JP2012251907A - State of charge value estimation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce restriction of regenerative charge and discharge more than required in a device which estimates a state of charge value (SOC) for a battery which performs the discharge and the regenerative charge to an electric load (for example, motor for travel) loaded on a vehicle.SOLUTION: A state of charge value estimation device includes: current dependence calculation means S10 for calculating SOC(i) (a current calculation state value) on the basis of an integrated value of charged/discharge current of a battery; voltage dependence calculation means S20 for calculating SOC(v) (a voltage calculation state value) on the basis of battery voltage; and target value setting means for setting target SOC according to a travel state of a vehicle. Then, a value closer to the target SOC of both calculated values SOC(i) and SOC(v) is adopted as an estimated SOC.

Description

  The present invention relates to a state-of-charge value estimation device for a battery that performs discharge and regenerative charging to an electric load (for example, a traveling motor) mounted on a vehicle.

  As a physical quantity representing the state of charge of a battery, SOC (State of charge) is generally used. And if the SOC falls into an overcharged state where the upper limit value is exceeded, there is a concern about battery performance deterioration. Therefore, if the SOC exceeds the upper limit value, it is necessary to limit the charging of the battery. is there. In addition, when the SOC becomes lower than the lower limit value, there is a concern about battery performance deterioration and output shortage. Therefore, when the SOC exceeds the lower limit value, it is also necessary to limit discharge from the battery. . And in order to perform these charge restrictions and discharge restrictions appropriately, it is required to accurately estimate the current SOC.

  In response to this requirement, Patent Documents 1 and 2 disclose that the SOC (hereinafter referred to as SOC (i)) is estimated based on the integrated value of the charge / discharge current of the battery, and the SOC (hereinafter referred to as SOC) based on the battery voltage. (V) is described.

JP 2006-71635 A Japanese Patent Laid-Open No. 11-223665

  However, in either SOC (i) or SOC (v), the actual situation is that sufficient accuracy cannot be obtained by the above-described estimation method. That is, various errors such as a current detection error are integrated over time, so there is a limit to estimating SOC (i) with high accuracy.

  Further, as illustrated in FIG. 2, the SOC (v) can be estimated from the correlation between the open circuit voltage of the battery and the SOC. However, since the battery open-circuit voltage used for this estimation is estimated in consideration of the battery internal resistance, the influence of polarization, etc. based on the battery terminal voltage detected at the time of charge / discharge, the SOC (v) is estimated with high accuracy. Has its limits.

  Therefore, the estimated SOC (i) or SOC (v) may exceed the upper limit value even if the actual SOC is still in a sufficiently large state with respect to the upper limit value. In this case, since charging is restricted more than necessary, the amount of charge due to regenerative power generation is reduced and fuel efficiency cannot be sufficiently improved.

  Moreover, even if the actual SOC is still in a state where there is still a sufficient margin with respect to the lower limit value, the estimated SOC (i) or SOC (v) may exceed the lower limit value. In this case, for example, since the discharge to the traveling motor (electric load) is restricted more than necessary, the drivability cannot be improved sufficiently such that the required acceleration traveling cannot be performed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a state-of-charge value estimation device that reduces reduction of regenerative charging and discharging more than necessary.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  According to the first aspect of the present invention, the state of charge estimation device is applied to a battery that discharges and regeneratively charges an electric load mounted on a vehicle, and estimates a state of charge that is a physical quantity representing the state of charge of the battery. A current dependency calculating means for calculating the charge state value (current calculation state value) based on an integrated value of the charge / discharge current of the battery, and the charge state value (voltage calculation state value) based on the voltage of the battery. Voltage dependence calculating means for calculating the charging state value, and target value setting means for setting the target value of the state of charge in accordance with the traveling state of the vehicle. Then, a value closer to the target value among the current calculation state value and the voltage calculation state value is estimated as an actual charge state value.

  Here, since the estimated SOC margin (discharge margin) with respect to the lower limit value increases as the estimated state-of-charge value (for example, the above-described SOC) increases, the chance that the estimated SOC exceeds the lower limit value decreases, and thus discharge is limited. Less chance of being done. However, since the margin (charge margin) of the estimated SOC with respect to the upper limit value is reduced, there are more opportunities for the estimated SOC to exceed the upper limit value, and in turn, there are more opportunities for charging to be restricted. On the other hand, as the estimated SOC is lower, the charging margin is increased, so that the opportunity for charging restriction is reduced, and the discharge margin is reduced, so that the opportunity for discharging restriction is increased.

  Then, the target value is set according to the traveling state of the vehicle so that the balance between the discharge margin and the charge margin is optimal. For example, when the amount of regenerative power generation is expected, such as when traveling at high speed, the target value is set low so as to increase the charging margin. Further, when an increase in the discharge amount is expected, such as when traveling on an uphill, the target value is set high so as to increase the discharge margin.

  In view of these points, in the above invention, both the current calculation state value SOC (i) and the voltage calculation state value SOC (v) are calculated, and the target value (that is, the discharge margin and the charge margin of the charge margin) is calculated from both the calculated values. The value closer to the optimal balance is adopted as the estimated SOC. For this reason, although the calculation accuracy of SOC (i) and SOC (v) is low, the opportunity for charging limitation due to a small charging margin and the opportunity for discharging limitation due to an excessive discharge margin are reduced in a balanced manner. it can.

  In a second aspect of the present invention, during high speed traveling in which the traveling speed of the vehicle is equal to or higher than a predetermined value, the smaller value of the current calculation state value and the voltage calculation state value is set regardless of the target value. It is characterized by estimating as an actual charge state value.

  Here, since the amount of regenerative power generation is expected to increase during high-speed travel, if the charging margin is large, the opportunity for charge restriction is reduced and the amount of regenerative charge can be increased. In the above invention in view of this point, during high speed traveling, the smaller value is adopted as the estimated SOC regardless of which of the two calculated values is close to the target value. Therefore, the regenerative charge amount is increased by increasing the charging margin. Can be increased.

  In a third aspect of the present invention, when the vehicle is traveling at a low speed where the traveling speed of the vehicle is less than a predetermined value, the larger one of the current calculation state value and the voltage calculation state value is set regardless of the target value. It is characterized by estimating as an actual charge state value.

  Here, since the amount of regenerative power generation is not expected during low-speed traveling, the balance between the discharge margin and the charge margin can be optimized by increasing the discharge margin in preference to the charge margin. In the above-mentioned invention in view of this point, during low speed traveling, the larger value is adopted as the estimated SOC regardless of which of the two calculated values is close to the target value, so that the charging margin is not excessively increased. The balance can be optimized.

  According to a fourth aspect of the present invention, a charging state value estimation device is applied to a battery that performs discharge and regenerative charging to an electric load mounted on a vehicle, and estimates a charging state value that is a physical quantity representing the charging state of the battery. A current dependency calculating means for calculating the charge state value (current calculation state value) based on an integrated value of the charge / discharge current of the battery, and the charge state value (voltage calculation state value) based on the voltage of the battery. Voltage dependence calculating means for calculating. When the vehicle travels at a high speed that is equal to or higher than a predetermined value, the smaller one of the current calculation state value and the voltage calculation state value is estimated as an actual charge state value.

  Here, since the amount of regenerative power generation is expected to increase during high-speed travel, if the above-described charging margin is large, the opportunity for charge restriction is reduced and the amount of regenerative charge can be increased. In the above invention in view of this point, the smaller value of the two calculated values is adopted as the estimated SOC during high speed traveling, so that the charging margin can be increased to increase the regenerative charge amount.

  In the invention according to claims 5 and 6, the charging is applied to a battery that performs discharge and regenerative charging to an electric load mounted on a vehicle, and estimates a charging state value that is a physical quantity representing the charging state of the battery. A state value estimation device, wherein the current dependence calculation means calculates the charge state value (current calculation state value) based on an integrated value of the charge / discharge current of the battery, and the charge state value (voltage) based on the voltage of the battery. Voltage dependence calculation means for calculating (calculation state value). When the vehicle travels at a low speed where the travel speed is less than a predetermined value, the larger one of the current calculation state value and the voltage calculation state value is estimated as an actual charge state value.

  Here, since the amount of regenerative power generation is not expected during low-speed traveling, the balance between the discharge margin and the charge margin can be optimized by increasing the discharge margin in preference to the above-described charge margin. In the above-mentioned invention in view of this point, during low speed traveling, the larger value is adopted as the estimated SOC regardless of which of the two calculated values is close to the target value, so that the charging margin is not excessively increased. The balance can be optimized.

The block diagram which shows the system configuration | structure of the battery to which a charge condition value estimation apparatus is applied in 1st Embodiment of this invention. The figure which shows the correlation with battery open voltage and SOC, and shows the upper limit value THu and lower limit value THd of SOC. 5 is a flowchart illustrating a procedure for calculating an estimated SOC in the first embodiment. The time chart which shows the one aspect | mode at the time of calculating estimated SOC in the procedure of FIG. The time chart which shows the one aspect | mode at the time of calculating estimated SOC in the procedure of FIG. The time chart which shows the one aspect | mode at the time of calculating estimated SOC in the procedure of FIG. The flowchart which shows the calculation procedure of estimated SOC in 2nd Embodiment of this invention. The flowchart which shows the calculation procedure of estimated SOC in 3rd Embodiment of this invention.

  Hereinafter, each embodiment which actualized the charge condition value estimation apparatus concerning this invention is described based on drawing.

(First embodiment)
FIG. 1 is a block diagram illustrating a configuration of a system in which a state of charge value estimation apparatus is applied to a hybrid electric vehicle. The battery 10 is a nickel metal hydride battery configured by connecting a large number of battery cells in series, and is assumed to have an output voltage of about 300V.

  The voltage of the battery 10 is detected by the voltage detector 12 and the detected value is output to the battery ECU 14. Further, the charging / discharging current (battery current) flowing through the battery 10 when charging / discharging the battery 10 is detected by the current sensor 16, and the detected value is also output to the battery ECU 14.

  The battery ECU 14 estimates the SOC (State of charge: the ratio of the actual charge amount with respect to the charge amount at the time of full charge) representing the charge state value of the battery 10 by a method described in detail later, and estimates the estimated SOC value ( Estimated SOC) is output to the HVECU 18.

  The HVECU 18 determines a torque command to the drive shaft based on information such as the accelerator opening, the brake depression amount, and the vehicle speed. Then, the required torque for the motor generator 22 and the engine 24 is determined so that the total torque value of the motor generator 22 (travel motor, generator) and the engine 24 (internal combustion engine) matches the torque command to the drive shaft, It outputs to motor generator ECU18a and engine ECU18b. The motor generator ECU 18a controls switching in the inverter 20 so that the required torque for the motor generator 22 can be realized. On the other hand, the engine ECU 18b controls the engine 24 so that the required torque for the engine 24 can be realized.

  When the required torque to motor generator 22 is negative, electric power is output from inverter 20 toward battery 10, and battery 10 is charged. On the other hand, when the required torque to motor generator 22 is positive, electric power is supplied from inverter 20 to motor generator 22 and battery 10 is discharged. Thus, the motor generator 22 functions as an electric means (electric load) and a power generation means.

  Further, the HVECU 18 (target value setting means) sets the required torque to the motor generator 22 and the engine 24 so that the SOC of the battery 10 becomes a target value (target SOC) according to the estimated SOC output from the battery ECU 14. decide. The target SOC is set according to the traveling state of the vehicle. For example, when an increase in regenerative power generation is expected, such as when driving at high speed, the target SOC is set low to increase the regenerative charge amount. Plan. Further, when an increase in power supply to the motor generator 22 is expected, such as when approaching an uphill road, the target SOC is set high to prepare for an increase in the required power supply amount.

  FIG. 2 is a graph showing the correlation between the open circuit voltage of the battery 10 and the SOC. As shown in FIG. 2, the SOC of the battery 10 has an optimum range. That is, if the battery 10 is in an overcharged state where the SOC is excessively high or an overdischarge state where the SOC is excessively low, the battery 10 may be degraded in performance. In view of this point, when the estimated SOC becomes higher than the upper limit value THu, charging is limited to avoid performance deterioration of the battery 10. For example, charging to the battery 10 may be prohibited, or the charging amount per unit time may be limited to be a predetermined amount or less. Further, when the estimated SOC becomes lower than the lower limit value THd, the discharge is limited to avoid the above-described battery performance deterioration and output shortage. For example, the discharge from the battery 10 may be prohibited, or the discharge amount per unit time may be limited to be a predetermined amount or less.

  Next, a method for calculating the estimated SOC described above will be described. FIG. 3 is a flowchart showing a calculation procedure of the estimated SOC by the microcomputer included in the battery ECU 14, and this process is repeatedly executed at a predetermined cycle (for example, the calculation cycle performed by the CPU described above or every predetermined crank angle).

  First, in step S10 (current dependence calculating means) shown in FIG. 3, the integrated value of the battery current detected by the current sensor 16 is calculated, and the SOC (i) is calculated based on the integrated current value. For example, SOC (i) is calculated by integrating the battery current during discharging as a negative value and the battery current during charging as a positive value, and multiplying the integrated value by a predetermined coefficient. Note that SOC (i) corresponds to a “current calculation state value”.

  In the subsequent step S20 (voltage dependence calculating means), SOC (v) is calculated based on the battery voltage detected by the voltage detector 12. For example, the battery voltage detected when the battery 10 is not charged and discharged is acquired as the open voltage of the battery 10, and the SOC (v) is calculated by multiplying the open voltage by a predetermined coefficient. Alternatively, based on the battery voltage detected at the time of charging / discharging, the open circuit voltage is estimated in consideration of the influence of the battery internal resistance and polarization, and the SOC (v) is calculated by multiplying the open circuit voltage by a predetermined coefficient. The SOC (v) corresponds to a “voltage calculation state value”.

  In the subsequent step S30, the difference ΔSOC (i) between the SOC (i) calculated in step S10 and the target SOC is calculated, and the difference ΔSOC (v) between the SOC (v) calculated in step S20 and the target SOC is calculated. To do. In subsequent step S40, the two differences ΔSOC (i) and ΔSOC (v) are compared in magnitude.

  If it is determined that ΔSOC (v) <ΔSOC (i) (S40: YES), the process proceeds to step S50, and the SOC (v) calculated in step S20 is adopted as the estimated SOC. On the other hand, if it is determined that ΔSOC (v) ≧ ΔSOC (i) (S40: NO), the process proceeds to step S51, and the SOC (i) calculated in step S10 is adopted as the estimated SOC. In short, both SOC (i) and SOC (v) are calculated, and the calculated value closer to the target SOC is adopted as the estimated SOC.

  4 to 6 are time charts showing various modes when the processing of FIG. 3 is performed. FIG. 4 shows a case where the SOC is close to the upper limit value THu, and both SOC (i) and SOC (v) are higher than the target SOC. FIG. 5 is a graph where the SOC is close to the lower limit value THd. FIG. 6 shows a case where SOC (i) and SOC (v) fluctuate so as to cross the target SOC. FIG. 6 shows a case where SOC (i) and SOC (v) are both lower than the target SOC. In addition, the dashed-dotted line in a figure shows the change of SOC (v), and the dotted line in a figure shows the change of SOC (i).

  First, the example of FIG. 4 will be described. In the period up to t1, SOC (v) is closer to the target SOC than SOC (i), so SOC (v) is adopted as the estimated SOC. As a result, the margin of the estimated SOC (charging margin Mc) with respect to the upper limit value THu becomes larger than when SOC (i) is adopted. Therefore, the chance that the estimated SOC exceeds the upper limit value THu and charging is limited is reduced. Therefore, the amount of regenerative charge increases and fuel efficiency improves.

  Further, in the period from t1 to t2, since SOC (i) is closer to the target SOC than SOC (v), SOC (i) is adopted as the estimated SOC. As a result, the charge margin Mc becomes larger than when SOC (v) is adopted. Therefore, the chance that the estimated SOC exceeds the upper limit value THu and charging is limited is reduced. Therefore, the amount of regenerative charge increases and fuel efficiency improves.

  Next, the example of FIG. 5 will be described. In the period up to t3, since SOC (v) is closer to the target SOC than SOC (i), SOC (v) is adopted as the estimated SOC. As a result, the margin (discharge margin Md) of the estimated SOC with respect to the lower limit value THd becomes larger than when SOC (i) is adopted. Therefore, the chance that the estimated SOC exceeds the lower limit value THd and the discharge is limited is reduced. Therefore, for example, during acceleration traveling, in the case where the output of the motor generator 22 is used as the travel drive source in addition to the output of the engine 24, it is possible to avoid a situation where the supplied power is insufficient with respect to the required power of the motor generator 22. . Therefore, drivability is improved.

  Also, during the period from t3 to t4, SOC (i) is closer to the target SOC than SOC (v), and therefore SOC (i) is adopted as the estimated SOC. As a result, the discharge margin Md becomes larger than when SOC (v) is adopted. Therefore, the chance that the estimated SOC exceeds the lower limit value THd and the discharge is limited is reduced. Therefore, drivability is improved as described above.

  Next, the example of FIG. 6 will be described. In the period up to t5 and the period after t6, SOC (v) is closer to the target SOC than SOC (i), and therefore SOC (v) is adopted as the estimated SOC. On the other hand, in the period from t5 to t6, since SOC (i) is closer to the target SOC than SOC (v), SOC (i) is adopted as the estimated SOC.

  Here, the magnitude of the charge margin Mc and the magnitude of the discharge margin Md are in a trade-off relationship. The target SOC can be said to be a value set in accordance with the traveling state of the vehicle so that the balance between the charging margin Mc and the discharging margin Md is optimal. For example, when the amount of regenerative power generation is expected, such as when traveling at high speed, the target SOC is set low so as to increase the charging margin Mc. Further, when an increase in the discharge amount is expected, such as when traveling on an uphill, the target SOC is set high so as to increase the discharge margin Md.

  Since a value closer to the target SOC (that is, a value at which the balance between the discharge margin Md and the charge margin Mc is optimal) among the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC, the charge margin In the case of FIG. 6, the effect that the chance that Mc becomes excessively small and charging is limited and the opportunity that discharge margin Md becomes excessively small and discharge is limited can be reduced in a balanced manner is achieved.

  As described above, according to the present embodiment, since the value closer to the target SOC among the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC, the calculation of SOC (i) and SOC (v) is performed. Although the accuracy is low, it is possible to improve the fuel efficiency by reducing the chance that the charging margin Mc becomes too small and the charging is restricted, and the drivability by reducing the chance that the discharging margin Md becomes too small and the discharging is restricted. Can be improved.

(Second Embodiment)
In the first embodiment, the value closer to the target SOC among the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC, whereas in the present embodiment shown in FIG. The lower value of the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC, and the higher value is adopted when the vehicle is not traveling at high speed.

  Hereinafter, the processing content of FIG. 7 is demonstrated centering on the difference with FIG. In FIG. 7, the description of the same reference numerals as those in FIG. The hardware configuration of the battery system in the present embodiment is the same as that of the first embodiment shown in FIG.

  First, in steps S10 and S20 shown in FIG. 7, SOC (i) and SOC (v) are calculated. In a succeeding step S41, it is determined whether or not the traveling state of the vehicle is high speed traveling. For example, if the vehicle speed SPD is equal to or higher than a preset value THa, it is determined that the vehicle is traveling at high speed.

  If it is determined that the vehicle is traveling at a high speed (S41: YES), the process proceeds to step S60, and the SOC (i) calculated in step S10 and the SOC (v) calculated in step S20 are the lower ones. Is used as the estimated SOC. On the other hand, if it is determined that the vehicle is not traveling at high speed (S41: NO), the process proceeds to step S61, and the higher value of the SOC (i) calculated in step S10 and the SOC (v) calculated in step S20 is selected. The SOC is adopted as the estimated SOC.

  Next, a time chart when the process of FIG. 7 is performed will be described.

  For example, as shown in FIG. 4, if both SOC (i) and SOC (v) fluctuate on the higher side than the target SOC and at high speed, SOC (v) is more SOC in the period up to t1. Since the value is lower than (i), SOC (v) is adopted as the estimated SOC. As a result, the charge margin Mc becomes larger than when SOC (i) is employed. Therefore, the chance that the estimated SOC exceeds the upper limit value THu and charging is limited is reduced.

  Also, during the period from t1 to t2, SOC (i) is a lower value than SOC (v), so SOC (i) is adopted as the estimated SOC. As a result, the charge margin Mc becomes larger than when SOC (v) is adopted. Therefore, the chance that the estimated SOC exceeds the upper limit value THu and charging is limited is reduced.

  For example, as shown in FIG. 5, if both SOC (i) and SOC (v) fluctuate on the lower side than the target SOC and the vehicle is not traveling at high speed, SOC (v) is more SOC in the period up to t3. Since the value is higher than (i), SOC (v) is adopted as the estimated SOC. As a result, the discharge margin Md becomes larger than when SOC (i) is employed. Therefore, the chance that the estimated SOC exceeds the lower limit value THd and the discharge is limited is reduced.

  Also, during the period from t3 to t4, SOC (i) has a higher value than SOC (v), so SOC (i) is adopted as the estimated SOC. As a result, the discharge margin Md becomes larger than when SOC (v) is adopted. Therefore, the chance that the estimated SOC exceeds the lower limit value THd and the discharge is limited is reduced.

  Here, since the amount of regenerative power generation is expected to increase during high-speed travel, if the charging margin Mc is large, the opportunity for charge restriction is reduced and the amount of regenerative charge can be increased. In this embodiment in view of this point, during high speed traveling, the smaller one of the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC. Therefore, the regenerative charge amount is increased by increasing the charging margin Mc. Can be increased, and fuel consumption can be improved.

  Further, when the vehicle is not traveling at high speed, the larger one of the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC, so that the discharge margin Md can be increased to improve drivability.

(Third embodiment)
In the second embodiment, which of the two calculated values SOC (i) and SOC (v) is to be adopted as the estimated SOC is determined depending on whether or not the vehicle is traveling at high speed. On the other hand, in the present embodiment shown in FIG. 8, the value closer to the target SOC is adopted as the estimated SOC at the time of medium speed running, and the lower value is adopted at the time of high speed running. The higher value is used when driving at low speeds.

  Hereinafter, the processing content of FIG. 8 is demonstrated centering on the difference with FIG. In FIG. 8, the description of the same reference numerals as those in FIG. The hardware configuration of the battery system in the present embodiment is the same as that of the first embodiment shown in FIG.

  First, in steps S10 and S20 shown in FIG. 8, SOC (i) and SOC (v) are calculated. In a succeeding step S42, it is determined whether or not the traveling state of the vehicle is medium speed traveling. For example, if the vehicle speed SPD is a predetermined range TH1 to TH2 set in advance, it is determined that the vehicle is traveling at a medium speed.

  If it is determined that the vehicle is traveling at a medium speed (S42: YES), the process proceeds to step S50a, and the SOC (i) calculated in step S10 and the SOC (v) calculated in step S20, which is closer to the target SOC. Is adopted as the estimated SOC. In short, the same processing as steps S30, S40, S50, and S51 in FIG. 3 is performed.

  On the other hand, when it is determined that the vehicle is not traveling at medium speed (S42: NO), the process proceeds to step S43, and it is determined whether the vehicle is traveling at high speed. For example, if the vehicle speed SPD is equal to or higher than a predetermined value TH2, it is determined that the vehicle is traveling at high speed, and otherwise, it is determined that SPD <TH1 and the vehicle is traveling at low speed.

  If it is determined that the vehicle is traveling at high speed (S43: YES), the process proceeds to step S60, and the lower value of the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC. On the other hand, when it is determined that the vehicle is traveling at a low speed (S43: NO), the process proceeds to step S61, and the higher value of the two calculated values SOC (i) and SOC (v) is adopted as the estimated SOC.

  As described above, according to this embodiment, the same effect as that of the second embodiment is exhibited during high-speed traveling and low-speed traveling, and the same effect as that of the first embodiment is exhibited during medium-speed traveling.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  In each of the above embodiments, the state-of-charge value estimation device is applied to the battery 10 of the hybrid vehicle that includes both the motor generator 22 and the engine 24 as the travel drive source. The battery is not limited.

  In the second embodiment shown in FIG. 7, the low-side SOC is adopted at high speed, and the high-side SOC is adopted at times other than high speed (low speed). As a modification, the lower SOC may be adopted at high speed, and the SOC closer to the target SOC may be adopted at low speed. Alternatively, the SOC close to the target SOC may be adopted at high speed, and the higher SOC may be adopted at low speed.

  In each of the above embodiments, SOC (ratio of charge amount with respect to full charge) is adopted as the charge state value, but for example, the charge amount itself may be adopted as the charge state value.

  DESCRIPTION OF SYMBOLS 10 ... Battery, 18 ... HVECU (target value setting means), 22 ... Motor generator (electric load), S10 ... Current dependence calculation means, S20 ... Voltage dependence calculation means, SOC (i) ... Current calculation state value, SOC (v ) ... Voltage calculation state value.

Claims (6)

A charging state value estimating device that is applied to a battery that performs discharge and regenerative charging to an electric load mounted on a vehicle, and that estimates a charging state value that is a physical quantity representing the charging state of the battery,
Current-dependent calculation means for calculating a current calculation state value as the charge state value based on an integrated value of the charge / discharge current of the battery;
Voltage dependence calculating means for calculating a voltage calculation state value as the state of charge based on the voltage of the battery;
Target value setting means for setting a target value of the state of charge according to the traveling state of the vehicle;
With
A charge state value estimation device that estimates a value closer to the target value among the current calculation state value and the voltage calculation state value as an actual charge state value.   During high-speed travel where the travel speed of the vehicle is equal to or higher than a predetermined value, the smaller one of the current calculation state value and the voltage calculation state value is estimated as an actual charge state value regardless of the target value. The state-of-charge value estimation device according to claim 1.   When the vehicle is traveling at a low speed where the traveling speed is less than a predetermined value, the larger one of the current calculation state value and the voltage calculation state value is estimated as an actual charge state value regardless of the target value. The state-of-charge value estimation device according to claim 1 or 2. A charging state value estimating device that is applied to a battery that performs discharge and regenerative charging to an electric load mounted on a vehicle, and that estimates a charging state value that is a physical quantity representing the charging state of the battery,
Current-dependent calculation means for calculating a current calculation state value as the charge state value based on an integrated value of the charge / discharge current of the battery;
Voltage dependence calculating means for calculating a voltage calculation state value as the state of charge based on the voltage of the battery;
With
A charging state value characterized by estimating a smaller value of the current calculation state value and the voltage calculation state value as an actual charging state value during high-speed traveling where the traveling speed of the vehicle is equal to or higher than a predetermined value. Estimating device.   5. The larger one of the current calculation state value and the voltage calculation state value is estimated as an actual charge state value when the vehicle is traveling at a low speed where the traveling speed is less than a predetermined value. The state-of-charge value estimation device according to 1. A charging state value estimating device that is applied to a battery that performs discharge and regenerative charging to an electric load mounted on a vehicle, and that estimates a charging state value that is a physical quantity representing the charging state of the battery,
Current-dependent calculation means for calculating a current calculation state value as the charge state value based on an integrated value of the charge / discharge current of the battery;
Voltage dependence calculating means for calculating a voltage calculation state value as the state of charge based on the voltage of the battery;
With
When the vehicle is traveling at a low speed where the traveling speed is less than a predetermined value, the larger one of the current calculation state value and the voltage calculation state value is estimated as an actual charge state value. Estimating device.

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