JP5018736B2 - Charge / discharge battery performance evaluation apparatus and charge / discharge battery performance evaluation method - Google Patents

Description

  The present invention relates to a performance evaluation apparatus for a chargeable / dischargeable battery and a performance evaluation method for a chargeable / dischargeable battery.

Conventionally, there are various standards for battery evaluation methods used in electric vehicles. For example, in the following Non-Patent Document 1, “JEVS: Japan Electric Vehicle Standard” “ A method defined as “JEVS D 703” may be mentioned.
FC / EV Standardization Committee, “Power Density and Peak Output Test Methods for Control Valve Lead Batteries for Electric Vehicles”, Japan Automobile Research Institute, January 12, 2006 (established), p. 3-4

However, the standard “JEVS D 703” is mainly defined for a battery used in a hybrid electric vehicle using both an engine and a battery, and is used for a pure electric vehicle not equipped with an engine. It has been found that there are cases where it is not suitable to evaluate the battery used.
That is, when the parallel hybrid electric vehicle is accelerated, if the torque (motor torque) output from the electric motor is not sufficient, the torque (engine torque) output from the engine and the motor torque can be combined. It is like that. In this case, the amount of current supplied from the battery to the electric motor temporarily maximizes the battery performance, but it is not necessary to maximize the amount of output current from the battery after the engine torque has risen.

  In a serial hybrid electric vehicle, in principle, engine torque and motor torque are not combined and used as drive torque. However, since the electric power output from the generator driven by the engine and the electric power output from the battery are both supplied to the electric motor, the period during which the output current amount of the battery must be maximized is relatively It's short.

For this reason, in the battery evaluation method defined in the “JEVS D 703” standard, the period defined as the period in which the amount of current output from the battery is maximized is 10 seconds.
On the other hand, in an electric vehicle, the power supply source of the electric motor is a battery, and during the period when the load of the electric motor is increasing (for example, the acceleration period of the vehicle), the output current amount of the battery can be continuously maximized. It is assumed that it is required.

This point will be described with reference to FIG.
The graph of FIG. 9 shows the result of an experiment as to how much voltage the battery can output when the target battery is discharged for 60 seconds. Here, the “estimated value” refers to a voltage value estimated as having been discharged for 60 seconds using the estimation method of the “JEVS D 703” standard, and the “complementary straight line” refers to the battery discharge depth ( A straight line that complements the voltage between each estimated value by connecting each estimated value for each DOD (Depth of Discharge) with a straight line. Further, the “actual value” herein refers to a value obtained by actually measuring the voltage at the battery terminal with a voltmeter 60 seconds after the start of discharge.

Moreover, the battery which is the object of this experiment is a lithium ion battery having a power capacity of about 16 kWh.
In FIG. 9, black diamonds indicate estimated values for batteries with a DOD of 50%, black triangles indicate estimated values for batteries with a DOD of 70%, and black circles indicate DOD of 90%. It is an estimated value in the battery.

Also, white diamonds indicate measured values for batteries with a DOD of 50%, white triangles indicate measured values for batteries with a DOD of 70%, white circles indicate batteries with a DOD of 90%. It is a measured value.
Further, the magnitudes of the current values I ₁₀₁ , I ₁₀₂ , I ₁₀₃ , I ₁₀₄ , I ₁₀₅ , and I ₁₀₆ indicating the discharge current I have the relationship shown in the following formula (A).

I ₁₀₁ <I ₁₀₂ <I ₁₀₃ <I ₁₀₄ <I ₁₀₅ <I ₁₀₆ (A)
In FIG. 9, when the discharge current I is I ₁₀₁ and I ₁₀₂ , it appears that only black diamonds, triangles, and circles are displayed. Overlap, the black triangle and the white triangle substantially overlap, and the black circle and the white circle substantially overlap. That is, there is almost no deviation between the estimated value and the actually measured value.

That is, when the discharge current I is I ₁₀₁ and I ₁₀₂ , there is no difference between the estimated value and the actually measured value even if the discharge is performed for 60 seconds, and no particular problem occurs.
However, when discharging is performed for 60 seconds with the discharge current I as I ₁₀₆ , the battery DOD is 50% and the DOD is 70% as shown by the white diamond and white triangle in the figure. And a gap will occur between the complementary straight line and the measured value.

Also, when discharging for 60 seconds from a battery with a DOD of 90% with the discharge current I set to I ₁₀₃ , a relatively large deviation occurs between the supplementary straight line and the measured value, and the discharge current I is further increased. It became clear that this gap became larger as I let it go.
That is, the battery evaluation method based on the “JEVS D 703” standard defined for the battery used in the hybrid electric vehicle cannot correctly evaluate the battery used in the electric vehicle. Is shown.

  In addition, even when evaluating a battery for a hybrid electric vehicle, depending on the hybrid electric vehicle to which the target battery is applied, the period of travel using only the torque from the electric motor (motor torque) is relatively long. In some cases. As described above, the battery evaluation method based on the “JEVS D 703” standard cannot be appropriately evaluated for such a hybrid electric vehicle battery.

For this reason, when accurately evaluating a battery that requires a high output for a relatively long period, the battery output voltage can be adjusted for each DOD while changing the discharge current I finely while changing the temperature condition. There is a need to actually measure.
However, there is a problem that such a method requires a great deal of labor and time.

In addition, since it is necessary to repeatedly charge and discharge the battery, there is a problem that the deterioration of the battery that occurs during the evaluation of the battery must be taken into consideration.
The present invention has been devised in view of such a problem, and provides a performance evaluation apparatus and a performance evaluation method for a chargeable / dischargeable battery that can accurately evaluate the performance of the chargeable / dischargeable battery. Objective.

  In order to achieve the above object, a battery performance evaluation apparatus (Claim 1) of the present invention is a battery performance evaluation apparatus capable of charging and discharging, and a voltage detection means for detecting the voltage of the battery. An assumed maximum output current setting means for setting an assumed value of the maximum output current of the battery as an assumed maximum output current, and the assumed maximum output current set by the assumed maximum output current setting means for a predetermined specified discharge period An assumed discharge capacity setting means for setting an assumed discharge capacity that is a discharge capacity when discharging from the battery, and a discharge for discharging the battery while keeping the assumed discharge capacity set by the assumed discharge capacity setting means constant A discharge means for repeatedly executing the control, a current setting means for gradually increasing the discharge current each time the discharge control is executed by the discharge means, and the discharge means. A charging means for performing charge control for charging the battery so that the discharge depth of the battery becomes a target discharge depth every time the discharge control is completed; and discharge of the assumed discharge capacity set by the assumed discharge capacity setting means Required discharge period calculation means for calculating a period necessary for performing the required discharge period, and the voltage of the battery when the required discharge period calculated by the required discharge period calculation means has elapsed is obtained as a corresponding voltage. Corresponding voltage acquisition means, and maximum output current estimation means for estimating the maximum output current of the battery based on the corresponding voltage set by the corresponding voltage acquisition means.

  According to a second aspect of the present invention, there is provided a battery performance evaluation apparatus according to the present invention, wherein the voltage of the battery is defined on one axis and the discharge current of the battery on the other axis. A voltage characteristic estimation line setting for setting a voltage characteristic estimation line of the battery on the voltage / current diagram based on the voltage / current diagram in which the voltage is defined and the corresponding voltage acquired by the corresponding voltage acquisition unit The maximum output current estimating means on the voltage / current diagram at the intersection of the voltage characteristic estimation line set by the voltage characteristic estimation line setting means and the limit discharge voltage of the battery When the current matches the assumed maximum output current set by the assumed maximum output current setting means, the assumed maximum output current is estimated to be the maximum output current of the battery.

  According to a third aspect of the present invention, there is provided a battery performance evaluation apparatus according to the present invention, wherein the battery voltage detected by the voltage detecting means reaches the limit discharge voltage. The discharge control is the Na-th discharge control, the discharge control before the Na-th time is the Nb-th discharge control, and the discharge control before the Nb-th time is the Nc-th discharge control. And the assumed maximum output current setting means includes the Nb-th discharge current set by the current setting means at the time of the Nb-th discharge control and the Na-th time of the discharge control. The assumed maximum output current is set between the Na-th discharge current set by the current setting means, and the necessary discharge period calculation means is a discharge current at the time of execution of the Nb-th discharge control. The assumed discharge capacity setting First required discharge period calculating means for calculating a period required for discharging the assumed discharge capacity set by the means from the battery as a first required discharge period; and at the time of executing the Nc-th discharge control. Second required discharge period calculation means for calculating a period required for discharging the assumed discharge capacity set by the assumed discharge capacity setting means with the discharge current from the battery as a second required discharge period; The corresponding voltage acquisition means performs the first correspondence to the voltage of the battery when the first required discharge period calculated by the first required discharge period calculation means has elapsed during the Nb-th discharge control execution. When the second necessary discharge period calculated by the second necessary discharge period calculation means has elapsed at the time of execution of the Nc-th discharge control, the first corresponding voltage acquisition means to acquire as a voltage Second corresponding voltage acquisition means for acquiring the voltage of the battery as a second corresponding voltage, and the voltage characteristic estimation line setting means indicates the first corresponding voltage acquired by the first corresponding voltage acquisition means. A straight line passing through a point and a point indicating the second corresponding voltage acquired by the second corresponding voltage acquisition means is set as a voltage characteristic estimation line of the battery.

  According to a fourth aspect of the present invention, there is provided a battery performance evaluation apparatus according to the present invention, wherein, when the intersection current does not match the assumed maximum output current, the assumed maximum output current in the contents of claim 2 or 3. Correction means for correcting the assumed maximum output current of the battery set by the setting means between the Nb-th discharge current and the Na-th discharge current; and the assumed discharge capacity setting means includes the correction means. The assumed discharge capacity is set on the assumption that the specified discharge period is discharged from the battery at the assumed maximum output current corrected by the above.

  And the performance evaluation method for a chargeable / dischargeable battery according to the present invention (Claim 5) is a performance evaluation method for a chargeable / dischargeable battery, and a target discharge depth setting step for setting a target discharge depth of the battery; An assumed maximum output current setting step for setting an assumed value of the maximum output current of the battery as an assumed maximum output current; and the assumed maximum output current set in the assumed maximum output current setting step for a predetermined specified discharge period. An assumed discharge capacity setting step for setting an assumed discharge capacity that is a discharge capacity when discharging from the battery, and a discharge control for discharging the battery while keeping the assumed discharge capacity set in the assumed discharge capacity setting step constant And repeatedly increasing the discharge current step by step each time the discharge control is executed in the discharge step. A current setting step and a charge control for charging the battery so that the discharge depth of the battery becomes the target discharge depth set in the target discharge depth setting step every time the discharge control is completed in the discharge step. A charging step, a required discharge period calculating step for calculating a period necessary for discharging the assumed discharge capacity set by the assumed discharge capacity setting step as a required discharge period, and a calculation by the required discharge period calculating step. A corresponding voltage acquisition step of acquiring the voltage of the battery when the required discharge period has elapsed as a corresponding voltage, and the maximum output current of the battery based on the corresponding voltage set by the corresponding voltage acquisition step And a maximum output current estimating step for estimating.

  Further, according to a sixth aspect of the present invention, there is provided a method for evaluating the performance of a chargeable / dischargeable battery according to the fifth aspect of the present invention, based on the corresponding voltage acquired by the corresponding voltage acquiring step. A voltage characteristic estimation line setting step for setting a voltage characteristic estimation line of the battery on a voltage / current diagram in which the voltage of the battery is defined and the discharge current of the battery is defined on the other axis; In the current estimation step, on the voltage / current diagram, an intersection current at an intersection between the voltage characteristic estimation line set in the voltage characteristic estimation line setting step and the limit discharge voltage of the battery is set to the assumed maximum output current setting. When the assumed maximum output current set by the step coincides, the assumed maximum output current is estimated to be the maximum output current of the battery.

  According to a seventh aspect of the present invention, there is provided a method for evaluating the performance of a chargeable / dischargeable battery according to the sixth aspect, wherein the discharge control when the battery voltage reaches the limit discharge voltage is controlled at the Nath time. Discharge control, the discharge control before the Nath time is the Nbth discharge control, the discharge control before the Nbth time is the Ncth discharge control, and the assumed maximum output current setting The step includes the Nb-th discharge current set by the current setting step when the Nb-th discharge control is executed and the current-set step set by the Nab-time discharge control. The assumed maximum output current is set with respect to the discharge current at the Nath time, and the required discharge period calculating step is a discharge current at the time of execution of the discharge control at the Nbth time according to the assumed discharge capacity setting step. A first required discharge period calculating step for calculating a period necessary for discharging the set assumed discharge capacity from the battery as a first required discharge period; and a discharge current at the time of executing the Nc-th discharge control. And a second required discharge period calculating step for calculating a period necessary for discharging the assumed discharge capacity set by the assumed discharge capacity setting step from the battery as a second required discharge period. The voltage acquisition step uses, as the first corresponding voltage, the voltage of the battery when the first required discharge period calculated in the first required discharge period calculation step has elapsed during the Nbth discharge control execution. The first corresponding voltage acquisition step to be acquired, and the second required discharge calculated by the second required discharge period calculation step at the time of executing the Nc-th discharge control. A second corresponding voltage acquisition step of acquiring the voltage of the battery when the interval has passed as a second corresponding voltage, and the voltage characteristic estimation line setting step is acquired by the first corresponding voltage acquisition step A straight line passing through the point indicating the first corresponding voltage and the point indicating the second corresponding voltage acquired in the second corresponding voltage acquisition step is set as a voltage characteristic estimation line of the battery.

  In addition, in the content evaluation method according to claim 6 or 7, when the intersection current does not coincide with the assumed maximum output current, the method for evaluating the performance of the chargeable / dischargeable battery of the present invention according to claim 8 provides the assumed maximum output current. A correction step for correcting the assumed maximum output current of the battery set by the setting step between the Nb-th discharge current and the Na-th discharge current; and the assumed discharge capacity setting step includes the correction step The assumed discharge capacity is set on the assumption that the specified discharge period is discharged from the battery at the assumed maximum output current corrected by the above.

According to the battery performance evaluation apparatus and method of the present invention, the performance of the battery can be evaluated quickly and accurately. (Claims 1 and 5)
In addition, by setting the voltage characteristic estimation line, it is possible to accurately estimate the maximum output current of the battery that can be charged and discharged. (Claims 2 and 6)
In addition, by setting the voltage characteristic estimation line more accurately, it is possible to accurately estimate the maximum output current of a chargeable / dischargeable battery. (Claims 3 and 7)
Further, by correcting the assumed value of the maximum output current of the chargeable / dischargeable battery, that is, the assumed maximum output current within a predetermined range, the maximum output current of the battery can be estimated without trouble and with high accuracy. (Claims 4 and 8)

1 is a schematic block diagram showing an overall configuration of the battery, and FIG. 2 is a schematic diagram showing an operation of the battery according to one embodiment of the present invention. Is a typical time chart.
3 is a schematic diagram of a voltage / current diagram when the voltage drop prediction line is overshooted, FIG. 4 is a schematic diagram of a voltage / current diagram when the voltage drop prediction line is undershooted, and FIG. 5 is a voltage diagram. It is a schematic diagram of a voltage / current diagram when a predicted fall line intersects with an assumed maximum output current.

  FIG. 6 is a schematic flowchart showing the operation of the battery performance evaluation apparatus and the battery performance evaluation method, and FIG. 7 is the operation of the chargeable / dischargeable battery performance evaluation apparatus and the battery performance evaluation method according to the embodiment. FIG. 8 is a schematic graph showing the voltage / current characteristics of the battery when the evaluation corresponding to the time chart of FIG. 7 is performed.

As shown in FIG. 1, a battery 11 for an electric vehicle is a chargeable / dischargeable lithium ion battery, and is electrically connected to a battery performance measuring device 12 via a cable 13. The battery 11 is also called a battery cell built in a battery unit (not shown).
The battery performance measuring device 12 is an electronic control unit including a CPU (Central Processing Unit), a memory, and a keyboard (interface device) (not shown), and can measure the performance of the battery 11. Yes.

In the memory of the battery performance measuring device 12, all of them as software include a battery voltage detection unit (voltage detection unit) 21, a discharge unit (discharge unit) 22, a charging unit (charging unit) 23, and a current setting unit (current setting unit). 24, an assumed maximum output current setting section (assumed maximum output setting means) 25 and an assumed discharge capacity setting section (assumed discharge capacity setting means) 26 are recorded.
Further, in the memory of the battery performance measuring device 12, a necessary discharge period calculation unit (necessary discharge period calculation unit) 27, a corresponding voltage acquisition unit (corresponding voltage acquisition unit) 28, a voltage characteristic estimation line setting unit are used as software. (Voltage characteristic estimation line setting unit) 29, maximum output current estimation unit (maximum output current estimation unit) 31, and correction unit (correction unit) 32 are recorded.

In addition, the above-described necessary discharge period calculation unit 27 has a first necessary discharge period calculation unit (first necessary discharge period calculation means) 27A and a second necessary discharge period calculation unit (second necessary discharge period calculation) as subprograms. Means) 27B.
Each of the above-described corresponding voltage acquisition units 28 includes a first corresponding voltage acquisition unit (first corresponding voltage acquisition unit) 28A and a second corresponding voltage acquisition unit (second corresponding voltage acquisition unit) 28B as subprograms. Have.

Further, a voltage / current diagram 33 is recorded in the memory of the battery performance measuring apparatus 12.
Among these, the battery voltage detection part 21 detects the terminal voltage _Ebatt of the battery 11 periodically. The battery voltage detection unit 21 records the detection result in the memory of the battery performance measurement device 12 as needed.

The discharge unit 22 repeatedly executes discharge control for discharging the battery 11. The initial value (initial current value) I _dis 0 of the discharge current I _dis in this discharge control is recorded in the memory of the battery performance measuring device 12, and the initial current value I _dis 0 is set by the current setting unit 24 described later. It is to be increased step by step. In the present embodiment, it is assumed that the initial current value I _dis 0 is 50 [A].

On the other hand, the target period (specified discharge period) _Tdis 0 in which this discharge control is executed is input by the user via the keyboard provided in the battery performance measuring device 12. In the present embodiment, it is assumed that the user sets the specified discharge period _Tdis 0 as 60 seconds in consideration of the specification of the electric vehicle (not shown) on which the battery 11 is mounted.
In addition, when the specified discharge period T _dis 0 is input, the discharge unit 22 sets the measurement discharge period T _dis 1 thereafter. The measured discharge period T _dis 1 is a period in which discharge control is actually executed, and the discharge unit 22 performs this measurement so as to be longer than the input specified discharge period T _dis 0 (= 60 [sec]). The discharge period T _dis 1 is set. In the present embodiment, it is assumed that the discharge unit 22 sets the measured discharge period _Tdis 1 as 120 seconds.

The charging unit 23 performs charging control for charging the battery 11 so that the actual DOD of the battery 11 becomes the target DOD every time the discharge control by the discharging unit 22 is completed. The target DOD is input by the user via a keyboard provided in the battery performance measuring device 12.
Note that the discharge control repeated by the discharge unit 22 and the charge control repeated by the charging unit 23 are as shown in the time chart of FIG. 2, but the time chart shown in FIG. 2 will be described later.

The current setting unit 24 increases the discharge current I _dis in a stepwise manner every time discharge control is executed by the discharge unit 22 described above.
Here, in order to describe the battery performance measuring device 12 more specifically, terms are defined as follows with reference to FIG.
The discharge control at the time when the terminal voltage E _batt of the battery 11 has dropped to the limit discharge voltage E _lim before the specified discharge period T _dis 0 (= 60 [sec]) elapses is referred to as the _Nath discharge control. To do.
The discharge control in the previous turn of Na is the Nbth discharge control.
The discharge control in the previous Nb round is referred to as Nc _second discharge control.
· Discharge control in Nc ₂ nd previous times and discharge control of the _first Nc.

The discharge control of these “Na-th”, “Nb-th”, “Nc _second- time” and “Nc _first- time” are respectively “fourth”, “third”, “second” and “first”. This may be described as discharge control.
The assumed maximum output current setting unit 25 sets the assumed maximum output current I _max S when the discharge control is executed by the discharge unit 22 described above. This assumed maximum output current I _max S is a value that assumes 11 maximum output currents I _max at the target DOD. The maximum output current I _max is the maximum current value that can be output from the battery 11 in a range where the terminal voltage E _batt of the battery 11 does not fall below the limit discharge voltage E _lim . The limit discharge voltage E _lim is a lower limit value of the voltage that can maintain the performance required of the battery 11. In other words, if the terminal voltage E _batt of the battery 11 is lower than the limit discharge voltage E _lim , it is defined as a lower limit voltage that causes operational problems in performance.

More specifically, as shown in FIG. 2, the assumed maximum output current setting unit 25 includes a discharge current I _dis Nb set by the current setting unit 24 at the time of execution of the third (Nb) discharge control, The assumed maximum output current I _max S is set with the discharge current I _dis Na set by the current setting unit 24 when the fourth (Na-th) discharge control is executed.
In the present embodiment, the Nb-th discharge current I _dis Nb is 150 [A], the Na-th discharge current I _dis Na is 200 [A], and the assumed maximum output current setting unit 25 has the assumed maximum _Assume that the output current I _max S is set to 160 [A].

The assumed maximum output current setting unit 25, when the assumed maximum output current I _max S that has been set is corrected by the correction unit 32 described later, sets the corrected value as the final assumed maximum output current I. _It is adopted as _max S.
The assumed discharge capacity setting unit 26 sets the assumed discharge capacity C _dis S. The assumed discharge capacity C _dis S is the assumed maximum output current I _max S (= 160 [A]) set by the assumed maximum output current setting unit 25, and the specified discharge period T _dis 0 (= 60 [sec]). ) Shows the electric capacity when the battery 11 is discharged. That is, the assumed discharge capacity setting unit 26 sets the assumed discharge capacity C _dis S using the following formula (1).

C _dis S = I _max S × T _dis 0 (1)
Therefore, in the present embodiment, the assumed discharge capacity setting unit 26 sets the assumed discharge capacity C _dis S as 9600 [As] (= 160 [A] × 60 [sec]).
The first required discharge period calculator 27A of the required discharge period calculator 27 calculates the first required discharge period T _nes 1. The first necessary discharge period T _nes 1 is a discharge current I _dis Nb (= 150 [A]) when the Nb-th discharge control is executed, and the assumed discharge capacity C _dis S (= 9600 [As]) from the battery 11. This is a period necessary to perform the discharge. That is, the first necessary discharge period calculation unit 27A sets the first necessary discharge period T _nes 1 using the following equation (2).

T _nes 1 = C _dis S ÷ I _dis Nb (2)
Therefore, in the present embodiment, the first necessary discharge period calculation unit 27A sets the first necessary discharge period T _nes 1 as 64 [sec] (= 9600 [As] / 150 [A]). Yes.
The second required discharge period calculation unit 27B of the required discharge period calculation unit 27 calculates the second required discharge period T _nes 2. The second required discharge period _{T nes} 2 is a discharge current _I dis Nc ₂ during execution of the discharge control of Nc ₂ round (Nc th) (100 [A]), assuming the discharge from the battery 11 capacity _{C dis} S (9600 [As]) is the period necessary to perform the discharge.

That is, the second necessary discharge period calculation unit 27B sets the second necessary discharge period T _nes 2 using the following formula (3).
T _nes 2 = C _dis S ÷ I _dis Nc ₂ (3)
Therefore, in the present embodiment, the second necessary discharge period calculation unit 27B sets the second necessary discharge period T _nes 2 as 96 [sec] (= 9600 [As] / 100 [A]). Yes.

The first corresponding voltage acquisition unit 28A of the corresponding voltage acquisition unit 28 acquires the first corresponding voltage Vc1. The first corresponding voltage Vc1 is obtained when the first required discharge period T _nes 1 (= 64 [sec]) calculated by the first required discharge period calculation unit 27A has elapsed during execution of the Nb-th discharge control. Corresponds to the terminal voltage _Ebatt of the battery 11.
The second corresponding voltage acquisition unit 28B of the corresponding voltage acquisition unit 28 acquires the second corresponding voltage Vc2. The second corresponding voltage Vc2 has passed the second required discharge period T _nes 2 (= 96 [sec]) calculated by the second required discharge period calculation unit 27B at the time of Nc _second discharge control execution. This corresponds to the terminal voltage _Ebatt of the battery 11 at the time.

The voltage characteristic estimation line setting unit 29 includes the first corresponding voltage Vc1 acquired by the first corresponding voltage acquisition unit 28A and the second corresponding voltage acquisition unit 28B on the voltage / current diagrams 33 shown in FIGS. The voltage characteristic estimation line Lvc of the battery 11 is set as a straight line passing through the second corresponding voltage Vc2 acquired by the above. The voltage-current diagram 33 is a blank two-dimensional diagram in which the vertical axis represents the terminal voltage _Ebatt of the battery 11 and the horizontal axis represents the discharge voltage _Idis of the battery 11.

In the voltage / current diagram 33, the maximum output current estimation unit 31 determines that the current (intersection current) I _{crs at} the intersection of the voltage characteristic estimation line Lvc and the limit discharge voltage E _lim of the battery 11 is the above-described assumed maximum output current. When it coincides with I _max S (= 160 [A]), the assumed maximum output current I _max S is estimated to be the maximum output current I _max of the battery 11 (see FIG. 5).

Correction unit 32, if the intersection current _{I crs} does not match the assumption maximum output current _{I max} S (see FIGS. 3 and 4), the assumption maximum output current _{I max} S set by the assumed maximum output current setting unit 25, Correction control for correcting between the Nb-th discharge current I _dis Nb (= 150 [A]) and the Na-th discharge current I _dis Na (= 200 [A]) is executed. The correction unit 32 repeatedly performs correction control on the voltage / current diagram 33 until the intersection current I _crs matches the assumed maximum output current I _max S.

Since the battery performance evaluation apparatus according to one embodiment of the present invention is configured as described above, the following operations and effects are achieved. In addition, a performance evaluation method for a chargeable / dischargeable battery according to an embodiment of the present invention will also be described here. Note that the flowchart of FIG. 6 and the time chart of FIG. 2 are mainly referred to.
As shown in the flowchart of FIG. 6, first, the user inputs a target DOD and a specified discharge period T _dis 0 via a keyboard (not shown) of the battery performance measuring device 12 (target discharge depth setting). Step; Step S11). Here, it is assumed that the target DOD is set to 90% (that is, the storage rate of the battery 11 is 10%), and the specified discharge period _Tdis 0 is set to 60 seconds.

Further, the discharge unit 22 sets the initial current value I _dis 0 (= 50 [A]) recorded in a memory (not shown) as the discharge current I _dis (step S12).
Thereafter, the discharge unit 22 executes the first discharge control (discharge step; step S13).
That is, in this step S13, the discharge unit 22 converts the discharge current I _dis into the first current value I _dis Nc1 (that is, the initial current value I _dis 0 = 50 [A]) in the first discharge control shown in FIG. The battery 11 is continuously discharged during the measured discharge period _Tdis 1 (= 120 [sec]). Further, when the discharge control by the discharge unit 22 is being performed, the battery voltage detection unit 21 records the detection result in the memory of the battery performance measurement device 12 as needed.

In the first discharge control, the terminal voltage E _batt of the battery 11 did not drop until the limit discharge voltage E _lim before the specified discharge period T _dis 0 (= 60 [sec]) passed. In the case (No route of step S14), the charging unit 23 executes the first charging control (step S15). That is, the charging unit 23 charges the power discharged from the battery 11 by executing the first discharge control.

Thereafter, when the charging unit 23 executes the charging control and the charging control is completed when the actual DOD of the battery 11 reaches the target DOD (= 90 [%]), the current setting unit 24 is executed next time. The discharge current I _dis in the discharge control is set as the second current value I _dis Nc2 (current setting step; step S16). At this time, the current setting unit 24 sets the second current value I _dis Nc2 as a value further increased by 50 [A] from the first current value I _dis Nc1, that is, 100 [A].

Then, the discharge unit 22 has the discharge current I _dis set as the second current value I _dis Nc2 (= 100 [A]) and the battery during the measured discharge period T _dis 1 (= 120 [sec]). 11 is discharged again (step S13). Further, when the discharge control by the discharge unit 22 is being performed, the battery voltage detection unit 21 records the detection result in the memory of the battery performance measurement device 12 as needed.

In this second discharge control, when the terminal voltage E _batt of the battery 11 does not drop until reaching the limit discharge voltage E _lim before the specified discharge period T _dis 0 (= 60 [sec]) elapses ( Again, the No route of step S14), the charging unit 23 executes the second charging control (step S15). At this time, the charging unit 23 charges the power discharged from the battery 11 by executing the second discharge control.

Thereafter, when the charge control is completed when the actual DOD of the battery 11 reaches the target DOD (= 90 [%]), the current setting unit 24 sets the discharge current I _dis in the discharge control executed for the third time to the third time. The current value I _dis Nb is set (step S16). At this time, the current setting unit 24 sets the third current value I _dis Nb as a value further increased by 50 [A] from the second current value I _dis Nc2, that is, 150 [A].

Then, the discharge unit 22 has the discharge current I _dis set as the third current value I _dis Nb (= 150 [A]) as the third (Nb) discharge, and the measured discharge period T _dis 1 (= 120 [sec]), the battery 11 is discharged (step S13). Further, when the discharge control by the discharge unit 22 is being performed, the battery voltage detection unit 21 records the detection result in the memory of the battery performance measurement device 12 as needed.

In this third discharge control, when the terminal voltage E _batt of the battery 11 does not drop until reaching the limit discharge voltage E _lim before the specified discharge period T _dis 0 (= 60 [sec]) elapses ( In step S14, the No route), the charging unit 23 executes the third charging control (step S15). At this time, the charging unit 23 charges the power discharged from the battery 11 by executing the third discharge control.

Thereafter, when the actual DOD of the battery 11 reaches the target DOD (= 90 [%]) and the charge control is completed, the current setting unit 24 sets the discharge current I _dis in the discharge control executed for the fourth time to the fourth time. The current value is set as I _dis Nc4 (step S16). At this time, the current setting unit 24 sets the fourth current value I _dis Nc4 as a value further increased by 50 [A] from the third current value I _dis Nb, that is, 200 [A].

Then, the discharge unit 22 has the discharge current I _dis set as the fourth current value I _dis Na (= 200 [A]) and the measured discharge period T _dis 1 (= 120 [sec]), the battery 11 is continuously discharged (step S13). Further, when the discharge control by the discharge unit 22 is being performed, the battery voltage detection unit 21 records the detection result in the memory of the battery performance measurement device 12 as needed.

In the fourth discharge control, before the specified discharge period _Tdis 0 (= 60 [sec]) elapses, the terminal voltage E _batt of the battery 11 drops until reaching the limit discharge voltage E _lim (FIG. 2 middle arrow A1 reference; yes route of step S14). At this time, the assumed maximum output current setting unit 25 performs the third current value I _dis Nb set by the current setting unit 24 at the time of the previous (Nb) discharge control and the current (Na) discharge control. The assumed maximum output current I _max S is set with the fourth current value I _dis Na set by the current setting unit 24 at the time of execution (assumed maximum output current setting step; step S17).

That is, as described above, the third current value I _dis Nb is 150 [A], and the fourth current value I _dis Na is 200 [A]. The output current I _max S is set as a value between 150 and 200 [A]. Here, it is assumed that the assumed maximum output current setting unit 25 sets the assumed maximum output current I _max S as 160 [A].

Thereafter, the assumed discharge capacity setting unit 26 sets the assumed discharge capacity C _dis S (assumed discharge capacity setting step; step S18). That is, in this step S18, the assumed discharge capacity setting unit 26 uses the assumed maximum output current I _max S (= 160 [A]) set in step S17 and the specified discharge period T _dis 0 (= 60 [sec]). ), The electric capacity when discharging from the battery 11, that is, the assumed discharge capacity C _dis S is calculated. That is, in this step S18, the assumed discharge capacity setting unit 26 sets the assumed discharge capacity C _dis S as 9600 [As] (= 160 [A] × 60 [sec]) using the above-described equation (1). .

Thereafter, the first necessary discharge period calculation unit 27A calculates the first necessary discharge period T _nes 1 (necessary discharge period calculation step; first necessary discharge period calculation step; step S19). That is, in this step S19, the first required discharge period calculation unit 27A uses the above-described equation (2) to perform the discharge current I _dis Nb (= 150 [A] when the third (Nb) discharge control is performed. ]), A period necessary for discharging the assumed discharge capacity C _dis S (= 9600 [As]) from the battery 11, that is, a first necessary discharge period T _nes 1 is calculated. In step S19, the first necessary discharge period calculation unit 27A sets the first necessary discharge period T _nes 1 as 64 [sec] (= 9600 [As] / 150 [A]).

Further, the second necessary discharge period calculation unit 27B calculates the second necessary discharge period T _nes 2 (necessary discharge period calculation step; second necessary discharge period calculation step; step S19). That is, in this step S19, the second required discharge period calculation unit 27B uses the above-described equation (3) to perform the discharge current I _dis Nc2 (= 100 [A] when the second (Nc second) discharge control is executed. ]), A period necessary for discharging the assumed discharge capacity C _dis S (= 9600 [As]) from the battery 11, that is, a second necessary discharge period T _nes 2 is calculated. In step S19, the second required discharge period calculation unit 27B sets the second required discharge period T _nes 2 as 96 [sec] (= 9600 [As] / 100 [A]).

That is, as indicated by hatching in FIG. 2, the region of the assumed discharge capacity C _{dis S} in the third discharge, the area of the assumed discharge capacity C _{dis S} in the second discharge are both areas are equal.
Thereafter, the first corresponding voltage acquisition unit 28A acquires the first corresponding voltage Vc1 (corresponding voltage acquisition step; first corresponding voltage acquisition step; step S20). That is, in this step S20, the first corresponding voltage acquisition unit 28A performs the above-described first required discharge period T _nes calculated by the first required discharge period calculation unit 27A when the third (Nb) discharge control is executed. The terminal voltage _Ebatt of the battery 11 when 1 (= 64 [sec]) has elapsed, that is, the first corresponding voltage Vc1 is read from a memory (not shown).

Further, the second corresponding voltage acquisition unit 28B acquires the second corresponding voltage Vc2 (corresponding voltage acquisition step; second corresponding voltage acquisition step; step S20). That is, in this step S20, the second corresponding voltage acquisition unit 28B performs the second required discharge period T _nes calculated by the second required discharge period calculation unit 27B at the time of executing the third (Nb) discharge control. The terminal voltage E _batt of the battery 11 when 2 (= 96 [sec]) has elapsed, that is, the second corresponding voltage Vc2 is read from a memory (not shown).

Thereafter, the voltage characteristic estimation line setting unit 29 shows a straight line passing through the first corresponding voltage Vc1 and the second corresponding voltage Vc2 obtained in step 20 on the voltage / current diagram 33 (see FIGS. 3 to 5). It is set as the voltage characteristic estimation line Lvc of the battery 11 (voltage characteristic estimation line setting step; step S21).
Then, the maximum output current estimation unit 31 sets a current (intersection current) I _crs at the intersection of the voltage characteristic estimation line Lvc and the limit discharge voltage E _lim of the battery 11 on the voltage / current diagram 33 (step S22). ).

When the intersection current I _crs set in step S22 matches the assumed maximum output current I _max S (= 160 [A]) set in step S17 (FIG. 5). Reference: Yes route of step S23), this assumed maximum output current I _max S is estimated to be the maximum output current I _max of the battery 11 (step S24). That is, here, the maximum output current estimation unit 31 estimates that the maximum output current I _max of the battery 11 is 160 [A].

On the other hand, when the intersection current I _crs does not match the assumed maximum output current I _max S (No route of step S23), that is, the intersection current I _crs overshoots the assumed maximum output current I _max S. Or when the assumed maximum output current I _max S is undershooted (see FIG. 4), the correction unit 32 causes the assumed maximum output current I _max S (= 160 [A]). ) _Is corrected between the third (Nb) discharge current I _dis Nb (= 150 [A]) and the fourth (Na) discharge current I _dis Na (= 200 [A]). Control is executed (correction step; step S25).

Then, when the correction control is executed by the correction unit 32, then, in step S18, the assumed discharge capacity setting unit 26 is corrected by the correction unit 32 as the assumed maximum output current I _max S in the above equation (1). Further, the post-correction value is employed to calculate the assumed discharge capacity C _dis S.
Then, the control in steps S18 to S22 and S25 is repeatedly executed until the intersection current I _crs and the assumed maximum output current I _max S match.

As described above, according to the battery performance evaluation apparatus and the battery maximum output characteristic evaluation method according to the embodiment of the present invention, it is defined by the assumed maximum output current I _max S (= 160 [A]). An assumed discharge capacity C _dis S (= 9600 [As] = 160 × 60), which is a discharge capacity when discharging from the battery 11 during the discharge period T _dis 0 (= 60 [sec]), is set. It has become.

Further, the measured discharge period T _dis 1 in the discharge control for the battery 11 is set to 120 seconds, and the discharge current I _{dis is changed} to the second current value I _dis Nc2 (= 100 [A]), 3 every time the discharge control is executed. The current value I _dis Nb (= 150 [A]) and the fourth current value I _dis Na (= 200 [A]) are increased stepwise.
Further, in any discharge control, the assumed discharge capacity C _dis S is controlled to be constant.

Further, a first necessary discharge period T _nes 1 (= 9600 ÷ 150 = 64 [sec]) and a second necessary period T _nes 2 necessary for discharging the assumed discharge capacity C _dis S (= 9600 [As]). (= 9600 ÷ 100 = 96 [sec]) is calculated.
Further, the terminal voltage E _batt of the battery 11 when the first necessary discharge period T _nes 1 (= 64 [sec]) has elapsed is acquired as the first corresponding voltage Vc1, and the second necessary discharge period T _nes 2 (= The terminal voltage _Ebatt of the battery 11 when 96 [sec]) has elapsed is acquired as the second corresponding voltage Vc2.

The maximum output current I _max of the battery 11 is estimated based on the first corresponding voltage Vc1 and the second corresponding voltage Vc2.
Thereby, the performance of the battery 11 which can be charged / discharged can be evaluated rapidly and correctly.
Moreover, since the frequency | count of repeating charging / discharging when evaluating the battery 11 can be reduced significantly compared with the past, degradation of the battery 11 which is an evaluation object can also be disregarded effectively.

Further, a voltage characteristic estimation line Lvc of the battery 11 is set on the voltage / current diagram 33 based on the first corresponding voltage Vc1 and the second corresponding voltage Vc2.
Then, on this voltage / current diagram 33, the intersection of the limit discharge voltage _{E lim} voltage characteristic estimation line Lvc and the battery 11, i.e., the intersection point current _{I crs} is, to match the assumed maximum output current _{I max} S, this assumptions maximum output current _{I max} S is adapted to estimate that the said maximum output current _{I max} of the battery 11.

Thus, by setting the voltage characteristic estimation line Lvc, it is possible to accurately estimate the maximum output current I _max of the battery 11 used in the electric vehicle.
The voltage E _batt of the battery 11, the discharge control times reaches a limit discharge voltage E _lim and discharge control of the 'Na th', the discharge control of the discharge control of the previous round of Na th 'Nb th' Further, the discharge control before the Nb-th time is referred to as “Nc second time (Nc time)” discharge control.

A value between the discharge current I _dis Nb at the time of executing the Nb-th discharge control and the discharge current I _dis Na at the time of executing the Na-th discharge control, that is, a value between 150 to 200 [A], An assumed maximum output current I _max S is set.
Further, a period necessary for discharging the assumed discharge capacity C _dis S (= 9600 [As]) from the battery 11 with the discharge current I _dis Nb (= 150 [A]) at the time of executing the Nb-th discharge control is set. The first required discharge period T _nes 1 (= 64 [sec] = 9600 ÷ 150) is calculated.

Further, a period necessary for discharging the assumed discharge capacity C _dis S (= 9600 [As]) from the battery 11 with the discharge current I _dis Nc (= 100 [A]) at the time of executing the Nc-th discharge control is set. The calculation is performed as the second necessary discharge period T _nes 2 (= 96 [sec] = 9600 ÷ 100).
Further, the voltage E _batt of the battery 11 when the first necessary discharge period T _nes 1 (= 64 [sec]) has elapsed during execution of the Nb-th discharge control is acquired as the first corresponding voltage Vc1. Yes.

Further, the voltage E _batt of the battery 11 when the second necessary discharge period T _nes 2 (= 96 [sec]) has elapsed during the Nc-th discharge control execution is acquired as the second corresponding voltage Vc2. ing.
Further, the voltage characteristic estimation line Lvc of the battery 11 is set on the voltage / current diagram 33 based on the first corresponding voltage Vc1 and the second corresponding voltage Vc2.

This makes it possible to accurately set the voltage characteristic estimation line and accurately estimate the maximum output current of the electric vehicle battery.
Also, if the intersection current _{I crs} does not match the assumption maximum output current _{I max} S, assumptions maximum output current _{I max} S of the battery 11 Nb th discharge current _{I dis Nb (= 150 [A} ]) and Na th Correction is made between the discharge current I _dis Na (= 200 [A]).

Then, it is assumed that the battery 11 has been discharged during the specified discharge period T _dis 0 (= 60 [sec]) with the corrected assumed maximum output current I _max S, and the above-described assumed discharge capacity C _dis S is set. It is like that.
In this way, by correcting the assumed maximum output current I _max S within a predetermined range of 150 to 200 [A], the maximum output current I _max of the battery 11 can be estimated without trouble and with high accuracy.

Here, the concept of the present invention will be described again.
As shown in FIG. 7, while increasing the discharge current I _dis stepwise, is performed repeatedly charged and discharged in a pulse form, either, that the discharge current I _dis reaches the maximum output current I _max of the electric vehicle battery Become.
The inventor of the present invention paid attention to the discharge capacity (see symbol C _dis 4 in FIG. 7) in the discharge control performed when the discharge current I _dis reached the maximum output current I _max of the battery.

When charging / discharging is repeatedly performed in a pulse shape, any discharge amount (C _dis 1, C _dis 2, C _dis 3 in FIG. 7) is any charge amount (C _cha 1, C in FIG. 7). _cha 2, C _cha 3) also has an electric capacity (current × discharge period) of discharge capacity C in the discharge control performed when the discharge current I _dis has reached the maximum output current I _max of the battery for electric vehicles. _It was set to be equal to _dis4 . That is, the discharge was repeated while keeping the discharge capacity constant and increasing the discharge current _Idis stepwise.

Then, as shown in FIG. 8, it has been found that the battery output characteristic when the discharge current I _dis is increased stepwise while keeping the discharge capacity constant can be expressed as a substantially straight line (FIG. 8). (Refer to black diamond and chain line in 8).
Further, the battery output characteristics (black circles and solid lines in FIG. 8) measured when the discharge current I _dis is increased stepwise while keeping the discharge period constant (for example, 60 seconds), the above-described black diamonds and Comparing with the chain line, in both cases, when repeated discharge is performed, the discharge current I _dis when the battery terminal voltage E reaches the limit discharge voltage E _lim , that is, the maximum output current I _max is the same. .

That is, as shown in FIG. 8, according to the performance evaluation apparatus and method for a chargeable / dischargeable battery of the present invention, the performance of the chargeable / dischargeable battery can be evaluated quickly and accurately.
Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and various modifications can be made without departing from the spirit of the present invention. An example is shown below.

In the above-described embodiment, the case where the battery 11 is configured by connecting a plurality of lithium ion batteries in series has been described as an example. However, the present invention is not limited to this. For example, a single lithium ion battery may be connected to the battery performance measuring device 12 and the performance of the lithium ion battery may be measured.
Further, there is no particular limitation as long as it is a chargeable / dischargeable battery (so-called secondary battery) such as a nickel metal hydride battery, nickel cadmium battery, nickel iron battery, nickel zinc battery, silver zinc oxide battery, etc. .

Moreover, in the above-mentioned embodiment, although demonstrated that the battery 11 was used for an electric vehicle, it is not limited to this. For example, it may be a battery used for a hybrid electric vehicle, or a battery used for a railway vehicle, an aircraft, a ship, and the like.
Moreover, the battery used for the apparatus (for example, electric tool etc.) for which a comparatively high output current with respect to electrical storage capacity is requested | required to continue over a certain period (for example, 10 second) may be sufficient.

In the above-described embodiment, it is assumed that the specified discharge period T _dis 0 set by the user is 60 seconds, and the measured discharge period T _dis1 set by the discharge unit 22 is 120 seconds. However, the present invention is not limited to this. The specified discharge period _Tdis0 is determined on the basis of how long the situation in which the battery 11 must output a large current continues. Should be set. Moreover, if the measured discharge period _Tdis1 is set as a period longer than the specified discharge period _Tdis0 , it is not necessarily required to be 120 seconds.

Further, in the above-described embodiment, specific numbers have been illustrated and described. However, it is not necessary to understand the present invention by limiting to these numbers, and these numbers are within the scope of the present invention. It is possible to change.
Moreover, in the above-mentioned embodiment, although the case where the performance evaluation of the battery 11 single-piece | unit was demonstrated, it does not limit to this. For example, the performance evaluation of the entire battery unit (not shown) having a plurality of batteries 11 may be performed.

Although not particularly described in the above embodiment, the battery 11 generates heat when discharge control or charge control is performed. For this reason, after the charge / discharge control after the discharge control is completed, the next discharge control may be executed after the temperature of the battery 11 is stabilized by being left for a predetermined time.
In addition, when such leaving is not performed or when the leaving time is shortened, correction control corresponding to the temperature of the battery 11 may be executed.

It is a typical block diagram which shows the whole structure of the performance evaluation apparatus of the chargeable / dischargeable battery which concerns on one Embodiment of this invention. It is a typical time chart which shows the procedure of the operation | movement of the performance evaluation apparatus of the battery which can be charged / discharged concerning one Embodiment of this invention, and the performance evaluation method of the battery which can be charged / discharged. It is a schematic diagram which shows the voltage / current diagram used for the performance evaluation apparatus and method of the battery which can be charged / discharged which concerns on one Embodiment of this invention, Comprising: The case where a voltage drop prediction line overshoots is shown. It is a schematic diagram which shows the voltage / current diagram used for the performance evaluation apparatus and method of the battery which can be charged / discharged based on one Embodiment of this invention, Comprising: The case where a voltage drop prediction line undershoots is shown. FIG. 4 is a schematic diagram showing a voltage / current diagram used in the apparatus and method for evaluating the performance of a chargeable / dischargeable battery according to an embodiment of the present invention, and showing a case where an expected voltage drop line intersects an assumed maximum output current. . It is a typical flowchart which shows the procedure of the operation | movement of the performance evaluation apparatus of the battery which can be charged / discharged based on one Embodiment of this invention, and the performance evaluation method of the battery which can be charged / discharged. It is a typical time chart which shows the development concept of operation | movement of the performance evaluation apparatus of the battery which can be charged / discharged concerning one Embodiment of this invention, and the performance evaluation method of the battery which can be charged / discharged. It is a typical graph which shows the voltage / current characteristic of the battery at the time of performing evaluation corresponding to the time chart of FIG. It is a typical graph which shows the difference between the estimated value in the case of evaluating a battery by background art, and an actual measurement value.

Explanation of symbols

11 Battery 21 Battery voltage detection part (battery voltage detection means)
22 Discharge part (discharge means)
23 Charging part (charging means)
24 Current setting section (current setting means)
25 Assumed maximum output current setting section (assumed maximum output current setting means)
26 Assumed discharge capacity setting section (assumed discharge capacity setting means)
27 Required discharge period calculation unit (Required discharge period calculation means)
27A 1st required discharge period calculating part (1st required discharge period calculating means)
27B 2nd required discharge period calculating part (2nd required discharge period calculating means)
28 Corresponding voltage acquisition unit (corresponding voltage acquisition means)
28A 1st corresponding voltage acquisition part (1st corresponding voltage acquisition means)
28B 2nd corresponding voltage acquisition part (2nd corresponding voltage acquisition means)
29 Voltage characteristic estimation line setting unit (voltage characteristic estimation line setting means)
31 Maximum output current estimation unit (maximum output current estimation means)
33 Voltage / Current Diagram C _dis S _Assumed Discharge Capacity E _Batt Battery Terminal Voltage (Battery Voltage)
E _lim limit discharge voltage I _dis discharge current I _dis Na discharge current in Na Na discharge control I _dis Nb discharge current in Nb discharge control I _dis Nc discharge current in Nc discharge control I _crs intersection current I _max maximum output Current I _max S Assumed maximum output current Lvc Voltage characteristic estimation line T _dis 0 Normal discharge period T _nes 1 First required discharge period T _nes 2 Second required discharge period Vc 1 First corresponding voltage Vc 2 Second corresponding voltage

Claims (8)

A battery performance evaluation device capable of charging and discharging,
Voltage detecting means for detecting the voltage of the battery;
An assumed maximum output current setting means for setting an assumed value of the maximum output current of the battery as an assumed maximum output current;
An assumed discharge capacity setting means for setting an assumed discharge capacity, which is a discharge capacity when discharging from the battery during a predetermined specified discharge period with the assumed maximum output current set by the assumed maximum output current setting means;
Discharge means for repeatedly executing discharge control for discharging the battery while keeping the assumed discharge capacity set by the assumed discharge capacity setting means constant;
Current setting means for gradually increasing the discharge current each time the discharge control is executed by the discharge means;
Charging means for performing charge control for charging the battery so that the discharge depth of the battery becomes a target discharge depth every time the discharge control by the discharge means is completed;
Required discharge period calculating means for calculating a period necessary for discharging the assumed discharge capacity set by the assumed discharge capacity setting means as a required discharge period;
Corresponding voltage acquisition means for acquiring the voltage of the battery when the required discharge period calculated by the required discharge period calculation means has elapsed, as a corresponding voltage;
A performance evaluation apparatus for a chargeable / dischargeable battery, comprising: maximum output current estimating means for estimating the maximum output current of the battery based on the corresponding voltage set by the corresponding voltage acquisition means. A voltage / current diagram in which the voltage of the battery is defined on one axis and the discharge current of the battery is defined on the other axis;
Voltage characteristic estimation line setting means for setting a voltage characteristic estimation line of the battery on the voltage / current diagram based on the corresponding voltage acquired by the corresponding voltage acquisition means,
The maximum output current estimating means includes:
On the voltage / current diagram, the intersection current at the intersection of the voltage characteristic estimation line set by the voltage characteristic estimation line setting means and the limit discharge voltage of the battery is set by the assumed maximum output current setting means. The apparatus for evaluating the performance of a chargeable / dischargeable battery according to claim 1, wherein when it matches the assumed maximum output current, the assumed maximum output current is estimated to be the maximum output current of the battery. The discharge control at the time when the battery voltage detected by the voltage detection means reaches the limit discharge voltage is the discharge control for the Nath time, and the discharge control before the Nath time is the Nbth discharge control. And the discharge control before the Nb-th time is the Nc-th discharge control,
The assumed maximum output current setting means is:
The Nb-th discharge current set by the current setting means when the Nb-th discharge control is executed, and the Na-th time set by the current-setting means when the Na-th discharge control is executed. Set the assumed maximum output current between the discharge current and
The necessary discharge period calculation means includes:
A first time required to calculate the period required for discharging the assumed discharge capacity set by the assumed discharge capacity setting means from the battery with the discharge current at the time of execution of the Nb-th discharge control is calculated as a first required discharge period. 1 required discharge period calculation means;
A second period is calculated as a second required discharge period, which is a period required for discharging the assumed discharge capacity set by the assumed discharge capacity setting means from the battery with a discharge current at the time of execution of the Nc-th discharge control. 2 required discharge period calculation means,
The corresponding voltage acquisition means is
When the Nb-th discharge control is executed, a first response for acquiring the voltage of the battery as the first corresponding voltage when the first required discharge period calculated by the first required discharge period calculation means has elapsed. Voltage acquisition means;
A second response for acquiring the voltage of the battery as the second corresponding voltage when the second required discharge period calculated by the second required discharge period calculation means has elapsed during the Nc-th discharge control execution. Voltage acquisition means,
The voltage characteristic estimation line setting means includes:
Estimating voltage characteristics of the battery through a straight line passing through the point indicating the first corresponding voltage acquired by the first corresponding voltage acquisition unit and the point indicating the second corresponding voltage acquired by the second corresponding voltage acquisition unit The charge / dischargeable battery performance evaluation apparatus according to claim 2, wherein the battery performance evaluation apparatus is set as a line. If the intersection current does not match the assumed maximum output current, the assumed maximum output current of the battery set by the assumed maximum output current setting means is calculated between the Nbth discharge current and the Nath discharge current. With correction means to correct with
The assumed discharge capacity setting means sets the assumed discharge capacity on the assumption that the specified discharge period is discharged from the battery with the assumed maximum output current corrected by the correction means. The battery performance evaluation apparatus according to 2 or 3, wherein the battery can be charged and discharged. A method for evaluating the performance of a chargeable / dischargeable battery,
A target discharge depth setting step for setting a target discharge depth of the battery;
An assumed maximum output current setting step for setting an assumed value of the maximum output current of the battery as an assumed maximum output current;
A hypothetical discharge capacity setting step for setting a hypothetical discharge capacity, which is a discharge capacity when discharging from the battery for a predetermined specified discharge period at the hypothetical maximum output current set in the hypothetical maximum output current setting step;
A discharge step for repeatedly executing discharge control for discharging the battery while keeping the assumed discharge capacity set in the assumed discharge capacity setting step constant;
A current setting step for gradually increasing the discharge current each time the discharge control is executed in the discharge step;
A charge step for performing charge control for charging the battery so that the discharge depth of the battery becomes the target discharge depth set in the target discharge depth setting step each time the discharge control is completed in the discharge step;
A required discharge period calculating step for calculating a period necessary for discharging the assumed discharge capacity set by the assumed discharge capacity setting step as a required discharge period;
A corresponding voltage acquisition step for acquiring the voltage of the battery as a corresponding voltage when the required discharge period calculated by the required discharge period calculation step;
And a maximum output current estimating step of estimating the maximum output current of the battery based on the corresponding voltage set by the corresponding voltage acquisition step. Based on the corresponding voltage acquired by the corresponding voltage acquisition step, the battery is on a voltage / current diagram in which the voltage of the battery is defined on one axis and the discharge current of the battery is defined on the other axis. A voltage characteristic estimation line setting step for setting the voltage characteristic estimation line of
The maximum output current estimation step includes:
On the voltage / current diagram, the intersection current at the intersection of the voltage characteristic estimation line set in the voltage characteristic estimation line setting step and the limit discharge voltage of the battery is set in the assumed maximum output current setting step. 6. The method for evaluating the performance of a chargeable / dischargeable battery according to claim 5, wherein when the assumed maximum output current is matched, the assumed maximum output current is estimated to be the maximum output current of the battery. The discharge control when the battery voltage reaches the limit discharge voltage is the Na-th discharge control, the discharge control before the Na-th is the Nb-th discharge control, and the Nb-th discharge control is further performed. The earlier discharge control is the Nc-th discharge control,
The assumed maximum output current setting step includes:
The Nb-th discharge current set by the current setting step when the Nb-th discharge control is executed, and the Na-th time set by the current-setting step when the Na-th discharge control is executed. Set the assumed maximum output current between the discharge current and
The necessary discharge period calculating step includes:
A period required to discharge the assumed discharge capacity set by the assumed discharge capacity setting step from the battery with a discharge current at the time of execution of the Nb-th discharge control is calculated as a first required discharge period. 1 required discharge period calculation step;
A second period is calculated as a second required discharge period, which is a period required to discharge the assumed discharge capacity set by the assumed discharge capacity setting step from the battery with a discharge current at the time of execution of the Nc-th discharge control. 2 necessary discharge period calculation step,
The corresponding voltage acquisition step includes:
When the Nb-th discharge control is executed, a first response for acquiring, as the first corresponding voltage, the voltage of the battery when the first required discharge period calculated in the first required discharge period calculation step has elapsed. A voltage acquisition step;
A second response for acquiring the voltage of the battery as the second corresponding voltage when the second required discharge period calculated in the second required discharge period calculation step has elapsed during the Nc-th discharge control execution. A voltage acquisition step,
The voltage characteristic estimation line setting step includes:
Estimating the voltage characteristic of the battery using a straight line passing through the point indicating the first corresponding voltage acquired in the first corresponding voltage acquisition step and the point indicating the second corresponding voltage acquired in the second corresponding voltage acquisition step The method for evaluating the performance of a chargeable / dischargeable battery according to claim 6, wherein the method is set as a line. If the intersection current does not match the assumed maximum output current, the assumed maximum output current of the battery set by the assumed maximum output current setting step is set between the Nbth discharge current and the Nath discharge current. With a correction step to correct with
The assumed discharge capacity setting step sets the assumed discharge capacity on the assumption that the specified discharge period is discharged from the battery with the assumed maximum output current corrected in the correction step. The method for evaluating the performance of a chargeable / dischargeable battery according to 6 or 7.

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