WO2013128757A1

WO2013128757A1 - Battery-state control method and device

Info

Publication number: WO2013128757A1
Application number: PCT/JP2012/082198
Authority: WO
Inventors: 田中　克典
Original assignee: 株式会社豊田自動織機
Priority date: 2012-03-01
Filing date: 2012-12-12
Publication date: 2013-09-06
Also published as: JP2013182779A

Abstract

If the SOC of a battery has reached a prescribed ceiling, said SOC being estimated on the basis of the OCV of the battery and/or an integrated current, the use of said battery is controlled on the basis of a pseudo-SOC estimation performed by using CCV in place of OCV with information indicating the OCV-SOC relationship.

Description

Battery state control method and apparatus

The present invention relates to a battery state control method and apparatus for controlling battery use.

For example, in a power supply system of a hybrid vehicle, electric power stored in a secondary battery (hereinafter simply referred to as a battery) is used as a drive power source for a vehicle driving force motor. The battery is charged by the generated power when the electric motor generates regenerative power or the generated power of the generator that generates power as the engine rotates. In such a system, the remaining capacity (SOC: State 使用 of Charge) with respect to the full charge of the battery is estimated in order to prevent the battery from being severely used so as to cause deterioration of the battery, and based on the estimated SOC. The battery state is controlled. Specifically, based on the estimated SOC, output restriction of an electric motor that obtains output from the battery, generation of a battery charge request or charge / discharge prohibition command, and the like are performed.

As a conventional method for estimating the SOC, the following cited reference 1 includes a method for estimating the SOC based on the open circuit voltage (OCV) of the battery, and an SOC based on the accumulated current value of the battery. The method of estimating is mentioned. Patent Document 2 listed below includes a method of estimating the SOC of the battery based on the OCV of the battery and correcting the estimated SOC based on the integrated current value.

JP 2000-150003 A JP 2000-306613 A

In the conventional method as described above, various measures are taken to improve the estimation accuracy, but the SOC cannot still be estimated with 100% accuracy. For this reason, the battery state control is performed on the assumption that the estimated SOC includes an error. For example, if it is considered that the estimation error is about ± 10%, it is originally intended to use the battery in the range of 0% to 100%, but in the range of about 20% to 80% in consideration of safety. I am trying to use batteries. If this safety width is increased, the range of use is further narrowed. That is, in the conventional method, the battery cannot be effectively utilized in order to avoid the occurrence of overcharge and overdischarge of the battery.

The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a battery state control method capable of more effectively utilizing the battery while avoiding the occurrence of overcharge and overdischarge of the battery. And providing an apparatus.

According to the battery state control method of the present invention, the SOC is estimated based on at least one of the battery OCV and the current integrated value, and when the SOC reaches an upper limit value or a lower limit value within a predetermined range, the OCV and the SOC are determined. For the information indicating the relationship, the pseudo SOC is estimated by using CCV instead of the OCV, and the use of the battery is controlled based on the pseudo SOC estimation.

In addition, the battery state control device according to the present invention estimates the SOC based on at least one of the battery OCV and the current integrated value, and when the SOC reaches an upper limit value or a lower limit value within a predetermined range, A control device body is provided that performs pseudo SOC estimation by using CCV instead of OCV for information indicating the relationship between the SOC and the SOC, and controls the use of the battery based on the pseudo SOC estimation. .

According to the battery state control method and apparatus of the present invention, when the SOC reaches the upper limit value or the lower limit value of the predetermined range, CCV is used instead of OCV for information indicating the relationship between OCV and SOC. Thus, the pseudo SOC is estimated, and the use of the battery is controlled based on the pseudo SOC estimation. Therefore, the battery can be used more effectively while avoiding the occurrence of overcharge and overdischarge of the battery.

It is a block diagram which shows the battery state control apparatus for enforcing the battery state control method by Embodiment 1 of this invention. It is a flowchart which shows the battery state control operation which a control apparatus main body performs, when the battery of FIG. 1 is discharged. It is a flowchart which shows the battery state control operation which a control apparatus main body performs when the battery of FIG. 1 is charged.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a battery state control apparatus for carrying out a battery state control method according to Embodiment 1 of the present invention. In the figure, for example, a vehicle 1 such as a hybrid vehicle or an electric vehicle is equipped with at least one battery 10, a switching means 11, an in-vehicle device 12, and a control device main body 13.

The battery 10 is composed of an assembled battery in which a plurality of battery cells (for example, lithium ion batteries) are connected in series and / or in parallel. The battery 10 is connected to the in-vehicle device 12 via the switching means 11.

The switching means 11 is constituted by a relay or the like, for example, and is opened and closed according to a control command from the control device body 13. The battery 10 is electrically connected to the in-vehicle device 12 by closing the switching means 11, and the battery 10 is disconnected from the in-vehicle device 12 by opening the switching means 11.

The in-vehicle device 12 includes a power consuming device 12a, a power generating device 12b, and a charger 12c. The power consuming device 12 a is configured by, for example, a driving motor for the vehicle 1 and consumes the power of the battery 10. The power generation device 12 b is configured by, for example, a regenerative generator or an alternator that generates power during regenerative braking of the vehicle 1, and supplies power to the battery 10. The charger 12 c receives AC power from an external power source 2 such as a charging stand, converts it into DC power, and supplies it to the battery 10. The battery 10 is discharged according to the operation of the power consuming device 12a and charged according to the operations of the power generation device 12b and the charger 12c. The operations of the power consuming device 12a, the power generating device 12b, and the charger 12c are controlled in accordance with a control command from the control device body 13.

The control device body 13 is constituted by, for example, a computer that operates in accordance with a predetermined program, and constitutes the battery state control device of the present embodiment. As is well known, the control device main body 13 determines the remaining capacity (SOC: State) with respect to the full charge of the battery 10 based on at least one of the open voltage (OCV: Open Circuit Voltage) (V) and the current integrated value (A). of Charge) (%) is estimated.

In the control device main body 13, an SOC range is set in advance so as not to be in a severe use state that causes deterioration of the battery 10. When the SOC is within this range, the use of the battery 10 is controlled based on the SOC estimated as described above. Specifically, based on the SOC, the output of the electric motor that obtains the output from the battery, the request for charging the battery, or the generation of a charge / discharge prohibition command are performed. Such control based on the SOC estimated based on at least one of the OCV and the current integrated value is referred to as normal control. The SOC range is set to about 20% to 80%. Even if it is originally desired to use the battery 10 in the range of 0% to 100%, the range is as described above in consideration of the estimation error included in the SOC based on at least one of the OCV and the current integrated value. .

Here, as a voltage index of the battery 10, there is a closed circuit voltage (CCV) (V) that can be expressed by the following equation (1) in addition to the OCV as described above. Here, I is the charge / discharge current (A), and R is the internal resistance (Ω).
CCV = OCV + I × R (1)

When the battery 10 is discharged, since I becomes a negative value, the CCV is always smaller than the OCV. That is, if CCV is used instead of OCV for information indicating the relationship between OCV and SOC, such as a table or a function expression indicating the relationship between OCV and SOC, SOC based on CCV (hereinafter referred to as pseudo SOC and Is always lower than the SOC based on the OCV when the battery 10 is discharged. In addition, when the battery 10 is charged, since I is a positive value, the CCV is always larger than the OCV. That is, the pseudo SOC is always higher than the SOC based on the OCV when the battery 10 is charged.

Therefore, by performing a pseudo estimation of the SOC using the CCV and controlling the use of the battery based on the pseudo estimation of the SOC, for example, the lower limit value at the time of discharging is set to 0% and at the time of charging. Even if the upper limit value and lower limit value are set such that the upper limit value is set to 100% so that it is within the range of use of the battery 10 that is originally intended to be used, it is always safe when converted to the SOC based on the OCV. become.

The control device main body 13 determines that the SOC estimated based on at least one of the OCV and the current integrated value is an upper limit value (for example, 80%, etc .; hereinafter, this upper limit value is referred to as a first upper limit value) or a lower limit value ( For example, when the lower limit value is hereinafter referred to as the first lower limit value), pseudo SOC is obtained by using CCV instead of OCV for information indicating the relationship between OCV and SOC. And the use of the battery is controlled based on this pseudo SOC estimation.

The operating SOC at the time of discharge falls in accordance with the discharge of the battery 10.
When the battery 10 is discharged, the control device body 13 starts the estimation of the pseudo SOC, and then the SOC based on the OCV is a second lower limit value (for example, 0%) that is smaller than the first lower limit value (for example, 20%). ) Is determined to determine whether the CCV is greater than the lower limit voltage of the OCV, and when it is determined that the CCV is not greater than the lower limit voltage, the switching means 11 is opened, Discontinue use. That is, when it is determined that the pseudo SOC is not in a state larger than the second lower limit value, the control device body 13 stops using the battery 10. When it is determined that the CCV is not in a state greater than the lower limit voltage (a state in which the pseudo SOC is greater than the second lower limit value), the use of the battery 10 is stopped when the battery 10 is used beyond this state. This is because the possibility of overdischarge of the battery 10 is increased.

On the other hand, if the control device body 13 determines that the CCV is greater than the lower limit voltage, the control device body 13 continues to use the battery 10. This is because it is considered that a safe value remains when converted to the SOC based on the OCV. Thereby, compared with the case where the battery 10 is used only up to the first lower limit value using the SOC based on the OCV, more energy stored in the battery can be used, and the battery can be used more effectively. When the first lower limit value is set to 20% or the like in consideration of the estimation error, the second lower limit value is set to 0% or the like that is the lower limit of the range that is originally desired to be used. The lower limit voltage of the OCV estimated to be 0% based on the OCV is, for example, 3V.

Further, the control device body 13 determines whether or not the CCV is equal to the lower limit voltage after starting the pseudo SOC estimation and before determining whether or not the CCV is larger than the lower limit voltage. If it is determined that the CCV is equal to the lower limit voltage, it is determined whether the CCV is greater than the lower limit voltage after limiting the discharge of the battery. Limiting the discharge of the battery is to suppress the operation of the power consuming device 12a, for example, by reducing the rotational speed of the driving motor.

When the discharge of the battery is limited, the absolute value of I in the above formula (1) becomes small, so the CCV is usually high. As described above, when the discharge of the battery is limited when the CCV is equal to the lower limit voltage, the CCV is expected to be larger than the lower limit voltage. For this reason, after limiting the discharge of the battery, even if it is determined whether the CCV is larger than the lower limit voltage, a positive determination result is obtained, and the use of the battery 10 can be continued as much as possible. Battery energy can be utilized more.

On the other hand, if the CCV does not become larger than the lower limit voltage even if the discharge of the battery is restricted, the control device body 13 opens the switching means 11 and stops using the battery 10. This is because it is considered that the battery energy can be sufficiently utilized within a range in which overdischarge does not occur.

Further, when the battery 10 is discharged, the control device body 13 determines whether or not the CCV is larger than the lower limit voltage before starting the estimation of the pseudo SOC, and the CCV is lower than the lower limit voltage. When it is determined that the state is not greater than the lower limit voltage, it is determined again whether the CCV is greater than the lower limit voltage after limiting the discharge of the battery, and it is determined again that the CCV is not greater than the lower limit voltage. In such a case, the use of the battery 10 is stopped. In this case, since the battery 10 is in a state close to overdischarge, it is difficult to further use the energy of the battery 10 while preventing overdischarge even if pseudo SOC estimation is performed.

Since the SOC is lowered during operation discharge during charging, the CCV is compared with a predetermined lower limit value. However, since the SOC is increased during charging, the CCV is compared with a predetermined upper limit value. .
That is, when the battery 10 is discharged, the control device main body 13 starts a pseudo SOC estimation, and then the SOC based on the OCV has a second upper limit value (for example, 80%) greater than the first upper limit value (for example, 80%). 100%), when it is determined whether the CCV is lower than the upper limit voltage of the OCV, and when it is determined that the CCV is not lower than the upper limit voltage, the switching means 11 is opened to Stop using 10. That is, the control device body 13 stops using the battery 10 when it is determined that the pseudo SOC is not in a state smaller than the second upper limit value. When it is determined that the CCV is not in a state smaller than the upper limit voltage (a state in which the pseudo SOC is smaller than the second upper limit value), the use of the battery 10 is stopped when the battery 10 is used beyond this state. This is because the possibility of overcharging the battery 10 is increased.

On the other hand, if the control device body 13 determines that the CCV is lower than the upper limit voltage, the control device body 13 continues to use the battery 10. This is because it is considered that a safe value remains when converted to the SOC based on the OCV. Thereby, compared with the case where the battery 10 is charged only to the first upper limit value using the SOC based on the OCV, the capacity of the battery 10 can be used more effectively, and the energy of the battery 10 can be used more effectively. Note that when the first upper limit value is set to 80% or the like in consideration of the estimation error, the second upper limit value is set to 100% or the like that is the upper limit of the range to be originally used. The upper limit voltage of the OCV estimated that the SOC based on the OCV is 100% is, for example, 4.1V.

Further, the control device body 13 determines whether or not CCV is equal to the upper limit voltage after starting pseudo SOC estimation and before determining whether or not CCV is lower than the upper limit voltage. If it is determined that the CCV is equal to the upper limit voltage, it is determined whether or not the CCV is lower than the upper limit voltage after limiting the charging of the battery. Limiting the charging of the battery means, for example, suppressing the power generation by the regenerative generator or consuming the power generated by the regenerative generator by another device, or suppressing the operation of the power generating device 12b or the power consuming device 12a It is to perform power consumption.

When the charging of the battery is restricted, the absolute value of I in the above formula (1) becomes small, so the CCV is usually low. As described above, it is expected that the CCV becomes smaller than the upper limit voltage by limiting the charging of the battery when the CCV is equal to the upper limit voltage. For this reason, after limiting the charging of the battery, a positive determination result can be obtained even if it is determined whether the CCV is lower than the upper limit voltage, and the use of the battery 10 can be continued as much as possible. , You can make better use of battery capacity.

On the other hand, if the CCV does not become lower than the upper limit voltage even if the charging of the battery is restricted, the control device main body 13 opens the switching means 11 and stops using the battery 10. This is because it is considered that the battery 10 can be sufficiently charged within a range where overcharging does not occur.

Furthermore, when the battery 10 is charged, the control device main body 13 determines whether or not the CCV is smaller than the upper limit voltage before starting the estimation of the pseudo SOC, and the CCV is the upper limit voltage. If it is determined that the state is not smaller than the upper limit voltage, it is determined again whether the CCV is lower than the upper limit voltage after limiting the charging of the battery, and it is determined again that the CCV is not lower than the upper limit voltage. In case, stop using the battery. In this case, since the battery 10 is in a state close to overcharging, it is difficult to further charge the battery 10 while preventing overcharging even if pseudo SOC estimation is performed.

Next, a specific example of the operation of the control device main body 13 will be described using a flowchart. FIG. 2 is a flowchart showing a battery state control operation performed by the control device body 13 when the battery 10 of FIG. 1 is discharged. In the figure, when the discharge of the battery 10 is detected, the SOC is estimated based on at least one of the OCV and the current integrated value of the battery 10, and the normal control is performed based on the estimated SOC (step S1). ). Next, it is determined whether or not the SOC estimation result has reached 20% (first lower limit value), which is a lower limit value of a preset range (step S2), and it is determined that it has not reached 20%. Then, normal control is continued.

On the other hand, if it is determined that the SOC estimation result has reached 20%, it is determined whether CCV is greater than 3V (step S3). 3V used for this determination is a lower limit voltage of the OCV estimated that the SOC based on the OCV becomes 0% (second lower limit value). At this time, if it is determined that CCV is greater than 3V, pseudo SOC estimation is started by using CCV instead of OCV for information indicating the relationship between OCV and SOC (step S4). ).

When the estimation of the pseudo SOC is started, it is determined whether or not the CCV is equal to 3V (step S5). At this time, if it is determined that the CCV is not equal to 3V, it is determined whether or not the CCV is greater than 3V (step S6). If it is further determined at this determination that the CCV is greater than 3V, the use of the battery 10 is continued while the determination operations in steps S5 and S6 are repeated. That is, as long as it is determined that the CCV is greater than 3V, the use of the battery 10 is continued, and the battery 10 is overdischarged as compared with the case where the battery 10 is used only up to 20% using the SOC based on the OCV. The battery energy is used more effectively while avoiding the above.

If it is determined at step S6 that the CCV is not greater than 3V, the switching means 11 is opened and the battery 10 is disconnected from the in-vehicle device 12 to stop using the battery 10 (step S6). S7). Thus, the use of the battery 10 is stopped, so that the battery 10 is prevented from being overdischarged. When the charge / discharge state of the battery 10 is switched after the use of the battery 10 is stopped (when charging of the battery 10 is started), the switching means 11 is closed and the battery 10 is It is electrically connected to the power generation device 12b.

If it is determined at step S5 that the CCV is equal to 3V, the operation of the power consuming device 12a is suppressed, thereby limiting the discharge of the battery 10 (step S8). Is determined to be greater than 3V (step S6). As described above, when it is determined that the CCV is equal to 3V, it is determined whether or not the CCV is greater than 3V after the discharge of the battery 10 is limited. The battery energy can be utilized more.

On the other hand, if it is determined at step S3 that the CCV is not larger than 3V, the operation of the power consuming device 12a is suppressed, and the discharge of the battery 10 is limited (step S9). Then, it is determined again whether the CCV is larger than 3V (step S10). If it is determined again that the CCV is not greater than 3V at the time of this determination, the switching means 11 is opened and the battery 10 is disconnected from the in-vehicle device 12, thereby stopping the use of the battery 10 (step S7). ). The reason why the use of the battery 10 is stopped in this way is that it is difficult to use the battery 10 any more even if the estimation of the pseudo SOC is started.

On the other hand, if a positive determination is made at the time of determination in step S10, pseudo SOC estimation is started (step S4), and the above-described determinations in steps S5 and S6 are performed. This is because, when the discharge of the battery 10 is restricted in this way and the CCV becomes larger than 3V, the battery 10 can be used more effectively by estimating the pseudo SOC.

Next, FIG. 3 is a flowchart showing a battery state control operation performed by the control device body 13 when the battery 10 of FIG. 1 is charged. Note that the same operations as those in discharging shown in FIG. 2 will be described using the reference numerals used in FIG. In the figure, when charging of the battery 10 is detected, the SOC is estimated based on at least one of the OCV and the current integrated value of the battery 10, and normal control is performed based on the estimated SOC (step S1). ). Next, it is determined whether or not the SOC estimation result has reached 80% (first upper limit), which is a lower limit value of a preset range (step S20), and it is determined that it has not reached 80%. Then, normal control is continued.

On the other hand, when it is determined that the SOC estimation result has reached 80%, the CCV is 4.1 V (the OCV upper limit voltage estimated that the SOC based on the OCV is 100% (second upper limit value)). It is determined whether it is smaller than (step S21). 4.1 V used for this determination is the upper limit voltage of the OCV estimated that the SOC based on the OCV becomes 100% (second upper limit value). At this time, if it is determined that CCV is smaller than 4.1V, pseudo SOC estimation is started by using CCV instead of OCV for information indicating the relationship between OCV and SOC ( Step S4).

When the estimation of the pseudo SOC is started, it is determined whether or not the CCV is equal to 4.1V (step S22). At this time, if it is determined that the CCV is not equal to 4.1V, it is determined whether or not the CCV is smaller than 4.1V (step S23). If it is further determined at this determination that the CCV is smaller than 4.1 V, the use of the battery 10 is continued while the determination operations in steps S22 and S23 are repeated. That is, as long as it is determined that the CCV is smaller than 4.1 V, the use of the battery 10 is continued. Compared to the case where the battery 10 is used only up to 80% using the SOC based on the OCV, the battery 10 Battery energy is used more effectively while avoiding overcharging.

If it is determined at step S23 that the CCV is not smaller than 4.1V, the switching means 11 is opened and the battery 10 is disconnected from the in-vehicle device 12, whereby the use of the battery 10 is stopped. (Step S7). Thus, the use of the battery 10 is stopped, so that the battery 10 is prevented from being overcharged. If the charge / discharge state of the battery 10 is switched after the use of the battery 10 is stopped (when the discharge of the battery 10 is started), the switching means 11 is closed and the battery 10 is It is electrically connected to the power consuming device 12a.

If it is determined at step S22 that the CCV is equal to 4.1, power generation by the power generation device 12b is suppressed, or power generated by the power generation device 12b is consumed by other devices. Thus, charging of the battery 10 is restricted (step S24), and then it is determined whether or not the CCV is smaller than 4.1V (step S23). Thus, when it is determined that the CCV is equal to 4.1V, it is determined whether the CCV is smaller than 4.1V after the charging of the battery 10 is limited, The use of the battery 10 can be continued, and the battery capacity can be further utilized.

On the other hand, if it is determined at step S21 that the CCV is not smaller than 4.1V, the power generation by the power generation device 12b is suppressed, or the power generated by the power generation device 12b is reduced to another device. Thus, after the charging of the battery 10 is restricted (step S25), it is determined again whether or not the CCV is smaller than 4.1V (step S26). If it is determined again that the CCV is not smaller than 4.1 V at the time of this determination, the switching means 11 is opened and the battery 10 is disconnected from the in-vehicle device 12, thereby stopping the use of the battery 10 ( Step S7). The reason why the use of the battery 10 is stopped in this way is that it is difficult to use the battery 10 any more even if the estimation of the pseudo SOC is started.

On the other hand, if a positive determination is made at the time of determination in step S26, pseudo SOC estimation is started (step S4), and the above-described determinations in steps S22 and S23 are performed. This is because, when the charging of the battery 10 is limited in this way and the CCV becomes smaller than 4.1V, the battery 10 can be used more effectively by estimating the pseudo SOC.

In such a battery state control method and apparatus, the SOC is estimated based on at least one of the OCV and the current integrated value of the battery 10, and the SOC reaches the first upper limit value or the first lower limit value within a predetermined range. In some cases, pseudo SOC estimation is performed by using CCV instead of OCV for information indicating the relationship between OCV and SOC, and use of battery 10 is controlled based on pseudo SOC estimation. Therefore, the battery 10 can be used more effectively while avoiding the occurrence of overcharge and overdischarge of the battery 10.

Further, when the battery 10 is discharged, the CCV is lower than the lower limit voltage of the OCV estimated that the SOC based on the OCV becomes the second lower limit value smaller than the first lower limit value after the pseudo SOC estimation is started. When it is determined whether or not the battery 10 is in a large state and it is determined that the CCV is not larger than the lower limit voltage, the use of the battery 10 is stopped. Energy can be used more effectively.

Further, after starting the estimation of the pseudo SOC and before determining whether or not the CCV is larger than the lower limit voltage, it is determined whether or not the CCV is equal to the lower limit voltage. When it is determined that the state is equal to the voltage, it is determined whether or not the CCV is larger than the lower limit voltage after limiting the discharge of the battery 10, so that the use of the battery 10 can be continued as much as possible. Can be used more.

Furthermore, when the battery 10 is discharged, before starting the estimation of the pseudo SOC, the CCV is lower than the lower limit voltage of the OCV estimated that the SOC based on the OCV becomes a second lower limit value smaller than the lower limit value. When it is determined whether or not the CCV is not greater than the lower limit voltage, it is determined whether or not the CCV is greater than the lower limit voltage after limiting the discharge of the battery 10, When it is determined again that the CCV is not larger than the lower limit voltage, the use of the battery 10 is stopped, so that it is possible to avoid the start of pseudo SOC estimation when the battery 10 is in a state of near overdischarge. Thus, overdischarge of the battery 10 can be prevented more reliably.

Further, when the battery 10 is charged, after the estimation of the pseudo SOC is started, the CCV is smaller than the upper limit voltage of the OCV estimated that the SOC based on the OCV becomes the second upper limit value larger than the upper limit value. If it is determined whether or not the CCV is not smaller than the upper limit voltage, the use of the battery 10 is stopped. Therefore, the battery capacity can be increased while avoiding the overcharge of the battery 10 more reliably. It can be used more effectively.

Further, after starting the estimation of the pseudo SOC and before determining whether the CCV is smaller than the upper limit voltage, it is determined whether the CCV is equal to the upper limit voltage, and the CCV is the upper limit. When it is determined that the state is equal to the voltage, it is determined whether or not the CCV is lower than the upper limit voltage after limiting the charging of the battery 10, so that the use of the battery 10 can be continued as much as possible. Can be used more.

Furthermore, when the battery 10 is charged, before starting the estimation of the pseudo SOC, the CCV is higher than the upper limit voltage of the OCV estimated that the SOC based on the OCV becomes a second upper limit value that is larger than the upper limit value. It is determined whether or not the state is small, and when it is determined that the CCV is not smaller than the upper limit voltage, it is determined again whether or not the CCV is smaller than the upper limit voltage after limiting the discharge of the battery 10; When it is determined again that the CCV is not lower than the upper limit voltage, the use of the battery 10 is stopped, so that it is possible to avoid the start of pseudo SOC estimation when the battery 10 is in a state close to overcharging. Thus, overcharge of the battery 10 can be prevented more reliably.

Claims

The SOC is estimated based on at least one of the battery OCV and the current integrated value, and information indicating the relationship between the OCV and the SOC when the SOC reaches an upper limit value or a lower limit value of a predetermined range. A battery state control method of performing pseudo SOC estimation by using CCV instead of the OCV and controlling use of the battery based on the pseudo SOC estimation.
When the battery is discharged, after starting the estimation of the pseudo SOC, the SOC based on the OCV is more than the lower limit voltage of the OCV estimated to be a second lower limit value smaller than the lower limit value. The battery state control method according to claim 1, wherein it is determined whether or not the CCV is large, and when it is determined that the CCV is not larger than the lower limit voltage, use of the battery is stopped.
Determining whether the CCV is equal to the lower limit voltage after starting the pseudo SOC estimation and before determining whether the CCV is greater than the lower limit voltage; 3. The battery according to claim 2, wherein when it is determined that the CCV is equal to the lower limit voltage, it is determined whether the CCV is greater than the lower limit voltage after limiting discharge of the battery. State control method.
When the battery is discharged, before starting the estimation of the pseudo SOC, the SOC based on the OCV is estimated to be a second lower limit value smaller than the lower limit value than the lower limit voltage of the OCV. Determining whether the CCV is large,
When it is determined that the CCV is not larger than the lower limit voltage, it is determined again whether or not the CCV is larger than the lower limit voltage after limiting the discharge of the battery,
When it is determined again that the CCV is not larger than the lower limit voltage, the use of the battery is stopped.
The battery state control method according to any one of claims 1 to 3.
When the battery is charged, after starting the estimation of the pseudo SOC, the SOC based on the OCV is more than the upper limit voltage of the OCV estimated to be a second upper limit value larger than the upper limit value. The battery state control method according to claim 1, wherein it is determined whether or not the CCV is small, and when it is determined that the CCV is not smaller than the upper limit voltage, use of the battery is stopped.
After starting the estimation of the pseudo SOC and before determining whether the CCV is smaller than the upper limit voltage, determine whether the CCV is equal to the upper limit voltage; The battery according to claim 5, wherein when it is determined that the CCV is equal to the upper limit voltage, it is determined whether or not the CCV is lower than the upper limit voltage after limiting charging of the battery. State control method.
When the battery is charged, before starting the estimation of the pseudo SOC, the SOC based on the OCV is higher than the upper limit voltage of the OCV estimated to be a second upper limit value that is larger than the upper limit value. Determine whether the CCV is small,
When it is determined that the CCV is not in a state lower than the upper limit voltage, it is determined again whether the CCV is lower than the upper limit voltage after limiting the discharge of the battery.
When it is determined again that the CCV is not smaller than the upper limit voltage, the use of the battery is stopped.
The battery state control method according to any one of claims 1, 5, and 6.
The SOC is estimated based on at least one of the battery OCV and the current integrated value, and the information indicating the relationship between the OCV and the SOC when the SOC reaches the upper limit or the lower limit of the predetermined range, A battery state control device comprising: a control device body that performs pseudo SOC estimation by using CCV instead of OCV, and controls use of the battery based on the pseudo SOC estimation.