JP2007205880A - Secondary battery capacity estimation system, program, and secondary battery capacity estimation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery capacity estimation system, a program, and a secondary battery capacity estimation method capable of estimating each battery capacity of a plurality of secondary batteries with light labor. <P>SOLUTION: This system has a secondary battery selection process for selecting one of the plurality of secondary batteries 30a, 30b, a request signal output process for outputting a signal to a secondary battery capacity estimation device 10, a charge control process for charging the selected secondary battery by a constant-current constant-voltage charging method, an input process for acquiring information on whether the battery capacity of another secondary battery is to be determined or not, a determination process for determining whether the battery capacity of another secondary battery is to be determined or not based on the information, a clocking process for measuring a constant-current charging duration which is a duration of a constant-current charging mode, a battery voltage measuring process for measuring a terminal voltage of the selected secondary battery in the constant-current charging mode, and a battery capacity estimation process for estimating the battery capacity of the selected secondary battery based on the constant-current charging duration or the terminal voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a secondary battery capacity estimation system, a program, and a secondary battery capacity estimation method, and in particular, when a secondary battery is charged using a constant current constant voltage charging method, the battery capacity of the secondary battery is estimated. The present invention relates to a secondary battery capacity estimation system, a program, and a secondary battery capacity estimation method.

  Lithium ion secondary batteries are high energy density batteries, and contribute to the downsizing of equipment as a main power source for personal computers and mobile phones. In recent years, attention has been paid to such a feature of high energy density, and a battery having a single battery capacity of about 100 Ah, which is supposed to be applied to applications such as automobile and stationary backup power supplies, has been manufactured.

  In such various applications, lithium ion secondary batteries are used, and in any application, an important point is to grasp the battery capacity of the lithium ion secondary batteries. This is because when the battery is the main power source of the device, the battery capacity directly affects the service provision time. This situation is the same for a battery for stationary use. In particular, with stationary batteries, there are many facilities that require reliability, such as a communication power supply system, and it is important to know the battery capacity of a lithium ion secondary battery.

Conventionally, grasping the battery capacities of various batteries has been often performed by measuring the internal resistance of those batteries. However, the measurement of the internal resistance of the battery requires the battery maintainer to connect a measuring instrument to the terminal of the target battery, and the battery capacity cannot be measured automatically.
For this reason, a method for estimating the battery capacity of a battery that is focused on the charge characteristics after the battery is discharged is also known (Patent Document 1).

  This Patent Document 1 pays attention to voltage aging characteristics during charging and discharging from cycle test data of a lithium ion secondary battery, and during charging, 4.0 (V) to 4.15 (V). The rate of change in time for the voltage to rise is obtained, and the relationship between this ratio and capacity is obtained. On the other hand, during discharge, the time during which the voltage decreases from 3.75 (V) to 3.6 (V) is used as an index for estimating the capacity, and the relationship between the rate of change of this time and the capacity is clarified. . However, the technique of Patent Document 1 estimates the deterioration state of the positive electrode and the negative electrode, and cannot estimate the battery capacity of the battery.

Further, a method described in Patent Document 2 is known as a method for estimating the capacity of a lithium ion secondary battery. In Patent Document 2, a lithium-ion secondary battery is charged by a constant current constant voltage charging method, and the charging current after reaching the constant voltage charging mode is a value that is 1/2 of the current value in the initial constant current charging mode. The time to decrease to a maximum is calculated, and the relationship between this time and battery capacity is clarified.
JP 2003-308885 A Japanese Patent No. 3370047

  However, in the method described in Patent Document 2, in order to estimate the capacity of a plurality of batteries, it is necessary for humans to perform processing such as monitoring of the charging mode, time measurement, and current measurement for each battery, Since it was necessary to reconnect the measuring device or the like for each battery, there was a problem that the managers required a lot of labor.

  The present invention has been made in view of the above circumstances, and a purpose thereof is a secondary battery capacity estimation system, a program, and a secondary battery capacity estimation capable of estimating the battery capacity of a plurality of secondary batteries with little effort. It is to provide a method.

  The present invention has been made to solve the above problems, and the invention according to claim 1 is a secondary battery capacity estimation system including a control device and a secondary battery capacity estimation device, and the control device. Outputs a secondary battery selection means for selecting one of a plurality of secondary batteries and a signal requesting the secondary battery capacity estimation device to determine the battery capacity of the selected secondary battery. Request signal output means, charge control means for charging the selected secondary battery by a constant current constant voltage charging method when the signal is output, and the battery capacity of the selected secondary battery is the secondary battery Input means for obtaining information on whether or not to obtain the battery capacity for other secondary batteries when obtained by the battery capacity estimation device, and other secondary batteries based on the information obtained by the input means Battery And determining means for determining whether or not the amount is to be obtained, wherein the secondary battery capacity estimating device outputs a constant current constant when the selected secondary battery is output when a signal is output from the request signal output means. A time measuring means for measuring a constant current charging duration time which is a duration time of a constant current charging mode when charging is performed by the voltage charging method; and when the signal is output from the request signal output means, the selected secondary Based on the battery voltage measuring means for measuring the terminal voltage of the selected secondary battery in the constant current charging mode when charging the battery by the constant current constant voltage charging method, and the constant current charging duration or the terminal voltage A secondary battery capacity estimation system comprising battery capacity estimation means for estimating a battery capacity of the selected secondary battery.

  According to a second aspect of the present invention, the battery capacity estimation means is based on a terminal voltage measured by the battery voltage measurement means when the selected secondary battery is charged in a constant current charging mode. The battery capacity of the selected secondary battery is estimated, and when the charging of the secondary battery in the constant current charging mode is completed, the selected battery is selected based on the constant current charging duration measured by the time measuring means. The secondary battery capacity estimation system according to claim 1, wherein the battery capacity of the secondary battery is estimated.

  The invention according to claim 3 further includes discharge control means for discharging the secondary battery selected by the secondary battery selection means, and the charge control means outputs a signal from the request signal output means. 3. The secondary battery capacity estimation system according to claim 1, wherein the secondary battery discharged by the discharge control means is charged by a constant current constant voltage charging method.

  The invention according to claim 4 further includes charging current measuring means for measuring a current value of the current flowing through the secondary battery, and the time measuring means is configured such that the current measured by the charging current measuring means is constant. The secondary battery capacity estimation system according to any one of claims 1 to 3, wherein the constant current charging duration is obtained based on a certain time.

  The invention according to claim 5 is characterized in that the time measuring means obtains the constant current charging duration based on a time when the voltage measured by the battery voltage measuring means reaches a predetermined value. To the secondary battery capacity estimation system according to any one of items 4 to 4.

  The invention according to claim 6 further includes battery data storage means for preliminarily storing battery capacity estimation data in which the relationship between the constant current charging duration and the battery capacity of the secondary battery is recorded, and the battery The capacity estimation means estimates the battery capacity of the secondary battery by reading out the battery capacity of the secondary battery corresponding to the constant current charging duration measured by the time measuring means from the battery capacity estimation data. A secondary battery capacity estimation system according to any one of claims 1 to 5.

  The invention according to claim 7 further includes a determination unit that determines that the secondary battery has deteriorated when the constant current charging duration time measured by the time measuring unit is shorter than a predetermined time. The secondary battery capacity estimation system according to any one of claims 1 to 6.

  The invention according to claim 8 further comprises alarm issuing means for issuing an alarm when the battery capacity estimated by the battery capacity estimating means is below a predetermined capacity. The secondary battery capacity estimation system according to any one of the preceding sections.

  According to a ninth aspect of the present invention, there is provided a secondary battery selection unit that selects any one of a plurality of secondary batteries, and a secondary battery selected with respect to the secondary battery capacity estimation device. Request signal output means for outputting a signal requesting to determine battery capacity, charge control means for charging the selected secondary battery by a constant current constant voltage charging method when the signal is output, and the selection Input means for obtaining information on whether or not to obtain battery capacity for other secondary batteries when the battery capacity of the secondary battery obtained is obtained by the secondary battery capacity estimation device; and A determination unit that determines whether or not to obtain a battery capacity for another secondary battery based on the acquired information, and when the signal is output from the request signal output unit, the selected secondary battery When the signal is output from the request signal output means, the time measuring means for measuring the constant current charge duration time which is the duration time of the constant current charge mode when charging by the current constant voltage charging method, the selected Battery voltage measuring means for measuring the terminal voltage of the selected secondary battery in the constant current charging mode when the secondary battery is charged by the constant current constant voltage charging method, and the constant current charging duration time or the terminal voltage A program for functioning as battery capacity estimation means for estimating the battery capacity of the selected secondary battery based on the program.

  The invention according to claim 10 is a secondary battery selection process for selecting one of a plurality of secondary batteries, and a battery capacity of the selected secondary battery with respect to the secondary battery capacity estimation device. A request signal output process for outputting a signal requesting to obtain, a charge control process for charging the selected secondary battery by a constant current constant voltage charging method when the signal is output, and the selected two When the battery capacity of the secondary battery is obtained by the secondary battery capacity estimation device, an input process for obtaining information on whether or not to obtain the battery capacity for other secondary batteries, and the information obtained in the input process A determination process for determining whether or not to determine a battery capacity for another secondary battery based on the output signal, and when the signal is output in the request signal output process, the selected secondary battery is a constant current constant voltage charging When the signal is output in the time measuring process for measuring the constant current charging duration, which is the duration of the constant current charging mode when charging with the battery, and in the request signal outputting process, the selected secondary battery is set. The battery voltage measuring process for measuring the terminal voltage of the selected secondary battery in the constant current charging mode when charging by the current constant voltage charging method, and the selected based on the constant current charging duration or the terminal voltage. And a battery capacity estimation process for estimating the battery capacity of the secondary battery.

In the control device of the present invention, a signal for selecting any of the plurality of secondary batteries by the secondary battery selection means and requesting the secondary battery capacity estimation device to determine the battery capacity of the selected secondary battery. Is output by the request signal output means, and the secondary battery selected when the signal is output is charged by the charge control means using the constant current constant voltage charging method, and the battery capacity of the selected secondary battery is When it is obtained by the secondary battery capacity estimation device, information on whether or not to obtain the battery capacity for other secondary batteries is obtained by the input means, and other secondary batteries are obtained based on the information obtained by the input means. Whether or not to obtain the battery capacity for the is determined by the determination means.
Further, in the secondary battery capacity estimation device, when a signal is output from the request signal output means, the duration of the constant current charging mode when the selected secondary battery is charged by the constant current constant voltage charging method is used. When a constant current charging duration is measured by the time measuring means and a signal is output from the request signal output means, the selected secondary battery is charged by the constant current constant voltage charging method in the constant current charging mode. The terminal voltage of the selected secondary battery is measured by the battery voltage measuring means, and the battery capacity of the secondary battery selected based on the constant current charging duration or the terminal voltage is estimated by the battery capacity estimating means.
Thereby, the administrator etc. can obtain the battery capacity of a plurality of secondary batteries only by inputting information on whether or not to obtain the battery capacity for other secondary batteries from the input means. Since it is not necessary to reconnect the measuring device for each secondary battery, etc., the labor of the manager can be reduced.
In addition, the battery capacity of the secondary battery can be estimated simply by measuring the constant current charging duration in the constant current charging mode or the terminal voltage of the secondary battery when performing the constant current constant voltage charging method. The secondary battery capacity can be easily estimated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an example of the configuration of a secondary battery capacity estimation system according to an embodiment of the present invention applied to a power system that supplies DC power. The secondary battery capacity estimation system includes a secondary battery capacity estimation device 10, secondary batteries 30a and 30b, a control device 50, a DC power supply device 70, a load 80, load devices 90a and 90b, current limiting circuits 100a and 100b, a circuit. It has disconnect switches 110a and 110b, load device connection switches 120a and 120b, and a modem 130.

The secondary battery capacity estimation device 10 measures the value of the current flowing through the secondary battery devices 30a and 30b and the terminal voltage of the secondary battery devices 30a and 30b, and obtains the battery capacity of the secondary batteries 30a and 30b. The specific configuration and processing of the secondary battery capacity estimation device 10 will be described later with reference to FIGS.
The control device 50 controls the secondary battery capacity estimation device 10, the DC power supply device 70, the load devices 90a and 90b, the current limiting circuits 100a and 100b, the circuit disconnect switches 120a and 120b, and the load device connection switches 120a and 120b. The control device 50 charges the secondary batteries 30a and 30b using a constant current and constant voltage charging method. The specific configuration and processing of the control device 50 will be described later with reference to FIGS.

The DC power supply device 70 is supplied with power from an AC power supply 21 such as a commercial power supply, and based on the control of the control device 50, the power is supplied to the secondary batteries 30a, 30b, the load 80, the load devices 90a, 90b, and the like. Supply.
The load 80 and the load devices 90a and 90b consume power supplied from the DC power supply device 70 and the secondary batteries 30a and 30b. Based on the control of the control device 50, the current limiting circuits 100a and 100b control the magnitude of the current output to the secondary batteries 30a and 30b and the load devices 90a and 90b.
The circuit disconnecting switches 110 a and 110 b open and close the switches based on the control of the control device 50. The load device connection switches 120 a and 120 b open and close the switches based on the control of the control device 50. The modem 130 is connected to a network such as a LAN (Local Area Network) and is used to perform data communication between the secondary battery capacity estimation device 10 and an external device.

FIG. 2 is a diagram for explaining the constant current constant voltage charging method according to the present embodiment. In FIG. 2, the horizontal axis represents the charging time (h). The scale on the left side of the vertical axis indicates the terminal voltage (V) of the secondary battery 30a, and the scale on the right side of the vertical axis indicates the charging current (CA). Note that CA in the current display indicates a current value obtained by setting the nominal capacity of the secondary battery to C (Ah) and multiplying this by a certain coefficient.
In the constant current constant voltage charging method, first, the power supplied from the DC power supply device 70 is controlled to a constant current by the power supply control circuit 100 a based on the control of the control device 50. The secondary battery 30a is charged by supplying a constant current (0.2 (CA) in FIG. 2) from the current limiting circuit 100a to the secondary battery 30a. A mode in which the power supply control circuit 100a charges the secondary battery 30a with a constant current based on the control of the control device 50 is called a constant current charging mode, and the time during which the constant current charging mode continues is a constant current duration (in FIG. 2). 5 (h)). In this constant current charging mode, the terminal voltage of the secondary battery 30a gradually increases toward a predetermined voltage (4.1 (V) in FIG. 2) (curve g01).

  When charging of the secondary battery 30a proceeds in the constant current charging mode and the terminal voltage of the secondary battery 30a reaches the set voltage (4.1 (V) in FIG. 2), thereafter, the control device 50 Based on the control, the secondary battery 30a is charged while maintaining the output voltage of the DC power supply device 70 at a constant voltage (4.1 (V) in FIG. 2). A mode in which the DC power supply 70 charges the secondary battery 30a with a constant voltage based on the control of the control device 50 is referred to as a constant voltage charging mode. In this constant voltage charging mode, the charging current flowing through the secondary battery 30a gradually decreases from the constant current (0.2 (CA) in FIG. 2) toward 0 (CA) (curve g02).

FIG. 3 is a diagram showing charging characteristics when the initial charging current in the constant current charging mode of FIG. 2 is changed. In FIG. 3, the horizontal axis represents the charging time (h). The scale on the left side of the vertical axis indicates the terminal voltage (V) of the secondary battery 30a, and the scale on the right side of the vertical axis indicates the charging current (CA). The curves g08 and g05 in FIG. 3 correspond to the curves g01 and g02 in FIG. 2, respectively.
A curve g03 to a curve g05 indicate current values of current flowing through the secondary battery 30a when the secondary battery 30a is charged by the constant current constant voltage charging method. Curves g06 to g08 indicate terminal voltages of the secondary battery 30a when the secondary battery 30a is charged by the constant current constant voltage charging method.

  Curves g03 and g06 show the charging characteristics when the initial charging current in the constant current charging mode is 1 (CA), and the duration of the constant current charging mode is t01. Curves g04 and g07 show the charging characteristics when the charging current in the constant current charging mode is 0.5 (CA), and the duration of the constant current charging mode is t02. Curves g05 and g08 show the charging characteristics when the charging current in the constant current charging mode is 0.2 (CA), and the duration of the constant current charging mode is t03. Thus, when the charging current in the constant current charging mode is increased, the duration of the constant current charging mode is shortened (t01 <t02 <t03). Therefore, when the initial charging current changes, the terminal voltage is measured within the duration of the constant current charging mode corresponding to the charging current. In FIG. 3, the terminal voltage of the secondary battery 30a in the constant voltage charging mode is 4.1 (V), and the terminal voltage of the secondary battery 30a in the constant current charging mode is the terminal voltage 4.1 (V ), The constant current constant voltage charging method is switched from the constant current charging mode to the constant voltage charging mode.

  Returning to FIG. 1, the secondary batteries 30 a and 30 b are batteries that can be repeatedly charged and discharged, and are, for example, lithium ion secondary batteries or lead storage batteries. Here, the case where the secondary batteries 30a and 30b are lithium ion secondary batteries will be described. The secondary batteries 30a and 30b have different battery capacities such as discharge characteristics and charge characteristics depending on the number of charge / discharge cycles and the passage of time.

FIG. 4 is a graph showing an example of the discharge characteristics of the secondary battery 30 whose capacity has been reduced to various values, and shows the relationship between the discharge time and the terminal voltage when discharged at a constant current. In FIG. 4, the horizontal axis represents the discharge time (h) of the secondary battery 30, the vertical axis represents the terminal voltage (V) during discharge of the secondary battery 30, and the discharge characteristics of the curves g1 to g4 are 2 This corresponds to the capacity of the secondary battery 30.
In FIG. 4, curves g1 to g4 indicate discharge characteristics when the battery capacities of the secondary batteries 30a are 60 (%), 70 (%), 80 (%), and 100 (%), respectively. . Here, when the battery capacity is 100 (%), it means that the secondary battery 30a is new.
As can be seen from FIG. 4, the capacity of the secondary battery 30a is 100 (%) (curve g4), 80 (%) (curve g3), 70 (%) (curve g2), 60 (%) (curve g1). As the battery deteriorates, the discharge time of the secondary battery 30a becomes as short as about 10 hours, about 8 hours, about 7 hours, and about 6 hours.

FIG. 5 is a graph showing an example of characteristics when the secondary batteries 30 having various capacities are charged by the constant current constant voltage method. In FIG. 5, the horizontal axis represents the charging time (h) of the secondary battery 30a. The scale on the left side of the vertical axis shows the terminal voltage (V) of the secondary battery 30a, and the scale on the right side of the vertical axis shows the charging current (CA) of the secondary battery 30a.
Curves g11 and g21 in FIG. 5 indicate that the secondary battery 30a having a discharge characteristic with a battery capacity of 60 (%) (curve g1 in FIG. 4) is completely discharged, and then determined under predetermined charging conditions. The charging characteristics when the secondary battery 30a is charged by the current constant voltage charging method are shown. Further, the curves g21 and g22, the curves g31 and g32, the curves g41 and g42 in FIG. 5 have a battery capacity of 70% (curve g2 in FIG. 4) and 80% (curve g3 in FIG. 4). , 100 (%) (curve g4 in FIG. 4), each of the secondary batteries 30a is completely discharged, and then the secondary batteries are subjected to a constant current and constant voltage method under a predetermined charging condition. The charge characteristic in the case of charging 30a is shown. Here, in any case of the secondary battery 30a having a battery capacity of 60 (%), 70 (%), 80 (%), or 100 (%), the charging initial current Ia, the charging setting are set as predetermined charging conditions. The voltage is Va (= 4.1 (V)).

Curves g11, g21, g31, and g41 show the relationship between the charging time (h) and the charging current (A) when the secondary battery 30a is charged by the constant current constant voltage charging method. Curves g12, g22, g32, and g42 show the relationship between the charging time (h) and the terminal voltage (V) when the secondary battery 30a is charged by the constant current constant voltage charging method.
As can be seen from the curves g11, g21, g31, and g41 in FIG. 5, the battery capacity of the secondary battery 30a deteriorates to 100 (%), 80 (%), 70 (%), and 60 (%). Accordingly, the durations t1, t2, t3, and t4 of the secondary battery 30a in the constant current charging mode are shortened.
Further, as can be seen from the curves g11, g21, g31, and g41 in FIG. 5, the battery capacity of the secondary battery 30a is 100 (%), 80 (%), 70 (%), and 60 (%). As the battery deteriorates, the terminal voltages V (100), V (80), V (70), and V (60) of the secondary battery 30a at a predetermined time tb within the duration of the constant current charging mode that is the constant current charging mode. Is getting bigger. V (100) indicates a terminal voltage when the battery capacity is 100%.
In the description of FIGS. 2 to 5 described above, the case where the secondary battery 30a and the current limiting circuit 100a of FIG. 1 are used has been described, but the same applies when the secondary battery 30b and the current limiting circuit 100b are used. Since the characteristics are obtained, the description thereof is omitted.

FIG. 6 is a block diagram illustrating an example of the configuration of the control device 50 according to the present embodiment. The control device 50 includes an input unit 51 (input unit), a storage unit 52, a secondary battery selection unit 53 (secondary battery selection unit), a determination unit 54 (determination unit), a switch control unit 55, a system control unit 56, It has a charge control unit 57 (charge control unit), a discharge control unit 58 (discharge control unit), and a request signal output unit 59 (request signal output unit).
The input unit 51 is configured by an input device such as a keyboard. The storage unit 52 includes measurement conditions (secondary battery capacity measurement time, set time) when estimating the secondary battery capacity based on the operation of the input unit 51 by the administrator of the secondary battery capacity estimation system according to the present embodiment. ) Etc. are recorded.
The secondary battery selection unit 53 selects which secondary battery among the plurality of secondary batteries is to be estimated based on the operation of the input unit 51 by the administrator.
The determination unit 54 determines whether or not to continue estimating the battery capacity for other secondary batteries when the battery capacity is estimated for a predetermined secondary battery based on the operation of the input unit 51 by the administrator. Determine.
The switch control unit 55 controls the opening / closing of each of the circuit disconnect switches 110a and 110b and the load device connection switches 120a and 120b.

The system control unit 56 controls each unit of the control device 50 in order to estimate the battery capacity of the secondary batteries 30a and 30b. When charging the secondary batteries 30a and 30b in the constant current charging mode of the constant current and constant voltage charging method, the charging control unit 57 controls the current limiting circuits 100a and 100b to control the constant current (for example, 0. 2 (CA)) is supplied to the secondary batteries 30a and 30b. Further, when charging the secondary batteries 30a and 30b in the constant voltage charging mode of the constant current constant voltage charging method, the charging control unit 57 controls the DC power supply device 70 to control a constant voltage (for example, 4.. 1 (V)) is supplied to the secondary batteries 30a and 30b.
The discharge control unit 58 controls the switch control unit 55 based on which secondary battery among the plurality of secondary batteries 30a, 30b is discharged to which of the load 80 and the load devices 90a, 90b. The request signal output unit 59 supplies the secondary battery capacity to the secondary battery capacity estimation apparatus 10 in the constant current charging mode of the constant voltage constant current charging method according to the constant current charging duration or the terminal voltage of the secondary battery 30a. Outputs a signal requesting the capacity.

FIG. 7 is a flowchart illustrating an example of processing of the control device 50 according to the present embodiment.
First, the system control unit 56 determines whether or not it is the measurement time of the battery capacity of the secondary battery, based on the measurement time of the battery capacity of the secondary battery stored in advance in the storage unit 52 (step S101). ). If it is not time to measure the battery capacity of the secondary battery, it waits until the time to measure the battery capacity of the secondary battery is reached. On the other hand, if it is time to measure the battery capacity of the secondary battery, “Yes” is determined in step S101, and the charging control unit 57 reduces the output voltage of the DC power supply device 70 (step S102).
And the discharge control part 58 discharges an assembled battery (the secondary battery 30a and the secondary battery 30b) (step S103). Specifically, the discharge control unit 58 controls the switch control unit 55 to close the circuit disconnect switches 110a and 110b, and opens the load device connection switches 120a and 120b, thereby supplying the secondary batteries 30a and 30b. The stored electric power is discharged to the load 80.

  Then, the system control unit 56 determines whether or not the set time has passed based on the set time stored in advance in the storage unit 52 (step S104). If the set time has not elapsed, “No” is determined in step S104, and the process of step S103 is continued. On the other hand, if the set time has elapsed, “Yes” is determined in step S104. The processes in steps S02 to S04 are performed for confirming the normality of the wiring by measuring the voltage of the discharge wiring. The time for discharging the secondary batteries 30a and 30b is not so long, and the complete discharge is not achieved. Absent.

Next, the discharge control unit 58 controls the switch control unit 55 to open the circuit disconnection switch of the first secondary battery (step S105). Here, the case where the circuit separation switch 110a of the secondary battery 30a is opened as the first secondary battery will be described.
Then, the charging control unit 57 returns the output voltage of the DC power supply device 70 to the output voltage value before the start of the battery capacity estimation test (step S106). Next, the discharge control unit 58 connects the first secondary battery 30a to the load device 90a (step S107). Specifically, the discharge control unit 58 controls the switch control unit 55 to open the circuit disconnect switch 110a and close the load device connection switch 120a to thereby reduce the electric power stored in the secondary battery 30a. Then, the load device 90a is discharged. Thereby, the electric power stored in the secondary battery 30a is completely discharged (step S108).

Then, the discharge control unit 58 disconnects the secondary battery 30a from the load device 60a (step S109). Specifically, the discharge control unit 58 controls the switch control unit 55 to open the load device connection switch 120a.
Then, the discharge controller 58 closes the circuit disconnect switch 110a of the secondary battery 30a (step S110). Next, the request signal output unit 59 outputs to the secondary battery capacity estimation device 10 a signal requesting to obtain the battery capacity of the secondary battery based on the constant current charge duration or the terminal voltage of the secondary battery. . Thereby, the secondary battery capacity estimation apparatus 10 is made to calculate the battery capacity of the secondary battery 30a (step S111). The process of step S111 will be described later with reference to FIG.

When the secondary battery capacity estimation device 10 calculates the battery capacity of the secondary battery 30a, the controller 50 determines whether the secondary battery 30a has another secondary battery (in this case, the secondary battery 30b). It is determined whether or not the capacity is estimated (step S112). This determination is performed based on data input from the input unit 51 by the administrator of the secondary battery capacity estimation system according to the present embodiment. In the case of estimating the battery capacity for other secondary batteries as well, “Yes” is determined in step S112, the process proceeds to step S102 again, and the processes of steps S103 to S111 are performed on the secondary battery 30b.
On the other hand, if the battery capacity is not estimated for the other secondary batteries, “No” is determined in step S112 in FIG. 7, and the process of the flowchart in FIG.

FIG. 8 is a block diagram illustrating an example of the configuration of the secondary battery capacity estimation apparatus 10 according to the present embodiment. The secondary battery capacity estimation apparatus 10 includes a battery voltage measuring unit 11 (battery voltage measuring unit), a charging current measuring unit 12 (charging current measuring unit), a timer unit 13 (timer unit), and a battery data / measurement condition input unit 14. , Battery data storage unit 15 (battery data storage unit), calculation unit 16 (battery capacity estimation unit, determination unit), power supply unit 17, display unit 18, alarm issuing / transmitting unit 19 (alarm issuing unit), external connection interface unit 20
The battery voltage measurement unit 11 measures the terminal voltage of the secondary batteries 30 a and 30 b and outputs the measured voltage value to the calculation unit 16. The charging current measurement unit 12 measures the current flowing through the secondary batteries 30 a and 30 b and outputs the measured current value to the calculation unit 16. The timekeeping unit 13 outputs time information such as the current time to the calculation unit 16.

The battery data / measurement condition input unit 14 includes an input device such as a keyboard. The battery data / measurement condition input unit 14 receives secondary battery data (manufacturer, manufacturing year, manufacturing lot) for the secondary batteries 30a and 30b based on the operation of the administrator of the secondary battery capacity estimation system according to the present embodiment. Etc.), secondary battery capacity estimation data, etc. are acquired and output to the battery data storage unit 15.
The battery data storage unit 15 stores secondary battery data and secondary battery capacity estimation data output from the battery data / measurement condition input unit 14. The secondary battery capacity estimation data is, for example, a secondary battery capacity estimation table as shown in FIGS. 9 and 10 below.

FIG. 9 is a diagram illustrating an example of a secondary battery capacity estimation table recorded in the battery data storage unit 15 according to the present embodiment. In FIG. 9, the horizontal axis indicates the duration (h) of the constant current charging mode, and the vertical axis indicates the battery capacity (%) of the secondary batteries 30a and 30b. A curve g6 shows a case where a lithium ion secondary battery having a rated capacity of 40 (Ah) is used as the secondary batteries 30a and 30b, the capacity of the battery is reduced by a high-temperature accelerated deterioration test, and the capacity test and the recovery charge (constant charge) are regularly performed. The relationship between the capacity | capacitance calculated | required by performing the current constant voltage charging method) and the continuation time of constant current charge mode is shown. The characteristics are shown when the charging current in the constant current charging mode is 0.2 (CA) and the terminal voltage in the constant voltage charging mode is 4.1 (V). The secondary battery capacity estimation table may be created using conditions other than these as the type of secondary battery, the charging current in the constant current charging mode, and the terminal voltage in the constant voltage charging mode.
As shown in FIG. 9, when the battery capacity of the secondary batteries 30a and 30b is reduced, the duration of the constant current charging mode is shortened. The secondary battery capacity estimation data such as the secondary battery capacity estimation table (FIG. 9) is obtained by the administrator of the secondary battery capacity estimation system according to the present embodiment and the duration of the constant current charging mode of the secondary batteries 30a and 30b. Obtained by examining the relationship with the battery capacity in advance.

FIG. 10 is a diagram illustrating another example of the secondary battery capacity estimation table recorded in the battery data storage unit 15 according to the present embodiment. In FIG. 10, the horizontal axis indicates the terminal voltage (V), and the vertical axis indicates the battery capacity (%) of the secondary battery 30. Curves g7 to g10 are obtained in the same manner as in FIG. 9, using a lithium ion secondary battery with a rated capacity of 40 (Ah) as the secondary battery 30a. The characteristics are shown when the charging current in the constant current charging mode is 0.2 (CA) and the terminal voltage in the constant voltage charging mode is 4.1 (V). Note that the secondary battery capacity estimation table may be created using values other than the above-described conditions using the secondary battery type, the charging current in the constant current charging mode, and the terminal voltage in the constant voltage charging mode as parameters. .
A curve g7 is data in which the relationship between the terminal voltage and the battery capacity when the time from the start of charging of the secondary battery 30a in the constant current charging mode is 30 minutes is recorded. Curves g8 to g10 show the relationship between the terminal voltage and the battery capacity when the time after starting charging of the secondary battery 30a in the constant current charging mode is 60 minutes, 90 minutes, and 120 minutes, respectively. Recorded data. Here, the relationship between the terminal voltage and the battery capacity at 30 minutes, 60 minutes, 90 minutes, and 120 minutes after the start of charging of the secondary battery 30 in the constant current charging mode is shown. Although the estimation table is recorded, the relationship between the terminal voltage and the battery capacity at other times may be recorded as the secondary battery capacity estimation table.
As shown in FIG. 10, when the battery capacity of the secondary battery 30a decreases, the terminal voltage increases. The secondary battery capacity estimation data such as the secondary battery capacity estimation table (FIG. 6) is obtained by the administrator of the secondary battery capacity estimation system according to the present embodiment and the like in the constant current charging mode of the secondary battery 30 and the battery capacity. It is acquired by examining the relationship with.

Returning to FIG. 8, the calculation unit 16 is a time during which the current value measured by the charging current measurement unit 12 is constant when a signal requesting the battery capacity of the secondary battery is output from the calculation device 50. The duration of a certain constant current charging mode is calculated based on the current time output by the timer unit 13. Then, the battery capacity corresponding to the duration of the constant current charging mode is read from the secondary battery capacity estimation table (FIG. 9) recorded in the battery data storage unit 15.
Moreover, the calculating part 16 acquires the value of the terminal voltage of the secondary battery 30a which the battery voltage measurement part 11 measures. Furthermore, the calculating part 16 acquires the time when the current output from the charging current measuring part 12 becomes a constant current and the current time from the time measuring part 13, so that the secondary battery 30 a of the constant current charging mode is obtained. The time from when charging is started is calculated. Then, the calculation unit 16 stores the battery capacity of the secondary battery 30a in the battery data based on the terminal voltage of the secondary battery 30a and the time since the charging of the secondary battery 30a is started in the constant current charging mode. It reads from the secondary battery capacity estimation table (FIG. 10) recorded in the unit 15.

  The power supply unit 17 is supplied with electric power from an AC power supply 21a such as a commercial power supply, and supplies power to the arithmetic unit 16 of the secondary battery capacity estimation device 10 to drive each unit of the secondary battery capacity estimation device 10. Let The display unit 18 includes a display device such as an LCD (Liquid Crystal Display). The display unit 18 displays data such as the battery capacity of the secondary battery 30 obtained by the calculation unit 16 on the screen.

The alarm issuing / transmitting unit 19 issues an alarm by sounding an alarm or the like when the battery capacity of the secondary battery 30 obtained by the calculation unit 16 is lower than a predetermined capacity stored in advance in the battery data storage unit 15. Issue. In addition, the alarm issuing / transmitting unit 19 transmits an e-mail to the administrator of the secondary battery capacity estimation system according to the present embodiment via the external connection interface unit 20 via a network such as the Internet. Then, it is notified that the battery capacity of the secondary battery 30 is lower than a predetermined capacity (for example, 30 (%)).
The external connection interface unit 20 performs data communication with an external device by connecting the secondary battery capacity estimation device 10 to a network such as a LAN.

FIG. 11 is a flowchart illustrating an example of processing of the secondary battery capacity estimation system according to the present embodiment. The flowchart in FIG. 11 shows the processing content of step S111 in FIG. Here, the case of estimating the battery capacity of the secondary battery 30a will be described, but the same applies to the case of estimating the battery capacity of the secondary battery 30b.
As a premise for estimating the battery capacity of the secondary battery 30a, the battery data / measurement condition input unit 14 includes storage battery data input from the battery data / measurement condition input unit 14 (manufacturer, year of manufacture, lot, etc. of the secondary battery 30a). ) Or secondary battery capacity estimation data (see FIGS. 9 and 10) is acquired (step S03) and recorded in the battery data storage unit 15.

  First, the calculating part 16 measures the constant current charge continuation time which is the continuation time of constant current charge mode, and the terminal voltage of the secondary battery 30 (step S01). That is, the arithmetic unit 16 calculates the constant current charging duration time by calculating the time during which the current value measured by the charging current measuring unit 12 is constant based on the time output from the time measuring unit 13. Note that the calculation unit 16 may obtain the constant current charging duration based on the time when the voltage value measured by the battery voltage measurement unit 11 reaches a predetermined value (for example, 4.1 (V)).

The calculating unit 16 stores the secondary battery capacity estimation data (see FIG. 5) recorded in the battery data storage unit 15 with the battery capacities corresponding to the constant current charging duration obtained in step S01 and the terminal voltage of the secondary battery 30a. 9 and FIG. 10), respectively.
The calculation unit 16 reads out the battery capacity read from the secondary battery capacity estimation data of FIG. 9 based on the constant current charging duration and the secondary battery capacity estimation data of FIG. 10 based on the terminal voltage of the secondary battery 30a. The average value with the battery capacity is calculated as the battery capacity (step S02).

In step S02, the calculation unit 16 estimates the battery capacity of the secondary battery 2a based on the terminal voltage measured by the battery voltage measurement unit 11 when the secondary battery 2a is charged in the constant current charging mode. When the charging of the secondary battery 2a in the constant current charging mode is completed, the battery capacity of the secondary battery 2a may be estimated based on the constant current charging duration time measured by the timer unit 13.
Moreover, in step S02, the calculating part 16 is a terminal which the battery voltage measuring part 11 measures according to the instruction | indication which the administrator of the secondary battery capacity estimation system by this embodiment inputs from the input part 51 of the control apparatus 50. You may make it determine whether the battery capacity of the secondary battery 2a is estimated based on a voltage, or the battery capacity of the secondary battery 2a is estimated based on the constant current charge continuation time which the time measuring part 13 measures.

  And the calculating part 16 determines whether the battery capacity of the secondary battery 30a calculated by step S02 is more than predetermined capacity (for example, 30 (%)) (step S04). The predetermined capacity data is input from the battery data / measurement condition input unit 14 together with the secondary battery data and the secondary battery capacity estimation data in the process of step S03, for example.

  If the battery capacity obtained in step S02 is not equal to or greater than the predetermined capacity, “No” is determined in step S04, and an alarm is issued (step S05). That is, a warning message such as “the battery capacity of the secondary battery has become smaller than the predetermined capacity” is displayed on the display unit 18, or from the alarm issuing / transmitting unit 19 through the external connection interface unit 20. A warning mail is transmitted to the administrator of the secondary battery capacity estimation system according to the present embodiment. Thereafter, the battery capacity of the secondary battery 30 is displayed on the display unit 18.

On the other hand, when the battery capacity calculated | required by step S02 is more than predetermined capacity, it determines with "Yes" by step S04, and the display part 18 displays the battery capacity of the secondary battery 30a (step S06).
And the calculating part 16 determines whether the charge of the secondary battery 30a by the constant current constant voltage charging method was completed (step S07). This determination is performed based on whether or not the current value output from the charging current measuring unit 12 is equal to or less than a predetermined threshold (for example, the measured value is 0).
If charging of the secondary battery 30a is not completed, “No” is determined in step S07, and charging of the secondary battery 30a by the constant current constant voltage charging method is continued (step S08). Then, the process proceeds again to step S07.

On the other hand, when the charging of the secondary battery 30a has been completed, “Yes” is determined in Step S07, and the processing according to the flowchart of FIG.
Note that, when the constant current charging duration obtained in step S02 described above is shorter than the predetermined time, the calculation unit 16 determines that the secondary battery 30a has deteriorated and displays it on the display unit 18. It may be. The data for the predetermined time is input from the battery data / measurement condition input unit 14 together with the secondary battery data and the secondary battery capacity estimation data in the process of step S03, for example.
In addition, the calculation unit 16 determines that the secondary battery 30a has deteriorated when the terminal voltage of the secondary battery 30a measured in step S02 described above is greater than a predetermined voltage, and displays the result on the display unit 18. You may make it do. The data for the predetermined time is input from the battery data / measurement condition input unit 14 together with the secondary battery data and the secondary battery capacity estimation data in the process of step S03, for example.

In the secondary battery capacity estimation system according to the embodiment of the present invention described above, when charging the secondary batteries 30a and 30b by the constant current and constant voltage charging method, the constant current charging duration time which is the duration time of the constant current charging mode is set. Measurement was performed, and the battery capacities of the secondary batteries 30a and 30b were obtained based on the constant current charging duration. Therefore, it is not necessary for a human to calculate the battery capacity by measuring the terminal voltage of the battery, so that the battery capacity of the secondary batteries 30a and 30b can be easily obtained.
Even in an assembled battery in which the secondary battery 30a and the secondary battery 30b are combined, it is possible to perform capacity estimation / deterioration judgment of an arbitrary cell simply by measuring the charging characteristics of each cell in the assembled battery during charging. Is possible.

  In the embodiment described above, the input unit 51, the storage unit 52, the secondary battery selection unit 53, the determination unit 54, the switch control unit 55, the system control unit 56, the charge control unit 57, and the discharge control unit 58 of FIG. , Request signal output unit 59, battery voltage measurement unit 11, charging current measurement unit 12, time measurement unit 13, battery data / measurement condition input unit 14, battery data storage unit 15, calculation unit 16, power supply unit 17, display The function of the unit 18, the alarm issue / transmission unit 19, the external connection interface unit 20, or a program for realizing a part of this function is recorded on a computer-readable recording medium, and the program recorded on the recording medium is recorded. You may control the control apparatus 50, the secondary battery capacity estimation apparatus 10, etc. by making a computer system read and run. The “computer system” here includes an OS and hardware such as peripheral devices.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

It is a block diagram which shows an example of the structure of the secondary battery capacity estimation system by embodiment of this invention applied to the electric power system which supplies direct-current power. It is a figure for demonstrating the constant current constant voltage charging method by this embodiment. It is a figure which shows the charge characteristic at the time of changing the initial stage charge current in the constant current charge mode of FIG. It is a graph which shows an example of the discharge characteristic of the secondary battery 30a in which the capacity | capacitance fell to various values. It is a graph which shows an example of the characteristic at the time of charging the secondary battery 30 of various capacity | capacitance with a constant current constant voltage method. It is a block diagram which shows an example of a structure of the control apparatus 50 by this embodiment. It is a flowchart which shows an example of a process of the control apparatus 50 by this embodiment. It is a block diagram which shows an example of a structure of the secondary battery capacity estimation apparatus 10 by this embodiment. It is a figure which shows an example of the secondary battery capacity estimation table recorded on the battery data storage part 15 by this embodiment. It is a figure which shows another example of the secondary battery capacity estimation table recorded on the battery data storage part 15 by this embodiment. It is a flowchart which shows an example of a process of the secondary battery capacity estimation system by this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Secondary battery capacity estimation apparatus, 11 ... Battery voltage measurement part, 12 ... Charging current measurement part, 13 ... Time measuring part, 14 ... Battery data and measurement condition input part, 15 ..Battery data storage unit, 16 ... calculation unit, 17 ... power supply unit, 18 ... display unit, 19 ... alarm issue / transmission unit, 20 ... external connection interface unit, 30a, 30b ... Secondary battery, 50 ... Control device, 51 ... Input unit, 52 ... Storage unit, 53 ... Secondary battery selection unit, 54 ... Determination unit, 55 ... Switch Control unit 56 ... System control unit 57 ... Charge control unit 58 ... Discharge control unit 59 ... Request signal output unit 70 ... DC power supply device 80 ... Load 90a, 90b ... load device, 100a, 100b ... current limiting circuit, 110a, 110b · Circuit disconnect switch, 120a, 120b ··· load device connected to a switch, 130 ... modem

Claims (10)

A secondary battery capacity estimation system comprising a control device and a secondary battery capacity estimation device,
The controller is
Secondary battery selection means for selecting one of a plurality of secondary batteries;
Request signal output means for outputting a signal requesting the secondary battery capacity estimation device to determine the battery capacity of the selected secondary battery;
Charging control means for charging the selected secondary battery by a constant current constant voltage charging method when the signal is output;
Input means for obtaining information on whether or not to obtain battery capacity for other secondary batteries when the battery capacity of the selected secondary battery is obtained by the secondary battery capacity estimation device;
Determination means for determining whether or not to obtain the battery capacity for other secondary batteries based on the information acquired by the input means;
The secondary battery capacity estimation device is:
When a signal is output from the request signal output means, a constant current charging duration time that is a duration time of a constant current charging mode when the selected secondary battery is charged by a constant current constant voltage charging method is measured. A timekeeping means,
When a signal is output from the request signal output means, the terminal voltage of the selected secondary battery in the constant current charging mode when the selected secondary battery is charged by the constant current constant voltage charging method. Battery voltage measuring means for measuring,
A secondary battery capacity estimation system comprising: battery capacity estimation means for estimating a battery capacity of the selected secondary battery based on the constant current charge duration or terminal voltage.   The battery capacity estimating unit is configured to charge the selected secondary battery based on a terminal voltage measured by the battery voltage measuring unit when the selected secondary battery is charged in a constant current charging mode. And estimating the battery capacity of the selected secondary battery based on the constant current charging duration measured by the time measuring means when the charging of the secondary battery in the constant current charging mode is completed. The secondary battery capacity estimation system according to claim 1, wherein the secondary battery capacity is estimated. A discharge control means for discharging the secondary battery selected by the secondary battery selection means;
The charge control means charges the secondary battery discharged by the discharge control means by a constant current constant voltage charging method when a signal is output from the request signal output means. Secondary battery capacity estimation system described in 1. Charging current measuring means for measuring the current value of the current flowing through the secondary battery;
The said time measuring means calculates | requires the said constant current charge continuation time based on the time when the electric current which the said charging current measurement means measured is constant, The 2nd description in any one of Claim 1 to 3 characterized by the above-mentioned. Secondary battery capacity estimation system.   The said time measuring means calculates | requires the said constant current charge continuation time based on the time when the voltage which the said battery voltage measurement means reaches | attains a predetermined value, The description in any one of Claim 1 to 4 characterized by the above-mentioned. Secondary battery capacity estimation system. Battery data storage means for preliminarily storing battery capacity estimation data in which the relationship between the constant current charging duration and the battery capacity of the secondary battery is recorded;
The battery capacity estimating means estimates the battery capacity of the secondary battery by reading out the battery capacity of the secondary battery corresponding to the constant current charging duration measured by the time measuring means from the battery capacity estimation data. The secondary battery capacity estimation system according to any one of claims 1 to 5, wherein   7. The apparatus according to claim 1, further comprising a determination unit that determines that the secondary battery has deteriorated when the constant current charging duration measured by the time measuring unit is shorter than a predetermined time. 8. The secondary battery capacity estimation system according to any one of the items.   The secondary battery according to any one of claims 1 to 7, further comprising an alarm issuing means for issuing an alarm when the battery capacity estimated by the battery capacity estimating means is below a predetermined capacity. Battery capacity estimation system. Computer
Secondary battery selection means for selecting one of a plurality of secondary batteries;
Request signal output means for outputting a signal requesting the secondary battery capacity estimation device to determine the battery capacity of the selected secondary battery;
Charging control means for charging the selected secondary battery by a constant current constant voltage charging method when the signal is output;
Input means for obtaining information on whether or not to obtain battery capacity for other secondary batteries when the battery capacity of the selected secondary battery is obtained by the secondary battery capacity estimation device;
Determination means for determining whether or not to obtain the battery capacity for other secondary batteries based on the information acquired by the input means;
When a signal is output from the request signal output means, a constant current charging duration time that is a duration time of a constant current charging mode when the selected secondary battery is charged by a constant current constant voltage charging method is measured. A timekeeping means,
When a signal is output from the request signal output means, the terminal voltage of the selected secondary battery in the constant current charging mode when the selected secondary battery is charged by the constant current constant voltage charging method. Battery voltage measuring means for measuring,
Battery capacity estimating means for estimating a battery capacity of the selected secondary battery based on the constant current charge duration or terminal voltage;
Program to function as. A secondary battery selection process of selecting one of a plurality of secondary batteries;
A request signal output step of outputting a signal requesting the secondary battery capacity estimation device to determine the battery capacity of the selected secondary battery;
A charge control process of charging the selected secondary battery by a constant current constant voltage charging method when the signal is output;
An input process for obtaining information on whether or not to obtain battery capacity for other secondary batteries when the battery capacity of the selected secondary battery is obtained by the secondary battery capacity estimation device;
A determination process for determining whether or not to obtain battery capacity for other secondary batteries based on the information acquired in the input process;
When a signal is output in the request signal output process, a constant current charge duration time which is a duration time of a constant current charge mode when the selected secondary battery is charged by a constant current constant voltage charging method is measured. The timing process,
When a signal is output in the request signal output process, the terminal voltage of the selected secondary battery in the constant current charging mode when the selected secondary battery is charged by a constant current constant voltage charging method is set. Battery voltage measurement process to be measured,
A battery capacity estimation process for estimating a battery capacity of the selected secondary battery based on the constant current charge duration or terminal voltage;
A secondary battery capacity estimation method comprising:

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