Operation management system, operation management device, and operation management method for power storage device

Abstract

To provide an operation management system, operation management device and operation management method for a power storage device.SOLUTION: An operation management system includes a control device for executing control related to a power storage device, and an operation management device for the power storage device that is communicably connected to the control device. The control device includes a storage unit for storing control parameters, and a control unit for executing the control based on the control parameters stored in the storage unit. The operation management device includes a detection unit for detecting the state of the power storage device, a derivation unit for deriving a control parameter to be set by the control device according to a detection result by the detection unit, and a transmission unit for transmitting the control parameter derived by the derivation unit to the control device. The control device includes an update unit for updating the control parameters stored in the storage unit based on the control parameter received from the operation management device.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an operation management system, an operation management device, and an operation management method for an electricity storage device. [Background technology]

[0002] The power storage device is used together with a control device that controls the charge / discharge state, temperature, and ambient temperature of the installation environment of the power storage device (see, for example, Patent Document 1).

[0003] The control parameters used in such a control device are generally designed based on the initial state of the power storage device and written in advance to a memory inside the control device. These control parameters are often designed based on assumptions at the time of product delivery. The control device reads the control parameters written in the memory as needed to control the charge / discharge state and temperature of the power storage device and the ambient temperature of the installation environment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-071100 Summary of the Invention [Problem to be solved by the invention]

[0005] However, control parameters set based on the initial state of the power storage device may deviate from appropriate values due to aging of the power storage device or special circumstances that could not be predicted at the time of design.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide an operation management system, operation management device, and operation management method for an energy storage device that can redesign control parameters in a control device depending on the state of the energy storage device. [Means for solving the problem]

[0007] The operation management system includes a control device that performs control related to an energy storage device, and an operation management device for the energy storage device that is communicatively connected to the control device, the control device including a memory unit that stores control parameters, and a control unit that performs the control based on the control parameters stored in the memory unit, the operation management device including a detection unit that detects the state of the energy storage device, a derivation unit that derives control parameters to be set in the control device based on the detection results by the detection unit, and a transmission unit that transmits the control parameters derived by the derivation unit to the control device, and the control device including an update unit that updates the control parameters stored in the memory unit based on the control parameters received from the operation management device.

[0008] The operation management device includes a detection unit that detects the state of the energy storage device, a derivation unit that derives control parameters to be set in a control device that executes control related to the energy storage device based on the detection results by the detection unit, and a transmission unit that transmits the control parameters derived by the derivation unit to the control device so that the control device can update the control parameters used for the control.

[0009] The operation and management method detects the state of an energy storage device, derives control parameters to be set in a control device that executes control related to the energy storage device based on the detected state, and transmits the derived control parameters to the control device so that the control device updates the control parameters used for the control. [Effects of the Invention]

[0010] According to the present application, the control parameters in the control device can be redesigned according to the state of the power storage device. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating the overall configuration of an operation management system according to a first embodiment. [Figure 2]FIG. 2 is a block diagram illustrating the internal configuration of a control device. [Figure 3] FIG. 2 is a block diagram illustrating the internal configuration of an operation management device. [Figure 4] 1 is a graph showing the relationship between terminal voltage and discharge capacity. [Figure 5] 1 is a graph showing the concentration distribution of lithium ions inside a battery. [Figure 6] 10 is a graph showing the relationship between terminal voltage and discharge capacity after control parameters are updated. [Figure 7] 10 is a graph showing the concentration distribution of lithium ions inside the battery after the control parameters are updated. [Figure 8] 10 is a flowchart illustrating a procedure of a process executed by an operation management device. [Figure 9] 4 is a flowchart illustrating a procedure of a process executed by a control device. [Figure 10] FIG. 10 is a schematic diagram illustrating the overall configuration of an operation management system according to a second embodiment. [Figure 11] FIG. 2 is a block diagram illustrating the internal configuration of a control device. [Figure 12] FIG. 11 is a schematic diagram illustrating the overall configuration of an operation management system according to a third embodiment. [Figure 13] FIG. 2 is a block diagram illustrating the internal configuration of a control device. [Figure 14] 10 is a graph showing temperature changes of an electricity storage device. DETAILED DESCRIPTION OF THE INVENTION

[0012] Conventionally, a control device that controls an electric storage device stores preset control parameters. The control device appropriately reads the pre-stored control parameters and performs control operations based on the read control parameters, thereby controlling the charge / discharge state, temperature, and ambient temperature of the electric storage device in a set environment.

[0013] Control parameters designed based on the initial state of the power storage device may deviate from appropriate values due to deterioration of the power storage device, special circumstances that could not be predicted at the time of design, etc. If the control device performs the above control using control parameters that deviate from appropriate values, the power storage device may not be able to exhibit the required performance. In contrast, an operation management system for a power storage device comprises a control device that executes control related to the power storage device, and an operation management device for the power storage device that is communicatively connected to the control device, the control device comprising a memory unit that stores control parameters, and a control unit that executes the control based on the control parameters stored in the memory unit, the operation management device comprising a detection unit that detects the state of the power storage device, a derivation unit that derives control parameters to be set in the control device based on the detection results by the detection unit, and a transmission unit that transmits the control parameters derived by the derivation unit to the control device, and the control device comprising an update unit that updates the control parameters stored in the memory unit based on the control parameters received from the operation management device. The operation management device automatically derives control parameters to be set in the control device based on the current state of the power storage device and transmits them to the control device. The control device updates the control parameters based on the control parameters received from the operation management device. Therefore, even if the state of the power storage device changes, the control parameters can be updated as needed to suit the changed state.

[0014] The derivation unit may identify a mathematical model representing characteristics of the power storage device based on the detection result by the detection unit, and derive control parameters to be set in the control device so as to conform to the identified mathematical model. With this configuration, even if the state of the power storage device changes, the operation management device can derive the control parameters based on the mathematical model representing the characteristics of the power storage device after the change.

[0015] The derivation unit may periodically derive the control parameters to be set in the control device. With this configuration, the control parameters are periodically updated.

[0016] The derivation unit may calculate a change amount of the state detected by the detection unit, and when the calculated change amount is greater than a threshold, derive a control parameter to be set in the control device. According to this configuration, the control parameter is updated when the change in the state of the power storage device is large.

[0017] The control may be charge / discharge control of the power storage device. With this configuration, it is possible to appropriately update control parameters relating to charge / discharge control of the power storage device.

[0018] The control may be control of an air conditioner that conditions the environment in which the power storage device is installed. With this configuration, it is possible to update control parameters of the air conditioner that adjusts the temperature, airflow direction, airflow rate, etc. in the environment in which the power storage device is installed.

[0019] The control may be temperature control of the power storage device. With this configuration, it is possible to update a control parameter of a cooling device that controls the temperature of the power storage device.

[0020] The operation management device for the energy storage device includes a detection unit that detects the state of the energy storage device, a derivation unit that derives control parameters to be set in a control device that executes control related to the energy storage device based on the detection results by the detection unit, and a transmission unit that transmits the control parameters derived by the derivation unit to the control device so that the control device updates the control parameters used for the control. Therefore, even if the state of the power storage device changes, the control parameters can be updated as needed to suit the changed state.

[0021] A method for managing the operation of an energy storage device detects the state of the energy storage device, derives control parameters to be set in a control device that executes control related to the energy storage device based on the detected state, and transmits the derived control parameters to the control device so that the control device updates the control parameters used for the control. Therefore, even if the state of the power storage device changes, the control parameters can be updated as needed to suit the changed state.

[0022] The present invention will now be described in detail with reference to the drawings showing embodiments thereof. (Embodiment 1) 1 is a schematic diagram illustrating the overall configuration of an operation management system according to Embodiment 1. The operation management system according to Embodiment 1 includes an electricity storage device 100, a control device 210 that executes control related to the electricity storage device 100, and an operation management device 300 that manages the operation of the electricity storage device 100.

[0023] The power storage device 100 includes rechargeable power storage elements (cells) such as lithium ion batteries, all-solid-state batteries, polymer batteries, and lead-acid batteries, but does not include electronic components such as capacitors. In other words, the power storage device 100 includes secondary batteries that undergo dynamic changes and time-series changes during charging and discharging, but does not include electronic components such as capacitors that complete charging and discharging operations instantaneously using only an electric double layer. The power storage device 100 may include a module in which multiple cells are connected in series, a bank in which multiple modules are connected in series, a domain in which multiple banks are connected in parallel, or the like.

[0024] The control device 210 measures the state of the power storage device 100 and executes control related to the power storage device 100 based on the measurement results. The state of the power storage device 100 measured by the control device 210 is, for example, the terminal voltage of the power storage device 100. Alternatively, the state may be the current flowing through the power storage device 100, the temperature of the power storage device 100, the ambient temperature of the environment in which the power storage device 100 is installed, etc. The control executed by the control device 210 is, for example, charge / discharge control of the power storage device 100. Alternatively, the state may be temperature control of the power storage device 100, control of an air conditioner, etc.

[0025] In the following first embodiment, as one of the controls relating to the power storage device 100, the charge / discharge control of the power storage device 100 by the control device 210 will be described.

[0026] The control device 210 has control parameters designed in advance to control charging and discharging of the power storage device 100. The control parameters are stored in a storage unit 212 (see FIG. 2 ) of the control device 210. One example of the control parameters is a lower limit value (lower limit voltage) of the terminal voltage of the power storage device 100. Alternatively, the control parameters may include an upper limit value (upper limit voltage) of the terminal voltage, a waiting time after charging, a current value of a discharging current, and the like. These control parameters are designed when the power storage device 100 is manufactured or installed, and are stored in a storage unit 212 of the control device 210 that is installed together with the power storage device 100.

[0027] When performing charge / discharge control of the power storage device 100, the control device 210 reads out the control parameters stored in the storage unit 212 and performs charge / discharge control based on the read out control parameters. As charge / discharge control based on the control parameters, the control device 210 may perform charge / discharge control such that the SOC fluctuation range is limited so that the terminal voltage of the power storage device 100 does not fall below a lower limit. Here, SOC is an abbreviation for State Of Charge, where a fully charged state is represented as 100% and a fully discharged state as 0%. Limiting the fluctuation range means that charge / discharge control is performed such that the battery is used only within the range of 10%≦SOC≦85%, for example.

[0028] The operation management device 300 is communicably connected to the control device 210 via a communication network N, and manages the operation of the power storage device 100 from a remote location. Specifically, the operation management device 300 remotely monitors the state of the power storage device 100, derives new control parameters to be used in charge / discharge control by the control device 210 according to the state of the power storage device 100, and remotely updates the control parameters stored in the storage unit 212 of the control device 210. Here, the remote location refers to a location far from the power storage device 100 and the control device 210, and may be overseas or in outer space. The remote location does not necessarily have to be a location far in distance, and may include a location that is far enough away that the power storage device 100 and the control device 210 cannot be directly operated.

[0029] In order to remotely monitor the state of the power storage device 100, the operation management device 300 acquires measurement values measured by the control device 210 through communication via the communication network N. The communication network N may be an intranet within a company, a domestic general line, an international line, or may include outer space. The operation management device 300 newly derives control parameters to be used in charge / discharge control according to the state of the power storage device 100 detected based on the measurement values. The operation management device 300 transmits the newly derived control parameters to the control device 210 via the communication network N.

[0030] The control device 210 updates the control parameters stored in the storage unit 212 based on the control parameters received from the operation management device 300. The control device 210 executes charge / discharge control using the updated control parameters. Therefore, even if the power storage device 100 is in a deteriorated state, the control device 210 can use control parameters that correspond to the deteriorated state, thereby achieving more preferable charge / discharge control.

[0031] 1, the power storage device 100 and the control device 210 are illustrated as separate, independent devices. Alternatively, the control device 210 may be a device that is mounted on the power storage device 100 and integrated with the power storage device 100. The control device 210 and the operation management device 300 may also be integrated. Furthermore, the power storage device 100, the control device 210, and the operation management device 300 may all be integrated.

[0032] 2 is a block diagram illustrating the internal configuration of the control device 210. The control device 210 in the first embodiment is, for example, a BMU (Battery Management Unit), and includes a control unit 211, a storage unit 212, a measurement unit 213, an output unit 214, and a communication unit 215. Alternatively, the control device 210 may be a BMS (Battery Management System) or a general-purpose computer.

[0033] The control unit 211 is configured with a microcomputer, etc. The control unit 211 executes various calculations and controls the operation of each hardware unit based on a control program stored in an internal memory and data stored in the storage unit 212, and causes the entire device to function as the control device 210.

[0034] The storage unit 212 includes a memory such as an EEPROM (Electronically Erasable Programmable Read Only Memory). The storage unit 212 stores various data and programs. The data stored in the storage unit 212 includes control parameters related to charge and discharge control that are designed when the power storage device 100 is manufactured or installed. The control unit 211 appropriately reads out the data and programs stored in the storage unit 212 and rewrites them as necessary. For example, when the control unit 211 receives control parameters derived in the operation management apparatus 300 from the communication unit 215, the control unit 211 updates the control parameters by rewriting the control parameters stored in the storage unit 212 with the derived control parameters.

[0035] The measurement unit 213 measures the terminal voltage of the power storage device 100, the current flowing through the power storage device 100, the temperature of the power storage device 100, the ambient temperature of the power storage device 100, and the like. The measurement target of the measurement unit 213 is selected as appropriate depending on the calculations and controls executed by the control device 210. For example, in charge / discharge control, when the lower limit or upper limit of the terminal voltage is to be limited, the terminal voltage of the power storage device 100 is measured. In order to measure the above values, the measurement unit 213 may include a voltage sensor that measures the terminal voltage of the power storage device 100, a current sensor that measures the current flowing through the power storage device, a temperature sensor that measures the temperature of the power storage device 100, a temperature sensor that measures the ambient temperature, and the like. Alternatively, the measurement unit 213 may acquire the above values using a sensor provided outside the control device 210.

[0036] The output unit 214 outputs a control signal for turning on or off, for example, a switch for connecting or disconnecting a charging path from a power source (not shown) to the power storage device 100, or a switch for connecting or disconnecting a discharging path from the power storage device 100 to a load (not shown), based on an instruction from the control unit 211. For example, a semiconductor element such as a field effect transistor (FET) or a relay is used as such a switch. The control unit 211 controls the on / off of a switch provided in the charging / discharging path of the power storage device 100, thereby controlling charging and discharging of the power storage device 100.

[0037] The communication unit 215 has a communication interface for communicating with the operation management device 300 via the communication network N. The communication unit 215 outputs data received from the operation management device 300 via the communication network N to the control unit 211, and when data to be transmitted to the operation management device 300 is input from the control unit 211, the communication unit 215 transmits the input data to the operation management device 300.

[0038] 3 is a block diagram illustrating the internal configuration of the operation management device 300. The operation management device 300 includes a control unit 301, a storage unit 302, a communication unit 303, an operation unit 304, and a display unit 305.

[0039] The control unit 301 is configured with a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The CPU included in the control unit 301 causes the entire device to function as the operation management device 300 by expanding various computer programs stored in the ROM or the storage unit 302 onto the RAM and executing them.

[0040] The control unit 301 is not limited to the above configuration, and may be any processing circuit or arithmetic circuit including multiple CPUs, a multi-core CPU, a GPU (Graphics Processing Unit), a microcomputer, a volatile or non-volatile memory, etc. The control unit 301 may also have functions such as a timer that measures the elapsed time from when an instruction to start measurement is given to when an instruction to end measurement is given, a counter that counts numbers, and a clock that outputs date and time information.

[0041] The storage unit 302 includes a storage device such as a hard disk drive (HDD) or a solid state drive (SSD). The storage unit 302 stores various computer programs executed by the control unit 301, data required for executing the computer programs, and the like. The computer programs stored in the storage unit 302 include a simulation program that simulates the behavior of the power storage device 100. The simulation program is, for example, an executable binary. The theoretical equation that forms the basis of the simulation program is described by an algebraic equation or a differential equation that represents the behavior of the power storage device 100.

[0042] The storage unit 302 may also store a mathematical model obtained as a result of the simulation. The mathematical model may be, for example, an execution code executed by a programming language or numerical analysis software. The mathematical model may also be definition information or a library file referenced by the programming language or numerical analysis software.

[0043] The program stored in the storage unit 302 may be provided by a non-transitory storage medium on which the program is readably recorded. The storage medium is, for example, a portable memory such as a CD-ROM, a Universal Serial Bus (USB) memory, a Secure Digital (SD) card, a micro SD card, or a CompactFlash (registered trademark). In this case, the control unit 301 reads the program from the storage medium using a reading device (not shown) and installs the read program in the storage unit 302. The program stored in the storage unit 302 may be provided by communication via the communication unit 303. In this case, the control unit 301 obtains the program through the communication unit 303 and installs the obtained program in the storage unit 302.

[0044] The communication unit 303 has an interface for communicating with the control device 210 via the communication network N. The communication unit 303 outputs data received from the control device 210 via the communication network N to the control unit 301, and when data to be transmitted to the control device 210 is input from the control unit 301, the communication unit 303 transmits the input data to the control device 210.

[0045] The operation unit 304 is equipped with an input interface such as a keyboard and a mouse, and accepts operations by an administrator, etc. The display unit 305 is equipped with a liquid crystal display device, etc., and displays information to be notified to an administrator, etc. In this embodiment, the operation management device 300 is configured to include the operation unit 304 and the display unit 305, but the operation unit 304 and the display unit 305 are not essential, and the operation management device 300 may be configured to accept operations via a computer connected externally to the operation management device 300, and to output information to be notified to the external computer.

[0046] Hereinafter, a lithium ion battery will be taken as an example of the power storage device 100, and an example of a state change that occurs in the power storage device 100 (lithium ion battery) will be described.

[0047] Figure 4 is a graph showing the relationship between terminal voltage and discharge capacity. The vertical axis of the graph in Figure 4 shows the terminal voltage (V) of the lithium-ion battery, and the horizontal axis shows the discharge capacity (Ah). The relationship between terminal voltage and discharge capacity shown in Figure 4 was obtained by actual measurement.

[0048] The solid line in Fig. 4 represents the discharge characteristics of a lithium-ion battery in an initial manufacturing state. The terminal voltage of a lithium-ion battery gradually decreases from a fully charged state as the battery discharges, and then drops sharply at the end of the discharge. When a lower limit value (lower limit voltage) for the terminal voltage is set as a control parameter for charge / discharge control, the control device 210 stops discharging when the terminal voltage reaches the lower limit value, so the terminal voltage of the lithium-ion battery drops to the lower limit voltage V shown in Fig. 4. L0 It drops to.

[0049] Lithium-ion batteries deteriorate with repeated charging and discharging. The dashed line in Figure 4 shows the discharge characteristics of a lithium-ion battery in a deteriorated state. The terminal voltage of a lithium-ion battery, even if deteriorated, gradually decreases from a fully charged state as it discharges, just like a lithium-ion battery in an initial manufacturing state, and then drops sharply at the end of discharge. The terminal voltage of a lithium-ion battery in a deteriorated state reaches a lower limit voltage V L0 reaches.

[0050] The decrease in discharge capacity is thought to be due to a decrease in lithium ion diffusivity in the separator, which increases the ohmic loss of the ion conductor, increasing the internal resistance of the battery and causing significant variations in the lithium ion concentration within the porous positive electrode.

[0051] Figure 5 is a graph showing the lithium ion concentration distribution inside the battery. The graph in Figure 5 shows the change in lithium ion concentration from the negative electrode to the positive electrode at the end of discharge of the lithium ion battery. The vertical axis of the graph in Figure 5 shows the simulated value of lithium ion concentration (mol / L), and the horizontal axis shows the distance (μm) from the negative electrode current collector foil. n,minis the position of the interface between the negative electrode current collector foil and the negative electrode (i.e., the origin on the X axis), and x n,max is the position of the interface between the negative electrode and the separator (the distance from the negative electrode current collector foil to the separator), and x p,min is the position of the interface between the separator and the positive electrode (the distance from the negative electrode current collector foil to the positive electrode), x p,max represents the position of the interface between the positive electrode and the positive electrode current collector foil (the distance from the negative electrode current collector foil to the positive electrode current collector foil).

[0052] The solid line in Figure 5 shows the change in lithium ion concentration in a lithium ion battery in its initial manufacturing state. In the initial manufacturing state, the lithium ion concentration on the negative electrode side is slightly higher and the lithium ion concentration on the positive electrode side is slightly lower, but overall it is roughly constant. This indicates that a uniform reaction is occurring inside the positive electrode. This is a desirable distribution of lithium ion concentration.

[0053] The dashed line in Figure 5 shows the change in lithium ion concentration in a degraded lithium ion battery. In a degraded state, the lithium ion battery gradually decreases from the negative electrode current collector foil to the positive electrode, and the lithium ion concentration decreases even more steeply inside the positive electrode.

[0054] If the lithium ion concentration varies greatly across the thickness of the porous electrode (i.e., if the reaction distribution varies greatly), the amount of active material absorbed and desorbed by the active particles will also vary greatly. In other words, the porous electrode will have both areas where a large amount of active material enters and exits and areas where a small amount of active material enters and exits.

[0055] Therefore, the operation management device 300 performs simulation trials to find a lithium ion diffusion coefficient that matches the charge / discharge curve. The operation management device 300 performs simulations using a mathematical model that expresses phenomena inside the lithium ion battery using mathematical formulas, etc.

[0056] The operation management device 300 uses the so-called Newman model as an example of a mathematical model. The Newman model includes the Nernst-Planck equation for solving ion migration and ion diffusion in an electrolyte or a porous electrode. The Nernst-Planck equation is expressed by the following equation.

[0057]

number

[0058] where σl is the liquid phase conductivity (S / m), φ l is the liquid phase potential (V), R is the gas constant (J / (K·mol)), T is the temperature (K), F is the Faraday constant (C / mol), f is the activity coefficient, and c l is the lithium ion concentration (mol / m 3 ), t + is the cation transference number, i tot is the reaction current density (A / m 3 ) D l is the diffusion coefficient of lithium ions in the electrolyte (m 2 / s).

[0059] The operation management device 300 calculates the diffusion coefficient of lithium ions after deterioration as α×D l (α is a real number satisfying 0<α<1), and the value of α is successively changed to 0.05, 0.10, ..., 0.95, etc., and simulations are performed multiple times based on the Newman model. As a result of the simulation, the operation management device 300 adopts the value that is closest to the measurement data as the diffusion coefficient of lithium ions after degradation.

[0060] Next, the operation management device 300 executes a simulation while changing the lower limit value (lower limit voltage) for the terminal voltage, and finds the conditions under which the distribution of the lithium ion concentration inside the positive electrode at the end of discharge is improved.

[0061] Lower limit voltage increase ΔV L is ΔV L =V L1 -V L0 where V L0is the lower limit voltage before the change, and V L1 is the lower limit voltage after the change. The lower limit voltage after the change V L1 is a value derived by the operation management unit 300 as one of the control parameters to be set in the control unit 210.

[0062] The variation in the lithium ion concentration in the positive electrode is evaluated by the following equation 2.

[0063]

number

[0064] where x p,min represents the distance from the negative electrode current collector foil to the positive electrode, and x p,max represents the distance from the negative electrode current collector foil to the positive electrode current collector foil. p,min and x p,max has the dimension of length (μm).

[0065] where c Li+ represents the concentration of lithium ions at the positive electrode, and c Li+ The bar represents the average concentration of lithium ions in the positive electrode. Li+ The bar is represented by the following number 3:

[0066]

number

[0067] W is zero when the concentration of lithium ions in the positive electrode is uniform, and the more non-uniform it is, the larger the value becomes.

[0068] From the above equation, ΔV L It can be seen that desirable control can be obtained by reducing W while reducing . Therefore, the operation management device 300 uses appropriate weights p and q (p and q are positive real numbers) to calculate p × (ΔV L ) 2 + ΔV that minimizes q×W LThe control parameters for the controller 210 may be derived by finding

[0069] In the above example, the control parameters are derived with a focus on the diffusion coefficient of lithium ions at the end of discharging. Alternatively, the operation management device 300 may derive the control parameters with a focus on the diffusion coefficient of lithium ions at the end of charging.

[0070] Figure 6 is a graph showing the relationship between terminal voltage and discharge capacity after the control parameters have been updated. The vertical axis of the graph shown in Figure 6 represents the terminal voltage (V) of the lithium-ion battery, and the horizontal axis represents the discharge capacity (Ah). The relationship between terminal voltage and discharge capacity shown in Figure 6 was obtained by actual measurement. For reference, Figure 6 also shows the relationship between terminal voltage and discharge voltage in an initial state and in a deteriorated state.

[0071] The graph in FIG. 6 shows that by increasing the lower limit voltage (control parameter), the decrease in discharge capacity can be suppressed and charge / discharge control close to the initial state can be performed.

[0072] Figure 7 is a graph showing the lithium ion concentration distribution inside the battery after the control parameters have been updated. The graph in Figure 7 shows the change in lithium ion concentration from the negative electrode to the positive electrode at the end of discharge of the lithium ion battery. The vertical axis of the graph in Figure 7 shows the simulated value of the lithium ion concentration (mol / L), and the horizontal axis shows the distance (μm) from the negative electrode current collector foil. For reference, Figure 7 also shows the distribution of lithium ion concentration in the initial state and in a deteriorated state.

[0073] The graph in FIG. 7 shows that by increasing the lower limit voltage (control parameter), the variation in the lithium ion concentration inside the positive electrode can be suppressed, and charge / discharge control close to the initial state can be performed.

[0074] 8 is a flowchart illustrating the procedure of the process executed by the operation management device 300. The control unit 301 of the operation management device 300 executes the following process periodically or at a timing instructed by an administrator or the like. The control unit 301 acquires a measurement value related to the power storage device 100 (step S101). An example of the measurement value related to the power storage device 100 is the terminal voltage of the power storage device 100. The control unit 301 may directly measure the terminal voltage of the power storage device 100 using a voltage sensor or the like, or may acquire the measurement value measured by the control device 210 via communication.

[0075] Next, the control unit 301 determines whether to update the control parameters (step S102). The control unit 301 may determine to update the control parameters, for example, periodically, at a predetermined timing, or at a timing instructed by an administrator or the like. Alternatively, the control unit 301 may determine whether to update the control parameters based on the state of the power storage device 100 estimated from the measurement values acquired in step S101. If the power storage device 100 is a lithium ion battery, the control unit 301 estimates the diffusion coefficient of lithium ions as the state quantity. The control unit 301 performs a process of converting the estimated state of the power storage device into a numerical value and storing it in the storage unit 302, and calculates the amount of change in the state by taking the difference from the previous estimated amount. If the calculated amount of change is greater than a threshold, the control unit 301 can determine to update the control parameters.

[0076] If it is determined that the control parameters are not to be updated (S102: NO), the control unit 301 ends the processing according to this flowchart.

[0077] When it is determined that the control parameters should be updated (S102: YES), the control unit 301 identifies a mathematical model that represents the characteristics of the power storage device 100 (step S103). Taking a lithium ion battery as an example, the control unit 301 may identify the above-mentioned Newman model.

[0078] Next, the control unit 301 derives control parameters to be set in the control device 210 so as to conform to the identified mathematical model (step S104). Taking the above-mentioned lithium ion battery as an example, the control unit 301 may derive a lower limit value (lower limit voltage) for the terminal voltage. Alternatively, the control unit 301 may derive control parameters that control an upper limit value (upper limit voltage) for the terminal voltage, a rest time after charging, and a current flowing through the power storage device 100. The control unit 301 may arbitrarily set control parameters to be updated based on the SOC, battery temperature, etc. In this case, the control unit 301 may derive control parameters within a preset range, taking into account the influence on the power storage device 100 and its peripheral components.

[0079] Next, the control unit 301 transmits the derived control parameters to the control device 210 via the communication unit 303 (step S105). At this time, the control unit 301 may provide the control device 210 with an instruction to update the control parameters together with the control parameters.

[0080] 9 is a flowchart illustrating the procedure of the process executed by the control device 210. The control unit 211 of the control device 210 determines whether the control parameters transmitted from the operation management device 300 have been received by the communication unit 215 (step S121). If the control parameters have not been received (S121: NO), the control unit 211 executes the process from step S123 onwards.

[0081] If it is determined that the control parameters have been received (S121: YES), the control unit 211 updates the control parameters (step S122). At this time, the control unit 211 executes a process of rewriting the control parameters stored in the storage unit 212 with the newly received control parameters.

[0082] Next, the control unit 211 determines whether or not to execute control related to the power storage device 100 (step S123). That is, the control unit 211 may determine whether or not to execute charge / discharge control of the power storage device 100. When it is determined that control related to the power storage device 100 is not to be executed (S123: NO), the control unit 211 ends the processing according to this flowchart.

[0083] When it is determined that control related to the power storage device 100 is to be executed (S123: YES), the control unit 211 executes control related to the power storage device 100 based on the control parameters stored in the storage unit 212 (step S124). When the control parameters have been updated, the control unit 211 can execute control related to the power storage device 100 based on the updated control parameters. Taking a lithium-ion battery as an example, the control unit 211 can perform current control to reduce the SOC fluctuation range, and can suppress capacity imbalance caused by increased reaction unevenness and increased activation overvoltage.

[0084] In the first embodiment, a lithium ion battery has been described as an example of the power storage device 100. Alternatively, the power storage device 100 may be an all-solid-state battery, a polymer battery, a lead sulfate battery, or the like.

[0085] In the first embodiment, the Newman model has been described as an example of a mathematical model that represents the characteristics of a lithium-ion battery. Alternatively, a polynomial model, such as the NTGK model, that represents the open-circuit potential and internal resistance as a function of temperature and state of charge (SOC) may be used, or an equivalent circuit model may be used. Furthermore, the mathematical model may be spatially two-dimensional or three-dimensional.

[0086] (Embodiment 2) In the second embodiment, an operation management system that controls air conditioning in the installation environment where the power storage device 100 is installed will be described.

[0087] 10 is a schematic diagram illustrating the overall configuration of an operation management system according to Embodiment 2. The operation management system according to Embodiment 2 includes an electricity storage device 100, a control device 220 that controls air conditioning in the installation environment in which the electricity storage device 100 is installed, and an operation management device 300 that manages the operation of the electricity storage device 100.

[0088] The control device 220 in the second embodiment is mounted on an air conditioner 22 having cooling, heating, dehumidifying, and fan functions, and controls the operation of the air conditioner 22 to control the air conditioning of the installation environment in which the energy storage device 100 is installed.

[0089] Hereinafter, as one type of control relating to the power storage device 100, control for cooling the surroundings of the power storage device 100 using the air conditioner 22 (that is, control for lowering the environmental temperature of the power storage device 100) will be described.

[0090] The control device 220 has control parameters designed in advance to control the ambient temperature of the power storage device 100. The control parameters include the cooling temperature, air volume, and air direction. These control parameters are designed when the power storage device 100 is manufactured or installed. The control parameters are designed, for example, based on the results of a simulation that estimates the amount of heat generated in the power storage device 100, so that the temperature of each cell falls within a specified value. The designed control parameters are stored in a storage unit 222 (see FIG. 11) of the control device 220.

[0091] The control device 220 reads out the control parameters stored in the storage unit 222 and controls the operation of the air conditioner 22 based on the read out control parameters, thereby controlling the ambient temperature. The temperature of each cell constituting the power storage device 100 is controlled to a temperature within a specified value by controlling the ambient temperature using the air conditioner 22.

[0092] 11 is a block diagram illustrating the internal configuration of control device 220. Control device 220 in embodiment 2 includes control unit 221, storage unit 222, measurement unit 223, output unit 224, and communication unit 225. The configurations of control unit 221, storage unit 222, measurement unit 223, and communication unit 225 are the same as those in embodiment 1, and therefore description thereof will be omitted.

[0093] The output unit 224 outputs control signals that control the operation of the heat exchanger, fan, horizontal louvers, vertical louvers, and other components installed in the air conditioner 22 in response to instructions from the control unit 221. The heat exchanger is a device for transferring heat from a high-temperature object to a low-temperature object, and creates cooled or heated air by transferring heat between the heat exchanger and an outdoor unit. The fan blows the air cooled or heated by the heat exchanger to the outside of the device. The horizontal louvers and vertical louvers adjust the air blowing direction along the horizontal and vertical directions, respectively. The control unit 221 controls the operation of the heat exchanger, fan, horizontal louvers, vertical louvers, and other components installed in the air conditioner 22 to achieve cooling, heating, and air blowing functions, and to control the ambient temperature of the power storage device 100.

[0094] Immediately after the power storage device 100 is installed, the control device 220 controls the operation of the air conditioner 22 and the ambient temperature of the power storage device 100 using control parameters designed when the power storage device 100 was manufactured or installed. However, if some of the cells constituting the power storage device 100 deteriorate and the internal resistance increases, the amount of heat generated increases, and even if the ambient temperature is controlled using the control parameters designed initially, cooling may become insufficient. Since the internal resistance inside the battery is strongly affected by temperature, the terminal voltage of the power storage device 100 changes significantly depending on the temperature. Furthermore, it is known that the power storage device 100 is prone to deterioration at high temperatures.

[0095] Therefore, the operation management device 300 finds the heat generation amount (or resistance) of the deteriorated cells through trial simulations. The operation management device 300 estimates the heat generation amount of each cell, for example, using a mathematical model that expresses the thermal phenomenon inside the battery as shown in Equation 4 below.

[0096]

number

[0097] where ρ, C p is the density (kg / m) of the electricity storage device 100 3 ), and specific heat (J / kg / K). Alternatively, the density and specific heat values may be set for each cell. T represents the temperature (K) of the power storage device 100, and t represents time (s). k, R, and I represent the thermal conductance (W / k), resistance (Ω), and current (A) of the power storage device 100, respectively. The amount of heat generated is expressed as RI in the second term on the right-hand side 2 is obtained by

[0098] The operation management device 300 refers to the results of the heat generation simulation to determine whether the heat generation amount in a specific cell is large. The operation management device 300 determines whether the heat generation amount is large by comparing the heat generation amount estimated by the simulation with a preset threshold. If the operation management device 300 determines that the heat generation amount in a specific cell is large, it uses the estimated heat generation amount to execute a thermal fluid simulation to determine the cooling temperature, air volume (wind speed), and wind direction for appropriately cooling the power storage device 100. This simulation may be a brute force simulation, or an optimization method such as response surface methodology may be used. The operation management device 300 may use, for example, the following equation 5 as a weighting function used for optimization. Alternatively, the operation management device 300 may execute the simulation at regular intervals or at times instructed by an administrator or the like.

[0099]

number

[0100] Here, p and q are arbitrarily determined positive real numbers.

[0101] The operation management device 300 transmits the cooling temperature, air volume (wind speed), and wind direction newly determined by the thermal fluid simulation to the control device 220 as control parameters to be set in the control device 220. Note that heating may also be performed in cold regions or outer space, and the method for setting the control parameters is the same as for cooling.

[0102] The control device 220 updates the control parameters by executing a process of rewriting the control parameters stored in the storage unit 222 with the control parameters newly received from the operation management device 300. The control unit 221 of the control device 220 reads the updated control parameters from the storage unit 222 and controls the operation of the air conditioner 22 to control the ambient temperature.

[0103] As described above, the operation management system in embodiment 2 autonomously finds settings that appropriately control the ambient temperature using the air conditioner 22, even if a specific cell in the energy storage device 100 deteriorates and generates a large amount of heat, thereby suppressing a rise in temperature of the energy storage device 100.

[0104] (Embodiment 3) In the third embodiment, an operation management system that controls the temperature of the power storage device 100 will be described.

[0105] 12 is a schematic diagram illustrating the overall configuration of an operation management system according to Embodiment 3. The operation management system according to Embodiment 3 includes an electricity storage device 100, a control device 230 that controls the temperature of the electricity storage device 100, and an operation management device 300 that manages the operation of the electricity storage device 100.

[0106] The control device 230 in the third embodiment is mounted on a cooling device 23 that cools the power storage device 100, and controls the operation of the cooling device 23 to control the temperature of the power storage device 100. The cooling device 23 is, for example, a water-cooled (liquid-cooled) cooling device. Alternatively, it may be an air-cooled cooling device.

[0107] In the following, as one type of control relating to the power storage device 100, control for cooling the power storage device 100 using a water-cooling type cooling device 23 will be described.

[0108] The control device 230 has control parameters designed in advance to control the temperature of the power storage device 100. The control parameters are, for example, a proportional control constant, an integral control constant, and a differential control constant when the control device 230 performs PID control on the cooling water flow rate of the cooling device 23. These control parameters are designed when the power storage device 100 is manufactured or installed, and are stored in a storage unit 232 (see FIG. 13 ) of the control device 230.

[0109] The control device 230 reads out the control parameters stored in the storage unit 232, and performs PID control of the cooling water flow rate based on the read out control parameters. The control device 230 controls the temperature of the power storage device 100 to be within a specified value through such PID control.

[0110] In the third embodiment, a description will be given of PID control of the cooling device 23. Alternatively, P control using only a proportional control constant may be used, or other feedback control including ON / OFF control may be used.

[0111] 13 is a block diagram illustrating the internal configuration of control device 230. Control device 230 in embodiment 3 includes control unit 231, storage unit 232, measurement unit 233, output unit 234, and communication unit 235. The configurations of control unit 231, storage unit 232, measurement unit 233, and communication unit 235 are the same as those in embodiment 1, and therefore description thereof will be omitted.

[0112] The output unit 234 outputs a control signal for controlling the operation of the cooling device 23 in response to an instruction from the control unit 231. The cooling device 23 includes a radiator that produces cooling water, a reservoir tank that stores the cooling water, a pump that sends the cooling water to the outside of the device, an adjustment valve that adjusts the flow rate of the cooling water that is sent out, etc. The control unit 231 controls the operation of the cooling device 23, and controls the temperature of the electricity storage device 100 by, for example, adjusting the flow rate of the cooling water that is sent out from the cooling device 23.

[0113] Immediately after the power storage device 100 is installed, the control device 230 controls the operation of the cooling device 23 and the temperature of the power storage device 100 using control parameters designed when the power storage device 100 is manufactured or installed. However, if some of the cells constituting the power storage device 100 deteriorate and the internal resistance increases, the amount of heat generated increases, and even if the operation of the cooling device 23 is controlled using the control parameters designed initially, there is a possibility that cooling will be insufficient. Since the internal resistance inside the battery is strongly affected by temperature, the terminal voltage of the power storage device 100 changes significantly depending on the temperature. Furthermore, it is known that the power storage device 100 is prone to deterioration at high temperatures.

[0114] Therefore, the operation management device 300 finds the temperature of the power storage device 100 by performing a trial simulation. The operation management device 300 estimates the amount of heat generated in the power storage device 100, for example, by using a mathematical model that expresses the thermal phenomenon inside the battery as shown in Equation 6 below.

[0115]

number

[0116] where ρ, C p is the density (kg / m) of the electricity storage device 100 3 ), specific heat (J / kg / K). T is temperature (K), t is time (s), and h is the heat transfer coefficient to the outside air (W / (m 3 K), S is the outer surface area of the electricity storage device 100 (m 2 ), Q is the amount of self-heating such as Joule heat (W), q is the flow rate of cooling water (m3 / s), A is a constant (J / m 3 )

[0117] The operation management device 300 refers to the results of the simulation of the amount of heat generated based on Equation 6, and performs PID control on the flow rate of cooling water sent out from the cooling device 23. The PID control is formulated by Equation 7 below.

[0118]

number

[0119] where K p is the proportional control constant, K i is the integral control constant, K d is the differential control constant, T s is the target temperature (K). p ,K i ,K d The stability and responsiveness of the control are determined by how it is taken.

[0120] The parameters of the mathematical model expressed by Equation 6 are determined by the design of the power storage device 100 at the time of manufacture. On the other hand, the parameters related to PID control expressed by Equation 7 are determined by the control design at the time of manufacture. These parameters are written into the storage unit 232 of the control device 230 at the time of manufacture or installation of the power storage device 100, and are used as control parameters in the initial state.

[0121] However, when the parameters in the mathematical model change due to aging of the power storage device 100 or the like, the parameters related to PID control that were initially optimal are no longer necessarily optimal values.

[0122] Therefore, the operation management apparatus 300 in the third embodiment identifies a mathematical model that represents the characteristics of the power storage device 100 after deterioration, and redesigns the parameters related to PID control using the identified mathematical model.

[0123] Fig. 14 is a graph showing the temperature change of the power storage device 100. The vertical axis of the graph shown in Fig. 14 represents the temperature (K) of the power storage device 100, and the horizontal axis represents the time (s) elapsed since the start of charging.

[0124] The graph shown as a solid line in Fig. 14 indicates the time dependency of the temperature of the electricity storage device 100 in an initial manufacturing state. The example in Fig. 14 shows that the temperature of the electricity storage device 100 increases over time, reaches a maximum temperature, and then settles at a temperature lower than the maximum temperature.

[0125] The electricity storage device 100 deteriorates due to repeated charging and discharging, etc. The dashed line in the graph of Fig. 14 indicates the time dependency of the temperature of the electricity storage device 100. The example of Fig. 14 shows that the temperature of the electricity storage device 100 increases over time and reaches a temperature even higher than the maximum temperature in the initial manufacturing state.

[0126] The operation management device 300 identifies the characteristics (thermal phenomenon in this example) of the power storage device 100 after deterioration indicated by the dashed line using a mathematical model. p Alternatively, the operations management device 300 may use optimization software to find the parameters in Equation 6 and identify the mathematical model.

[0127] The operation management device 300 refers to the identified mathematical model and calculates the control parameters (K p ,K i ,K d) is derived. The operations management device 300 may use, for example, the Ziegler-Nichols limit sensitivity method as an optimization method for PID control. Alternatively, the operations management device 300 may use an optimization method based on the Riccati equation. Furthermore, the operations management device 300 may use the optimization function of commercially available analysis software such as Maple (registered trademark), ANSYS Twin Builder (registered trademark), ANSYS Simplorer (registered trademark), or MATLAB Simulink (registered trademark). The operations management device 300 may use, as a simulation model used to identify control parameters, a three-dimensional finite element method model, a one-dimensional simulation model, or a model obtained by degenerating a three-dimensional finite element method model.

[0128] The operation management device 300 calculates the newly derived control parameter (K p ,K i ,K d ) is transmitted to the control device 220 as a control parameter to be set in the control device 220.

[0129] The control device 220 updates the control parameters by executing a process of rewriting the control parameters stored in the storage unit 222 with the control parameters newly received from the operation management device 300. The control unit 221 of the control device 220 reads the updated control parameters from the storage unit 222 and controls the operation of the cooling device 23 to control the temperature of the power storage device 100.

[0130] As described above, the operation management system in embodiment 3 can appropriately control the temperature of the power storage device 100 using the cooling device 23, even if the power storage device 100 deteriorates and the amount of heat generated increases, thereby suppressing a rise in the temperature of the power storage device 100.

[0131] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0132] 100 Energy storage device 210,220,230 Control device 211,221,231 Control section 212,222,232 Storage section 213,223,233 Measurement section 214,224,234 Output section 215,225,235 Communications Department 300 Operation management equipment 301 Control Unit 302 Storage section 303 Communications Department 304 Operation section 305 Display section N Communication Network

Claims

1. a control device that executes control related to the power storage device; an operation management device for the power storage device that is communicably connected to the control device; Equipped with The control device a storage unit that stores control parameters; a control unit that executes the control based on the control parameters stored in the storage unit; Equipped with The operation management device a detection unit that detects a state of the power storage device; a derivation unit that derives control parameters to be set in the control device according to a detection result by the detection unit; a transmission unit that transmits the control parameters derived by the derivation unit to the control device; Equipped with The control device an update unit that updates the control parameters stored in the storage unit based on the control parameters received from the operation management device; Equipped with An operation and management system for energy storage devices.

2. The lead-out portion is identifying a mathematical model representing characteristics of the power storage device based on a detection result by the detection unit; Derive control parameters to be set in the control device so as to fit the identified mathematical model. The operation management system according to claim 1 .

3. The derivation unit periodically derives control parameters to be set in the control device.

3. The operation management system according to claim 1 or 2.

4. The derivation unit calculates a change amount of the state detected by the detection unit, and when the calculated change amount is greater than a threshold value, derives a control parameter to be set in the control device.

3. The operation management system according to claim 1 or 2.

5. The control is charge / discharge control of the power storage device.

5. The operation management system according to claim 1.

6. The control is control of an air conditioner that conditions the installation environment of the power storage device.

5. The operation management system according to claim 1.

7. The control is a temperature control of the power storage device.

5. The operation management system according to claim 1.

8. a detection unit that detects a state of the power storage device; a derivation unit that derives control parameters to be set in a control device that executes control related to the power storage device according to a detection result by the detection unit; a transmission unit that transmits the control parameters derived by the derivation unit to the control device so that the control device updates the control parameters used for the control; An operation management apparatus for a power storage device comprising:

9. Detect the state of the power storage device, deriving control parameters to be set in a control device that executes control related to the power storage device according to the detection result of the state; Transmitting the derived control parameters to the control device to cause the control device to update the control parameters used for the control. A method for managing the operation of an electricity storage device.

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