Control device for power storage device, operation management device, control system, and operation management system

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 One aspect of A control device for an electricity storage device 、 Operation management device , control system and operation management system Regarding. [Background technology]

[0002] The power storage device is used together with a control device that controls the charge / discharge state, temperature, and environmental temperature in 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 in 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 out the control parameters written in the memory as necessary and controls the charge / discharge state and temperature of the power storage device and the environmental temperature of the installation environment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-071100 A Summary of the Invention [Problem to be solved by the invention]

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

[0006] The present invention has been made in view of the above circumstances, and provides a control device for an electricity storage device that can redesign control parameters in the control device according to the state of the electricity storage device. 、 Operation management device , control system and operation management system The purpose is to provide. [Means for solving the problem]

[0007] Control device teeth, Energy storage device A storage unit for storing control parameters, Is Based on control parameters , relating to the electricity storage device A control unit for executing the control, Control Unit detects a state of the power storage device Then, the control parameters for updating are obtained from an operation management device that derives control parameters for updating the power storage device in accordance with the detection result, and the obtained control parameters for updating are The control parameters stored in the storage unit are updated based on the control parameters. R .

[0008] The operation management device is A storage unit that stores control parameters of a power storage device, and a control unit that executes control regarding the power storage device based on the control parameters stored in the storage unit; A detection unit that detects a state of the power storage device, and Set A derivation unit for deriving a power control parameter; updating the control parameters stored in the storage unit based on the control parameters derived by the derivation unit; It also has a department. Effect 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 description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating an overall configuration of an operation management system according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram illustrating an internal configuration of a control device. [Diagram 3] 2 is a block diagram illustrating an internal configuration of an operation management device. [Figure 4] 1 is a graph showing the relationship between terminal voltage and discharge capacity. [Diagram 5] 4 is a graph showing the concentration distribution of lithium ions inside a battery. [Figure 6] 13 is a graph showing the relationship between terminal voltage and discharge capacity after a control parameter is updated. [Figure 7] 11 is a graph showing the concentration distribution of lithium ions inside the battery after the control parameters are updated. [Figure 8] 11 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. 11 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 an 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 an internal configuration of a control device. [Figure 14] 1 is a graph showing a change in temperature of an electricity storage device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[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 executes 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 an energy storage device comprises a control device that executes 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 comprises 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 comprises 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 comprises 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. Thus, 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 a characteristic of the power storage device based on a detection result by the detection unit, and derive a control parameter to be set in the control device so as to conform to the identified mathematical model. With this configuration, even if a state of the power storage device changes, the operation management device can derive the control parameter based on the mathematical model representing the characteristic 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 an amount of change in the state detected by the detection unit, and when the calculated amount of change 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, a control parameter related to charge / discharge control of the power storage device can be appropriately updated.

[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, air direction, air volume, etc. in the environment in which the power storage device is installed.

[0019] The control may be a 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 as to cause the control device to update 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 an operation of an energy storage device detects a 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 detection results of the state, and transmits the derived control parameters to the control device so as to cause the control device to update 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] Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof. (Embodiment 1) 1 is a schematic diagram illustrating an 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 result. 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, it may be the current flowing through the power storage device 100, the temperature of the power storage device 100, the environmental 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, it may be temperature control of the power storage device 100, control of an air conditioner, etc.

[0025] In the following first embodiment, as one type of control related to the power storage device 100, charging and discharging control of the power storage device 100 by a control device 210 will be described.

[0026] The control device 210 has control parameters designed in advance to execute charge / discharge control 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 in 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 discharge 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 as limiting the fluctuation range of SOC 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, and a fully charged state is represented as 100%, and a completely discharged state is represented as 0%. Limiting the fluctuation range means performing charge / discharge control 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, and 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 point far from the power storage device 100 and the control device 210, and may be overseas or outer space. The remote location does not necessarily need to be a point far in distance, and may include a point 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 the measurement values ​​measured by the control device 210 through communication via the communication network N. The communication network N may be an intranet in 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 and 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 according to the deteriorated state, and can realize more preferable charge / discharge control.

[0031] 1, the power storage device 100 and the control device 210 are described as separate, independent devices. Alternatively, the control device 210 may be a device 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 be integrated. Furthermore, the power storage device 100, the control device 210, and the operation management device 300 may 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 composed of a microcomputer or the like. Based on the control program stored in the built-in memory and the data stored in the storage unit 212, the control unit 211 executes various operations and controls the operations of each part of the hardware, causing 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). Various data and programs are stored in the storage unit 212. The data stored in the storage unit 212 includes control parameters related to charge and discharge control designed during the manufacturing or introduction of the power storage device 100. The control unit 211 appropriately reads out and, if necessary, rewrites the data and programs stored in the storage unit 212. For example, when the control unit 211 receives the control parameters derived in the operation management device 300 via the communication unit 215, it 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, etc. The measurement target by the measurement unit 213 is appropriately selected according to the operations and controls executed in the control device 210. For example, in charge and discharge control, when limiting the lower or upper limit value of the terminal voltage, the terminal voltage of the power storage device 100 is measured. The measurement unit 213 may include a voltage sensor for measuring the terminal voltage of the power storage device 100, a current sensor for measuring the current flowing through the power storage device, a temperature sensor for measuring the temperature of the power storage device 100, a temperature sensor for measuring the ambient temperature, etc. to measure the above values. Alternatively, the measurement unit 213 may acquire the above values using sensors 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, a switch for connecting or disconnecting a discharging path from the power storage device 100 to a load (not shown), etc., based on an instruction from the control unit 211. As such a switch, for example, a semiconductor element such as a field effect transistor (FET) or a relay is used. The control unit 211 performs charge and discharge control for the power storage device 100 by controlling the on / off of a switch provided in the charge and discharge path of the power storage device 100.

[0037] The communication unit 215 includes 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 composed of 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 equipped with 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 a measurement start instruction is given to when a measurement end instruction 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 using a hard disk drive (HDD), a solid state drive (SSD), or the like. The storage unit 302 stores various computer programs executed by the control unit 301, data necessary 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. A theoretical equation on which the simulation program is based is described by an algebraic equation or a differential equation that represents the behavior of the power storage device 100.

[0042] A mathematical model obtained as a result of the simulation may be stored in the storage unit 302. 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 recording medium on which the program is readably recorded. The recording 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 Compact Flash (registered trademark). In this case, the control unit 301 reads the program from the recording 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 acquires the program through the communication unit 303 and installs the acquired program in the storage unit 302.

[0044] The communication unit 303 includes 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 has an input interface such as a keyboard and a mouse, and accepts operations by an administrator, etc. The display unit 305 has 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 have 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 may be accepted via a computer connected externally to the operation management device 300, and information to be notified may be output 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 state changes that occur 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 is obtained by actual measurement.

[0048] The solid line in the graph of 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 is discharged, and then suddenly decreases 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 that the terminal voltage of the lithium-ion battery is lower than the lower limit voltage V L0 It drops to.

[0049] Lithium-ion batteries deteriorate due to repeated charging and discharging. The dashed line in the graph 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 is discharged, just like a lithium-ion battery in an initial manufacturing state, and then decreases suddenly 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 reason for the decrease in discharge capacity is believed to be 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 variation in the lithium ion concentration in 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 a lithium ion battery. The vertical axis of the graph in Figure 5 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. n,minis the position of the interface between the negative 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 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), and x p,max indicates the position of the interface between the positive electrode and the positive current collector foil (the distance from the negative current collector foil to the positive current collector foil).

[0052] The solid line in Figure 5 shows the change in lithium ion concentration in a lithium ion battery in an 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 approximately constant. In other words, it shows that a uniform reaction is occurring inside the positive electrode. This is a desirable distribution of lithium ion concentration.

[0053] The dashed line in the graph 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] When the lithium ion concentration varies greatly in the thickness direction of the porous electrode (i.e., when the reaction distribution varies greatly), the amount of active material absorbed and desorbed by the active particles also varies 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 finds a lithium ion diffusion coefficient that fits the charge / discharge curve by performing a simulation trial. The operation management device 300 executes the simulation using a mathematical model that expresses the phenomenon inside the lithium ion battery by using mathematical expressions or the like.

[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, c l is the lithium ion concentration (mol / m 3 ), t + is the cation transport 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 a simulation is 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 deterioration.

[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 in the positive electrode at the end of discharge is improved.

[0061] Lower limit voltage increase ΔV L is ΔV L =V L1 -V L0 Here, 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 device 300 as one of the control parameters to be set in the control device 210.

[0062] The variation in 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 current collector to the positive electrode, and x p,max represents the distance from the negative current collector foil to the positive current collector foil. x p,min and x p,max has the dimension of length (μm).

[0065] where c Li+ represents the concentration of lithium ions in the positive electrode, and c Li+ The bars represent 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 its value becomes.

[0068] From the above formula, 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 + q × W to minimize ΔV LBy finding , the control parameters for the controller 210 may be derived.

[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] Fig. 6 is a graph showing the relationship between terminal voltage and discharge capacity after the control parameters are updated. The vertical axis of the graph shown in Fig. 6 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 Fig. 6 is obtained by actual measurement. In addition, Fig. 6 shows the relationship between terminal voltage and discharge voltage in an initial state and in a deteriorated state for reference.

[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] Fig. 7 is a graph showing the lithium ion concentration distribution inside the battery after the control parameters have been updated. The graph in Fig. 7 shows the change in lithium ion concentration from the negative electrode to the positive electrode at the end of discharge of a lithium ion battery. The vertical axis of the graph shown in Fig. 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. In addition, Fig. 7 shows the distribution of lithium ion concentration in the initial state and in a deteriorated state for reference.

[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, enabling charge / discharge control close to the initial state.

[0074] 8 is a flowchart explaining 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 through 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, at regular timing, at a predetermined timing, at a timing instructed by an administrator, etc. 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 value acquired in step S101. When 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, calculates the amount of change in the state by taking the difference from the previous estimated amount, and can determine to update the control parameters when the calculated amount of change is greater than a threshold value.

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

[0077] When it is determined that the control parameters are to be updated (S102: YES), the control unit 301 identifies (step S103) a mathematical model that represents the characteristics of the power storage device 100. In the case of 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 lithium-ion battery described above as an example, the control unit 301 may derive a lower limit value (lower limit voltage) with respect to the terminal voltage. Alternatively, the control unit 301 may derive control parameters for controlling an upper limit value (upper limit voltage) with respect to 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 according to the SOC, battery temperature, etc. At this time, the control unit 301 may derive control parameters within a preset range in consideration of the influence on the power storage device 100 and its peripheral members.

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

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

[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 regarding the power storage device 100 is to be executed (S123: YES), the control unit 211 executes control regarding 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 regarding 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, 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 expressing the characteristics of a lithium-ion battery. Alternatively, a polynomial model such as the NTGK model that expresses 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. In addition, 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 of the installation environment in which the power storage device 100 is installed will be described.

[0087] 10 is a schematic diagram illustrating an overall configuration of an operation management system in embodiment 2. The operation management system in embodiment 2 includes an electricity storage device 100, a control device 220 that controls air conditioning of 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 a cooling function, a heating function, a dehumidifying function, a fan function, etc., and controls the operation of the air conditioner 22 to control the air conditioning of the installation environment in which the power storage device 100 is installed.

[0089] In the following, as one type of control related 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 environmental temperature of the power storage device 100. The control parameters include 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 memory 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 environmental temperature. The temperature of each cell constituting the power storage device 100 is controlled to within a specified value by controlling the environmental 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 for controlling the operation of a heat exchanger, a fan, horizontal louvers, vertical louvers, and the like mounted on 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 air or heated air by transferring heat between the heat exchanger and an outdoor unit. The fan blows out 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 realizes a cooling function, a heating function, a blowing function, and the like by controlling the operation of the heat exchanger, a fan, horizontal louvers, vertical louvers, and the like mounted on the air conditioner 22, and controls the environmental temperature of the electricity 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 controls the environmental temperature of the power storage device 100 using control parameters designed when the power storage device 100 is manufactured or installed. However, when 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 environmental temperature is controlled using the control parameters designed initially, cooling may 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.

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

[0096]

number

[0097] Here, ρ, C p is the density (kg / m) of the electricity storage device 100 3 ), and specific heat (J / kg / K). Alternatively, the values ​​of density and specific heat 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. When the operation management device 300 determines that the heat generation amount in a specific cell is large, it executes a thermal fluid simulation using the estimated heat generation amount to determine the cooling temperature, air volume (wind speed), and wind direction when appropriately cooling the power storage device 100. This simulation may be a brute force simulation, or an optimization method such as a response surface method 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 above simulation periodically or at a timing 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 be performed in cold regions or in outer space, but the method of 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 environmental temperature.

[0103] As described above, the operation management system in embodiment 2 autonomously finds settings for appropriately controlling the ambient temperature using the air conditioner 22, even if a particular 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 for controlling the temperature of the power storage device 100 will be described.

[0105] 12 is a schematic diagram illustrating an 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 related 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 the storage unit 232 of the control device 230 (see FIG. 13 ).

[0109] The control device 230 reads out the control parameters stored in the storage unit 232, and performs PID control of the water-cooling 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 by 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 according to an instruction from the control unit 231. The cooling device 23 includes a radiator for producing cooling water, a reservoir tank for storing the cooling water, a pump for sending the cooling water to the outside of the device, an adjustment valve for adjusting the flow rate of the cooling water 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 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 controls the temperature of the power storage device 100 using control parameters designed when the power storage device 100 is manufactured or installed. However, when 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, cooling may 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 by using, for example, a mathematical model that expresses the thermal phenomenon inside the battery as shown in the following equation 6.

[0115]

number

[0116] Here, ρ, C p is the density (kg / m) of the electricity storage device 100 3 ), and 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), and S is the outer surface area (m 2 ), Q is the amount of self-heating such as Joule heat (W), and 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 executes PID control for 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] Here, 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 the control is performed.

[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 introduction 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 the 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 elapsed time (s) from the start of charging.

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

[0125] The power storage device 100 deteriorates due to repeated charging and discharging, etc. The dashed line in Fig. 14 indicates the time dependency of the temperature of the power storage device 100. The example in Fig. 14 indicates that the temperature of the power storage device 100 increases over time and reaches a temperature 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 by using a mathematical model. p Alternatively, the operation 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 operation management device 300 may use, for example, the Ziegler-Nichols limit sensitivity method as an optimization method for PID control. Alternatively, the operation management device 300 may use an optimization method based on the Riccatti equation. Furthermore, the operation management device 300 may use an optimization function in commercially available analysis software such as Maple (registered trademark), ANSYS Twin Builder (registered trademark), ANSYS Simplorer (registered trademark), and MATLAB Simulink (registered trademark). The operation management device 300 may use, as a simulation model used to identify the 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 temperature of the power storage device 100.

[0131] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. 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 department 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 storage unit that stores control parameters of the power storage device; a control unit that executes control of an air conditioner that conditions an installation environment of the power storage device based on the control parameters stored in the storage unit, as control related to the power storage device; Equipped with The control unit is acquiring a control parameter for updating from an operation management device that detects a state of the power storage device and derives a control parameter for updating the power storage device in accordance with a detection result; The control parameters stored in the storage unit are updated based on the acquired control parameters for update. A control device for an electricity storage device.

2. A storage unit that stores control parameters of an electricity storage device; a control unit that executes a temperature control of the power storage device based on the control parameters stored in the storage unit, as a control related to the power storage device; Equipped with The control unit is acquiring a control parameter for updating from an operation management device that detects a state of the power storage device and derives a control parameter for updating the power storage device in accordance with a detection result; The control parameters stored in the storage unit are updated based on the acquired control parameters for update. A control device for an electricity storage device.

3. The control parameters for update are control parameters derived so as to conform to a mathematical model that represents the characteristics of the power storage device identified based on the detection result. The control device according to claim 1 or 2.

4. The control parameter for update is a control parameter that is derived when an amount of change in the state of the power storage device calculated based on the detection result is greater than a threshold value. The control device according to claim 1 or 2.

5. The temperature control is a temperature control of the power storage device using a liquid-cooling type cooling device. The control device according to claim 2.

6. A storage unit that stores control parameters of the power storage device; a control unit that executes control regarding the power storage device based on the control parameters stored in the storage unit; A detection unit that detects a state of the power storage device; a derivation unit that derives a control parameter to be set in accordance with a detection result by the detection unit; an update unit that updates the control parameters stored in the storage unit based on the control parameters derived by the derivation unit; Equipped with The control is control of an air conditioner that conditions the environment in which the power storage device is installed, or temperature control of the power storage device. An operation management device for power storage devices.

7. An electricity storage device; A liquid-cooling type cooling device that cools the power storage device; The control device according to claim 5 . A control system comprising:

8. An electricity storage device; A liquid-cooling type cooling device that cools the power storage device; The control device according to claim 5 ; The operation management device according to claim 6 . An operation management system equipped with:

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