JP2014235017A - Apparatus and method for calculating remaining capacity of power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To find the remaining capacity of a power storage device with high accuracy when a vehicle power source is switched from off to on.SOLUTION: An apparatus for calculating the remaining capacity of a power storage device is provided which includes: a remaining capacity calculation part for calculating the remaining capacity of the power storage device by integrating the current of the power storage device mounted in a vehicle; a detection determination part for determining whether an open-circuit voltage of the power storage device has been detected; an integration constant setting part for setting an integration constant in the integration of the current on the basis of the result of determination by the detection determination part at first timing when the power source of the vehicle switches from on to off and the result of determination by the detection determination part at second timing when the power source of the vehicle switches from off to on. The remaining capacity calculation part integrates the current by using the integration constant set by the integration constant setting part, thereby calculating the remaining capacity at the second timing.

Description

  The present invention relates to a remaining capacity computing device and a remaining capacity computing method for an electricity storage device that computes the remaining capacity of an electricity storage device mounted on a vehicle.

  A power storage device such as a lead storage battery or a lithium ion secondary battery is mounted on a vehicle such as an automobile as a battery. In order to effectively use this power storage device, it is important to accurately grasp the remaining capacity of the power storage device (see Patent Document 1).

  As a technique for obtaining the remaining capacity of the electricity storage device, there is a technique for obtaining the remaining capacity from the detection value of the battery sensor based on the open voltage of the electricity storage device. Here, the open circuit voltage is a voltage between the terminals of the electricity storage device in a state where a load is not applied to the electricity storage device for a long time.

JP 08-29505 A

  Normally, a vehicle equipped with an electricity storage device is turned on when used, and turned off when not used. However, the remaining capacity detected by the battery sensor retains the accuracy that can be used only when the open circuit voltage can be detected. Therefore, the open circuit voltage may not be detected particularly immediately after the battery sensor is started when the power is turned on. In some cases, it is difficult to obtain an accurate remaining capacity. Therefore, when the open circuit voltage is not detected when the vehicle is turned on, the open circuit voltage is detected, and therefore it is necessary to leave the load on the power storage device for a long time. For this reason, it is necessary to wait for a long time (for example, about 3 hours) until an open circuit voltage necessary for obtaining the remaining capacity of the electricity storage device is detected.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to accurately determine the remaining capacity of the electricity storage device when the vehicle power source is switched on.

  In order to solve the above-described problem, according to an aspect of the present invention, a remaining capacity calculation unit that calculates a remaining capacity of the power storage device by integrating currents of power storage devices mounted on a vehicle; A detection determination unit that determines whether or not an open-circuit voltage is detected, a determination result by the detection determination unit at a first timing when the power of the vehicle is turned off, and a second timing at which the power of the vehicle is switched on An integration constant setting unit that sets an integration constant in the integration of the current based on a determination result by the detection determination unit, and the remaining capacity calculation unit uses the integration constant set by the integration constant setting unit Thus, the remaining capacity calculating device for the electricity storage device is provided, wherein the remaining capacity at the second timing is calculated by integrating the current.

  In addition, the integration constant setting unit sets the integration constant that is set when the presence or absence of the detection of the open-circuit voltage at the first timing and the second timing is the same, and at the first timing and the second timing. The integration constant set when the presence / absence of detection of the open circuit voltage is different may be made different.

  The storage device remaining capacity calculation device further includes an acquisition unit that acquires the remaining capacity of the storage device based on the voltage of the storage device detected by a detection sensor, and the integration constant setting unit includes the first timing. And when the open circuit voltage is detected at the second timing, the remaining capacity at the first timing is calculated from the remaining capacity at the first timing calculated by the remaining capacity calculator. A value obtained by subtracting the difference in remaining capacity acquired from the detection sensor may be set as the integration constant.

  Further, when the open circuit voltage is detected at the first timing and the open circuit voltage is not detected at the second timing, the integration constant setting unit performs the first timing calculated by the remaining capacity calculation unit. May be set as the integration constant.

  The storage device remaining capacity calculation device further includes an acquisition unit that acquires the remaining capacity of the storage device based on the voltage of the storage device detected by a detection sensor, and the open circuit voltage is detected at the first timing. When the open circuit voltage is detected at the second timing, the integration constant setting unit may set the remaining capacity detected by the detection sensor at the second timing as the integration constant. .

  In addition, the remaining capacity calculation unit uses the integration constant set when calculating the remaining capacity of the power storage device in the power-on state of the vehicle after the second timing when calculating the remaining capacity at the second timing. It may be calculated.

  The first timing may be a timing at which the power of the vehicle is switched off immediately before the second timing.

  In addition, the first timing may be a timing that goes back a predetermined time or more from the second timing.

  In order to solve the above problem, according to an aspect of the present invention, there is provided a remaining capacity calculation method for calculating a remaining capacity of the electricity storage device by integrating currents of the electricity storage devices mounted on a vehicle, It is determined whether or not the open circuit voltage of the power storage device is detected at a first timing when the power source of the vehicle is switched off, and whether or not the open voltage is detected at a second timing when the power source of the vehicle is switched on is determined. Based on the determination result at the first timing and the determination result at the second timing, an integration constant in the integration of the current is set, and the current is integrated using the set integration constant, A remaining capacity calculation method for an electricity storage device is provided, wherein the remaining capacity at the second timing is calculated.

  According to the above-described present invention, the remaining capacity calculation device for the power storage device includes the determination result of whether or not the open circuit voltage is detected by the detection determination unit at the first timing when the vehicle power supply is turned off by the integration constant setting unit, and An integration constant in current integration is set based on the determination result by the detection determination unit at the second timing when the power supply of the vehicle is switched on. In the remaining capacity calculation device, the remaining capacity calculation unit calculates the remaining capacity at the second timing by integrating the current using the integration constant set by the integration constant setting unit. Based on the determination of whether or not the open circuit voltage is detected at the first timing and the second timing, by setting the integration constant in the integration of current for calculating the remaining capacity of the power storage device, the set integration constant is reliable. It becomes a highly accurate and highly accurate value. By calculating the remaining capacity by integrating the current of the power storage device using such a highly reliable integration constant, the remaining capacity of the power storage device at the second timing can be accurately obtained. In particular, even if the open circuit voltage is not detected at the second timing, the remaining capacity of the electricity storage device at the second timing can be quickly obtained with high accuracy.

  As described above, according to the present invention, it is possible to accurately obtain the remaining capacity of the power storage device when the power source of the vehicle is turned on.

It is a block diagram showing a schematic structure about an electrical storage device of vehicle 1 concerning a 1st embodiment. FIG. 3 is a schematic diagram for explaining an on / off switching state of the power supply of the vehicle 1. It is a block diagram which shows an example of a function structure of the control unit 20 which concerns on 1st Embodiment. It is a schematic diagram for demonstrating the setting method of the integration constant C which concerns on 1st Embodiment. It is a flowchart which shows the calculation process of the remaining capacity of the battery 10 which concerns on 1st Embodiment. It is a schematic diagram which shows the relationship between the 1st timing and 2nd timing which concern on 2nd Embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. First Embodiment>
(1-1. Vehicle configuration)
With reference to FIG. 1, an example of a configuration of a vehicle on which an electricity storage device according to the first embodiment of the present invention is mounted will be described.

  FIG. 1 is a block diagram illustrating a schematic configuration related to the power storage device of the vehicle 1 according to the first embodiment. The vehicle 1 is, for example, an automobile using an engine as a power source, an electric vehicle using a motor as a power source, or a hybrid car using an engine and a motor as a power source. As shown in FIG. 1, the vehicle 1 includes a battery 10 that is an example of an electricity storage device, a control unit 20, and a power supply state switching unit 30.

  The battery 10 is, for example, a 12V lead storage battery. The battery 10 supplies power to the starter when the engine of the vehicle 1 is started, and supplies power to electrical components such as lights when the engine is stopped. In order to effectively use such a battery 10, it is important to accurately grasp the remaining capacity of the battery 10.

  The battery 10 is provided with a battery sensor 12 for detecting the state of the battery 10. The battery sensor 12 is referred to as an IBS (intelligent battery sensor) as an example, and includes a sensor that detects the voltage (terminal voltage), current (charge / discharge current), temperature, and the like of the battery 10. Further, the battery sensor 12 can detect the remaining capacity of the battery 10 based on the voltage. In particular, if an open voltage of the battery 10 is detected, the battery sensor 12 can detect the remaining capacity with high accuracy. The detection result of the battery sensor 12 is transmitted to the control unit 20. The battery 10 may be provided with a control unit that controls the battery 10 including the battery sensor 12.

  The control unit 20 controls the vehicle 1 as a whole. In addition, the control unit 20 according to the present embodiment has a function (details will be described later) as a remaining capacity calculation device that calculates the remaining capacity SOC of the battery 10 in order to accurately grasp the remaining capacity SOC of the battery 10. .

  The power supply state switching unit 30 detects whether the power source (ignition switch) of the vehicle 1 is switched on (ON) or off (OFF) by the user. For example, the user switches on the power supply by a key operation when driving the vehicle 1, and switches off the power supply when the driving ends. If the power-off time is long, it is easy to detect the open circuit voltage OCV of the battery 10 described above. The power supply state switching unit 30 transmits the detection result to the control unit 20.

(1-2. Remaining battery capacity when the vehicle is powered on)
In the vehicle 1, as described above, when the battery sensor 12 can detect the open circuit voltage OCV that is a voltage between the terminals of the battery 10 in a state where the load is not applied to the battery 10 for a long time (for example, 3 hours), Ten accurate remaining capacities can be detected. The remaining capacity detected by the battery sensor 12 is also referred to as a detected remaining capacity for convenience of explanation.

  By the way, the power of the vehicle 1 is switched on and off by the user's key operation. When the power is switched on, the battery sensor 12 may not accurately detect the remaining capacity SOC of the battery 10 as described below.

  FIG. 2 is a schematic diagram for explaining the on / off switching state of the power source of the vehicle 1. In FIG. 2, the power is switched on at t1, the power is switched off at t2, and the power is switched on again at t3. Hereinafter, the period between t1 and t2 and the period between t3 and t4 are referred to as operation cycles, respectively.

  Here, the remaining capacity SOC of the battery 10 when the power source is switched on at t3 shown in FIG. 2 will be described. When the power-off time between t2 and t3 is shorter than the detection time during which the open circuit voltage OCV can be detected, the open circuit voltage OCV cannot be detected when the power is switched on at t3. For this reason, the battery sensor 12 cannot accurately detect the remaining capacity SOC of the battery 10 at time t3. This is due to the fact that the battery sensor 12 detects the remaining capacity based on the dark current at the open circuit voltage OCV. Even after time t3, the battery sensor 12 cannot accurately detect the remaining capacity SOC of the battery 10 until the open circuit voltage is detected. If the remaining capacity of the battery 10 is not accurately detected and then control is performed afterward, the battery 10 may be deteriorated due to overdischarge or overcharge.

  In order to solve the above problem, the control unit 20 according to the first embodiment calculates the remaining capacity SOC of the battery 10 by integrating the current of the battery 10. Specifically, the control unit 20 detects whether or not the open circuit voltage OCV is detected when the power of the battery 10 is turned off (for example, at time t2 shown in FIG. 2), and immediately after that the power is turned on. An integration constant for integrating the current of the battery 10 is set based on whether or not the open circuit voltage OCV is detected at the time of ON (at time t3 shown in FIG. 2). Then, the control unit 20 integrates the current using the set integration constant to calculate the remaining capacity SOC of the battery 10 when the power is turned on (at t3). The remaining capacity calculated in this way is also referred to as a calculated remaining capacity for convenience of explanation.

  By calculating the calculated remaining capacity of the battery 10 in this manner, the remaining capacity SOC of the battery 10 when the power is turned on can be accurately obtained even when the open circuit voltage OCV when the power is turned on cannot be detected. In the first embodiment, when the first power-off (at t2) is the first timing while the power is repeatedly turned on and off, the power-on immediately after the one power-off (at t3) Is at the second timing.

(1-3. Functional Configuration of Control Unit 20)
Next, an example of a functional configuration of the control unit 20 according to the first embodiment will be described with reference to FIG.

  FIG. 3 is a block diagram illustrating an example of a functional configuration of the control unit 20 according to the first embodiment. As illustrated in FIG. 3, the control unit 20 includes a communication unit 102, a detection determination unit 104, an integration constant setting unit 106, a remaining capacity calculation unit 108, and a storage unit 110.

(Communication unit 102)
The communication unit 102 transmits / receives data to / from the battery sensor 12. The communication unit 102 receives the detection result of the battery sensor 12 (voltage, current, temperature, etc. of the battery 10). The communication unit 102 outputs the received information to the detection determination unit 104.

  The communication unit 102 functions as an acquisition unit that acquires the remaining capacity of the battery 10 detected by the battery sensor 12. Note that the detected remaining capacity of the battery 10 acquired by the battery sensor 12 does not include a factor due to a temperature change, and therefore is more accurate than the calculated remaining capacity of the battery 10 that is calculated by integrating the current of the battery 10. Is low.

(Detection determination unit 104)
The detection determination unit 104 determines the state of the battery 10 based on the detection result of the battery sensor 12. The detection determination unit 104 according to the present embodiment determines whether or not the open circuit voltage OCV of the battery 10 is detected. The detection determination unit 104 outputs a determination result on whether or not the open circuit voltage OCV is detected to the integration constant setting unit 106.

式（１）のＩｂはバッテリ１０の電流（Ａ）を示し、Ｋは充放電ゲインを示し、Ｆはバッテリ１０の満充電容量（Ａｈ）を示し、Ｃは積算定数である。 (Integration constant setting unit 106)
The control unit 20 calculates the calculated remaining capacity SOC (%) of the battery 10 by integrating the current of the battery 10 as shown in the following equation (1).

In the formula (1), Ib represents the current (A) of the battery 10, K represents the charge / discharge gain, F represents the full charge capacity (Ah) of the battery 10, and C represents an integration constant.

  As shown in the equation (1), the calculated remaining capacity SOC can be obtained from an integral constant C that is an initial value and an integrated value of a charge / discharge current Ib that is an input / output of a current to / from the battery 10. As will be described later, since the temperature factor is included in the charge / discharge gain K, the calculated remaining capacity SOC includes fluctuation due to temperature characteristics, and the calculated remaining capacity SOC is higher in accuracy than the detected remaining capacity. It will be a thing. Here, assuming that the detected remaining capacity detected from the battery sensor 12 is used as an initial value (integral constant C), the value of the integral constant C as an initial value under a situation where the open circuit voltage OCV cannot be detected, such as when the sensor is activated. The reliability is low. In addition, it is desirable to set the initial value (integral constant) in consideration of the amount of natural discharge between power-off and power-on. Therefore, the integration constant setting unit 106 sets the integration constant C in the above equation (1) by the following method. Based on the determination result by the detection determination unit 104 when the vehicle 1 is powered off and the determination result by the detection determination unit 104 when the vehicle 1 is powered on, the integration constant setting unit 106 calculates the current for calculating the remaining capacity. The integration constant C in the integration of is set. The integration constant setting unit 106 outputs the setting result of the integration constant C to the remaining capacity calculation unit 108. In the following description, the time t2 and the time t3 shown in FIG.

  The integration constant setting unit 106 sets the integration constant C that is set when the detection of the open circuit voltage OCV is the same when the power is turned off (at t2) and when the power is turned on (at t3), and when the power is turned off and when the power is turned on. The integration constant C set when the presence or absence of detection of the voltage OCV is different is made different. As a result, the optimum integration constant C corresponding to the detection state of the open circuit voltage OCV is set, so that the remaining capacity of the battery 10 can be obtained with higher accuracy. The case where the open / closed voltage OCV is detected is the same when the open voltage OCV is detected when the power is turned off and when the power is turned on, or when the open voltage OCV is not detected when the power is turned off and when the power is turned on. Also, when the open voltage OCV is detected or not, the open voltage OCV is detected when the power is turned off and the open voltage OCV is not detected when the power is turned on, or the open voltage OCV is not detected when the power is turned off and the power is turned on. It sometimes refers to the case where the open circuit voltage OCV is detected.

  Specifically, when the open circuit voltage OCV is detected at the same time when the power is turned off (at time t2) and when the power is turned on (at time t3), the integration constant setting unit 106 represents the following equation (2). Set the integration constant C. That is, the integration constant setting unit 106 detects the detected remaining capacity detected by the battery sensor 12 when the power is turned off and when the power is turned on from the calculated remaining capacity SOC calculated when the power is turned off calculated by the remaining capacity calculation unit 108 (referred to as the calculated SOC when the power is turned off). A value obtained by subtracting the difference between the capacities (also referred to as an off-time sensor value and an on-time sensor value) is set as the integration constant C. The off-time calculated SOC and the off-time sensor value are stored in the storage unit 110 when setting the integration constant at time t2. C = Calculated SOC at OFF-(Sensor value at OFF-Sensor value at ON) ·· Equation (2)

  When the detection of the open circuit voltage OCV is the same when the power is off (at t2) and when the power is on (at t3), the difference between the off-time sensor value at t2 and the on-time sensor value at t3 is It has been found that this is a reliable value for the difference in electromotive force due to spontaneous discharge. In particular, when the open circuit voltage OCV is not detected at the time of power-off and power-on, the sensor value itself at power-off and power-on is low in reliability, but the difference Δ is a reliable value as the amount of spontaneous discharge. . It is known that discharge is performed at a constant slope between time t2 and time t3 when the power is off. In the present embodiment, taking this viewpoint into consideration, the integration constant C at the time of power-on is set.

  FIG. 4 is a schematic diagram for explaining a method for setting the integration constant C according to the first embodiment. In FIG. 4, the power on / off state, the detected remaining capacity by the battery sensor 12, and the calculated remaining capacity SOC are shown in order from the top. As described above, the detected remaining capacity and the calculated remaining capacity SOC are different from each other by the temperature factor. Here, it is assumed that the open-circuit voltage OCV is not detected when the power is turned off (at t2) and when the power is turned on (at t3). The integration constant C when integrating the current in order to obtain the calculated remaining capacity at the time of power-on (time t3) is the sensor value at the time t2 and t3 from the calculated remaining capacity SOC at the time of the previous power-off (time t2). By subtracting the difference Δ (equation (2)), the value is reduced by the amount of spontaneous discharge. Therefore, the integration constant C is a highly reliable value even if the open circuit voltage OCV at the time of power-on is not detected.

  In the present embodiment, the integration constant C is set by the above-described equation (2) even when the open circuit voltage OCV is detected when the power is turned off and when the power is turned on. When the open circuit voltage OCV is detected, the sensor value itself at the time of power-off and power-on is highly reliable. Then, by setting the integration constant using a highly reliable sensor value, the battery sensor 12 is more accurately detected when the power is turned on than the detected remaining capacity detected based on the open circuit voltage OCV when the power is turned on. Can be obtained. In addition, by setting an integration constant using a highly reliable sensor value when the power is turned off and when the power is turned on, the remaining capacity when the power is turned on can be obtained in consideration of the spontaneous discharge.

  When the presence or absence of detection of the open circuit voltage OCV at the time of power off and power on is different, the integration constant setting unit 106 sets according to whether the open circuit voltage OCV is detected at power off or power on. Different integration constants C are used. As a result, the most reliable value can be set as the integration constant when the power is turned on.

Specifically, when the open circuit voltage OCV is detected when the power is turned off (at t2) and the open circuit voltage OCV is not detected when the power is turned on (at t3), the integration constant setting unit 106: The calculated remaining capacity at t2 (off-state calculated SOC) calculated by the remaining capacity calculation unit 108 is set in the integration constant C as shown in Expression (3). That is, the integration constant C is set using the calculated remaining capacity (the calculated SOC at the off time) with high reliability at t2 when the open circuit voltage OCV is detected.
C = Calculated SOC at OFF-Formula (3)

On the other hand, when the open circuit voltage OCV is not detected when the power is turned off (at t2) and the open circuit voltage OCV is detected when the power is turned on (at t3), the integration constant setting unit 106 uses the following formula ( As in 4), the detected remaining capacity (on-time sensor value) detected by the battery sensor 12 when the power is turned on (at time t3) is set to the integration constant C. That is, the integration constant C is set using a detected remaining capacity (on-time sensor value) with high reliability at t3 when the open circuit voltage OCV is detected.
C = Sensor value at ON ・ ・ Expression (4)

(Remaining capacity calculator 108)
The remaining capacity calculation unit 108 integrates the current (charge / discharge current) of the battery 10 to calculate the calculated remaining capacity SOC of the battery 10. Specifically, the remaining capacity calculation unit 108 calculates the remaining capacity SOC as in the above-described equation (1).

  The remaining capacity calculation unit 108 integrates the current using the integration constant C corresponding to the power-on time (at t3) set by the integration constant setting unit 106 in Equation (1), and after the power-on time (at t3). The remaining capacity SOC is calculated. Thereby, the remaining capacity SOC corresponding to the detection state of the open circuit voltage OCV can be calculated. In particular, even if the open-circuit voltage OCV when the power is turned on is not detected, the remaining capacity SOC when the power is turned on can be obtained with high accuracy.

  The remaining capacity calculation unit 108 calculates the remaining capacity continuously after the power is turned on (t3). At this time, the remaining capacity calculation unit 108 calculates the remaining capacity of the battery 10 in the power-on state of the vehicle 1 after the power is turned on using the integration constant C set when calculating the remaining capacity when the power is turned on. That is, while the power is on, the integration constant C may be set at the first operation cycle, and the processing load of the control unit 20 thereafter is reduced. As described above, the remaining capacity calculation unit 108 continues by adding the integrated value of the charge / discharge current to the battery 10 based on the equation (1), with the integration constant C set when the power is turned on as an initial value. The calculated remaining capacity SOC is calculated. Thereby, the remaining capacity of the battery 10 can be obtained at an arbitrary timing.

(Storage unit 110)
The storage unit 110 stores various data controlled by the control unit 20. For example, the storage unit 110 stores the integration constant C set by the integration constant setting unit 106 and the remaining capacity SOC calculated by the remaining capacity calculation unit 108. Further, the remaining capacity detected by the battery sensor 12 is also stored. The remaining capacity SOC stored in the storage unit 110 is then used, for example, for various controls of the vehicle 1.

  In the above description, the battery 10 is a 12V lead acid battery, but is not limited thereto. For example, when the vehicle 1 is a hybrid vehicle, the battery 10 may be a battery connected to a motor. In such a case, the power source can be switched efficiently by switching between the engine and the motor using the remaining capacity SOC stored in the storage unit 110.

(1-4. Remaining capacity calculation processing)
The remaining capacity calculation process of the battery 10 according to the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing a calculation process of the remaining capacity of the battery 10 according to the first embodiment. This calculation process is realized by the CPU of the control unit 20 executing a program stored in the ROM.

  First, the integration constant setting unit 106 of the control unit 20 sets the integration constant C to the set value set last time (step S102). Next, the control unit 20 determines whether or not the communication establishment with the battery 10 is the first time after the power is switched on (step S104).

  When communication is established for the first time in step S104 (Yes), the detection determination unit 104 detects whether or not the open circuit voltage OCV is detected when the power is turned off in the previous operation cycle, and opens when the power is turned on in the current operation cycle. It is determined whether or not the voltage OCV is detected (steps S106 and S108).

  First, the detection determination unit 104 determines whether or not the detection of the open circuit voltage OCV is the same when the power is off and when the power is on (step S106). When the detection determination unit 104 determines that the open circuit voltage OCV is detected when the power is turned off and when the power is turned on, or when it is determined that the open circuit voltage OCV is not detected when the power is turned off and when the power is turned on (step S106). : Yes), the process proceeds to step S110.

  On the other hand, if the detection of the open circuit voltage OCV is different when the power is off and the power is on (step S106: No), the detection determination unit 104 does not detect the open circuit voltage OCV when the power is off and opens when the power is turned on. It is determined whether or not the voltage OCV is detected (step S108).

  When the detection determination unit 104 determines that the open circuit voltage OCV is not detected when the power is turned off and the open circuit voltage OCV is detected when the power is turned on (step S108: Yes), the process proceeds to step S112. On the other hand, when the detection determination unit 104 determines that the open circuit voltage OCV is detected when the power is off and the open circuit voltage OCV is not detected when the power is on (step S108: No), the process proceeds to step S114. .

  Next, in steps S110, S112, and S114, the integration constant setting unit 106 sets an integration constant C for integrating current. Specifically, in step S110, the integration constant setting unit 106 determines the battery sensor 12 when the power is turned off and when the power is turned on from the remaining capacity SOC when the power is turned off calculated by the remaining capacity calculation unit 108 (calculated SOC when the power is turned off). A value obtained by subtracting the difference between the remaining capacities detected by the sensor (off-time sensor value and on-time sensor value) is set as the integration constant C. At this time, the integration constant setting unit 106 uses values stored in the storage unit 110 for the off-time calculated SOC and the off-time sensor value.

  In step S112, the remaining capacity calculation unit 108 sets the remaining capacity (on-time sensor value) detected by the battery sensor 12 when the power is turned on to the integration constant C. In step S <b> 114, the remaining capacity calculation unit 108 sets the remaining capacity when the power is turned off (off-time calculated SOC) calculated by the remaining capacity calculation unit 108 as the integration constant C.

When the integration constant C is set, the remaining capacity calculation unit 108 calculates the charge amount gain K (step S116). Here, the charge amount gain K is defined by a function f of the temperature Tb of the battery 10 as in the following formula (5), and reflects a change in the internal resistance of the battery 10 according to the temperature. For this reason, the calculated remaining capacity SOC reflects a gain related to temperature, and becomes a more accurate value than the remaining capacity detected by the battery sensor 12.
K = f (Tb) Equation (5)

  Next, the remaining capacity calculation unit 108 uses the equation (1) based on the integration constant C set in steps S110 to S114 and the charge amount gain calculated in step S116, and the remaining capacity of the battery 10 when the power is turned on. The capacity SOC is calculated (step S118). Next, the remaining capacity calculation unit 108 causes the storage unit 110 to store the calculated remaining capacity SOC of the battery 10 when the power is turned on (step S120).

  Thereafter, the remaining capacity SOC of the battery 10 for the second and subsequent times of the current operation cycle is calculated. At this time, the integration constant setting unit 106 sets the setting value set in steps S110 to S114 as the integration constant C (step S102). Then, the processing of steps S106 to S114 is omitted (step S104: No), and the remaining capacity calculation unit 108 calculates the remaining capacity SOC for the second and subsequent times using the integration constant C set in step S102 (step S118). ). Thereby, the remaining capacity SOC of the battery 10 can be accurately obtained during the operation cycle.

(1-5. Summary)
In the first embodiment described above, the integration constant setting unit 106 of the control unit 20 determines the determination result by the detection determination unit 104 when the power of the vehicle 1 is turned off (time t2 in FIG. 2) and the power supply. Based on the determination result by the detection determination unit 104 at the time of turning on the power source (at time t3 in FIG. 2), an integration constant C used for current integration for calculating the remaining capacity of the battery 10 at the time of power on is set. . In this way, by setting the integration constant C corresponding to the time when the power is turned on according to the detection state of the open voltage when the power is turned off and when the power is turned on, the set integration constant becomes a highly reliable and highly accurate value. .

  Further, the remaining capacity calculation unit 108 integrates the current using the integration constant C set by the integration constant setting unit 106 to calculate the remaining capacity SOC of the battery 10 when the power is turned on. Thereby, the remaining capacity SOC of the battery 10 when the power is turned on can be obtained with higher accuracy than when the battery sensor 12 detects the remaining capacity. In particular, even if the open circuit voltage is not detected when the power is turned on, the remaining capacity of the battery 10 when the power is turned on can be obtained quickly and accurately.

<2. Second Embodiment>
In the first embodiment described above, when the power supply of the vehicle is repeatedly turned on and off, one power-on time (in this case, at time t3 shown in FIG. 2), which is a timing for calculating the remaining capacity SOC of the battery 10. Is set to the second timing, the power-off time (time t2) immediately before the time t3 is set to the first timing. Then, the integration constant C was set according to whether or not the open circuit voltage OCV was detected at the first timing and at the second timing.

  On the other hand, in the second embodiment, the first timing (when the power is turned off) is a timing that goes back a predetermined time or more from the second timing (when the power is turned on). Therefore, the first timing varies with respect to the second timing (power on) for calculating the remaining capacity SOC according to the on / off switching state of the power.

  FIG. 6 is a schematic diagram illustrating a relationship between the first timing and the second timing according to the second embodiment. Here, the description will be made assuming that the integration constant C at t5 (second timing) is set. In the example shown in FIG. 6, the time t2 is not the time t4 immediately before the time t5 but the first timing. The reason why the time t4 is not the first timing is that the operation stop time between t4 and t5 is short, so the difference between the sensor value of the battery sensor 12 at t4 and the sensor value of the battery sensor 12 at t5 (see FIG. 6). This is because the difference Δ ′) is small, the difference is determined to be an error, and the integration constant C may not be set appropriately.

  On the other hand, in the second embodiment, since the time between time t2 and time t5 when the power is turned off before time t4 is long, the sensor value of the battery sensor 12 at t2 and the battery at time t5 The difference Δ between the sensor values of the sensor 12 becomes large, so that it is not determined that an error or the like occurs. As a result, the integration constant C at t5 can be set appropriately. Then, the calculated remaining capacity SOC of the battery 10 at t5 is calculated by applying the obtained integration constant C to Equation (1). The second embodiment is particularly effective for obtaining the remaining capacity of the battery 10 when the power supply is frequently switched on and off.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Battery 12 Battery sensor 20 Control unit 102 Communication part 104 Detection determination part 106 Integration constant setting part 108 Remaining capacity calculation part 110 Storage part

Claims (9)

A remaining capacity calculator that calculates the remaining capacity of the electricity storage device by integrating the current of the electricity storage device mounted on the vehicle;
A detection determination unit that determines presence or absence of detection of an open-circuit voltage of the power storage device;
Based on the determination result by the detection determination unit at the first timing when the vehicle power source is switched off and the determination result by the detection determination unit at the second timing when the vehicle power source is switched on. An integration constant setting section for setting an integration constant for integration;
With
The remaining capacity calculation unit integrates the current using the integration constant set by the integration constant setting unit, and calculates the remaining capacity at the second timing. Arithmetic unit. The integration constant setting unit
The integration constant that is set when the presence / absence of the detection of the open voltage at the first timing and the second timing is the same, and the presence / absence of the detection of the open voltage at the first timing and the second timing. The remaining capacity calculation device for an electricity storage device according to claim 1, wherein the integration constant set when different is different. An acquisition unit for acquiring the remaining capacity of the electricity storage device based on the voltage of the electricity storage device detected by the detection sensor;
The integration constant setting unit
When the presence or absence of the detection of the open circuit voltage at the first timing and the second timing is the same,
A value obtained by subtracting the difference between the remaining capacity acquired from the detection sensor at the first timing and the second timing from the remaining capacity at the first timing calculated by the remaining capacity calculating unit is the integration constant. The remaining capacity computing device for an electricity storage device according to claim 2, wherein When the open circuit voltage is detected at the first timing and the open circuit voltage is not detected at the second timing,
The said accumulation constant setting part sets the remaining capacity at the said 1st timing which the said remaining capacity calculation part calculated to the said accumulation constant, The remaining capacity calculation apparatus of the electrical storage device of Claim 2 characterized by the above-mentioned. An acquisition unit for acquiring the remaining capacity of the electricity storage device based on the voltage of the electricity storage device detected by the detection sensor;
When the open voltage is not detected at the first timing and the open voltage is detected at the second timing,
The said accumulation constant setting part sets the remaining capacity which the said detection sensor detected at the said 2nd timing to the said accumulation constant, The remaining capacity calculation apparatus of the electrical storage device of Claim 2 characterized by the above-mentioned. The remaining capacity calculation unit
The remaining capacity of the power storage device in the power-on state of the vehicle after the second timing is calculated using an integration constant set when calculating the remaining capacity at the second timing. The remaining capacity calculation device for an electricity storage device according to any one of 1 to 5.   The said 1st timing is a timing when the power supply of the said vehicle switched off immediately before the said 2nd timing, The remaining capacity calculating apparatus of the electrical storage device of any one of Claims 1-6 characterized by the above-mentioned. .   The remaining capacity calculation device for an electricity storage device according to any one of claims 1 to 6, wherein the first timing is a timing that is a predetermined time or more from the second timing. A remaining capacity calculation method for calculating the remaining capacity of the electricity storage device by integrating the current of the electricity storage device mounted on the vehicle,
Determining whether or not the open circuit voltage of the power storage device is detected at a first timing when the power of the vehicle is switched off;
Determining whether or not the open-circuit voltage is detected at a second timing when the vehicle is turned on;
Based on the determination result at the first timing and the determination result at the second timing, an integration constant in the integration of the current is set,
A method of calculating a remaining capacity of an electricity storage device, wherein the remaining current at the second timing is calculated by integrating the current using the set integration constant.

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