JP7388964B2 - Secondary battery equipment and secondary battery system - Google Patents

Description

The present disclosure relates to a secondary battery device and a secondary battery system.

BACKGROUND ART Conventionally, inventions related to battery deterioration calculation devices that are small-scale, inexpensive, and capable of easily calculating battery deterioration even during system operation have been known (see Patent Document 1 below). The battery deterioration calculation device described in Patent Document 1 is communicably connected to a secondary battery device (see the document, abstract, claim 1, paragraph 0007, etc.).

The secondary battery device includes a control section having a nonvolatile memory. The non-volatile memory stores average battery capacity data indicating the average battery capacity of the secondary battery in a predetermined time unit, average temperature data indicating the average battery temperature of the secondary battery, and the number of charging or discharging cycles of the secondary battery. data is stored as battery usage history data.

The battery deterioration calculation device includes a memory, a receiving section, and a battery deterioration calculation section. The memory stores battery deterioration tendency data calculated in advance using battery capacity and temperature as parameters. The receiving unit receives battery usage history data from the control unit. The battery deterioration calculation unit calculates a battery capacity according to battery deterioration by combining battery deterioration trend data and battery usage history data.

JP2015-007616A

In the conventional battery deterioration calculation device, the reception unit receives the battery usage history data stored in the nonvolatile memory of the control unit of the secondary battery device, and the battery deterioration calculation unit calculates the battery usage history data in advance using the battery capacity and temperature as parameters. By combining this data with battery deterioration trend data, the battery capacity is calculated according to battery deterioration. Here, this conventional battery deterioration calculation device is characterized in that the battery capacity calculation algorithm and the like can be updated freely without time constraints. When updating such algorithms, we believe that if there is a function to determine whether the information to be updated is appropriate information, it will be possible to realize a secondary battery device that can perform control more reliably.

The present disclosure provides a secondary battery device and a secondary battery system that can more reliably control a secondary battery.

One aspect of the present disclosure includes a secondary battery, a detection unit that detects voltage, current, and temperature of the secondary battery, and a state calculation unit that calculates a battery state based on the detection result of the detection unit. A secondary battery device comprising: a first storage area for storing calculation information for calculating the battery state; a second storage area for storing update information for updating the calculation information, and the processing device performs a state detection process of calculating the current battery state using the calculation information; an update verification process that calculates a new battery state using the update information; and an update verification process that calculates a new battery state using The secondary battery device is characterized in that it executes an update process of updating the calculation information by storing it in the first storage area.

According to the present disclosure, it is possible to provide a secondary battery device and a secondary battery system that can more reliably control a secondary battery.

FIG. 1 is a block diagram showing an embodiment of a secondary battery system of the present disclosure. 2 is a schematic configuration diagram of a secondary battery device that constitutes the secondary battery system of FIG. 1. FIG. FIG. 3 is a functional block diagram of a state calculation unit of the secondary battery device of FIG. 2. FIG. 3 is a graph showing the relationship between the open circuit voltage and SOC of a unit cell of the secondary battery device of FIG. 2. FIG. FIG. 3 is an equivalent circuit diagram of a unit cell that constitutes a unit cell group of the secondary battery device of FIG. 2; A graph showing an example of a time change in the current flowing through a battery and the voltage of the battery. A graph showing changes in battery voltage over time. The graph which shows an example of the relationship between the resistance increase rate and capacity maintenance rate of a battery. 3 is a histogram showing an example of history information of a group of single cells of the secondary battery device of FIG. 2. FIG. 2 is a functional block diagram of a management device that constitutes the secondary battery system of FIG. 1. FIG. FIG. 10 is a flow diagram showing an example of the processing flow of the management device in FIG. 9; FIG. 10 is a functional block diagram of calculation functions of the management device in FIG. 9; 12 is a graph showing an example of a state change amount calculated by the calculation function of FIG. 11. FIG. 4 is a flow diagram showing an example of the flow of processing of the state calculation unit in FIG. 3; FIG. 4 is a flowchart showing a modification of the processing flow of the state calculation unit in FIG. 3; FIG. 10 is a functional block diagram showing a modification of the management device shown in FIG. 9;

Hereinafter, one embodiment of a secondary battery device and a secondary battery system of the present disclosure will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the secondary battery system of the present disclosure. In the example shown in FIG. 1, the secondary battery system 1 of this embodiment constitutes, for example, a part of the solar power generation system PGS. The solar power generation system PGS includes, for example, in addition to the secondary battery system 1, a solar power generation panel 2, an electric power system 3, power conditioners (PCS) 4 and 5, and a control device 6.

The secondary battery system 1 is connected to the PCS 5 via power wiring, for example. The solar power generation panel 2 is connected to the PCS 4 via power wiring, for example. Power system 3 is connected to PCS4 and PCS5 via power wiring, for example. The control device 6 is connected to the secondary battery system 1, the PCS 4, and the PCS 5 via an information communication line, for example. The control device 6 is a computer system that controls the secondary battery system 1, the PCS 4, and the PCS 5 by communicating information with them via an information communication line.

The solar power generation system PGS operates, for example, as follows under the control of the control device 6. The solar power generation panel 2 receives sunlight and generates DC power. The PCS 4 converts the DC power output from the solar power generation panel 2 into AC power and supplies it to the power system 3. The PCS 5 converts part or all of the AC power output from the PCS 4 and supplied to the power system 3 into DC power depending on the situation, and supplies the DC power to the secondary battery system 1 .

The secondary battery system 1 is charged with DC power supplied from the PCS 5 and stores electrical energy. The secondary battery system 1 outputs accumulated electrical energy as DC power depending on the situation. The PCS 5 converts the DC power output from the secondary battery system 1 into AC power and supplies it to the power system 3. In this way, the solar power generation system PGS can compensate for the power generated by the solar power generation panel 2, which varies depending on the weather, with the output of the secondary battery system 1, and can smooth the output to the power grid 3. can. The secondary battery system 1 includes, for example, a secondary battery device 11 and a management device 12.

FIG. 2 is a schematic configuration diagram of the secondary battery device 11 that constitutes the secondary battery system 1 of FIG. 1. As shown in FIG. The secondary battery device 11 includes, for example, a cell group 111, a pair of external terminals 112, a current sensor 113, a temperature sensor 114, a battery management section 115, a state calculation section 116, an information input terminal 117, An information output terminal 118 is provided.

The unit cell group 111 is composed of, for example, a plurality of unit cells connected in series. The unit cell is, for example, a prismatic lithium ion secondary battery, although it is not particularly limited. Although not shown, the secondary battery device 11 may include, for example, a plurality of cell groups 111. The plurality of cell groups 111 are connected, for example, in series or in parallel. Moreover, a plurality of cell groups 111 connected in series may be connected in parallel.

The pair of external terminals 112 has one external terminal 112 connected to the negative terminal of the cell group 111 via power wiring, and the other external terminal 112 connected to the positive terminal of the cell group 111 via the power wiring. ing. Further, the pair of external terminals 112 are connected to the PCS 5 shown in FIG. 1 via power wiring, for example.

The current sensor 113 is connected, for example, to the power wiring between the cell group 111 and the external terminal 112, and measures the current flowing through the cell group 111. For example, the temperature sensor 114 is attached to at least one of the plurality of cells making up the cell group 111, and measures the temperature of the cell group 111.

The battery management unit 115 and the state calculation unit 116 are, for example, microcontrollers or firmware that include a processing device such as a CPU, a storage device such as a RAM or ROM, a timer, a signal input/output unit, and the like. The battery management unit 115 and the state calculation unit 116 implement various functions described below by, for example, executing a program stored in a storage device using a processing device.

The battery management unit 115 has, for example, a function as a voltage sensor that measures the voltage of each cell forming the cell group 111, and a function that equalizes the voltage between the individual cells. There is. The state calculation unit 116 is connected to the current sensor 113, the temperature sensor 114, and the battery management unit 115, for example, via a signal input/output unit. The state calculation unit 116 has a function of calculating the battery state, which is the state of the unit cell group 111, for example.

The battery status of the cell group 111 calculated by the state calculation unit 116 includes, for example, the state of charge (SOC), state of deterioration (SOH), maximum power or maximum current that can be input/output, presence or absence of abnormality, and characteristics of the cell group 111. Contains parameters, history information, etc. Further, the state calculation unit 116 calculates the output power and input power of the unit cell group 111 by, for example, multiplying the current value obtained from the current sensor 113 and the voltage of each unit cell obtained from the battery management unit 115. It has a calculation function.

For example, the state calculation unit 116 transmits information including the calculated battery state of the unit cell group 111 to the management device 12 of the secondary battery system 1 shown in FIG. output to the control device 6. Further, the state calculation unit 116 obtains information used for various calculations from the management device 12 via the information input terminal 117, for example.

FIG. 3 is a functional block diagram of the state calculation unit 116 shown in FIG. 2. The status calculation unit 116 has, for example, a data reception function F1, a characteristic parameter storage function F2, an update parameter storage function F3, a calculation algorithm storage function F4, an update algorithm storage function F5, and a battery status storage function F2. It has an arithmetic function F6. Further, the state calculation unit 116 has, for example, a history management function F7, a battery state determination function F8, and a data transmission function F9.

The reception function F1 receives, for example, information input from the management device 12 of the secondary battery system 1 shown in FIG. 1 to the information input terminal 117 of the secondary battery device 11. Further, the reception function F1 outputs the received information to each function such as a storage function F2, a storage function F3, a storage function F4, a storage function F5, and a determination function F8. Further, the reception function F1 receives the determination result from the determination function F8.

The storage function F2 is, for example, a function for storing characteristic parameters included in calculation information for calculating the battery state of the unit cell group 111 in a first storage area of the storage device of the state calculation unit 116. The storage function F3 is, for example, a function for storing update parameters included in update information for updating calculation information in a second storage area of the storage device of the state calculation unit 116.

The storage function F4 is a function that stores, for example, a calculation algorithm included in calculation information for calculating the battery state of the unit cell group 111 in a first storage area of the storage device of the state calculation unit 116. The storage function F5 is, for example, a function for storing an update algorithm included in update information for updating calculation information in a second storage area of the storage device of the state calculation unit 116.

The calculation function F6 uses, for example, the calculation information stored in the first storage area storage of the storage device of the state calculation unit 116 to calculate the current battery state of the unit battery group 111 before updating the calculation information with the update information. This is a function to Further, the calculation function F6 uses, for example, the update information stored in the second storage area storage of the storage device of the state calculation unit 116 to generate a new cell group 111 when the calculation information is updated with the update information. This function calculates the battery status.

Note that, as described above, the calculation information for calculating the battery state of the unit cell group 111 includes, for example, a characteristic parameter and a calculation algorithm. Further, the update information for updating the calculation information includes, for example, an update parameter and an update algorithm.

For example, the management function F7 receives information about the cell group 111 including the current value I, temperature T, and voltage value V from the current sensor 113, temperature sensor 114, and battery management unit 115, and receives the current status from the calculation function F6. The battery status of the unit cell group 111 is input. The management function F7 is a function of managing the history information, for example, by calculating the history information of the cell group 111 described later, storing it in the storage device of the state calculation unit 116, and outputting it to the transmission function F9 as necessary. It is.

For example, the determination function F8 determines whether the amount of change in state between the current battery state and the new battery state of the unit cell group 111 input from the calculation function F6 is within a specified range. It is a function. The determination function F8 outputs the determination result to the reception function F1, for example. The transmission function F9, for example, transmits information input from the calculation function F6 and the management function F7 to the management device 12 of the secondary battery system 1 shown in FIG. It is output to the control device 6 of the solar power generation system PGS.

The battery status of the unit cell group 111 calculated by the calculation function F6 will be described below. As described above, the battery status of the unit cell group 111 includes, for example, the SOC, SOH of the unit battery group 111, the maximum power or maximum current that can be input/output, the presence or absence of an abnormality, and history information.

FIG. 4 is a graph showing an example of the relationship between the open circuit voltage OCV and SOC of the single cells forming the single cell group 111. The SOC of the unit cell group 111 can be calculated based on a voltage standard, for example. In this case, as shown in FIG. 4, the relationship between the open circuit voltage OCV and SOC of each cell forming the cell group 111 is specified in advance and stored in the storage device of the state calculation unit 116. Thereby, by calculating the open circuit voltage OCV of the unit cell, the SOC of the unit cell can be estimated from the relationship between the open circuit voltage OCV of the unit cell and the SOC shown in FIG. 4. The open circuit voltage OCV of a single cell can be calculated as follows, for example.

FIG. 5 is an example of an equivalent circuit diagram of the single cells that constitute the single cell group 111. In FIG. 5, the open circuit voltage OCV and the internal resistance R of a cell are connected in series, and the polarization resistance component Rp and the capacitance component C, which are connected in parallel, are connected to the open circuit voltage OCV and the internal resistance R. This shows a state where they are connected in series. When a current I flows through this unit cell, the voltage CCV between the terminals of the unit cell is expressed by the following equation (1) using the open circuit voltage OCV, internal resistance R, and polarization voltage Vp. Note that the polarization voltage Vp is a voltage across a polarization resistance component and a capacitance component connected in parallel.

CCV=OCV+IR+Vp...(1)

The open circuit voltage OCV of a cell cannot be directly measured when the cell is being charged or discharged. However, in this case, as shown in equation (2) below, by subtracting the voltage drop I・R due to the internal resistance and the polarization voltage Vp from the voltage CCV between the terminals of the cell, the open circuit voltage of the cell can be calculated. OCV can be calculated.

OCV=CCV-I・R-Vp...(2)

Although details will be described later, the management device 12 shown in FIG. 1 includes a processing device such as a CPU (not shown), and a storage device such as a ROM or RAM. The relationship between the open circuit voltage OCV and the SOC of the unit cell, the internal resistance R, the polarization resistance component Rp, and the capacitance component C are calculated by the processing device of the management device 12, for example, and are stored in the storage device of the management device 12 as calculation information. Stored as a characteristic parameter. The characteristic parameters of the cell stored as calculation information in the storage device of the management device 12 are distributed to the secondary battery device 11, and the voltage CCV and current I between the terminals of the cell obtained by the secondary battery device 11 are calculated. The arithmetic processing described above is realized using the sequence information.

Note that, in order to improve the accuracy of SOC estimation, it is preferable that the characteristic parameters of the unit cell be specified in advance for each unit cell SOC and temperature, and stored in the storage device of the state calculation unit 116. However, if the materials constituting the cell are different, the relationship between the open circuit voltage OCV and the SOC will be different. Therefore, in this voltage-based SOC estimation method, there may be a difference in SOC estimation accuracy depending on the characteristics of the unit cell.

Furthermore, the SOC of the battery can also be calculated, for example, by integrating current values. In this case, the current value input to the battery and the current value output from the battery are measured, and the SOC is calculated by integrating these current values. Specifically, the SOC is first estimated using the voltage reference described above. Then, using the voltage reference SOC as the initial value SOCv, and further using the current I measured by the current sensor 113 and the full charge capacity Qmax of the battery, the SOC is calculated by integrating the current value using the following equation (3). Calculate SOCi.

SOCi=SOCv+100×∫Idt/Qmax...(3)

In this method of estimating the SOC by integrating current values, the measurement error included in the measured value of the current I is also integrated, so the SOC error may increase over time. Therefore, countermeasures are required, such as correcting the SOC error after integrating the current value over a predetermined period of time. As described above, the methods for estimating SOC using a voltage reference or current value integration have their own advantages and disadvantages. Therefore, an SOC estimation method is appropriately selected depending on conditions such as the characteristics of the cell, the performance of the sensor, and the surrounding environment to ensure the accuracy of SOC estimation.

Furthermore, the SOC may be estimated with higher accuracy by combining the SOC estimation based on the voltage reference and the SOC estimation based on the integration of current values. In this case, a coefficient W for combining SOCv, which is the SOC estimated by the voltage reference, and SOCi, which is the SOC estimated by integrating the current values, is appropriately set. Thereby, SOCc, which is the SOC based on the combination of the voltage reference and the current value integration, can be calculated using the following equation (4).

SOCc=W×SOCv+(1-W)×SOCi...(4)

As described above, the characteristic parameters of a single cell required for calculating the SOC differ depending on the estimation method. The characteristic parameters of the battery include, for example, the relationship between the open circuit voltage OCV and SOC of the battery as shown in FIG. 4, the internal resistance R, polarization resistance component Rp, and capacitance C of the battery as shown in FIG. Further, the characteristic parameters include, for example, the full charge capacity Qmax of the battery. These characteristic parameters change as the battery deteriorates. Therefore, in order to improve the accuracy of SOC estimation, it is necessary to understand changes in characteristic parameters due to battery deterioration. Furthermore, it is necessary to appropriately select the method for calculating SOC.

In addition to SOC, the various characteristic parameters described above are also used to calculate other information included in the battery status, such as the maximum current and maximum power that can be charged and discharged, and the amount of power that can be supplied. It is necessary to understand. Specifically, the maximum current Ic_max that can charge the battery and the maximum current Id_max that can discharge the battery are expressed by, for example, the following equations (5) and (6).

Ic_max=(Battery upper limit voltage-OCV)/Rt...(5)
Id_max=(OCV-Battery lower limit voltage)/Rt...(6)

In the above equations (5) and (6), the internal resistance Rt is determined based on the charging and discharging duration, taking into account all of the internal resistance R, polarization resistance component Rp, and capacitance component C of the battery. Therefore, by understanding the effects of deterioration of the internal resistance R, polarization resistance component Rp, and capacitance component C of the battery, the maximum currents Ic_max and Id_max can be estimated with high accuracy. Further, by multiplying the estimated maximum currents Ic_max and Id_max by a voltage, the maximum power that can be charged and discharged can be estimated with high accuracy.

As described above, by accurately grasping the battery characteristic parameters, which are calculation information, and by appropriately selecting the calculation method, the calculation function F6 of the state calculation unit 116 constituting the secondary battery device 11 can The state can be calculated accurately. Below, a method for calculating internal resistance and SOH, which are indicators of deterioration, will be explained as examples of calculation information for calculating the battery state.

As the battery deteriorates, the parameters of the components of the equivalent circuit shown in FIG. 5 change. Specifically, for example, the internal resistance of the battery increases, and the full charge capacity Qmax of the battery in equation (3) also decreases. The SOH of the battery includes, for example, a resistance increase rate SOHR as the rate of increase in internal resistance of the battery, and a capacity maintenance rate SOHQ as the rate of maintenance of the full charge capacity of the battery. Below, first, a method for calculating the resistance increase rate SOHR will be explained with reference to FIG. This resistance increase rate SOHR is calculated, for example, by the calculation function F6 of the state calculation unit 116 that constitutes the secondary battery device 11.

FIG. 6 is a graph showing an example of a time change in the current flowing through the battery and the voltage of the battery. From time t0 to time t1, the battery is in a rest state in which no current flows through the battery. At time t1, discharging of the battery is started and continues until time t2. At this time, current I flows through the battery, and the voltage of the battery drops by the product of current I and internal resistance R. When the voltage at each time is CCV(t), the current at each time is I(t), and the voltage and current measurement interval is Δt, the internal resistance R is expressed by the following equation (7). In the example of FIG. 6, by using the following equation, R can be found at two points, time t1 and time t2, at which a change in current occurs.

R={CCV(t)-CCV(t-Δt)}/{I(t)-I(t-Δt)}
...(7)

Note that the method for calculating the internal resistance R is not limited to the above method. Next, as shown in Equation (8) below, by calculating the 100% ratio of the battery's current internal resistance R obtained using Equation (7) above to the internal resistance Ro at the beginning of use or the initial stage of the battery. , the resistance increase rate SOHR of the battery can be estimated.

SOHR=100×(R/Ro)...(8)

The internal resistance R can be determined by, for example, storing the above equations (7) and (8) in the storage device of the state calculation unit 116 by the storage function F4 of the state calculation unit 116 that constitutes the secondary battery device 11, and calculating the state. It can be calculated using equations (7) and (8) by the calculation function F6 of the unit 116. Next, a method for calculating the battery capacity maintenance rate SOHQ will be described with reference to FIGS. 7A and 7B.

FIG. 7A is a graph showing changes in battery voltage over time. The full charge capacity Qmax of the battery can be calculated as follows, for example. In the example shown in FIG. 7A, like the example shown in FIG. 6, the battery is in a rest state from time t0 to time t1. Thereafter, discharging of the battery starts at time t1, continues discharging from time t1 to time t2, and stops discharging after time t2.

In this case, the SOC (SOC1) of the battery before the start of discharging before time t1 is estimated based on the relationship between the open circuit voltage OCV and SOC of the battery as shown in FIG. Similarly, the SOC (SOC2) of the battery at time t3, when sufficient time has passed and the voltage has stabilized after the discharging pause after time t2, is estimated. Using SOC1 and SOC2, which are the SOCs of these batteries in the rest state before and after discharging, the full charge capacity Qmax of the battery can be calculated by the following equation (9).

Qmax=100×∫Idt/(SOC2-SOC1)...(9)

Further, the full charge capacity Qmax_o at the start of use or the initial stage of use of the battery and the current full charge capacity Qmax of the battery are determined using equation (9). Then, by calculating the percentage of the current full charge capacity Qmax to the initial full charge capacity Qmax_o of the battery, as in the following equation (10), the capacity maintenance rate SOHQ of the battery can be estimated.

SOHQ=100×(Qmax/Qmax_o)...(10)

In this method of estimating the battery capacity maintenance rate SOHQ, the measurement error included in the measured value of the current I is also integrated as shown in equation (9) above, so the error in the full charge capacity Qmax of the battery increases over time. There is a possibility of expansion. Therefore, for example, by selecting a charging/discharging pattern that increases the difference between the battery's SOC (SOC1) before charging and discharging and the battery's SOC (SOC2) after charging and discharging in a short period of time, the above formula (9) is calculated. By doing this, it becomes possible to suppress errors.

FIG. 7B is a graph showing an example of the relationship between the battery resistance increase rate SOHR and the capacity maintenance rate SOHQ. Below, a method for estimating the capacity maintenance rate SOHQ that is different from the estimation method described above will be described. In this estimation method, as shown in FIG. 7B, the relationship between the resistance increase rate SOHR and the capacity maintenance rate SOHQ is specified in advance and stored in the storage device of the state calculation unit 116.

Thereby, by calculating the resistance increase rate SOHR using the above equation (8), the capacity maintenance rate SOHQ can be estimated based on the resistance increase rate SOHR, as shown in FIG. 7B. Furthermore, the current full charge capacity Qmax of the battery can be estimated based on equation (10) using the capacity maintenance rate SOHQ estimated by this method and the initial full charge capacity Qmax_o of the battery.

In this method, since the current I is not integrated as in equation (9) above, measurement errors included in the measured values do not accumulate. However, the relationship between the resistance increase rate SOHR and the capacity maintenance rate SOHQ as shown in FIG. 7B may change depending on history information including the usage conditions of the battery. Therefore, in order to estimate the capacity retention rate SOHQ of a battery with high accuracy, a test is performed to degrade the battery using various historical information, and the resistance increase rate SOHR and capacity retention rate as shown in FIG. 7B are determined for each historical information. Identify the relationship with SOHQ.

The relationship between the resistance increase rate SOHR and the capacity maintenance rate SOHQ of the battery for each of various historical information obtained through such tests is stored, for example, in the storage device of the management device 12 as a characteristic parameter that is calculation information of the battery. be remembered. The processing device of the management device 12 stores characteristic parameters stored in the storage device of the management device 12, such as battery characteristic parameters, in accordance with history information including the usage history of the unit battery group 111 acquired from the secondary battery device 11, for example. The relationship between the resistance increase rate SOHR and the capacity maintenance rate SOHQ is selected.

FIG. 8 is a histogram showing an example of history information of the unit cell group 111 of the secondary battery device 11. FIG. 8 shows the frequency of occurrence of the battery staying SOC, the battery staying temperature, and the charging/discharging current of the battery. In the state calculation unit 116 of the secondary battery device 11, the history management function F7 shown in FIG. It has a function of extracting history information in a histogram format as shown in FIG. Furthermore, the transmission function F9 of the state calculation unit 116 has a function of outputting the history information of the cell group 111 extracted by the management function F7 to the management device 12 via the information output terminal 118.

FIG. 9 is a functional block diagram of the management device 12 shown in FIG. 1. The management device 12 is, for example, a microcontroller or firmware that includes a processing device such as a CPU, a storage device such as a RAM or ROM, a timer, a signal input/output unit 121, and the like. The management device 12 is communicably connected to, for example, an information input terminal 117 and an information output terminal 118 of the secondary battery device 11 shown in FIG. 2 via an input/output unit 121.

The management device 12 realizes various functions described below by, for example, executing a program stored in a storage device using a processing device. The management device 12 has, for example, a calculation information search function F10 for calculating the battery state, a calculation information storage function F11, and a specified range calculation function F12.

The search function F10 has a function of acquiring history information and battery status of the unit cell group 111 output from the secondary battery device 11 via the input/output unit 121. As mentioned above, the battery status includes, for example, the battery's SOC and SOH, the maximum current or maximum power that the battery can charge, the maximum current and maximum power that the battery can discharge, the presence or absence of battery abnormality, battery characteristic information, Contains battery history information, etc.

Further, the search function F10 has a function of searching and selecting calculation information stored in the storage device of the management device 12 by the storage function F11 based on battery information including history information and battery type. The search function F10 also has a function of outputting the selected calculation information to the calculation function F12 and to the secondary battery device 11 via the input/output unit 121. The calculation information output from the search function F10 to the secondary battery device 11 includes, for example, at least one of a battery characteristic parameter and a calculation algorithm for calculating the battery state by the state calculation unit 116 of the secondary battery device 11.

The storage function F11 stores, for example, calculation information including characteristic parameters for each battery history information obtained through a battery test including a charge/discharge test that deteriorates the battery with various history information in the storage device of the management device 12 as a database. It has a memorization function. For the battery test, for example, a discharge pattern as shown in FIG. 6 can be used.

More specifically, in the battery test, for example, a battery having the same configuration as the cell group 111 of the secondary battery device 11 is charged to a fully charged state, and the voltage of the battery is lowered to the lower limit using a discharge pattern as shown in FIG. Discharge until the voltage is reached. Note that the current value when discharging the battery is set to be small. In this battery test, the full charge capacity Qmax of the battery can be calculated by measuring the current value during discharge of the battery and integrating the measured current value over time.

In addition, in the battery test, for example, a battery having the same configuration as the unit cell group 111 of the secondary battery device 11 is charged to a fully charged state, and a discharge pattern as shown in FIG. 6 is used until the battery reaches a predetermined SOC. Discharge. The relationship between this predetermined SOC and the open circuit voltage OCV of the battery after a sufficient period of time has passed after the discharge test is recorded by repeatedly performing the discharge test. As a result, a relationship between the open circuit voltage OCV and SOC of the battery as shown in FIG. 4 is obtained.

In addition, a battery test was performed using the discharge pattern shown in Figure 6, and the internal resistance R of the battery was extracted from the fluctuation of the battery voltage immediately before the start of discharge, immediately after the start of discharge, immediately before the end of discharge, and immediately after the end of discharge. Measure and analyze the voltage change during rest after completion. Thereby, it is possible to specify the polarization resistance Rp and the capacitance C.

Characteristic parameters for each battery history information obtained through the charge/discharge test, such as the above-mentioned full charge capacity Qmax, open circuit voltage OCV, polarization resistance Rp, and capacitance C, are obtained in real time while the secondary battery device 11 is in use. includes characteristic parameters whose current values are difficult to determine.

Characteristic parameters whose current values are difficult to obtain in real time during use of the secondary battery device 11 include, for example, the relationship between the open circuit voltage OCV and SOC of the battery shown in FIG. 4, and the polarization resistance Rp of the battery shown in FIG. , and capacitance C, the relationship between the resistance increase rate SOHR and the capacity retention rate SOHQ of the battery shown in FIG. 7B, and the full charge capacity Qmax and the capacity retention rate SOHQ. Furthermore, the storage function F11 causes the storage device of the management device 12 to store characteristic parameters for each type of battery history information, for example. The storage function F11 may also store the internal resistance R of the battery as a characteristic parameter.

The calculation function F12 has a function of acquiring calculation information for calculating the battery state of the secondary battery device 11 from the secondary battery device 11 via the input/output unit 121. Furthermore, the calculation function F12 uses the current calculation information acquired from the secondary battery device 11 and the new calculation information selected by the search function F10 to calculate the current battery state and the new battery state. It has the function of Further, the calculation function F12 has a function of calculating the amount of state change between the current battery state and the new battery state. Further, the calculation function F12 has a function of defining a range of the amount of state change based on the calculated amount of state change.

The operation of the secondary battery device 11 and the secondary battery system 1 of this embodiment will be described below with reference to FIGS. 10 to 14.

FIG. 10 is a flow diagram showing an example of the process flow of the secondary battery system 1. When the secondary battery system 1 shown in FIG. 1 starts processing, the management device 12 of the secondary battery system 1 executes a process P1 of receiving battery status and calculation information from the secondary battery device 11.

Specifically, in process P1, as shown in FIG. 2, the state calculation unit 116 of the secondary battery device 11 calculates the battery state of the unit battery group 111 using the calculation information stored in the storage device by the processing device. is calculated, and the calculated battery state is output to the management device 12 via the information output terminal 118. The management device 12 receives the battery status and battery history information output from the secondary battery device 11 via the input/output unit 121 shown in FIG. 9 by the processing device.

More specifically, the state calculation unit 116 of the secondary battery device 11 calculates the battery state using calculation information using the calculation function F6 shown in FIG. The calculation function F6 calculates the battery state using, as calculation information, for example, the battery characteristic parameters and calculation algorithm stored in the first storage area of the storage device of the state calculation unit 116 by the storage function F2 and the storage function F4. do. The battery state calculated by the calculation function F6 includes the battery's SOC, internal resistance R, and resistance increase rate SOHR. This battery state is output to the management device 12 via the information output terminal 118 by the transmission function F9 shown in FIG. Received by search function F10.

In addition, the state calculation unit 116 of the secondary battery device 11 calculates battery history information as shown in FIG. 8 as the battery state using the management function F7 shown in FIG. to be memorized. The battery history information stored in the storage device of the status calculation unit 116 is output to the management device 12 via the information output terminal 118 by the transmission function F9 shown in FIG. It is received by the search function F10 of the management device 12. With the above steps, the process P1 shown in FIG. 10 ends.

Next, the search function F10 of the management device 12 uses the calculation information corresponding to the battery state received from the secondary battery device 11 to search for a plurality of calculations included in the database stored in the storage device of the management device 12 using the storage function F11. Select and obtain information. The database stored in the storage device of the management device 12 includes, for example, a plurality of calculation information corresponding to various battery history information obtained by the above-described battery test. This calculation information includes characteristic parameters whose current values are difficult to obtain in real time while the secondary battery device 11 is in use.

The search function F10 uses the history information received from the secondary battery device 11 as a reference to find new calculation information corresponding to similar history information from among the plurality of calculation information corresponding to various history information as described above. Select and get. With the above steps, the process P2 shown in FIG. 10 is completed. In the following, the calculation information received by the search function F10 from the secondary battery device 11 will be referred to as "current calculation information", and the new calculation information acquired by the search function F10 from the database stored in the storage device of the management device 12 will be referred to as "current calculation information". It is called "update information." After the process P2 ends, the calculation function F12 of the management device 12 executes a process P3 for setting a virtual charging/discharging pattern of the battery, which is used in the process P4 for defining the range of the amount of state change, for example.

FIG. 11 is a functional block diagram of the calculation function F12 shown in FIG. The calculation function F12 includes, for example, a charge/discharge pattern setting function F121, a current battery state calculation function F122, a new battery state calculation function F123, and a state change amount calculation function F124.

In process P3, the setting function F121 extracts, for example, the frequency of occurrence of the charging/discharging current included in the battery history information D1 acquired from the secondary battery device 11 by the search function F10. Further, the setting function F121 selects and sets a charging/discharging pattern similar to the frequency of occurrence of the extracted charging/discharging current from among the plurality of charging/discharging patterns stored in the storage device of the management device 12. Although the above-mentioned charging/discharging pattern selection method has been described as an example, it is also possible to record information that can identify the application (UPS, automobile, etc.) in which the secondary battery device 11 is used in the history information, The setting function F121 may refer to this and select and set a charge/discharge pattern for the same purpose from among the charge/discharge patterns according to the purpose stored in the storage device of the management device 12. With the above steps, the process P3 shown in FIG. 10 ends.

Next, the calculation function F12 of the management device 12 executes, for example, a process P4 for setting the range of the amount of state change. Specifically, as shown in FIG. 11, the calculation function F122 and the calculation function F123 each obtain the charging/discharging pattern D2 set in the setting function F121. In addition, the calculation function F122 and the calculation function F123 respectively acquire the current calculation information D3 and the new calculation information D4 from the search function F10, and use the set charging/discharging pattern D2 to determine the battery status. Perform a simulation to calculate. Note that, as described above, the battery state includes, for example, SOC, maximum current, and maximum power.

Here, the calculation function F122 calculates the current battery state D5 using the current calculation information D3 received from the secondary battery device 11 by the search function F10. Specifically, the calculation function F122 calculates the current battery state D5 using, for example, the current calculation algorithm D31 and the current characteristic parameter D32 included in the current calculation information D3.

Furthermore, the calculation function F123 uses the new calculation information D4 to calculate a new battery state D6. Specifically, the calculation function F12 uses, for example, the current calculation algorithm D31 included in the current calculation information D3 and the new characteristic parameter D42 included in the new calculation information D4 to determine the new battery state. Calculate D6.

Note that the new battery state D6 may be calculated using, for example, a new calculation algorithm D41 and a new characteristic parameter D42 included in the new calculation information D4. Further, the new battery state D6 may be calculated using, for example, the new calculation algorithm D41 included in the new calculation information D4 and the current characteristic parameter D32 included in the current calculation information D3.

FIG. 12 is a graph showing an example of the amount of change in state, which is the amount of change in battery state. The calculation function F124 calculates, for example, a state change amount that is the difference between the current battery state D5 calculated by the calculation function F122 and the new battery state D6 calculated by the calculation function F123. More specifically, the state change amount includes, for example, the SOC change amount ΔSOC, which is the difference between the current SOC (a) and the new SOC (b) shown in FIG. 12.

Further, the amount of state change includes, for example, the amount of change in maximum current, the amount of change in maximum power, and the like. The calculation function F124 defines the range D7 of the amount of state change based on, for example, the expected fluctuation range of the amount of state change. The calculation function F124 outputs the defined state change amount range D7 to the secondary battery device 11 via the input/output unit 121, for example. Further, the calculation function F12 outputs, for example, the new calculation information D4 used by the calculation function F123 to the secondary battery device 11 via the input/output unit 121, together with the state change amount range D7, as update information. With the above steps, the process P4 shown in FIG. 10 ends.

FIG. 13 is a flowchart illustrating an example of the processing flow of the state calculation unit 116 of the secondary battery device 11. When the state calculation unit 116 starts the process shown in FIG. 13, it first executes a process P5 to determine whether update information has been received from the management device 12. Specifically, in process P5, the status calculation unit 116 determines whether update information has been received from the management device 12, for example, by the reception function F1 shown in FIG. If the receiving function F1 determines in process P5 that update information has not been received (NO), it ends the process shown in FIG. 13, for example.

On the other hand, in process P5, if the receiving function F1 determines that the update information has been received (YES), the status calculation unit 116 executes, for example, process P6 to record the update information. In this process P6, the storage function F3 or F5 stores the update information received by the reception function F1 in the second storage area of the storage device of the state calculation unit 116. This second storage area is a storage area different from the first storage area of the storage device of the state calculation unit 116 in which the current calculation information used for calculation by the calculation function F6 is stored. With the above steps, processing P6 ends.

Next, the state calculation unit 116 executes, for example, a process P7 for calculating the current battery state. In this process P7, the state calculation unit 116 uses the current calculation information stored in the first storage area of the storage device by the storage function F2 and the storage function F4 to calculate the current battery state by the calculation function F6. calculate. The current battery state calculated here is outputted to, for example, the battery management unit 115 shown in FIG. and is output to the management device 12. With the above steps, processing P7 ends.

Further, the state calculation unit 116 executes a process P8 for calculating a new battery state, for example, in parallel with the process P7. In this process P8, the state calculation unit 116 uses the update information, which is new calculation information stored in the second storage area of the storage device by the storage function F3 and the storage function F5, to update the new calculation information by the calculation function F6. Calculate the battery status of. With the above steps, processing P8 ends.

Next, the state calculation unit 116 executes, for example, a process P9 for calculating the amount of state change. In this process P9, the state calculation unit 116 obtains the current battery state and the new battery state from the calculation function F6 using the battery state determination function F8, and compares the current battery state and the new battery state with each other. Calculate the state change amount, which is the difference. Process P9 ends with the above steps.

Next, the state calculation unit 116 executes, for example, a process P10 that determines whether the amount of state change is within a defined range. In this process P10, the state calculation unit 116 uses the determination function F8 to obtain, for example, the prescribed range of the amount of state change that the receiving function F1 receives from the management device 12 together with the update information. Further, the determination function F8 determines whether the state change amount calculated in process P9 is within the specified range obtained from the reception function F1.

In this process P10, if the determination function F8 determines that the state change amount calculated in process P9 is not within the defined range (NO), the state calculation unit 116 ends the process shown in FIG. 13. On the other hand, in process P10, if the determination function F8 determines that the state change amount calculated in process P9 is within the specified range (YES), the state calculation unit 116 executes process P11 to update the calculation information. .

In this process P11, the state calculation unit 116 notifies the reception function F1 of the determination result using the determination function F8, for example. When the reception function F1 is notified of the determination result from the determination function F8, it outputs the update information received from the management device 12 to the storage function F2 or the storage function F4. The storage function F2 or the storage function F4 stores the update information input from the reception function F1 in the first storage area of the storage device of the state calculation unit 116, and overwrites and updates the calculation information. With the above, the process shown in FIG. 13 ends.

In this way, after the calculation information stored in the first area of the storage device of the state calculation unit 116 is updated by the process shown in FIG. 13, this new calculation information is used by the calculation function F6 to provide more accurate A new battery status is calculated. Note that in the process P11, the calculation information stored in the first storage area of the storage device of the state calculation unit 116 does not need to be overwritten and updated.

For example, in process P11, the calculation information stored in the first storage area of the storage device is set to be used as calculation information while the calculation information stored in the second storage area of the storage device is used as calculation information. You may update the information. An example of employing such processing P11 will be described with reference to FIG. 14.

FIG. 14 is a flowchart showing a modification of the processing flow of the state calculation unit 116 in FIG. 3. In FIG. In FIG. 14, the same processes as those shown in FIG. 13 are given the same reference numerals, and the description thereof will be omitted. In the example shown in FIG. 14, in process P11, the state calculation unit 116 uses the update information stored in the second storage area of the storage device by the storage function F3 and the storage function F5 as calculation information, for example, by the calculation function F6. and update the calculation information.

Next, the state calculation unit 116 performs a process of determining, for example, whether an abnormality or warning such as overcharging, overdischarging, or excessive high temperature has occurred in the cell group 111 over a predetermined period of time using the determination function F8. Execute P12.

In this process P12, if the determination function F8 determines that an abnormality or warning has occurred (YES), the status calculation unit 116 executes process P13 using the calculation information before updating. In this process P13, the state calculation unit 116, for example, uses the calculation function F6 to set the calculation information before update stored in the first storage area of the storage device as calculation information for calculating the battery state again. Then, the process shown in FIG. 14 ends.

On the other hand, in process P12, if the determination function F8 determines that no abnormality or warning has occurred (NO), the status calculation unit 116 executes process P14 of overwriting and updating the calculation information, for example. In this process P14, the storage function F2 and the storage function F4 of the state calculation section 116 store the update information input from the reception function F1 in the first storage area of the storage device of the state calculation section 116, thereby storing the calculation information. overwrite and update. With the above, the process shown in FIG. 14 ends.

Hereinafter, the functions of the secondary battery device 11 and the secondary battery system 1 of this embodiment will be explained.

Currently, global environmental issues are attracting attention. In order to prevent global warming, environmentally friendly vehicles such as hybrid electric vehicles and electric vehicles are becoming popular. In such eco-friendly vehicles, the power of a motor driven by electrical energy stored in a secondary battery replaces part or all of the power of a conventional engine.

Furthermore, in the electric power field, renewable energy such as solar power generation, which does not emit greenhouse gases, is attracting attention and its introduction is progressing. Since the power output from solar power generation fluctuates greatly depending on the weather, there is a risk of causing voltage and frequency fluctuations in the power grid. Therefore, as shown in Figure 1, the solar power generation system PGS is equipped with a secondary battery system 1 that suppresses fluctuations in voltage, etc., and by charging and discharging the secondary battery system 1, it is possible to connect to the power grid 3. The output is smoothed.

As described above, secondary batteries are frequently used in systems that make it possible to prevent environmental warming, and it is expected that the scope of application of secondary batteries will continue to expand in the future. In a system that uses a secondary battery, if the required performance of the secondary battery in the system can no longer be met, or if the specified number of years of use have passed, it is determined that the secondary battery has reached its lifespan, and a new battery is required. be exchanged. In the future, it is expected that the reuse of secondary batteries will accelerate, for example, used secondary batteries removed from eco-friendly vehicles will be repurposed for other purposes.

There are various types of secondary batteries, such as lead batteries, nickel-metal hydride batteries, and lithium ion secondary batteries. Among them, lithium ion secondary batteries have particularly excellent output and energy performance, so their range of applications is expanding. For lithium ion secondary batteries, specifications for guaranteeing operation include, for example, usable temperature range, voltage range, charging state range, and maximum chargeable/dischargeable current.

If a battery is used outside the range stipulated as such specifications, the battery will deteriorate significantly, and in the worst case, it may cause the battery to malfunction. Therefore, the secondary battery device 11 that constitutes the secondary battery system 1 includes a state calculation unit 116 for calculating the battery state. The state calculation unit 116 detects the SOC and SOH of the secondary battery, the maximum chargeable and dischargeable current and power, the presence or absence of an abnormality, and characteristic information.

In the conventional battery deterioration calculation device described in Patent Document 1, a receiving section receives battery usage history data stored in a nonvolatile memory of a control section of a secondary battery device, and the battery deterioration calculation section calculates the battery capacity in advance. By combining this with battery deterioration trend data calculated using temperature as a parameter, battery capacity is calculated according to battery deterioration. Here, this conventional battery deterioration calculation device is characterized in that the battery capacity calculation algorithm and the like can be updated freely without time constraints. When updating such algorithms, we believe that if there is a function to determine whether the information to be updated is appropriate information, it will be possible to realize a secondary battery device that can perform control more reliably.

On the other hand, as described above, the secondary battery device 11 of this embodiment includes a unit cell group 111 which is a secondary battery, and a current sensor 113 as a detection unit that detects the voltage, current, and temperature of the secondary battery. , a temperature sensor 114, and a battery management section 115. Further, the secondary battery device 11 includes a state calculation section 116 that calculates the battery state based on the detection result of the detection section. Further, the state calculation unit 116 includes a storage device and a processing device. The storage device of the status calculation unit 116 has a first storage area that stores calculation information for calculating the battery status, and a second storage area that stores update information for updating the calculation information. . Further, the processing device of the state calculation unit 116 executes a state detection process, an update verification process, and an update process. The state detection process is a process P7 that calculates the current battery state using calculation information. The update verification process includes a process P8 in which a new battery state is calculated using the update information, and a process P9 in which a state change amount between the current battery state and the new battery state is calculated. The update process is a process P11 that stores update information in the first storage area and updates the calculation information when the amount of state change between the current battery state and the new battery state is within a specified range. .

With such a configuration, the secondary battery device 11 of this embodiment can more reliably perform control according to the state of the secondary batteries that constitute the unit cell group 111. Specifically, the state calculation unit 116 of the secondary battery device 11 stores calculation information for calculating the battery state of the secondary battery in a first storage area of the storage device. The calculation information includes, for example, a characteristic parameter of the secondary battery and a calculation algorithm for calculating the battery state using the characteristic parameter. As described above, the battery status includes, for example, the SOC, SOH, the maximum power or maximum current that can be input/output, and the presence or absence of an abnormality. For example, the status calculation unit 116 can acquire update information for updating calculation information from the management device 12 in accordance with deterioration of the secondary battery, and can store it in the second storage area of the storage device. . Then, the state calculation unit 116 calculates the current battery state using the current calculation information through the state detection process, calculates a new battery state using the update information through the update verification process, and calculates the current battery state and the new battery state using the update information. Calculate the amount of state change between the battery state and the battery state. Furthermore, the state calculation unit 116 causes the update information to be stored in the first storage area only when the amount of state change between the current battery state and the new battery state is within a specified range through the update process. to update the calculation information. Therefore, according to the secondary battery device 11 of this embodiment, it is possible to prevent calculation information from being overwritten by problematic update information and to more reliably perform control according to the state of the secondary battery. become.

Further, in the secondary battery device 11 of the present embodiment, the update process by the processing device of the state calculation unit 116 may include a change amount determination process, a temporary update process, an abnormality determination process, and an actual update process. . As shown in FIG. 14, the change amount determination process is a process P10 that determines whether the state change amount is within a defined range. Further, the temporary update process is a process P11 that sets the updated battery status to the output of the status calculation unit for a predetermined period when the amount of status change is within a specified range. The abnormality determination process is a process P12 in which the presence or absence of an abnormality is determined over a predetermined period of time. The actual update process is a process P14 in which update information is stored in the first storage area of the storage device to update the calculation information when it is determined that there is no abnormality in the abnormality determination process.

With such a configuration, in addition to the above-mentioned effects, the secondary battery device 11 can use the update information as calculation information for a limited period and overwrite the calculation information with the update information when there is no abnormality. . Therefore, according to this secondary battery device 11, it becomes possible to more reliably perform control according to the state of the secondary batteries that constitute the unit cell group 111.

Furthermore, in the secondary battery device 11 of this embodiment, the calculation information includes characteristic parameters of the secondary battery. With such a configuration, the state calculation unit 116 acquires new characteristic parameters from the management device 12 as update information, stores them in the second storage area of the storage device, and updates the current state stored in the first storage device of the storage device. The characteristic parameters of can be updated with new characteristic parameters.

Further, in the secondary battery device 11 of this embodiment, the characteristic parameters include the internal resistance R of the single cell constituting the secondary battery, the open circuit voltage OCV, the capacitance C that is the capacitance of the polarization resistance Rp and the capacitor, and the full charge. Includes capacity Qmax. With such a configuration, according to the secondary battery device 11 of the present embodiment, characteristic parameters whose current values are difficult to obtain in real time during use are acquired from the management device 12 as update information, and the characteristic parameters are updated. Can be updated. Note that although the above description has been about updating the characteristic parameters, the updating process is similarly applied to the arithmetic algorithm.

Further, the secondary battery system 1 of this embodiment includes the above-described secondary battery device 11 and a management device 12 communicably connected to the secondary battery device 11. The management device 12 includes a storage device and a processing device. As described above, the storage device of this management device 12 stores a plurality of pieces of calculation information. In addition, the processing device of the management device 12 selects one calculation information from among the plurality of calculation information stored in the storage device of the management device 12 based on the information acquired from the secondary battery device 11 and updates the information. It is output to the secondary battery device 11 as . Further, the processing device of the management device 12 defines a range of state change amounts between the current battery state and the new battery state in the secondary battery device 11 and outputs the range to the secondary battery device 11 .

With such a configuration, the storage device of the management device 12 can store a plurality of characteristic parameters as a plurality of calculation information, for example, for each of various battery history information. Here, the characteristic parameters include battery characteristic parameters whose current values are difficult to obtain in real time while the secondary battery device 11 is in use, as described above. Battery characteristic parameters whose current values are difficult to obtain in real time while using the secondary battery device 11 include, for example, the full charge capacity Qmax, the relationship between the open circuit voltage OCV and the SOC, the polarization resistance Rp and the capacitance C, and the battery This includes the relationship between the resistance increase rate SOHR and the capacity maintenance rate SOHQ.

That is, after the start of operation of the secondary battery system 1, the above-mentioned battery test is conducted in parallel, the battery is degraded under various conditions, calculation information including battery characteristic parameters is identified, and the multiple calculation information is It can be stored in the storage device of the management device 12. Thereby, it is possible to significantly reduce the preparation period required for operation of the secondary battery system 1. Furthermore, in the battery test described above, by conducting a battery test in which deterioration accelerates more than in actual battery operation, battery deterioration characteristics that anticipate the actual state of the secondary battery system 1 can be stored in the storage of the management device 12. It is possible to store it in That is, while shortening the preparation period until the start of operation of the secondary battery system 1, changes in characteristics due to battery deterioration that occur after the operation of the secondary battery system 1 can be detected using calculation information stored in the storage device of the management device 12. This can be reflected in the control of the secondary battery device 11.

Further, the processing device of the management device 12 acquires information including battery history information from the secondary battery device 11, and selects among the plurality of calculation information stored in the storage device of the management device 12 according to the history information. It is possible to select one calculation information from the list and output it to the secondary battery device 11 as update information. Thereby, the secondary battery device 11 can acquire parameters whose current values are difficult to obtain in real time while the secondary battery device 11 is in use from the management device 12 at any time, depending on the history information of the battery. I can do it. Furthermore, the processing device of the management device 12 defines a range of state change amounts between the current battery state and the new battery state in the secondary battery device 11 and outputs the range to the secondary battery device 11 . Thereby, the processing device of the secondary battery device 11 can execute the above-described update process using the prescribed range of the amount of state change acquired from the management device 12.

As described above, according to the present embodiment, it is possible to provide the secondary battery device 11 and the secondary battery system 1 that can more reliably control the secondary battery. Note that the secondary battery device 11 and the secondary battery system 1 according to the present disclosure are not limited to the above-described embodiments. Hereinafter, a modification of the secondary battery system 1 of the above-described embodiment will be described with reference to FIG. 15.

FIG. 15 is a functional block diagram showing a modification of the management device 12 shown in FIG. 9. As shown in FIG. The secondary battery system according to this modification differs from the secondary battery system 1 according to the above-described embodiment in the configuration of the management device 12. Other points of the secondary battery system according to this modification are the same as those of the secondary battery system according to the above-described embodiment, so similar parts are given the same reference numerals and explanations are omitted.

In the secondary battery system of this modification, the management device 12 has a function F13 for selecting the destination type of the secondary battery device 11 in addition to the above-mentioned functions. In addition, in this modification, the function F11 of the management device 12 for storing calculation information stores a plurality of history information of secondary batteries and a plurality of application types of the secondary battery systems 1 in the storage device of the management device 12. It has a function to store the associated diversion database. The function F13 for selecting the diversion destination type of the secondary battery device 11 determines the similarity between the history information of the secondary battery acquired from the secondary battery system 1 and the history information of the diversion database, and based on the similarity. to select the destination type of the diversion database.

As described above, in the secondary battery system according to the present modification, the storage device of the management device 12 is a diversion device that associates a plurality of history information of secondary batteries with a plurality of application types of secondary battery systems 1. database is stored. Then, the processing device of the management device 12 determines the similarity between the history information of the secondary battery acquired from the secondary battery device and the history information of the diversion database, and determines the application destination type of the diversion database based on the similarity. Select. With this configuration, the most suitable diversion destination for each secondary battery device 11 can be determined based on the history information and deterioration information of the unit cell group 111.

Although the embodiments of the secondary battery device and the secondary battery system according to the present disclosure have been described above in detail using the drawings, the specific configuration is not limited to this embodiment, and the gist of the present disclosure has been described in detail. Even if there are design changes within the scope, they are included in the present disclosure.

1 Secondary battery system 11 Secondary battery device 111 Cell group (secondary battery)
113 Current sensor (detection part)
114 Temperature sensor (detection part)
115 Battery management section (detection section)
116 Status calculation unit 12 Management device P7 Status detection process P8 Update verification process P11 Update process P10 Change amount determination process P11 Temporary update process P12 Abnormality determination process P13 Actual update process

Claims (6)

A secondary battery device comprising a secondary battery, a detection unit that detects voltage, current, and temperature of the secondary battery, and a state calculation unit that calculates a battery state based on the detection result of the detection unit. hand,
The state calculation unit has a storage device and a processing device,
The storage device has a first storage area that stores calculation information for calculating the battery state, and a second storage area that stores update information for updating the calculation information,
The processing device performs a state detection process that calculates the current battery state using the calculation information, an update verification process that calculates a new battery state using the update information, and a state detection process that calculates the current battery state using the update information. performing an update process of storing the update information in the first storage area and updating the calculation information when the amount of change in state from the new battery state is within a specified range; A secondary battery device featuring: The updating process includes a change amount determination process of determining whether the state change amount is within the range, and a change amount determination process of determining whether the state change amount is within the range, and updating the updated battery state for a predetermined period of time. a provisional update process that sets the output of the status calculation unit; an abnormality determination process that determines the presence or absence of an abnormality over the predetermined period; and when it is determined that there is no abnormality in the abnormality determination process, the update information is stored in the first storage area 2. The secondary battery device according to claim 1, further comprising: an actual update process of updating the calculated information by storing the calculated information in the calculated information. The secondary battery device according to claim 1, wherein the calculation information is a characteristic parameter or calculation processing content of the secondary battery. The characteristic parameters include an internal resistance of a unit cell constituting the secondary battery, an open circuit voltage, a resistance value of a parallel connection portion of a resistor and a capacitor in an equivalent circuit, a capacitance of the capacitor, and a full charge capacity. The secondary battery device according to claim 3. A secondary battery system comprising the secondary battery device according to any one of claims 1 to 4 and a management device communicably connected to the secondary battery device,
The management device includes a storage device and a processing device,
The storage device of the management device stores a plurality of the calculation information,
The processing device of the management device selects one of the calculation information from the plurality of calculation information based on the information acquired from the secondary battery device, and outputs the selected calculation information as the update information to the secondary battery device. At the same time, the secondary battery system is characterized in that the range of the state change amount is defined and output to the secondary battery device. The storage device of the management device stores a diversion database that associates a plurality of history information of the secondary batteries with application types of the plurality of secondary battery systems,
The processing device of the management device determines the similarity between the history information of the secondary battery acquired from the secondary battery device and the history information of the diversion database, and the processing device determines the similarity between the history information of the secondary battery acquired from the secondary battery device and the history information of the diversion database. 6. The secondary battery system according to claim 5, wherein the application destination type is selected.