresponding to the number of battery containers expanded in the first stage, and after the first stage expansion, receives the battery containers initially provided in the third sector and is composed of all used battery containers; Includes, The total number of the above sectors is, Corresponding to the increasing degree i, it is composed of 2 + (2 xi), (where i is a natural number), When considering a second expansion, it is characterized by being composed of a total of 6 sectors, and A fifth sector (45) having initially a number y of remaining connectable battery containers, composed of a plurality of power conversion devices corresponding to the number of battery containers to be expanded in the second stage, and composed entirely of new battery containers after the second expansion; and A sixth sector (46) is initially provided with a number of remaining connectable battery containers y, and is composed of a plurality of power conversion devices corresponding to the number of battery containers to be expanded in the second stage, and after the second stage expansion, receives the battery containers initially provided in the fifth sector and is composed of all used battery containers. An energy storage system capable of expanding battery containers, characterized by further including 7. In a method of operating an energy storage system capable of expanding battery containers, The number of battery containers that can be connected to each power conversion device (PCS) is classified into two categories, and An expandable design step (S10) for configuring an energy storage system according to the rated capacity, operating capacity, and unit capacity of the above PCS, the unit capacity of each battery container, the number of battery containers initially installed, the number of battery containers additionally added according to the battery replenishment plan, the batch ratio according to the total number of PCS, the number of blank slots, and the number of sectors; A first operation step (S20) for operating the energy storage system using the configuration of multiple battery containers and PCS set in the above expandable design step; After a first preset time, a first expansion step (S30) in which remaining connectable battery containers linked to PCS corresponding to a preset blank slot are transferred according to the battery replenishment plan, and a new battery container capable of being connected to the maximum number of empty PCSs is added; A first adjustment step (S40) for calculating the PCS operating capacity of a sector that is changed by the above battery replenishment plan, adjusting the charge / discharge rate (C-rate), and recalculating the PCS operating capacity of each sector; and A second operation step (S50) of operating the energy storage system according to the adjusted C-rate and recalculated PCS operating capacity using the configuration of multiple battery containers and PCS set in the first expansion step above. A method of operating an energy storage system capable of expanding battery containers including 8. In Paragraph 7, If the number of expansions in the above battery replenishment plan is 2, After a second preset time, a second expansion step (S60) in which remaining connectable battery containers linked to PCS corresponding to a preset blank slot are transferred according to the second battery replenishment plan, and a new battery container capable of being connected to the maximum number of empty PCSs is added; A second adjustment step (S70) for calculating the PCS operating capacity of a sector changed by the second battery replenishment plan, adjusting the C-rate, and recalculating the PCS operating capacity of each sector; and A third operation step (S80) of operating the energy storage system according to the adjusted C-rate and recalculated PCS operating capacity using the configuration of multiple battery containers and PCS set in the second expansion step above. A method of operating an energy storage system capable of expanding a battery container, characterized by further including 9. In Paragraph 8, In the above expandable design stage (S10), The number of battery containers capable of being linked above is, It is characterized by being divided into the maximum number of connectable battery containers and the remaining number of connectable battery containers, and The above total number of PCS units is characterized by being divided into a PCS equipped with the maximum connectable battery container and a PCS equipped with the remaining connectable battery container, x is defined as the maximum number of battery containers that can be linked, and Define y as the number of the remaining connectable battery containers, (where x and y are natural numbers, x > y, and x ≠ y), Total PCS_x is defined as a PCS algebra linked by x numbers, and Total PCS_y is defined as a PCS algebra linked by y numbers, and Total PCS is defined as the total number of the above PCS, and If Total Batt. Container is defined as the number of the initial battery containers installed above, A method of operating an energy storage system capable of expanding battery containers, characterized in that the above-mentioned placement ratio satisfies the following [Mathematical Formula 1]. [Mathematical Formula 1] 10. In Paragraph 9, The above first adjustment step (S40) is, A determination step (S620) for determining whether the number of linked battery containers has changed from y to x after the battery containers have been relocated according to the above battery replenishment plan; A step (S630) of calculating the operating capacity of x connected PCSs of a sector that is changed by the battery replenishment plan, as the number of connected battery containers changes from y to x based on the result of the judgment step (S620) above; A step (S640) of calculating the operating capacity of y connected PCSs of a sector that is changed by the battery replenishment plan, based on the result of the judgment step (S620) above, where the number of connected battery containers does not change from y to x. A step of updating the C-rate calculation of the sector changed by the above battery replenishment plan (S650); and Step of recalculating the PCS operating capacity of each sector (S660) A method of operating an energy storage system capable of expanding a battery container, characterized by including 11. In Paragraph 10, The above second adjustment step (S70) is, A second determination step (S720) for determining whether the number of linked battery containers has changed from y to x after the battery containers have been relocated according to the above second battery replenishment plan; A step (S730) of calculating the operating capacity of x connected PCSs of a sector that is changed by the battery replenishment plan as the number of connected battery containers changes from y to x based on the result of the judgment of the second judgment step (S720); A step (S740) of calculating the operating capacity of y connected PCSs of a sector that is changed by the battery replenishment plan, based on the result of the judgment of the second judgment step (S720), which indicates that the number of connected battery containers does not change from y to x; A step of updating the C-rate calculation of the sector changed by the above battery replenishment plan (S750); and Step of recalculating the PCS operating capacity of each sector (S760) A method of operating an energy storage system capable of expanding a battery container, characterized by including

Images