JP2022147160A - battery management system - Google Patents

Abstract

To provide a battery management system capable of collecting batteries at a price commensurate with the actual performance of the battery.SOLUTION: A battery cellar 2 includes: a storage unit 21 for storing multiple batteries collected in exchange for payment of compensation; and a server 20. The server 20 is configured to determine the compensation and to manage the evaluation results of the deterioration degree of multiple batteries. The server 20 is configured to evaluate the batteries that are collected together with battery data recording the degree of deterioration out of the multiple batteries with higher compensation compared to the batteries collected without battery data.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to battery management systems.

Japanese Patent Laying-Open No. 2018-205873 (Patent Document 1) describes prompting a user of an electric vehicle having a storage battery compatible with an electric power storage system to replace the storage battery.

JP 2018-205873 A

2. Description of the Related Art In recent years, vehicles equipped with an assembled battery for running are rapidly becoming popular. As a result, the number of second-hand batteries collected as these vehicles are replaced or dismantled is increasing. From the viewpoint of promoting Sustainable Development Goals (SDGs), it is desired to manufacture a new assembled battery using collected used batteries and reuse the used batteries. The inventors have noticed that the following problems may occur when reusing used batteries.

Batteries are stored at a distribution center or the like while waiting for use. Proper storage of batteries is costly. In addition, it may take a certain amount of time (storage period) from when the battery is stored to when it is released for the next use. Therefore, it is desirable to effectively utilize the storage period of the battery.

Batteries are generally collected by a collection company or the like. The battery management system collects batteries from collection companies. At the time of this collection, the battery management system pays the collection trader a price for the battery. Unlike new batteries, the degree of deterioration of batteries varies from battery to battery. However, in many cases, how the collected batteries were used before collection (usage history) is not managed. If the usage history of the battery is unknown, it is not clear how much should be paid for the battery. Therefore, it may not be possible to collect the batteries at a price that matches the actual performance of the batteries.

The present disclosure has been made to solve the above problems, and the purpose of the present disclosure is to collect batteries at a price commensurate with the actual performance of the batteries.

A battery management system according to an aspect of the present disclosure includes a storage that stores a plurality of batteries collected in exchange for payment of consideration, and a storage that determines the consideration and manages the evaluation results of the degree of deterioration of the plurality of batteries. and a server configured to: Among the plurality of batteries, the server pays a higher price for the batteries collected together with the battery data in which the degree of deterioration is recorded, compared to the batteries collected without the battery data.

In the above configuration, the server determines the price of the battery depending on whether or not the battery data regarding the degree of deterioration of the battery is attached when the battery is collected from the collecting company or the like. More specifically, the server charges a higher price for batteries collected with battery data than for batteries collected without battery data. This provides an incentive for collection companies and the like to prepare battery data, so that it becomes possible to collect batteries at a price commensurate with the actual performance (degree of deterioration).

According to the present disclosure, in a battery management system, batteries can be collected at a price commensurate with the actual performance of the batteries.

FIG. 3 is a diagram showing one mode of distribution of assembled batteries in the present embodiment. FIG. 4 is a diagram showing an example of how used batteries are stored in a storage unit; 4 is a flow chart showing an outline of a work process for reusing used batteries. FIG. 4 is a diagram for explaining the ranking of used batteries; FIG. 2 is a system configuration diagram showing an electrical configuration of a battery cellar; FIG. FIG. 4 is a diagram showing an example of the data structure of battery data; FIG. 10 is a flowchart showing an example of a processing procedure regarding price determination for used batteries in the present embodiment; FIG. FIG. 4 is a conceptual diagram for explaining a method of determining a purchase price of a used battery; FIG. 4 is a functional block diagram of a server relating to deterioration evaluation of used batteries; FIG. 4 is a functional block diagram of a server for power coordination between a battery cellar and a power system;

In the present disclosure and embodiments, charging and discharging of a battery means at least one of charging and discharging of a battery. That is, charging and discharging of the battery is not limited to both charging and discharging of the battery, and may be only charging of the battery or only discharging of the battery.

In the present disclosure and embodiments, an assembled battery includes multiple modules (also called blocks or stacks). A plurality of modules may be connected in series or may be connected in parallel with each other. Each of the multiple modules includes multiple cells (single batteries).

In general, "reuse" of assembled batteries is broadly classified into reuse, rebuild, and material recycling. In the case of reuse, the collected assembled battery undergoes necessary shipping inspections and is shipped as it is as a reused product. In the case of rebuilding, the collected assembled battery is once disassembled into modules. Then, among the disassembled modules, usable modules (which may be usable after recovery of performance) are combined to manufacture a new assembled battery. A newly manufactured assembled battery is shipped as a rebuilt product through shipping inspection. In material recycling, on the other hand, recyclable materials (resources) are extracted from each cell. The collected assembled battery is never used as another assembled battery.

In the embodiments described below, assembled batteries collected from vehicles are once disassembled into modules. Then, various processes are performed for each module. That is, hereinafter, a reusable used battery means a module that can be rebuilt. However, the decomposition into modules is not mandatory. Depending on the configuration of the assembled battery or the degree of deterioration of the assembled battery, it is possible to reuse the assembled battery without disassembling it into modules.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[Embodiment]
<Battery logistics model>
FIG. 1 is a diagram showing one mode of distribution of an assembled battery according to the present embodiment. Hereinafter, the physical distribution mode shown in FIG. 1 is referred to as a "battery physical distribution model." The battery distribution model 100 includes a collector 1 , a battery seller 2 , a sale destination 3 , a recycling plant 4 , a power system 5 , and a distributed energy resource (DER) 6 .

A collection company 1 collects used assembled batteries (used batteries 9) from a plurality of vehicles. The collection company 1 may be a vehicle store (dealer) or a vehicle dismantling company.

In the battery distribution model 100 according to the present embodiment, inventory management and sales management using battery data (indicated by DATA in the figure) are introduced (see FIG. 6). Battery data is associated with each used battery 9 . More specifically, identification information (battery ID) is assigned to each used battery 9 . Also, for each used battery 9, the evaluation result of the degree of deterioration of the used battery is recorded. Therefore, in the battery distribution model 100, it is possible to identify the used battery 9 using the battery ID, manage the degree of deterioration of the used battery, and trace the distribution route of the used battery.

The battery cellar 2 is a facility for appropriately managing the used batteries 9 collected by the collector 1, like a wine cellar that stores wine bottles under temperature and humidity control. The battery cellar 2 is installed at a distribution base near a port in the example shown in FIG. The battery cellar 2 includes a server 20 that manages data on used batteries 9 and a plurality of storage units 21 . Note that the battery cellar 2 corresponds to the "battery management system" according to the present disclosure. The storage unit 21 corresponds to a "storage box" according to the present disclosure. The batteries stored in the battery cellar 2 are not limited to used batteries, and may include new batteries.

FIG. 2 is a diagram showing an example of how the used batteries 9 are stored in the storage unit 21. As shown in FIG. As shown in FIG. 2, a plurality of storage units 21 are arranged in the building of the battery cellar 2 . Each of the plurality of storage units 21 is configured to store many used batteries 9 . Although the details will be described later, in the present embodiment, the battery seller 2 performs a deterioration evaluation test on each of the used batteries 9 stored in the storage unit 21 . Then, the battery seller 2 determines whether each used battery 9 is reusable or not reusable (whether it is suitable for reuse or not) based on the result of the deterioration evaluation test.

Returning to FIG. 1, the seller 3 sells the used battery 9 determined by the battery seller 2 to be reusable. The sales destinations 3 may include dealers 31 who sell used batteries 9 for vehicles, and users 32 who use the batteries for stationary use in factories, buildings, and the like. The sales destination 3 may also include a store 33 that sells the used battery 9 as a supply item (replacement part for maintenance/repair).

The recycling plant 4 performs material recycling for regenerating used batteries 9 that have been determined to be unreusable by the battery seller 2 as raw materials for other products.

The power system 5 is a power network constructed by power plants, power transmission and distribution facilities, and the like. In this embodiment, the electric power company serves as both a power generation company and a power transmission/distribution company. The power company corresponds to a general power transmission and distribution business operator and also to a manager of the power system 5 and maintains and manages the power system 5 . A business server 50 is provided in the power system 5 . The business operator server 50 belongs to an electric power company and manages power supply and demand of the electric power system 5 . The server 20 and the provider server 50 are configured to be capable of two-way communication.

The DER 6 is a relatively small-scale power facility that is installed at a physical distribution base (or its surrounding area) where the battery cellar 2 is installed and that can exchange power with the battery cellar 2 . DER 6 includes, for example, a power generation type DER and a power storage type DER.

A power-generating DER may include a naturally fluctuating power source and a generator. Naturally fluctuating power sources are power generation facilities whose power generation output fluctuates depending on weather conditions. Although photovoltaic power generation equipment (solar panels) is illustrated in FIG. 1, the naturally fluctuating power supply may include wind power generation equipment instead of or in addition to photovoltaic power generation equipment. On the other hand, a generator is a power generation facility that does not depend on weather conditions. Generators may include steam turbine generators, gas turbine generators, diesel engine generators, gas engine generators, biomass generators, stationary fuel cells, and the like. The generator may include a cogeneration system that utilizes heat generated during power generation.

A storage-type DER may include a power storage system and a heat storage system. A power storage system is a stationary power storage device that stores power generated by a variable natural power source or the like. The power storage system may be a Power to Gas device that uses electrical power to produce gaseous fuels (hydrogen, methane, etc.). The heat storage system includes a heat storage tank provided between a heat source and a load, and is configured to temporarily store a liquid medium in the heat storage tank in a heat-retaining state. Heat generation and consumption can be staggered by using a heat storage system. Therefore, for example, the heat generated by consuming electric power to operate the heat source equipment at night is stored in the heat storage tank, and the heat can be consumed during the daytime for air conditioning.

In this way, the used batteries 9 collected by the collection company 1 are stored in the battery cellar 2 while waiting for shipment to the sale destination 3 or the recycling plant 4 . However, proper storage of used batteries 9 using the battery cellar 2 also requires maintenance costs (running costs). Furthermore, a certain amount of time may be required between the collection of the collected used batteries 9 and the shipment to the sales destination 3 or the recycling plant 4 . Therefore, it is desirable to make effective use of the storage period of the used batteries 9 in the battery cellar 2 .

In this embodiment, the battery cellar 2 functions as a virtual power plant (VPP) in addition to a storage place for used batteries 9 . As a result, the opportunity to charge and discharge the used battery 9 serves both as a deterioration evaluation of the used battery 9 for determining the reuse mode of the used battery 9 and as an electric power supply and demand balance adjustment of the electric power system 5 using the used battery 9. . As a result, in the battery cellar 2, the storage of the used batteries 9, the degradation evaluation of the used batteries 9, and the power supply and demand balance adjustment by the used batteries 9 are performed in a “three-in-one” manner.

<Process of reusing used batteries>
FIG. 3 is a flow chart showing an overview of the work process for reusing the used battery 9. As shown in FIG. First, the used battery 9 collected by the collecting company 1 is handed over to the battery seller 2 (S1).

In the present embodiment, server 20 performs a deterioration evaluation test (performance test) on each used battery 9 while it is stored in storage unit 21 (S2). The server 20 evaluates the degree of deterioration of each used battery 9 based on electrical characteristics such as full charge capacity and internal resistance. Then, the server 20 determines whether each used battery 9 is reusable or not reusable according to the result of the deterioration evaluation test (S3). In the present embodiment, ranking is performed as follows according to the results of the deterioration evaluation test.

FIG. 4 is a diagram for explaining the ranking of used batteries 9. As shown in FIG. In this example, the used batteries 9 that can be rebuilt are ranked into four ranks of S rank, A rank, B rank, and C rank in descending order of deterioration. The degree of deterioration of used battery 9 is evaluated, for example, based on its full charge capacity and internal resistance. The used battery 9 is ranked higher as the full charge capacity is larger and as the internal resistance is lower. This makes it possible to set the price of the used battery 9 in association with the rank, and to guarantee the quality of the used battery 9 according to the rank. Therefore, the used batteries 9 that have passed through the battery seller 2 can be smoothly distributed to the market. A used battery 9 with a full charge capacity lower than the specified value is ranked lower than the C rank (denoted as Re), and is recycled for material recycling.

Returning to FIG. 3, if it is determined that the device is reusable (YES in S3), the work process proceeds to the performance recovery process (S4). In the performance recovery process, a process (performance recovery process) for recovering the performance of the used battery 9 is performed. For example, by overcharging the used battery 9, the full charge capacity of the used battery 9 can be recovered. However, the performance recovery process may be omitted. Further, as a result of the deterioration evaluation test, the used battery 9 with a large degree of deterioration (the performance is greatly degraded) is subjected to the performance recovery process, while the used battery 9 with a small degree of deterioration (the performance is not much degraded). Performance recovery processing may not be performed for .

Subsequently, a new assembled battery is manufactured (rebuilt) using the used battery 9 whose performance has been recovered by the performance recovery process (S5). The used battery 9 used for rebuilding the assembled battery is basically the used battery 9 whose performance has been recovered through the performance recovery process. Batteries (new modules) may be included. After that, the assembled battery is sold and shipped to the customer 3 (S6).

As a result of the deterioration evaluation test, if it is determined that the used battery 9 cannot be reused (NO in S3), the used battery 9 is transported to the recycling plant 4 (S7). In the recycling plant 4, the used batteries 9 are dismantled and recycled.

In this way, the used battery 9 is stored in the battery cellar 2 until it is collected by the collection agent 1 and delivered to the sale destination 3 or the recycling plant 4, and a deterioration evaluation test is performed during that time. When measuring electrical characteristics such as the full charge capacity of the used battery 9 in the deterioration evaluation test, the used battery 9 is charged and discharged. In the present embodiment, electric power exchanged between battery cellar 2 (and DER 6) and electric power system 5 is used for this charge/discharge. Thereby, the battery cellar 2 functions as a VPP (or one of the DERs) and contributes to load leveling of the power grid 5 . More specifically, the battery cellar 2 absorbs the surplus power by charging the used battery 9 with the surplus power during the period when the power system 5 has a surplus of supply to the demand. On the other hand, when there is a shortage of supply in the power system 5, the battery cellar 2 discharges the shortage of power from the used batteries 9 to alleviate the power shortage.

However, the battery cellar 2 may not be configured to contribute to both absorption of surplus power and alleviation of power shortage in the power system 5 . The battery cellar 2 may be configured to contribute only to one of absorbing power surplus and alleviating power shortage. For example, while the battery cellar 2 charges the used battery 9 with the surplus power in the power system 5 , it is also possible not to include the power system 5 in the discharge destination of the used battery 9 . The discharge destination from the used battery 9 may be, for example, only the DER 6 .

<System configuration of the battery cellar>
FIG. 5 is a system configuration diagram showing the electrical configuration of the battery cellar 2. As shown in FIG. Battery cellar 2 includes storage unit 21 , AC/DC converter 22 , DC/DC converter 23 , and server 20 , for example. Although only one storage unit 21 is shown in FIG. 5 due to space limitations, a typical battery cellar 2 includes a plurality of storage units 21 as shown in FIG.

A storage unit 21 stores a plurality of used batteries 9 . Although the plurality of used batteries 9 are connected in parallel in FIG. 5, this is merely an example, and the manner in which the plurality of used batteries 9 are connected is not particularly limited. The plurality of used batteries 9 may be connected in series, or may be connected in series and in parallel. Storage unit 21 includes voltage sensor 211 , current sensor 212 and relay 213 .

Voltage sensor 211 detects voltage VB of used battery 9 and outputs the detected value to server 20 . The current sensor 212 detects the current IB that charges and discharges the used battery, and outputs the detected value to the server 20 . Note that if the temperature is used to evaluate the deterioration of the used battery 9, the storage unit 21 may further include a temperature sensor (not shown). Moreover, each sensor may be a sensor attached to the used battery 9 .

Relay 213 includes, for example, a first relay electrically connected to the positive electrode side of used battery 9 and a second relay electrically connected to the negative electrode side of used battery 9 . The relay 213 is configured to switch between electrical connection and disconnection between the used battery 9 and the power system 5 . As a result, any used battery 9 can be electrically disconnected even while other used batteries 9 are being charged and discharged, and the used battery 9 can be taken out from the storage unit 21 .

AC/DC converter 22 is electrically connected between power system 5 and DC/DC converter 23 . The AC/DC converter 22 is configured to be capable of bi-directional power conversion operation for charging and discharging the used batteries 9 stored in the storage unit according to a control command (charging/discharging command) from the server 20 . More specifically, AC/DC converter 22 converts AC power supplied from power system 5 into DC power for charging used battery 9 . AC/DC converter 22 also converts DC power discharged from used battery 9 into AC power to be supplied to power system 5 .

DC/DC converter 23 is electrically connected between AC/DC converter 22 and storage unit 21 and electrically connected between DER 6 and storage unit 21 . As with the AC/DC converter 22 , the DC/DC converter 23 is configured to be capable of bidirectional power conversion operation according to a control command (charge/discharge command) from the server 20 . DC/DC converter 23 charges used battery 9 with DC power from AC/DC converter 22 and/or DER 6, or discharges DC power stored in used battery 9 to AC/DC converter 22 and/or DER 6. You can let

The server 20 includes a processor such as a CPU (Central Processing Unit), memories such as ROM (Read Only Memory) and RAM (Random Access Memory), and input/output ports through which various signals are input and output (none of which are shown). including. Server 20 performs various controls based on signals received from each sensor and programs and maps stored in memory. Server 20 includes battery data storage unit 201 , deterioration evaluation unit 202 , power adjustment unit 203 , timing adjustment unit 204 , price determination unit 205 , and display unit 206 .

The battery data storage unit 201 stores battery data used to manage the used batteries 9 in the battery cellar 2 . Information on the degree of deterioration of the used battery 9 is recorded in the battery data.

FIG. 6 is a diagram showing an example of the data structure of battery data. Battery data is stored, for example, in a map format. The battery data includes parameters such as identification information (battery ID) for identifying the used battery 9, the model number of the used battery 9, the date of manufacture, the current SOC (State Of Charge), and the full charge capacity. , internal resistance, rank, deterioration evaluation date and time (latest date and time when the deterioration evaluation test was performed), storage location (identification information of the storage unit in which the used battery 9 is stored, etc.), purchase price, and sale price. , and a remarks column. In addition to the above, the battery data may also include evaluation results of the degree of deterioration (specifically, an index ΣD indicating the bias of the salt concentration distribution in the electrolytic solution of the used battery 9, etc.). The battery data can also be said to be a “medical record” of the used battery 9 in that various evaluation results (deterioration evaluation results) regarding the degree of deterioration of the used battery 9 are recorded.

Referring again to FIG. 5, deterioration evaluation unit 202 performs a deterioration evaluation test of used battery 9 based on voltage VB and current IB detected by voltage sensor 211 and current sensor 212, respectively, when used battery 9 is charged and discharged. implement. An example of this evaluation method will be described with reference to FIG. The deterioration evaluation unit 202 ranks the used batteries 9 based on the results of the deterioration evaluation test.

Power adjustment unit 203 performs power adjustment between battery cellar 2 (and DER 6 ) and power system 5 . More specifically, the server 20 selects used batteries 9 that are charged and discharged from among a plurality of used batteries 9 in order to respond to a demand response (DR) request from the provider server 50 (see FIG. 1). to select. Power adjustment unit 203 outputs commands to relay 213, AC/DC converter 22 and DC/DC converter 23 so that selected used battery 9 is charged and discharged. An example of this control method will be described with reference to FIG.

The timing adjustment unit 204 adjusts the timing of the deterioration evaluation test of the used battery 9 by the deterioration evaluation unit 202 and the timing of power adjustment between the battery cellar 2 and the power system 5 by the power adjustment unit 203 . More specifically, the timing adjustment unit 204 performs the deterioration evaluation test of the used battery 9 in accordance with the timing of the DR of the battery seller 2 in response to the DR request from the operator server 50. Adjust the timing. It should be noted that the performance recovery process (see S4 in FIG. 3) may be performed in addition to the deterioration evaluation test of the used battery 9, not limited to the deterioration evaluation test of the used battery 9, which is performed in accordance with the DR of the battery seller 2.

The price determination unit 205 determines the purchase price and sale price of the used battery 9 based on the evaluation result of the degree of deterioration of the used battery 9 by the deterioration evaluation unit 202 and/or the battery data stored in the battery data storage unit 2. determine the price.

The display unit 206 displays battery data according to the operation of the manager of the battery cellar 2 (which may be a worker working in the battery cellar 2). Also, the display unit 206 displays the progress and results of the deterioration evaluation test by the deterioration evaluation unit 202 . The display unit 206 also displays the purchase price and sale price determined by the price determination unit 205 . This allows the administrator to grasp the status of the deterioration evaluation test. Furthermore, the display unit 206 displays the state of the used battery 9 selected by the power adjustment unit 203 and being charged/discharged. This allows the administrator to grasp the state of power adjustment between the battery cellar 2 and the power system 5 .

<Purchase of used batteries>
When the battery seller 2 collects the used batteries 9 from the collector 1 , the operator of the battery seller 2 pays the collector 1 for the used batteries 9 . The present inventors have noticed that how to determine this consideration can be a problem.

Specifically, unlike new batteries, the degree of deterioration of used batteries varies from battery to battery. However, in many cases, information regarding how the used battery 9 was used before collection (history of use of the used battery 9 so far) is not managed. Therefore, the battery seller 2 does not know the actual performance of the used battery 9 and does not know how much to pay for the used battery 9 (how to set the purchase price). In that case, there is a possibility that the used battery 9 cannot be purchased at a price commensurate with the actual performance of the used battery 9 . Therefore, in the present embodiment, the purchase price is determined depending on whether or not the deterioration evaluation result (battery data) is attached to the used battery 9 .

FIG. 7 is a flow chart showing an example of a processing procedure for determining the value of used battery 9 according to the present embodiment. This flowchart is invoked and executed from a main routine (not shown) when a predetermined condition is satisfied (such as an operation when purchasing a used battery 9). Each step is implemented by software processing by the server 20 , but may be implemented by hardware (electrical circuits) arranged within the server 20 . A step is abbreviated as S below.

In S11, the server 20 determines whether or not the used battery 9 collected from the collection agency 1 has a deterioration evaluation result (specifically, an evaluation result regarding full charge capacity and internal resistance) attached.

If the deterioration evaluation result is not attached to used battery 9 (NO in S11), server 20 determines to purchase used battery 9 at the normal price (S14). This normal price is determined based on information such as the model number and manufacturing date of the used battery 6 . The normal price may reflect the market trend of used batteries (the supply and demand balance of used batteries). The server 20 records in the remarks column of the battery data that the used battery 9 should undergo a deterioration evaluation test later (S15).

On the other hand, if the deterioration evaluation result is attached to used battery 9 (YES in S11), server 20 determines to buy used battery 9 at a price higher than the normal price (S12). The server 20 records in the remarks column of the battery data that the deterioration evaluation test can be omitted for the used battery 9 (S13). This completes a series of processes.

FIG. 8 is a conceptual diagram for explaining the method of determining the purchase price of the used battery 9. As shown in FIG. The horizontal axis represents the degree of deterioration of the used battery 9 by rank. The vertical axis represents the purchase price of the used battery 9 .

If the used batteries 9 to be collected do not have deterioration evaluation results attached, the server 20 determines a uniform purchase price regardless of the actual degree of deterioration of the used batteries 9 . On the other hand, when the deterioration evaluation result is attached to the used battery 9 , the server 20 determines the purchase price according to the actual degree of deterioration of the used battery 9 . More specifically, the server 20 sets a rank corresponding to the actual degree of deterioration of the used battery 9, and determines a purchase price corresponding to the rank. As a result, the higher the rank of the used battery 9 is, the higher the purchase price is set.

<Deterioration evaluation>
FIG. 9 is a functional block diagram of the server 20 (deterioration evaluation unit 202) regarding deterioration evaluation of the used battery 9. As shown in FIG. In the following, for simplification of explanation, one used battery 9 will be focused on and explained. However, in reality, if there are a plurality of used batteries 9 that have not undergone deterioration evaluation, the same process can be performed on those used batteries 9 at the same time. The deterioration evaluation unit 202 includes a current integration unit 71, an OCV (Open Circuit Voltage) calculation unit 72, an SOC variation calculation unit 73, a full charge capacity calculation unit 74, an internal resistance calculation unit 75, and a ranking unit 76. including.

Based on the current IB detected by the current sensor 212, the current accumulator 71 calculates the integrated value of the current charged and discharged from the used battery 9 from when the current integration start condition is satisfied until when the current integration end condition is satisfied. (Current integrated amount) ΔAh (unit: Ah) is calculated. In the present embodiment, as described above, the used battery 9 is charged and discharged in response to a DR request from the operator server 50, and the current flowing during the DR is integrated. More specifically, when performing an increase DR (request for increase in power demand), the used battery 9 is charged in order to increase the power demand of the battery cellar 2, and the charging current at that time is integrated. On the other hand, when the lowered DR is performed, the used battery 9 is discharged in order to reduce the power demand of the battery cellar 2, and the discharge current at that time is integrated. Current integrating portion 71 outputs the calculated integrated current amount ΔAh to full charge capacity calculating portion 74 .

The OCV calculator 72 calculates the OCV of the used battery 9 at the start of current integration and the OCV of the used battery 9 at the end of current integration. OCV can be calculated, for example, according to the following formula (1).
OCV=VB-ΔVp-IB×R (1)

In formula (1), the internal resistance of the used battery 9 is described as R, and the polarization voltage is described as Vp. At the start of current integration (immediately before charging/discharging), current IB=0. Further, when the second-hand battery 9 has been left without being charged or discharged before the start of current integration, it can be approximated that the polarization voltage Vp≈0. Therefore, OCV at the start of current integration can be calculated based on voltage VB detected by voltage sensor 211 . On the other hand, the internal resistance R can be specified from the relationship (Ohm's law) between the voltage VB and the current IB. Further, when the used battery 9 is charged and discharged at a constant current, the relationship between the current and the polarization voltage Vp is measured in advance, so that the current IB detected by the current sensor 212 can be used to determine the polarization. A voltage Vp can also be specified. Therefore, the OCV of the used battery 9 at the end of the current integration can also be calculated based on the voltage VB and the current IB. The OCV calculator 72 outputs the two calculated OCVs to the SOC variation calculator 73 .

The SOC change amount calculator 73 calculates the SOC change amount ΔSOC of the used battery 9 from the start of current integration to the end of current integration based on two types of OCV. The SOC change amount calculator 73 has in advance a characteristic curve (OCV-SOC curve) that indicates the SOC dependency of OCV. Therefore, by referring to the OCV-SOC curve, the SOC change amount calculation unit 73 reads out the SOC corresponding to the OCV at the start of current integration and the SOC corresponding to the OCV at the end of current integration. can be calculated as ΔSOC. SOC change amount calculation unit 73 outputs the calculated ΔSOC to full charge capacity calculation unit 74 .

The full charge capacity calculation unit 74 calculates the full charge capacity C of the used battery 9 based on ΔAh from the current integration unit 71 and ΔSOC from the SOC change amount calculation unit 73 . Specifically, the full charge capacity C of the used battery 9 can be calculated according to the following equation (2), where the ratio of ΔAh to ΔSOC is equal to the ratio of the full charge capacity C to ΔSOC=100%. Note that since the full charge capacity C0 in the initial state is known from the specification of the used battery 9, the full charge capacity calculator 74 may further calculate the capacity retention rate Q from the full charge capacity C (Q=C/ C0). In the present embodiment, the full charge capacity calculator 74 can also acquire the evaluation result of the full charge capacity C from the purchaser 1 . The full charge capacity calculator 74 outputs the calculated or obtained full charge capacity C to the ranking section 76 .
C=ΔAh/ΔSOC×100 (2)

Internal resistance calculator 75 calculates internal resistance R of used battery 9 based on voltage VB detected by voltage sensor 211 and current IB detected by current sensor 212 (R=VB/IB). In the present embodiment, the internal resistance calculator 75 can also acquire the evaluation result of the internal resistance R from the purchaser 1 . The internal resistance calculator 75 outputs the calculated or acquired internal resistance R to the ranking unit 76 .

The ranking unit 76 ranks the used batteries 9 according to the full charge capacity C and the internal resistance R. The ranking unit 76 may determine the rank of the used battery 9 according to the length of time the used battery 9 has been charged/discharged and/or the number of times the used battery 9 has been charged/discharged. The ranking unit 76 may determine the rank of the used battery 9 according to the time that has passed since the used battery 9 was manufactured, although the accuracy may be somewhat reduced. The ranking unit 76 determines the rank of the used battery 9 by combining each of the above elements (full charge capacity C, internal resistance R, index ΣD, charging/discharging time, number of charging/discharging, elapsed time from manufacturing, etc.). is also possible. The ranking section 76 outputs the rank to the price determination section 76 . As a result, the purchase price of the used battery 9 is determined by the price determination unit 205 .

<Power adjustment>
FIG. 10 is a functional block diagram of the server 20 (power adjustment unit 203) regarding power adjustment between the battery cellar 2 and the power system 5. As shown in FIG. In this example, in order to facilitate understanding, a description will be given assuming that the DER 6 is a power generation type DER (in particular, a naturally fluctuating power source such as a photovoltaic power generation facility). The power adjustment unit 203 includes an overall adjustment amount calculation unit 81, a DER adjustment amount calculation unit 82, a battery cellar adjustment amount calculation unit 83, a used battery selection unit 84, a conversion calculation unit 85, and a command generation unit 86. include.

The total adjustment amount calculation unit 81 receives a DR request from the operator server 50, and uses the battery cellar 2 and DER 6 to calculate the total power amount that requires power adjustment during a predetermined period (for example, 30 minutes). This power amount is hereinafter referred to as the total adjustment amount, and is also described as kWh (total). Overall adjustment amount calculation portion 81 outputs the calculated kWh (total) to battery cellar adjustment amount calculation portion 83 .

The DER adjustment amount calculator 82 acquires the operating state of each DER 6 (more specifically, the expected amount of power generated by each DER 6 during a predetermined period) through communication with the DER 6 . This power amount is hereinafter referred to as the DER adjustment amount, and is also described as kWh (DER). The DER adjustment amount calculation unit 82 outputs the acquired kWh (DER) to the battery cellar adjustment amount calculation unit 83 .

The battery cellar adjustment amount calculation unit 83 requires power adjustment using the battery cellar 2 based on the kWh (total) from the total adjustment amount calculation unit 81 and the kWh (DER) from the DER adjustment amount calculation unit 82. Calculate the amount of power. This amount of electric power is hereinafter referred to as a battery celler adjustment amount, and is also described as kWh (bat). The battery cellar adjustment amount calculator 83 can calculate, for example, ΔkWh=kWh(total)−kWh(DER), which is the difference between the two electric power amounts, as the battery cellar adjustment amount kWh(bat). The battery cellar adjustment amount calculation unit 83 outputs the calculated kWh (bat) to the used battery selection unit 84 .

The used battery selection unit 84 grasps the chargeable/dischargeable power amount of each of the large number of used batteries 9 stored in the plurality of storage units 21 . Based on the kWh (bat) from the battery celler adjustment amount calculation unit 83 , the used battery selection unit 84 selects a used battery to be used for power adjustment from among a large number of used batteries 9 . When kWh (bat)>0, the power shortage in the power system 5 is compensated for by discharging from the battery cellar 2 . Therefore, the used battery selection unit 84 selects used batteries 9 in a quantity capable of discharging a power amount equal to or greater than kWh (bat). On the other hand, when kWh (bat)<0, the surplus power of the power system 5 is absorbed by charging the battery cellar 2 . Therefore, the second-hand battery selection unit 84 selects second-hand batteries 9 in a quantity capable of being charged with a power amount equal to or greater than kWh (bat) (absolute value).

For each used battery 9 selected by the used battery selection unit 84 , the conversion calculation unit 85 calculates the electric power charged to and discharged from the used battery 9 . More specifically, the conversion calculation unit 85 converts the power amount (unit: kWh) adjusted by the used battery 9 to power (unit: kW) using the remaining time of power adjustment for each used battery 9. Convert. As an example, if the power adjustment amount assigned to a certain used battery 9 is 10 kWh and the remaining power adjustment time is 15 minutes, it can be calculated as 10 kWh×(60 minutes/15 minutes)=40 kW. The conversion calculation unit 85 outputs the electric power charged/discharged to each used battery 9 to the command generation unit 86 .

Command generation unit 86 generates a charge/discharge command for AC/DC converter 22 and DC/DC converter 23 and an opening/closing command for relay 213 based on the calculation result of conversion calculation unit 85 . More specifically, the command generator 86 electrically connects the selected used battery 9 to the DC/DC converter 23 , while the unselected used battery 9 is electrically connected to the DC/DC converter 23 . Generate an open/close command so that the The command generator 86 generates a charge/discharge command so that the total power allocated to the selected used battery 9 is charged/discharged.

It should be noted that the power adjustment technique shown in FIG. 10 is also just an example. In this example, it is assumed that the DER 6 is a power-generating DER, especially a naturally fluctuating power source whose power generation cannot be controlled. Therefore, the battery cellar adjustment amount calculation unit 83 calculates the battery cellar adjustment amount kWh (bat) based on the difference kWh (total) - kWh (DER) obtained by subtracting the DER adjustment amount kWh (DER) from the total adjustment amount kWh (total). Calculate That is, in this example, after the DER adjustment amount kWh (DER) is determined, final power adjustment is performed using the battery cellar adjustment amount kWh (bat). However, if the DER 6 includes a storage-type DER, for example, the battery cellar adjustment amount calculation unit 83 divides the total adjustment amount kWh (total) into the DER adjustment amount kWh (DER) and the battery cellar adjustment amount kWh (bat). Both the DER adjustment amount kWh (DER) and the battery cell adjustment amount kWh (bat) may be used for power adjustment.

As described above, in the present embodiment, the degree of deterioration of each used battery 9 is evaluated while stored in storage unit 21 . As a result, the storage period of the used battery 9 can be effectively used in terms of time. Further, charging and discharging of the used battery 9 for evaluating the degree of deterioration of the used battery 9 is basically performed in response to a DR request from the provider server 50 . Also, when the number of used batteries 9 is large, a large amount of power is charged and discharged, and the large amount of power is exchanged between the battery cellar 2 and the electric power system 5 in response to a DR request from the operator server 50. . As a result, the operating company of the battery seller 2 can receive compensation (incentives) from the electric power company, so that the compensation can be used as the running cost of the battery seller 2 . Alternatively, the operating company of the battery seller 2 can recover part of the initial investment (initial cost) of the battery seller 2 . As a result, the storage period of the used battery 9 can be effectively used financially.

Furthermore, in the present embodiment, when the used batteries 9 are collected from the collection company 1, the server 20 attaches the deterioration evaluation results of the used batteries 9 (specifically, measurement data regarding full charge capacity and internal resistance). The purchase price of the used battery 9 is determined according to whether the used battery 9 is used. The server 20 makes the purchase price of the used battery 9 higher when the deterioration evaluation result of the used battery 9 is attached than when the deterioration evaluation result of the used battery 9 is not attached. This means that the purchaser 1 can sell the used battery 9 at a high price by attaching the deterioration evaluation result of the used battery 9 . Therefore, the purchaser 1 has an incentive to attach the degradation evaluation result to the used battery 9 . As a result, deterioration evaluation results are attached to more used batteries 9, and the battery seller 2 can purchase the used batteries 9 at a price commensurate with the actual performance (degree of deterioration). Further, when the deterioration evaluation result is attached to the used battery 9, the deterioration evaluation test need not be performed again, so the number of man-hours for the deterioration evaluation test can be reduced.

The embodiments disclosed this time should be considered as examples and not restrictive in all respects. The scope of the present disclosure is indicated by the scope of claims rather than the description of the above-described embodiments, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

100 battery distribution model, 1 collector, 2 battery seller, 3 purchaser, 31, 33 dealer, 32 user, 4 recycling plant, 5 power system, 50 business server, 6 distributed energy resource (DER), 9 used Battery 20 Server 201 Battery data storage unit 202 Degradation evaluation unit 203 Power adjustment unit 204 Timing adjustment unit 205 Price determination unit 206 Display unit 21 Storage unit 211 Voltage sensor 212 Current sensor 213 Relay 22 AC/DC converter, 23 DC/DC converter, 71 current integration unit, 72 OCV calculation unit, 73 SOC variation calculation unit, 74 full charge capacity calculation unit, 75 internal resistance calculation unit, 76 ranking unit, 81 overall adjustment Quantity calculation unit 82 Adjustment amount calculation unit 83 Battery celler adjustment amount calculation unit 84 Used battery selection unit 85 Conversion calculation unit 86 Instruction generation unit.

Claims (1)

a vault storing a plurality of batteries collected in exchange for payment;
A server configured to determine the consideration and manage evaluation results of the degree of deterioration of the plurality of batteries,
A battery management system according to claim 1, wherein, among the plurality of batteries, the server pays a higher price for batteries collected together with battery data in which a degree of deterioration is recorded, compared to batteries collected without the battery data.

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