JP5126150B2 - Storage capacity estimation device and storage capacity estimation method - Google Patents

Description

  The present invention relates to a storage capacity estimation device and a storage capacity estimation method, and more specifically, a secondary battery can be discharged based on an open-circuit voltage of a secondary battery having a characteristic that an internal resistance increases as a dischargeable storage capacity decreases. The present invention relates to a storage capacity estimation device and a storage capacity estimation method for estimating a storage capacity.

  Conventionally, as this type of storage capacity estimation device, a device that estimates the SOC of a secondary battery based on the open-circuit voltage of a secondary battery such as a lithium ion battery or a nickel metal hydride battery has been proposed (for example, Patent Documents). 1). In this device, the voltage value when the current value is 0 in the voltage-current characteristic calculated based on the voltage between the terminals of the secondary battery and the charge / discharge current when charging / discharging the secondary battery is the secondary battery. The SOC of the secondary battery is estimated using a map or model formula set in advance based on the calculated open-end voltage.

Japanese Patent Laid-Open No. 2008-222008

  It is desirable that the SOC estimation as in the above-described apparatus is performed as appropriately as possible. For example, in a drive device including an electric motor that exchanges power with a secondary battery, an input / output limit is calculated as the maximum allowable power when charging / discharging the secondary battery based on the SOC of the secondary battery, and this input / output limit is calculated. If the motor is driven within the range, but when the SOC is not estimated properly, the battery cannot be adequately protected, such as being charged or discharged exceeding the power allowed for the secondary battery. Occurs. In particular, when the SOC is estimated by calculating the open-circuit voltage of the secondary battery as in the above-described device, it is desirable to appropriately calculate the open-circuit voltage.

  The main object of the storage capacity estimation device and storage capacity estimation method of the present invention is to more appropriately estimate the dischargeable storage capacity of the secondary battery.

  The storage capacity estimation device and the storage capacity estimation method of the present invention employ the following means in order to achieve the main object described above.

The storage capacity estimation device of the present invention is
A storage capacity estimation device that estimates the dischargeable storage capacity of the secondary battery based on the open-circuit voltage of the secondary battery having a characteristic that the internal resistance tends to increase as the dischargeable storage capacity decreases.
As the relationship between the estimated storage capacity, which is the dischargeable storage capacity of the secondary battery estimated to date, and the correction coefficient for correcting the internal resistance of the secondary battery, the correction coefficient increases as the estimated storage capacity decreases. The secondary battery is obtained by correcting a reference internal resistance serving as a reference of the internal resistance of the secondary battery by the correction coefficient obtained by applying the estimated storage capacity to a correction relationship having a storage capacity relationship of Internal resistance voltage calculation means for calculating a voltage generated by the internal resistance of the secondary battery when the secondary battery is charged and discharged by multiplying the charge / discharge current of
Unit time is calculated by multiplying the voltage generated by the polarization of the secondary battery calculated up to now by a ratio corresponding to a predetermined time constant and the maximum polarization voltage which is the maximum value of the voltage generated by the polarization of the secondary battery. A polarization voltage calculating means for calculating a voltage generated by polarization of the secondary battery when the secondary battery is charged / discharged by a sum of the product divided by the predetermined time constant;
Based on the open-circuit voltage of the secondary battery obtained by subtracting the voltage generated by the calculated internal resistance of the secondary battery from the voltage between the terminals of the secondary battery and the voltage generated by the polarization of the calculated secondary battery. Storage capacity estimation means for estimating the dischargeable storage capacity of the secondary battery,
It is a summary to provide.

  In the storage capacity estimation apparatus of the present invention, the estimated storage capacity is calculated as a relationship between the estimated storage capacity that is the dischargeable storage capacity of the secondary battery estimated up to now and the correction coefficient for correcting the internal resistance of the secondary battery. A correction coefficient obtained by applying the estimated storage capacity to a correction relationship having a storage capacity relationship in which the correction coefficient tends to increase as the correction coefficient decreases. The voltage generated by the internal resistance of the secondary battery when the secondary battery is charged and discharged by multiplying the charge / discharge current of the secondary battery is calculated, and the voltage generated by the polarization of the secondary battery calculated so far Rechargeable battery by the sum of the ratio according to the constant multiplied by the maximum polarization voltage, which is the maximum value of the voltage generated by the polarization of the secondary battery, multiplied by the unit time divided by the predetermined time constant Calculating a voltage generated by the polarization of the secondary battery when charging and discharging. Then, based on the open voltage of the secondary battery obtained by subtracting the voltage generated by the internal resistance of the secondary battery calculated from the voltage between the terminals of the secondary battery and the voltage generated by the polarization of the calculated secondary battery. Estimate the dischargeable storage capacity of the secondary battery. Thereby, since the open circuit voltage of a secondary battery can be calculated more appropriately, the storage capacity of the secondary battery that can be discharged can be estimated more appropriately.

  In such a storage capacity estimation device according to the present invention, the correction relationship is a relationship between the temperature of the secondary battery and the correction coefficient. When the temperature of the secondary battery is equal to or higher than a predetermined temperature, the correction coefficient increases as the temperature decreases. When the temperature of the secondary battery is less than the predetermined temperature, the correction coefficient tends to be smaller as the temperature is lower, and the relationship between the storage capacity and the storage capacity relationship. The reference internal resistance may be corrected by the correction coefficient obtained by applying the temperature of the secondary battery and the estimated storage capacity to the relationship. In this way, the reference internal resistance can be corrected more appropriately.

  In the storage capacity estimation device of the present invention, the polarization voltage calculation means may be configured to provide a current voltage generated by the first polarization of the secondary battery that changes with a first time constant when the secondary battery is charged / discharged. The unit time is calculated by multiplying the value calculated so far by a ratio corresponding to the first time constant and the first maximum polarization voltage which is the maximum value of the voltage generated by the first polarization of the secondary battery. The voltage generated by the first polarization of the secondary battery when the secondary battery is charged / discharged by the sum of the product divided by the first time constant is multiplied by the secondary battery. A value calculated by the present time of the voltage generated by the second polarization of the secondary battery that changes with a second time constant larger than the first time constant when discharged corresponds to the second time constant. Multiplied by the ratio and the second polarization of the secondary battery When the secondary battery is charged / discharged by the sum of the second maximum polarization voltage, which is the maximum value of the generated voltage, multiplied by the unit time divided by the second time constant. The voltage generated by the second polarization of the battery is calculated, and the secondary battery is calculated as the sum of the voltage generated by the calculated first polarization of the secondary battery and the voltage generated by the calculated second polarization of the secondary battery. It is also possible to use a means for calculating a voltage generated by the polarization. In this way, the voltage generated by the polarization of the secondary battery can be calculated more appropriately.

  In the storage capacity estimation device according to the aspect of the present invention, wherein the voltage generated by the polarization of the secondary battery is calculated as the sum of the voltage generated by the first polarization of the secondary battery and the voltage generated by the second polarization, the polarization voltage calculation According to a first aspect of the present invention, the first polarization correction coefficient tends to increase as the estimated storage capacity decreases as the relationship between the estimated storage capacity and the first polarization correction coefficient that corrects the first maximum polarization voltage. The first maximum polarization voltage is corrected by the first polarization correction coefficient obtained by applying the estimated storage capacity to the first polarization correction relation having two storage capacity relations. As a relationship between the estimated storage capacity and the second polarization correction coefficient that corrects the second maximum polarization voltage by calculating the voltage generated by the first polarization of the secondary battery using instead of the maximum polarization voltage The estimation For the second polarization obtained by applying the estimated storage capacity to a second polarization correction relation having a third storage capacity relation in which the second polarization correction coefficient tends to increase as the electric capacity decreases. It is a means for calculating a voltage generated by the second polarization of the secondary battery by using the correction of the second maximum polarization voltage by a correction coefficient instead of the second maximum polarization voltage. You can also. In this way, the voltage generated by the first polarization and the voltage generated by the second polarization of the secondary battery can be calculated more appropriately.

  The voltage generated by the polarization of the secondary battery as the sum of the voltage generated by the first polarization of the secondary battery and the voltage generated by the second polarization by correcting the first maximum polarization voltage and the second maximum polarization voltage. In the storage capacity estimation device of the present invention that calculates A, the first polarization correction relationship is the relationship between the temperature of the secondary battery and the first polarization correction coefficient. If the temperature is lower than the second predetermined temperature, the first polarization correction coefficient becomes larger as the temperature is lower. If the temperature of the secondary battery is lower than the second predetermined temperature, the lower the temperature is, the lower the first polarization correction coefficient is. The second polarization relationship is a relationship having a second temperature relationship in which the coefficient tends to be smaller and the second storage capacity relationship, and the second polarization correction relationship is the temperature of the secondary battery and the second polarization correction. As a relationship with the coefficient, the temperature of the secondary battery is the third If the temperature is lower than a predetermined temperature, the second polarization correction coefficient increases as the temperature decreases. If the temperature of the secondary battery is lower than the third predetermined temperature, the second polarization correction coefficient decreases as the temperature decreases. A third voltage relationship and a third power storage capacity relationship, and the polarization voltage calculating means includes the second battery temperature and the estimated power storage capacity in the first polarization correction relationship. The first maximum polarization voltage is corrected by the first polarization correction coefficient obtained by applying the above and the temperature of the secondary battery and the estimated storage capacity are applied to the second polarization correction coefficient. The second maximum polarization voltage can be corrected by the second polarization correction coefficient obtained as described above. In this way, the first maximum polarization voltage and the second maximum polarization voltage can be corrected more appropriately.

  Further, the first maximum polarization voltage and the second maximum polarization voltage are corrected, and the sum of the voltage generated by the first polarization of the secondary battery and the voltage generated by the second polarization is generated by the polarization of the secondary battery. In the storage capacity estimation device of the present invention that calculates a voltage, the polarization voltage calculation means includes FI as the first maximum polarization voltage, Kb as the first correction coefficient for polarization, and the first time constant as the first time constant. τ1, Vdyn1 (previous) a value calculated to date of the voltage generated by the first polarization of the secondary battery, FI2 as the second maximum polarization voltage, Kc as the second correction coefficient for polarization, Vdyn1 (previous) when τ2 is a second predetermined time constant, Vdyn2 (previous) is a value calculated to date of the voltage generated by the second polarization of the secondary battery, and Δt is the unit time. Exp (−Δt / τ1) + FI The voltage generated by the first polarization of the secondary battery is calculated by 1 · Kb · Δt / τ1, and the secondary battery's second voltage is calculated by Vdyn2 (previous) · exp (−Δt / τ2) + FI2 · Kc · Δt / τ2. It can also be a means for calculating a voltage generated by the polarization of 2.

The storage capacity estimation method of the present invention is:
A storage capacity estimation method for estimating a dischargeable storage capacity of the secondary battery based on an open circuit voltage of the secondary battery having a characteristic that the internal resistance tends to increase as the dischargeable storage capacity decreases,
(A) The correction as the estimated storage capacity is smaller as the relationship between the estimated storage capacity that is the dischargeable storage capacity of the secondary battery estimated up to now and the correction coefficient for correcting the internal resistance of the secondary battery The reference internal resistance that is a reference of the internal resistance of the secondary battery is corrected by the correction coefficient obtained by applying the estimated storage capacity to the correction relation having the storage capacity relation in which the coefficient tends to increase. The voltage generated by the internal resistance of the secondary battery when the secondary battery is charged / discharged by multiplying the charge / discharge current of the secondary battery, and the voltage generated by the polarization of the secondary battery calculated so far Multiplied by a ratio corresponding to a predetermined time constant multiplied by a maximum polarization voltage, which is the maximum voltage generated by the polarization of the secondary battery, divided by a unit time divided by the predetermined time constant By the sum of calculating the voltage generated by the polarization of the secondary battery when charging and discharging the secondary battery,
(B) Opening of the secondary battery obtained by subtracting the voltage generated by the calculated internal resistance of the secondary battery from the voltage between the terminals of the secondary battery and the voltage generated by the polarization of the calculated secondary battery Estimating the dischargeable storage capacity of the secondary battery based on the voltage;
This is the gist.

  In this method of estimating the storage capacity of the present invention, the estimated storage capacity is calculated as the relationship between the estimated storage capacity that is the dischargeable storage capacity of the secondary battery estimated up to now and the correction coefficient for correcting the internal resistance of the secondary battery. A correction coefficient obtained by applying the estimated storage capacity to a correction relationship having a storage capacity relationship in which the correction coefficient tends to increase as the correction coefficient decreases. The voltage generated by the internal resistance of the secondary battery when the secondary battery is charged and discharged by multiplying the charge / discharge current of the secondary battery is calculated, and the voltage generated by the polarization of the secondary battery calculated so far Rechargeable battery by the sum of the ratio according to the constant multiplied by the maximum polarization voltage, which is the maximum value of the voltage generated by the polarization of the secondary battery, multiplied by the unit time divided by the predetermined time constant Calculating a voltage generated by the polarization of the secondary battery when charging and discharging. Then, based on the open voltage of the secondary battery obtained by subtracting the voltage generated by the internal resistance of the secondary battery calculated from the voltage between the terminals of the secondary battery and the voltage generated by the polarization of the calculated secondary battery. Estimate the dischargeable storage capacity of the secondary battery. Thereby, since the open circuit voltage of a secondary battery can be calculated more appropriately, the storage capacity of the secondary battery that can be discharged can be estimated more appropriately.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 carrying the electrical storage capacity estimation apparatus which is one Example of this invention. It is a flowchart which shows an example of the electrical storage amount estimation routine performed by battery ECU52 of an Example. It is explanatory drawing which shows typically an example of the mode of the time change of the voltage Vb between terminals when the battery 50 is charging, and the open circuit voltage Vo. It is explanatory drawing which shows typically an example of the mode of the time change of the voltage Vb between terminals when the battery 50 is discharged, and the open circuit voltage Vo. 4 is an explanatory diagram showing an example of a storage amount setting map of a battery 50. FIG. It is explanatory drawing which shows an example of the correction coefficient setting map for internal resistance. 6 is an explanatory diagram showing an example of a relationship among a voltage Vdyn1, a first time constant τ1, and a first maximum polarization voltage FI1 generated by the first polarization of the battery 50. FIG. It is explanatory drawing which shows an example of the correction coefficient setting map for 1st polarization. It is explanatory drawing which shows an example of the correction coefficient setting map for 2nd polarization. It is explanatory drawing which shows an example of the mode of a time change of the voltage Vb between terminals when the battery 50 is discharged, and the open circuit voltage Vo. It is explanatory drawing which shows an example of the correction coefficient setting map of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a storage capacity estimation device according to an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment is for an engine 32 configured as an internal combustion engine using gasoline, light oil, or the like as fuel, and an engine for driving and controlling the engine 32 by inputting various detection values and control values. A carrier is connected to an electronic control unit (hereinafter referred to as an engine ECU) 36 and a crankshaft 34 of the engine 32, and a ring gear is connected to a drive shaft 22 connected to drive wheels 26a and 26b via a differential gear 24. A planetary gear mechanism 38, for example, a motor MG1 configured as a synchronous generator motor and having a rotor connected to the sun gear of the planetary gear mechanism 38, and a motor configured as a synchronous generator motor and having a rotor connected to the drive shaft 22, for example. MG2, inverters 41 and 42 for driving motors MG1 and MG2, and various detection values The inverters 41 and 42 are commonly used by a motor electronic control unit (hereinafter referred to as a motor ECU) 44 that drives and controls the motors MG1 and MG2 by inputting control values to control switching of the switching elements (not shown) of the inverters 41 and 42. A battery 50 that exchanges power with the motors MG1 and MG2 via the power line 46, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 that manages the battery 50, and the battery 50 externally via the power line 46. A charger 54 that charges using electric power from a power source 70 and a hybrid electronic control unit 60 that controls the entire vehicle are provided. Note that the battery ECU 52 mainly corresponds to the storage capacity estimation device of the embodiment.

  The battery 50 is configured as a secondary battery in which a plurality of battery modules formed by connecting a plurality of cells configured as lithium ion batteries or the like in series are connected in series. When the connector 72 to which the external power source 70 is connected and the connector 56 to which the charger 54 is connected, the battery 54 is charged by using the power from the external power source 70 before the vehicle starts traveling. Can be done. The charger 54 includes an AC / DC converter or a DC / DC converter (not shown), a relay that cuts off power supply to the battery 50, and the like.

  The battery ECU 52 is configured as a microprocessor centered on the CPU 52a, and includes a ROM 52b for storing a processing program, a RAM 52c for temporarily storing data, an input / output port and a communication port (not shown), in addition to the CPU 52a. The battery ECU 52 is charged / charged from a current sensor 51b that detects an inter-terminal voltage Vb from a voltage sensor 51a attached between terminals of the battery 50 and a current that is attached near the positive terminal of the battery 50 and charges / discharges the battery 50. The discharge current Ib, the battery temperature Tb from the temperature sensor 51c attached to a part of the battery 50 (for example, one of the battery modules, etc.), and the inter-terminal voltage of each of the battery modules are illustrated. Voltages from a plurality of voltage sensors that are not input are input via the input port, and data related to the state of the battery 50 is output to the hybrid electronic control unit 60 by communication as necessary. Further, the battery ECU 52 estimates the stored amount SOC, which is the ratio of the stored capacity to the total capacity of the battery 50 (the ratio of the dischargeable storage capacity to the total capacity), or the estimated remaining capacity SOC and the battery temperature Tb. Based on the above, the input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated. The input / output limits Win and Wout of the battery 50 set basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the input limiting correction coefficient and the output limiting correction coefficient based on the storage amount SOC of the battery 50. Can be set by multiplying the basic values of the set input / output limits Win and Wout by a correction coefficient. In the battery 50, each cell is configured to be the same, and each battery module having the same number of cells is also configured to be the same. Further, each cell constituting the battery 50 has a characteristic that the internal resistance increases as the ratio of the stored capacity to the capacity of each cell (the ratio of the dischargeable storage capacity to the capacity) decreases. The battery 50 has a characteristic that the internal resistance increases as the charged amount SOC of the battery 50 decreases.

  The hybrid electronic control unit 60 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM, a RAM, an input / output port, and a communication port in addition to the CPU. The hybrid electronic control unit 60 detects the shift position from the shift position sensor 62 that detects the position of the shift lever, the accelerator opening degree from the accelerator pedal position sensor 64 that detects the depression amount of the accelerator pedal, and the depression amount of the brake pedal. The brake position from the brake pedal position sensor 66 and the vehicle speed from the vehicle speed sensor 68 are input via the input port, and a control signal for driving an AC / DC converter, DC / DC converter, and relay (not shown) of the charger 54. Etc. are output via the output port, and various control signals and data are exchanged with the engine ECU 36, the motor ECU 44, and the battery ECU 52 connected via the communication port.

  Further, in the drive control executed by the hybrid electronic control unit 60, when the battery 50 is charged by the charger 54 using the electric power from the external power source 70 and the battery 50 is in a fully charged state or the like, An operation stop command is transmitted to the engine ECU 36 so that the operation of the engine 32 is stopped until the charged amount SOC of the battery 50 is less than a predetermined lower limit value (for example, 25%, 35%, etc.), and the motor MG1 The torque command of the motor MG2 is set so that the required torque is output to the drive shaft 22 within the range of the input / output limits Win and Wout of the battery 50, and the set torque command is set to the motor ECU 44. Send to. The engine ECU 36 that has received the operation stop command stops operation control such as fuel injection control and ignition control of the engine 32, and the motor ECU 44 that has received the torque command controls the inverter 41 to stop driving the motor MG 1 and uses the torque command. Switching control of the switching element of the inverter 42 is performed so that the motor MG2 is driven. By such control, the hybrid vehicle 20 of the embodiment travels by the power from the motor MG2 using the electric power of the battery 50 until the charged amount SOC of the battery 50 reaches less than a predetermined lower limit value.

  Next, the operation of the storage capacity estimation device mounted on the hybrid vehicle 20 of the embodiment thus configured, that is, the estimation of the storage amount SOC of the battery 50 will be described. FIG. 2 is a flowchart illustrating an example of a storage amount estimation routine executed by the battery ECU 52. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the stored charge amount estimation routine is executed, the CPU 52a of the battery ECU 52 firstly has a voltage Vb between the terminals of the battery 50 from the voltage sensor 51a, a charge / discharge current Ib of the battery 50 from the current sensor 51b, and a battery from the temperature sensor 51c. A process of inputting data necessary for estimating the storage amount SOC such as the battery temperature Tb of 50 is executed (step S100). Subsequently, it is determined whether or not the input charging / discharging current Ib has a value of 0 (step S110). When the charging / discharging current Ib has a value of 0, a value of 0 is set to the charging / discharging coefficient Ki used in the calculation formula described later. (Step S120) When the charge / discharge current Ib is not 0, a value obtained by dividing the charge / discharge current Ib by the absolute value of the charge / discharge current Ib is calculated as the charge / discharge coefficient Ki (step S130). In the embodiment, the charge / discharge current Ib is a positive value when the battery 50 is charged and a negative value when the battery 50 is discharged. Therefore, the charge / discharge coefficient Ki is calculated as a value 1 when the battery 50 is charged, and a value −1 when the battery 50 is discharged, and a value 0 when the battery 50 is not charged / discharged. Become.

  When the data is input and calculated in this way, the voltage as a voltage generated by the internal resistance of the battery 50 when the battery 50 is charged / discharged (a voltage increase with respect to the open circuit voltage Vo during charging and a voltage drop with respect to the open circuit voltage Vo during discharging) Vr is calculated (step S135), and a voltage Vdyn as a voltage generated by polarization of the battery 50 (for example, polarization due to decrease in the electrolyte concentration on the electrode surface) when the battery 50 is charged / discharged is calculated ( In step S155), a value obtained by subtracting the voltage Vr due to the internal resistance and the voltage Vdyn due to polarization calculated from the input terminal voltage Vo is calculated as the open circuit voltage Vo of the battery 50 (step S210), and based on the calculated open circuit voltage Vo. Then, the storage amount SOC of the battery 50 is estimated (step S220), and the storage amount estimation is performed. To end the routine. FIG. 3 and FIG. 4 schematically show an example of how the terminal voltage Vb and the open circuit voltage Vo change with time when the battery 50 is charged and discharged, respectively. 3 and 4, the voltage Vdyn1 indicates a voltage generated by the first polarization having a characteristic that changes with the first time constant τ1 (for example, reaches a maximum value in about several hundred msec), and the voltage Vdyn2 is the first time constant. A voltage generated by the second polarization having a characteristic that changes with a second time constant τ2 larger than the constant τ1 (for example, reaches a maximum value in several seconds) is shown. As shown in FIG. 3, when the battery 50 is charged, the inter-terminal voltage Vb is considered to be larger than the open circuit voltage Vo by the sum of the voltage Vr due to the internal resistance and the voltage Vdyn due to polarization. As shown in FIG. 4, when the battery 50 is discharged, the inter-terminal voltage Vb is considered to be smaller than the open circuit voltage Vo by the sum of the voltage Vr due to internal resistance and the voltage Vdyn due to polarization. . In addition, in the embodiment, the estimation of the storage amount SOC is obtained by previously obtaining the relationship between the open circuit voltage Vo and the storage amount SOC based on the characteristics of the battery 50 through experiments or the like, and stored in the ROM 52b as a storage amount setting map. When the open circuit voltage Vo is given, the corresponding stored power amount SOC is derived from the stored map and set. FIG. 5 shows an example of the storage amount setting map. Therefore, if the voltage Vr due to the internal resistance and the voltage Vdyn due to the polarization can be calculated more accurately, the open circuit voltage Vo can be calculated more accurately from the inter-terminal voltage Vb, and the open circuit voltage Vo thus calculated can be stored. By applying to the setting map, the charged amount SOC of the battery 50 can be estimated more accurately. Hereinafter, details of calculation of the voltage Vr generated by the internal resistance of the battery 50 and calculation of the voltage Vdyn generated by the polarization of the battery 50 will be described.

  In the calculation of the voltage Vr due to the internal resistance of the battery 50, the amount of stored electricity estimated when the routine was executed last time with the internal resistance correction coefficient Ka for correcting the reference internal resistance Rbase serving as the reference for the internal resistance of the battery 50. (Previous SOC) is set based on the battery temperature Tb (step S140), and the product of the set internal resistance correction coefficient Ka and the reference internal resistance Rbase is multiplied by the charge / discharge current Ib to obtain a voltage Vr due to the internal resistance. (Step S150). Here, the reference internal resistance Rbase is, for example, a target value for managing the storage amount SOC of the storage amount SOC of the battery 50 when the battery temperature Tb of the battery 50 is normal temperature (for example, 15 ° C. or 20 ° C.). For example, as the internal resistance of the battery 50 at 55%, 60%, or the like, it is possible to use what is obtained in advance through experiments or the like based on the characteristics of the battery 50. Further, in the embodiment, the internal resistance correction coefficient Ka is obtained by experimentally determining in advance the relationship between the previous SOC, the battery temperature Tb, and the internal resistance correction coefficient Ka based on the characteristics of the battery 50 and setting the internal resistance correction coefficient Ka. It is stored in the ROM 52b as an operational map, and when the previous SOC and battery temperature Tb are given, the corresponding internal resistance correction coefficient Ka is derived and set from the stored map. FIG. 6 shows an example of the internal resistance correction coefficient setting map. In the drawing, the predetermined amount Sref and the predetermined temperature Tbref are assumed to use the charged amount SOC and the battery temperature Tb when the reference internal resistance Rbase is obtained in the embodiment. As shown in the figure, the internal resistance correction coefficient Ka is set to a value of 1.0 when the previous SOC is equal to or larger than the predetermined amount Sref, and is set to a value that becomes larger than the value 1.0 as the previous SOC is smaller than the predetermined amount Sref. Is done. This is based on the characteristics of the battery 50 in which the internal resistance increases as the charged amount SOC of the battery 50 decreases. The internal resistance correction coefficient Ka increases as the battery temperature Tb decreases to temperatures Tb6, Tb5, Tb4 when the battery temperature Tb is equal to or higher than the predetermined temperature Tbref, and the battery temperature Tb decreases to the temperature Tb3 when the battery temperature Tb is lower than the predetermined temperature Tbref. , Tb2 and Tb1 are set to be smaller values. This is based on the specification of the battery 50 for efficiently charging and discharging when the battery temperature Tb is in the vicinity of the predetermined temperature Tbref. This means that when the battery temperature Tb is in the vicinity of the predetermined temperature Tbref, more charge can be exchanged. However, when the charged amount SOC is reduced and the internal resistance is increased, the exchange of charge is more restricted. This is considered to be based on the dependence of the battery temperature Tb on the storage amount SOC. Since the voltage Vr generated by the internal resistance of the battery 50 is calculated using the corrected reference internal resistance Rbase, the voltage Vr can be calculated more appropriately.

  In the calculation of the voltage Vdyn due to the polarization of the battery 50, first, the first maximum polarization voltage FI1 used for the calculation of the voltage Vdyn1 due to the first polarization that changes with the first time constant τ1 when the battery 50 is charged or discharged is corrected. Therefore, the correction coefficient Kb for the first polarization is set based on the previous SOC and the battery temperature Tb (step S160), the voltage by the first polarization (previous Vdyn1) calculated when the routine was executed last time, and the present routine. The following equation (1) is used by using a unit time Δt as an execution interval, a first time constant τ1, a first maximum polarization voltage FI1 multiplied by a first polarization correction coefficient Kb, and a charge / discharge coefficient Ki. The voltage Vdyn1 due to the first polarization is calculated (step S170). Expression (1) is for calculating the voltage Vdyn1 approximated to the first-order lag system caused by the first polarization. In the expression (1), the first time constant τ1 is previously determined based on the characteristics of the battery 50. What was calculated | required by etc. can be used. The maximum polarization voltage FI1 is the maximum value of the voltage generated by the first polarization that reaches the maximum value in a relatively short time (for example, the maximum value when the battery temperature Tb of the battery 50 is normal temperature and the charged amount SOC is at the target value). (Final value) etc.) can be used that has been obtained in advance by experiments or the like based on the characteristics of the battery 50. In the formula (1), a value (exp (−Δt / τ1)) by an exponential function indicates an attenuation rate. FIG. 7 shows an example of the relationship among the voltage Vdyn1, the first time constant τ1, and the first maximum polarization voltage FI1 generated by the first polarization of the battery 50 calculated by the equation (1). Since the left side of Equation (1) is multiplied by the charge / discharge coefficient Ki, the voltage Vdyn1 due to the first polarization is a positive value when the battery 50 is being charged, and is negative when the battery 50 is being discharged. When the battery 50 is not charged or discharged, the value is 0 regardless of the previous Vdyn1. Further, in the embodiment, the first polarization correction coefficient Kb is obtained by previously obtaining the relationship among the previous SOC, the battery temperature Tb, and the first polarization correction coefficient Kb based on the characteristics of the battery 50 by experiments or the like. The correction coefficient setting map is stored in the ROM 52b, and when the previous SOC and battery temperature Tb are given, the corresponding first polarization correction coefficient Kb is derived and set from the stored map. FIG. 8 shows an example of the first polarization correction coefficient setting map. As shown in the drawing, in the example, the internal SOC correction coefficient Ka in the internal resistance correction coefficient setting map shown in FIG. 6 has the same tendency as the previous SOC and the battery temperature Tb with respect to the previous SOC and the battery temperature Tb. On the other hand, it is determined in advance so that the first polarization correction coefficient Kb is set. This is based on the fact that the magnitude of the voltage generated by the polarization of the battery 50 tends to increase as the internal resistance increases. Since the voltage Vdyn1 generated by the first polarization of the battery 50 is calculated using the corrected first maximum polarization voltage FI1, the voltage Vdyn1 can be calculated more appropriately.

  Vdyn1 = [previous Vdyn1 ・ exp (-Δt / τ1) + (FI1 ・ Kb) ・ Δt / τ1] ・ Ki (1)

  In the calculation of the voltage Vdyn due to the polarization of the battery 50, the second voltage Vdyn2 used for the calculation of the voltage Vdyn2 due to the second polarization that changes with the second time constant τ2 larger than the first time constant τ1 when the battery 50 is charged or discharged. In order to correct the maximum polarization voltage FI2, the second polarization correction coefficient Kc is set based on the previous SOC and battery temperature Tb (step S180), and the voltage due to the second polarization calculated when this routine was executed last time. (Previous Vdyn2), unit time Δt as the execution interval of this routine, the second time constant τ2, the second maximum polarization voltage FI2 multiplied by the second polarization correction coefficient Kc, and the charge / discharge coefficient Ki are used. Then, the voltage Vdyn2 due to the second polarization is calculated by the following equation (2) (step S190), and the second polarization is converted to the calculated voltage Vdyn1 due to the first polarization. The plus According voltage Vdyn2 calculated as the voltage Vdyn caused by polarization of the battery 50 (step S200). Expression (2) is for calculating the voltage Vdyn2 approximated to the first-order lag system generated by the second polarization, and in the expression (2), the second time constant τ2 is previously tested based on the characteristics of the battery 50. What was calculated | required by etc. can be used. The second maximum polarization voltage FI2 is the maximum value of the voltage generated by the second polarization that reaches the maximum value in a relatively long time (for example, when the battery temperature Tb of the battery 50 is normal temperature and the charged amount SOC is at the target value). As a maximum value (final value, etc.), a value that has been obtained in advance through experiments or the like based on the characteristics of the battery 50 can be used. The formula (2) is obtained by replacing the previous Vdyn1, the first time constant τ1, the first maximum polarization voltage FI1, the first polarization correction coefficient Kb of the formula (1) with the previous Vdyn2, the second time constant τ2, and the second time constant τ2. This is for performing the same calculation as the equation (1) except that the maximum polarization voltage FI2 and the second polarization correction coefficient Kc are used. Further, in the embodiment, the second polarization correction coefficient Kc is obtained by experimentally determining the relationship between the previous SOC, the battery temperature Tb, and the second polarization correction coefficient Kb based on the characteristics of the battery 50 in advance. The correction coefficient setting map is stored in the ROM 52b, and when the previous SOC and battery temperature Tb are given, the corresponding second polarization correction coefficient Kc is derived and set from the stored map. FIG. 9 shows an example of the second polarization correction coefficient setting map. As shown in the drawing, in the example, the internal SOC correction coefficient Ka in the internal resistance correction coefficient setting map shown in FIG. 6 has the same tendency as the previous SOC and the battery temperature Tb with respect to the previous SOC and the battery temperature Tb. On the other hand, the second polarization correction coefficient Kc is set in advance. The reason for this is the same as described above. Since the voltage Vdyn2 generated by the second polarization of the battery 50 is calculated using the correction of the second maximum polarization voltage FI2 in this way, the voltage Vdyn2 can be calculated more appropriately, and as the sum of the voltage Vdyn1 and the voltage Vdyn2 The voltage Vdyn generated by the polarization of the battery 50 can be calculated more appropriately. Thereby, the open circuit voltage Vo obtained by subtracting the voltage Vr and the voltage Vdyn from the inter-terminal voltage Vb can be calculated more accurately, and the open circuit voltage Vo thus calculated is applied to the storage amount setting map. The amount of charge SOC of the battery 50 can be estimated more accurately.

  Vdyn2 = [previous Vdyn2 ・ exp (-Δt / τ2) + (FI2 ・ Kc) ・ Δt / τ2] ・ Ki (2)

  FIG. 10 shows an example of how the terminal voltage Vb and the open circuit voltage Vo change with time when the battery 50 is discharged. In the figure, a broken line indicates a comparison calculated without using the internal resistance correction coefficient Ka, the first polarization correction coefficient Kb, and the second polarization correction coefficient Kc in the calculation of the open circuit voltage Vo of the battery 50 in the embodiment. The open circuit voltage Vo of the battery 50 of an example is shown. When the battery 50 is discharged, the inter-terminal voltage Vb is smaller than the open circuit voltage Vo, but without correcting the reference internal resistance Rbase, the first maximum polarization voltage FI1, and the second maximum polarization voltage FI2 as in the comparative example. That is, when the open-circuit voltage Vo of the battery 50 is calculated without considering the characteristics of the battery 50 in which the internal resistance increases as the charged amount SOC decreases, the calculated open-circuit voltage Vo becomes smaller than the actual open-circuit voltage Vo, The difference between the estimated storage amount SOC and the actual storage amount SOC tends to be large. On the other hand, in the embodiment, the open-circuit voltage Vo is calculated by correcting the reference internal resistance Rbase, the first maximum polarization voltage FI1, and the second maximum polarization voltage FI2 in consideration of the characteristics of the battery 50. The quantity SOC can be estimated more accurately. In particular, in the hybrid vehicle 20 of the embodiment, since the electric power from the battery 50 is used to drive the electric power from the battery 50 until the electric storage amount SOC of the battery 50 reaches less than a predetermined lower limit value, the electric storage amount SOC is relatively small. Although charging / discharging of the battery 50 is performed in the region, the storage amount SOC of the battery 50 is less than a predetermined lower limit value because the storage amount SOC is estimated reflecting the characteristics of the battery 50 in which the internal resistance increases. Can be performed more appropriately. Further, since the torque command of the motor MG2 is set within the range of the input / output limits Win and Wout of the battery 50 calculated based on the storage amount SOC, the torque from the motor MG2 is set to be more appropriate for the drive shaft 22. Can be output.

  According to the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment described above, the internal resistance based on the previous SOC of the battery 50 is considered in consideration of the characteristics of the battery 50 in which the internal resistance increases as the storage amount SOC decreases. The voltage Vr generated by the internal resistance of the battery 50 is calculated by multiplying the reference internal resistance Rbase corrected by the correction coefficient Ka by the charge / discharge current Ib, and the voltage Vdyn approximated to the first-order lag system generated by the polarization of the battery 50 is calculated. Then, by estimating the charged amount SOC based on the open circuit voltage Vo obtained by subtracting the voltage Vr and the voltage Vdyn from the inter-terminal voltage Vb of the battery 50, the charged amount SOC of the battery 50 can be estimated more appropriately. it can.

  In the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment, when correcting the reference internal resistance Rbase, the first maximum polarization voltage FI1, and the second maximum polarization voltage FI2, a correction coefficient based on the previous SOC and the battery temperature Tb However, it may be multiplied by a correction coefficient based only on the previous SOC that is not related to the battery temperature Tb. Further, depending on the characteristics of the battery, when correcting the reference internal resistance Rbase, the first maximum polarization voltage FI1, and the second maximum polarization voltage FI2, the correction coefficient increases as the previous SOC decreases as shown in FIG. The correction coefficient may be multiplied by a correction coefficient that is set using a map that has a tendency that the correction coefficient increases as the temperature Tb decreases.

  In the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment, when calculating the voltage Vdyn1 generated by the first polarization of the battery 50 and the voltage Vdyn2 generated by the second polarization, the first maximum polarization voltage FI1 is calculated as the previous SOC. The first polarization correction coefficient Kb based on the battery temperature Tb and the second maximum polarization voltage FI2 are corrected using the second polarization correction coefficient Kc based on the previous SOC and the battery temperature Tb. The voltage Vdyn1 may be calculated without correcting the maximum polarization voltage FI1, the voltage Vdyn2 may be calculated without correcting the second maximum polarization voltage FI2, and the first maximum polarization voltage FI1 and the first The voltage Vdyn1 and the voltage Vdyn2 may be calculated without correcting both of the two maximum polarization voltages FI2.

  In the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment, a battery that changes with a voltage Vdyn1 generated by the first polarization of the battery 50 that changes with the first time constant τ1 and a second time constant τ2 that is larger than the first time constant τ1. The voltage Vdyn generated by the polarization of the battery 50 is calculated as the sum of the voltage Vdyn2 generated by the second polarization of 50 and used for the calculation of the open circuit voltage Vo. However, depending on the characteristics of the battery, the voltage Vdyn calculated in this way is used. Instead, the voltage generated by the polarization of the battery 50 that changes with one time constant may be used for the calculation of the open circuit voltage Vo.

  In the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment, in each map for setting the internal resistance correction coefficient Ka, the first polarization correction coefficient Kb, and the second polarization correction coefficient Kc, the previous SOC and battery temperature A value of 1.0 or more is set based on Tb, but depending on the value and setting method of the reference internal resistance Rbase, the first maximum polarization voltage Vdyn1, and the second maximum polarization voltage Vdyn2, the previous SOC and battery A value less than 1.0 may be set based on the temperature Tb.

  In the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment, a predetermined amount Sref common to the internal resistance correction coefficient setting map, the first polarization correction coefficient setting map, and the second polarization correction coefficient setting map. Each correction coefficient is set using the predetermined temperature Tref, but instead of the predetermined amount Sref and the predetermined temperature Tref, the internal resistance correction coefficient setting map, the first polarization correction coefficient setting map, and the second Each correction coefficient may be set using a predetermined amount as the storage amount SOC and a predetermined temperature as the battery temperature Tb that are different from each other in the polarization correction coefficient setting map.

  In the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment, as the first maximum polarization voltage FI1 and the second maximum polarization voltage FI2, the maximum value of the voltage generated by the first polarization and the maximum value of the voltage generated by the second polarization are used. For example, the maximum value of the voltage generated by the first polarization and the second polarization that increase as the charge / discharge current Ib increases and increase as the battery temperature Tb decreases. The maximum value of the generated voltage may be used.

  In the hybrid vehicle 20 equipped with the storage capacity estimation device of the embodiment, the storage amount SOC as a ratio of the dischargeable storage capacity to the total capacity of the battery 50 is estimated. It is good also as what estimates the electrical storage amount (here module electrical storage amount SOCm) as a ratio of the electrical storage capacity which can be discharged with respect to a capacity | capacitance. In this case, when estimating the charged amount SOC of the battery 50, the voltage Vb between the terminals of the battery 50 used in the embodiment or the previous SOCm as the previous value of the module charged amount SOCm instead of the previous SOC or between the terminals of each battery module. The module power storage amount SOCm can be estimated using the voltage and the charge / discharge current Ib of the battery 50 and the battery temperature Tb.

  Moreover, it is not limited to what is applied to such a hybrid vehicle, The form of the storage capacity estimation apparatus of a secondary battery mounted on a moving body such as a vehicle other than an automobile, a ship, an aircraft, or a construction facility does not move. A storage capacity estimation device for a secondary battery incorporated in the facility may be used. Furthermore, it is good also as a form of the storage capacity estimation method of a secondary battery.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the battery 50 corresponds to a “secondary battery”, and the internal resistance correction coefficient set using the internal resistance correction coefficient setting map based on the previous SOC and the battery temperature Tb from the temperature sensor 51c. Steps S140 and S150 of the storage amount estimation routine of FIG. 2 for calculating the voltage Vr generated by the internal resistance of the battery 50 by multiplying the correction obtained by multiplying Ka by the reference internal resistance Rbase and the charge / discharge current Ib from the current sensor 51b. The battery ECU 52 that executes the above process corresponds to “internal resistance voltage calculation means”, and the unit time Δt is set to the unit time Δt to the maximum polarization voltage FI1 obtained by multiplying the previous Vdyn1 by the decay rate corresponding to the first time constant τ1. The voltage Vdyn1 generated by the first polarization of the battery 50 is calculated as the sum of the product divided by τ1 and multiplied by the previous Vdyn2 The voltage generated by the second polarization of the battery 50 as the sum of the product of the decay rate corresponding to the second time constant τ2 and the product of the maximum polarization voltage FI2 multiplied by the unit time Δt divided by the second time constant τ2. The battery ECU 52 that executes steps S160 to S200 of the storage amount estimation routine of FIG. 2 for calculating Vdyn2 and calculating the voltage Vdyn generated by the polarization of the battery 50 corresponds to the “polarization voltage calculating means”, and is a voltage sensor. Step S210 of the storage amount estimation routine of FIG. 2 for estimating the storage amount SOC of the battery 50 based on the open circuit voltage Vo obtained by subtracting the voltage Vr due to internal resistance and the voltage Vdyn due to polarization from the inter-terminal voltage Vb from 51a, The battery ECU 52 that executes the process of S220 corresponds to “power storage capacity estimating means”.

  Here, the “secondary battery” is not limited to the battery 50, and a secondary battery having a characteristic that the internal resistance tends to increase as the dischargeable storage capacity decreases, such as a battery module constituting the battery 50. Any battery can be used. As the “internal resistance voltage calculation means”, the internal resistance correction coefficient Ka set using the internal resistance correction coefficient setting map based on the previous SOC and the battery temperature Tb from the temperature sensor 51c is used as the reference internal resistance Rbase. Is not limited to calculating the voltage Vr generated by the internal resistance of the battery 50 by multiplying the corrected value by the charge / discharge current Ib from the current sensor 51b, but the secondary battery estimated to date As the relationship between the estimated storage capacity that is the dischargeable storage capacity of the battery and the correction coefficient that corrects the internal resistance of the secondary battery, the estimated storage capacity is in a correction relationship having a storage capacity relationship in which the correction coefficient tends to increase as the estimated storage capacity decreases. Charge / discharge the secondary battery against the standard internal resistance that is the standard of the internal resistance of the secondary battery by the correction coefficient obtained by applying the capacity As long as it calculates a voltage generated by the internal resistance of the secondary battery when charging and discharging the secondary battery by multiplying the current may be any ones. The “polarization voltage calculation means” is obtained by multiplying the previous Vdyn1 by an attenuation factor corresponding to the first time constant τ1, and multiplying the maximum polarization voltage FI1 by the unit time Δt divided by the first time constant τ1. The voltage Vdyn1 generated by the first polarization of the battery 50 is calculated as the sum of the above, or the previous Vdyn2 multiplied by the decay rate corresponding to the second time constant τ2, and the maximum polarization voltage FI2 with the unit time Δt as the second time constant τ2. The voltage Vdyn2 generated by the second polarization of the battery 50 is calculated as the sum of the product obtained by dividing the divided value and the voltage Vdyn generated by the polarization of the battery 50 is not limited. The voltage generated by the polarization of the secondary battery calculated so far, such as calculating the voltage generated by one polarization, multiplied by the ratio according to the predetermined time constant When the secondary battery is charged / discharged by the sum of the maximum polarization voltage, which is the maximum value of the voltage generated by the polarization of the secondary battery, multiplied by the unit time divided by the predetermined time constant, the polarization of the secondary battery Anything can be used as long as it can calculate the generated voltage. As the “storage capacity estimation means”, the storage amount SOC of the battery 50 is estimated based on the open-circuit voltage Vo obtained by subtracting the voltage Vr due to the internal resistance and the voltage Vdyn due to polarization from the inter-terminal voltage Vb from the voltage sensor 51a. It is not limited to the above, but the voltage generated by the internal resistance of the secondary battery calculated from the voltage between the terminals of the secondary battery, such as the one that estimates the stored amount of the battery module that constitutes the battery 50, is calculated. Any battery can be used as long as it can estimate the dischargeable storage capacity of the secondary battery based on the open-circuit voltage of the secondary battery obtained by reducing the voltage generated by the polarization of the secondary battery.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of a storage capacity estimation device.

  20 hybrid vehicle, 22 drive shaft, 24 differential gear, 26a, 26b drive wheel, 32 engine, 34 crankshaft, 36 electronic control unit for engine, 38 planetary gear, 41, 42 inverter, 44 electronic control unit for motor, 46 power line 50 battery, 51a voltage sensor, 51b current sensor, 51c temperature sensor, 52 battery electronic control unit, 52a CPU, 52b ROM, 52c RAM, 54 charger, 56 connector, 60 hybrid electronic control unit, 61 ignition switch, 62 Shift position sensor, 64 Accelerator pedal position sensor, 66 Brake pedal position sensor, 68 Vehicle speed sensor, 70 External power supply, 72 Connector, MG1, MG 2 Motor.

Claims (7)

A storage capacity estimation device that estimates the dischargeable storage capacity of the secondary battery based on the open-circuit voltage of the secondary battery having a characteristic that the internal resistance tends to increase as the dischargeable storage capacity decreases.
As the relationship between the estimated storage capacity, which is the dischargeable storage capacity of the secondary battery estimated to date, and the correction coefficient for correcting the internal resistance of the secondary battery, the correction coefficient increases as the estimated storage capacity decreases. The secondary battery is obtained by correcting a reference internal resistance serving as a reference of the internal resistance of the secondary battery by the correction coefficient obtained by applying the estimated storage capacity to a correction relationship having a storage capacity relationship of Internal resistance voltage calculation means for calculating a voltage generated by the internal resistance of the secondary battery when the secondary battery is charged and discharged by multiplying the charge / discharge current of
Unit time is calculated by multiplying the voltage generated by the polarization of the secondary battery calculated up to now by a ratio corresponding to a predetermined time constant and the maximum polarization voltage which is the maximum value of the voltage generated by the polarization of the secondary battery. A polarization voltage calculating means for calculating a voltage generated by polarization of the secondary battery when the secondary battery is charged / discharged by a sum of the product divided by the predetermined time constant;
Based on the open-circuit voltage of the secondary battery obtained by subtracting the voltage generated by the calculated internal resistance of the secondary battery from the voltage between the terminals of the secondary battery and the voltage generated by the polarization of the calculated secondary battery. Storage capacity estimation means for estimating the dischargeable storage capacity of the secondary battery,
A storage capacity estimation device comprising: The storage capacity estimation device according to claim 1,
The correction relationship is a relationship between the temperature of the secondary battery and the correction coefficient. When the temperature of the secondary battery is equal to or higher than a predetermined temperature, the correction coefficient increases as the temperature decreases, and the temperature of the secondary battery becomes the predetermined temperature. If the temperature is lower than the temperature, the correction coefficient tends to be smaller as the temperature is lower.
The internal resistance voltage calculation means is means for correcting the reference internal resistance by the correction coefficient obtained by applying the temperature of the secondary battery and the estimated storage capacity to the correction relationship.
Storage capacity estimation device. The storage capacity estimation device according to claim 1 or 2,
The polarization voltage calculating means is configured to calculate the first voltage to a value calculated so far by the first polarization of the secondary battery that changes with a first time constant when the secondary battery is charged and discharged. Multiplying the ratio according to the time constant and the first maximum polarization voltage, which is the maximum value of the voltage generated by the first polarization of the secondary battery, divided by the unit time by the first time constant The voltage generated by the first polarization of the secondary battery when the secondary battery is charged / discharged by the sum of the multiplied value and the secondary battery is charged / discharged. From the first time constant when the secondary battery is charged / discharged A value obtained by multiplying the voltage calculated by the second polarization of the secondary battery, which changes with a large second time constant, to a current value by a ratio corresponding to the second time constant, A second maximum which is the maximum value of the voltage produced by the second polarization The voltage generated by the second polarization of the secondary battery when the secondary battery is charged / discharged by the sum of the polar voltage multiplied by the unit time divided by the second time constant is calculated. A means for calculating a voltage generated by the polarization of the secondary battery as a sum of a voltage generated by the first polarization of the calculated secondary battery and a voltage generated by the second polarization of the calculated secondary battery;
Storage capacity estimation device. The storage capacity estimation device according to claim 3,
The polarization voltage calculation means is configured such that the first polarization correction coefficient increases as the estimated storage capacity decreases as the relationship between the estimated storage capacity and the first polarization correction coefficient for correcting the first maximum polarization voltage. The first maximum polarization voltage corrected by the first polarization correction coefficient obtained by applying the estimated storage capacity to the first polarization correction relation having the second storage capacity relation of the tendency A second correction coefficient for polarization for calculating the voltage generated by the first polarization of the secondary battery instead of the first maximum polarization voltage and correcting the estimated storage capacity and the second maximum polarization voltage Obtained by applying the estimated storage capacity to a second polarization correction relation having a third storage capacity relation in which the second polarization correction coefficient tends to increase as the estimated storage capacity decreases. For the second polarization A means for calculating a voltage generated by the second polarization of the secondary battery used in place of those obtained by correcting the second maximum polarization voltage to the second maximum polarization voltage by a positive factor,
Storage capacity estimation device. The storage capacity estimation device according to claim 4,
The first polarization correction relationship is the relationship between the temperature of the secondary battery and the first polarization correction coefficient. The lower the temperature of the secondary battery is equal to or higher than a second predetermined temperature, the lower the temperature. When the temperature of the secondary battery is lower than the second predetermined temperature and the temperature of the secondary battery is lower than the second predetermined temperature, the first temperature correction coefficient tends to decrease as the temperature decreases. Two storage capacity relationships,
The second polarization correction relationship is the relationship between the temperature of the secondary battery and the second polarization correction coefficient, and the second battery correction temperature is lower when the temperature of the secondary battery is equal to or higher than a third predetermined temperature. When the temperature of the secondary battery is lower than the third predetermined temperature and the temperature of the secondary battery is lower than the third predetermined temperature, the second temperature correction coefficient tends to decrease as the temperature decreases, and the second temperature correction coefficient increases. 3 storage capacity relationship,
The polarization voltage calculation means uses the first polarization correction coefficient obtained by applying the temperature of the secondary battery and the estimated storage capacity to the first polarization correction relationship, and the first maximum polarization voltage. And the second maximum polarization voltage is corrected by the second polarization correction coefficient obtained by applying the temperature of the secondary battery and the estimated storage capacity to the second polarization correction coefficient. Means,
Storage capacity estimation device. The storage capacity estimation device according to claim 4 or 5,
The polarization voltage calculation means includes the first maximum polarization voltage as FI1, the first polarization correction coefficient as Kb, the first time constant as τ1, and the voltage generated by the first polarization of the secondary battery. The value calculated to date is Vdyn1 (previous), the second maximum polarization voltage is FI2, the second polarization correction coefficient is Kc, the second predetermined time constant is τ2, and the secondary battery Vdyn2 (previous) · exp (−Δt / τ1) + FI1 · Kb · Δt / τ1 where Vdyn2 (previous) is the value of the voltage generated by the second polarization so far and Δt is the unit time. To calculate the voltage generated by the first polarization of the secondary battery, and the voltage generated by the second polarization of the secondary battery by Vdyn2 (previous) · exp (−Δt / τ2) + FI2 · Kc · Δt / τ2. Is a means to calculate,
Storage capacity estimation device. A storage capacity estimation method for estimating a dischargeable storage capacity of the secondary battery based on an open circuit voltage of the secondary battery having a characteristic that the internal resistance tends to increase as the dischargeable storage capacity decreases,
(A) The correction as the estimated storage capacity is smaller as the relationship between the estimated storage capacity that is the dischargeable storage capacity of the secondary battery estimated up to now and the correction coefficient for correcting the internal resistance of the secondary battery The reference internal resistance that is a reference of the internal resistance of the secondary battery is corrected by the correction coefficient obtained by applying the estimated storage capacity to the correction relation having the storage capacity relation in which the coefficient tends to increase. The voltage generated by the internal resistance of the secondary battery when the secondary battery is charged / discharged by multiplying the charge / discharge current of the secondary battery, and the voltage generated by the polarization of the secondary battery calculated so far Multiplied by a ratio corresponding to a predetermined time constant multiplied by a maximum polarization voltage, which is the maximum voltage generated by the polarization of the secondary battery, divided by a unit time divided by the predetermined time constant By the sum of calculating the voltage generated by the polarization of the secondary battery when charging and discharging the secondary battery,
(B) Opening of the secondary battery obtained by subtracting the voltage generated by the calculated internal resistance of the secondary battery from the voltage between the terminals of the secondary battery and the voltage generated by the polarization of the calculated secondary battery Estimating the dischargeable storage capacity of the secondary battery based on the voltage;
Storage capacity estimation method.

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