JP4680783B2 - Secondary battery state detection device, state detection method, and state detection program - Google Patents

Description

  The present invention relates to a state detection device for a secondary battery that detects the state of a secondary battery mounted on a vehicle and the like, and a state detection method thereof.

  In recent years, hybrid electric vehicles (“HEV”) equipped with an engine and a motor as power sources have been put into practical use and attract attention. In such HEV, a secondary battery such as a nickel metal hydride battery is mounted as a power source, and electric power is supplied to each part of the HEV such as a motor and an air conditioner by discharging the secondary battery. ing. Moreover, in such HEV, the said motor is comprised so that it may function also as a generator, and at the time of braking or deceleration of a vehicle, the said motor is made to regenerate and the secondary battery is charged. As described above, in the HEV, energy that has been released into the atmosphere as heat in the conventional automobile can be stored in the secondary battery of the power supply device, so that energy efficiency can be improved and fuel consumption can be improved compared to the conventional automobile. Can be dramatically improved.

  In addition, the secondary battery has a problem that battery performance deteriorates when overdischarge or overcharge is performed. For this reason, in the HEV, the battery control device (hereinafter referred to as “battery ECU: Electric Control Unit”) indicates the state of charge of the secondary battery (SOC: State of Charge, hereinafter referred to as “battery remaining amount”). While estimating, charge / discharge (input / output) control of the secondary battery is performed based on the estimated SOC. In addition, in a secondary battery such as the above-mentioned nickel-metal hydride battery, a phenomenon called a memory effect may occur, and the electromotive voltage (discharge voltage) of the secondary battery may decrease, or the apparent battery capacity may decrease. There are things to do. When such a memory effect occurs, the battery ECU cannot accurately estimate the SOC, and there is a possibility that charge / discharge control for the secondary battery cannot be performed appropriately.

  Therefore, in a conventional secondary battery state detection device, for example, as described in Patent Document 1 below, predetermined information such as current and temperature at the time of charge and discharge of the secondary battery is constantly monitored, and the information Some data is stored in a storage unit. Further, in this conventional secondary battery state detection device, data of predetermined information such as time and temperature when the secondary battery is left is also stored in the storage unit, and all the data stored in the storage unit are stored. It has been proposed to correct the SOC by determining the memory state due to the memory effect in the secondary battery based on the data.

Further, in the conventional secondary battery state detection device, as described in Patent Document 2 below, for example, when the SOC is out of a predetermined level range, the SOC is temporarily and forcibly changed. Has been shown to let In this conventional secondary battery state detection device, the influence of the memory state is eliminated by correcting the SOC-electromotive voltage characteristics based on the voltage value and current value of the secondary battery when the secondary battery is varied. The SOC could be estimated.
JP 2004-22322 A JP 2000-348780 A

  However, the conventional secondary battery state detection device as described above has a problem in that the memory state of the secondary battery cannot be easily determined with high accuracy.

  Specifically, in the conventional secondary battery state detection device described in Patent Document 1 above, in order to determine the memory state of the secondary battery, the charge / discharge state and neglect of all the past of the secondary battery are determined. It was necessary to monitor the predetermined information in the state. For this reason, in this conventional secondary battery state detection device, it is difficult to prevent an increase in processing load in the battery ECU or to increase the size and complexity of the processing circuit. It couldn't be done easily. Furthermore, in order to determine the memory state with high accuracy, it is necessary to collect and accumulate many types of data.

  Further, in the conventional secondary battery state detection device described in Patent Document 2, when the SOC is within a predetermined level range, the memory state in the secondary battery cannot be easily determined. . Further, in this conventional secondary battery state detection device, when the SOC is out of a predetermined level range, the secondary battery is forcibly driven by rotating the load connected to the secondary battery, for example, a motor. It was necessary to forcibly charge the secondary battery by discharging the battery or regenerating the motor. Therefore, as in the conventional example described in Patent Document 1, it is difficult to easily determine the memory state with high accuracy in the secondary battery.

  In view of the above problems, an object of the present invention is to provide a state detection device for a secondary battery and a state detection method thereof that can easily and accurately determine the memory state in the secondary battery. To do.

In order to achieve the above object, a state detection device for a secondary battery according to the present invention is a state detection device for detecting the state of a secondary battery,
A current measuring unit that measures a current value of a current during charging and discharging of the secondary battery;
A voltage measuring unit for measuring a voltage value of a terminal voltage of the secondary battery;
A plurality of set data of the current value and the voltage value corresponding to the current value, and a no-load voltage calculation unit that calculates a no-load voltage based on the acquired set data;
When a specific current condition or voltage condition is continuously satisfied for a predetermined time, an open-circuit voltage calculation unit that calculates an open-circuit voltage from the terminal voltage of the secondary battery;
A zero current voltage change amount calculation unit that calculates a change amount of the no-load voltage or the open-circuit voltage in a predetermined period as a change amount of the zero current voltage of the secondary battery;
An estimated charge / discharge amount calculation unit for calculating an estimated charge / discharge amount of the secondary battery based on the change amount of the zero current voltage;
An integrated charge / discharge amount calculation unit for calculating an integrated charge / discharge amount of the secondary battery by integrating the current value of the current in the predetermined period;
A memory state determination unit that determines the memory state of the secondary battery by comparing the estimated charge / discharge amount and the integrated charge / discharge amount.

  In the state detection device of the secondary battery configured as described above, by comparing the estimated charge / discharge amount and the accumulated charge / discharge amount in a predetermined period, the inventor of the present invention can obtain the memory effect in the secondary battery. It has been found that it is possible to determine whether or not a memory state has occurred and to what extent. That is, when a memory state occurs in the secondary battery, it is confirmed that only the estimated charge / discharge amount of the estimated charge / discharge amount and the accumulated charge / discharge amount varies depending on the degree of the generated memory state. Acquired by repeating. The present invention has been completed based on the above-described knowledge, and the memory state determination unit compares the estimated charge / discharge amount with the integrated charge / discharge amount to determine whether or not a memory state has occurred in the secondary battery. And the extent can be determined with high accuracy and easily.

The secondary battery state detection apparatus further includes an SOC estimation unit that estimates a remaining battery level of the secondary battery using the estimated charge / discharge amount or the accumulated charge / discharge amount.
It is preferable that the SOC estimation unit corrects the estimated remaining battery capacity according to a comparison result between the estimated charge / discharge amount from the memory state determination unit and the integrated charge / discharge amount.

  In this case, the SOC estimation unit can correct the remaining battery level (SOC) according to the degree of the memory state of the secondary battery determined by the memory state determination unit, and easily estimate the remaining battery level with high accuracy. Can be obtained.

The secondary battery state detection device further includes an SOC range determination unit that determines whether or not the remaining battery level in the predetermined period is within a predetermined range,
The SOC estimation unit may correct the estimated remaining battery level according to the determination result from the SOC range determination unit.

  In this case, the SOC estimation unit can more appropriately correct the remaining battery level according to the usage state of the secondary battery, and easily estimate the remaining battery level with high accuracy according to the usage state of the secondary battery. Can be obtained.

The secondary battery state detection method of the present invention is a state detection method for detecting the state of the secondary battery,
Obtaining a plurality of set data of the current value of the current at the time of charge and discharge of the secondary battery and the voltage value of the terminal voltage of the secondary battery corresponding to the current value;
A step of calculating a no-load voltage based on the acquired set data;
When a specific current condition or voltage condition is continuously satisfied for a predetermined time, a step of calculating an open circuit voltage from the terminal voltage of the secondary battery;
Calculating a change amount of the no-load voltage or the open-circuit voltage in a predetermined period as a change amount of a zero current voltage of the secondary battery;
Calculating an estimated charge / discharge amount of the secondary battery based on a change amount of the zero current voltage;
Calculating an accumulated charge / discharge amount of the secondary battery by integrating the current value of the current in the predetermined period;
A step of determining a memory state in the secondary battery by comparing the estimated charge / discharge amount with the accumulated charge / discharge amount.

The secondary battery state detection program of the present invention is a state detection program for causing a computer to execute a secondary battery state detection method,
The state detection program acquires a plurality of set data of a current value of a current at the time of charge and discharge of the secondary battery and a voltage value of a terminal voltage of the secondary battery corresponding to the current value;
Calculating a no-load voltage based on the acquired set data;
When a specific current condition or voltage condition is continuously satisfied for a predetermined time, calculating an open circuit voltage from the terminal voltage of the secondary battery;
Calculating a change amount of the no-load voltage or the open-circuit voltage in a predetermined period as a change amount of a zero current voltage of the secondary battery;
Calculating an estimated charge / discharge amount of the secondary battery based on a change amount of the zero current voltage;
Calculating an accumulated charge / discharge amount of the secondary battery by integrating the current value of the current in the predetermined period;
Comparing the estimated charge / discharge amount with the accumulated charge / discharge amount, the computer is caused to execute a step of determining a memory state in the secondary battery.

  In the state detection method and state detection program of the secondary battery of the present invention configured as described above, the estimated charge / discharge amount and the cumulative charge / discharge amount of the secondary battery in a predetermined period are calculated, and the calculated estimated charge / discharge amount is calculated. The memory state in the secondary battery is determined by comparing the discharge amount with the accumulated charge / discharge amount. Thereby, the presence or absence and the extent of occurrence of the memory state in the secondary battery can be easily determined with high accuracy.

Moreover, in the state detection method of the secondary battery, using the estimated charge / discharge amount or the integrated charge / discharge amount, estimating a battery remaining amount of the secondary battery;
Preferably, the method includes a step of correcting the estimated remaining battery level according to a comparison result between the estimated charge / discharge amount and the accumulated charge / discharge amount.

Further, in the secondary battery state detection program, using the estimated charge / discharge amount or the accumulated charge / discharge amount, estimating a remaining battery level of the secondary battery;
It is preferable to cause the computer to execute a step of correcting the estimated remaining battery level in accordance with a comparison result between the estimated charge / discharge amount and the accumulated charge / discharge amount.

  In this case, the remaining battery level can be corrected in accordance with the determined level of the memory state of the secondary battery, and the remaining battery level can be easily estimated and obtained.

Further, in the secondary battery state detection method, a step of determining whether or not the remaining battery level in the predetermined period is within a predetermined range;
A step of correcting the estimated remaining battery level according to the determination result of the remaining battery level.

In the secondary battery state detection program, the step of determining whether or not the remaining battery level in the predetermined period is within a predetermined range;
According to the determination result of the remaining battery level, the computer may execute a step of correcting the estimated remaining battery level.

  In this case, the remaining battery level can be more appropriately corrected according to the usage state of the secondary battery, and the remaining battery level can be easily estimated and obtained according to the usage state of the secondary battery. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the state detection apparatus of the secondary battery which can determine the memory state in a secondary battery accurately and easily, and its state detection method.

  Hereinafter, a preferred embodiment showing a state detection device and a state detection method of a secondary battery of the present invention will be described with reference to the drawings. In the following description, a case where the present invention is applied to a secondary battery mounted on an HEV will be described as an example.

[Embodiment 1]
FIG. 1 is a diagram for explaining a state detection apparatus for a secondary battery according to a first embodiment of the present invention and a configuration of a main part of a vehicle equipped with the same. As shown in FIG. 1, the electric vehicle equipped with the secondary battery state detection device according to the first embodiment is an HEV. The electric vehicle includes an engine 24 and a motor 26 as a power source that transmits power to the drive shaft 28. The drive shaft 28 is connected to wheels (not shown). Further, the electric vehicle includes a secondary battery 40 as a power supply source to the motor 26. The electric power of the secondary battery 40 is supplied to the motor 26 via the relay unit 29 and the inverter 22. The inverter 22 converts direct current from the secondary battery 40 into alternating current for driving the motor.

  The engine 24 transmits power to the wheels via a power split mechanism 25, a speed reducer 27, and a drive shaft 28. The motor 26 transmits power to the wheels via a speed reducer 27 and a drive shaft 28. When the secondary battery 40 needs to be charged, a part of the power of the engine 24 is transmitted to the generator 23 via the power split mechanism 25.

  The electric power generated by the generator 23 is supplied to the secondary battery 40 via the inverter 22 and the relay unit 29 and used for charging. Further, when the electric vehicle is decelerated or braked, the motor 26 is used as a generator. The electric power generated by the motor 26 is also supplied to the secondary battery 40 via the inverter 22 and the relay unit 29 and used for charging.

  The relay unit 29 includes relays 30 to 32 and a resistor 33. The relay 31 is connected between the positive terminal of the secondary battery 40 and the high potential input terminal of the inverter 22. The relay 32 is connected between the negative terminal of the secondary battery 40 and the low potential input terminal of the inverter 22. The relay 30 is connected in series to the resistor 33 and connected in parallel to the relay 31. The relay 30 is used together with the resistor 33 to precharge a smoothing capacitor (not shown) of the inverter 22 when the vehicle is started.

  The electric vehicle also includes a battery control device (battery ECU) 1, a vehicle control device (vehicle ECU) 20, and an engine control device (engine ECU) 21 as control devices. The engine ECU 21 mainly controls the ignition timing of the engine 24, the fuel injection amount, and the like. The battery ECU 1 measures the voltage of the secondary battery 40, calculates the SOC (remaining battery level; State of Charge), determines the deterioration (including the presence or absence of the occurrence of the memory state and the degree thereof), and provides information on these results. To the vehicle ECU 20. The battery ECU 1 is configured to function as a state detection device for a secondary battery according to the present invention, as will be described in detail later.

  The vehicle ECU 20 controls the inverter 22 based on information input from the battery ECU 1, the engine ECU 21, and the like, thereby controlling the driving of the motor 26. Information input from the engine ECU 21 includes the operating state of the engine 24, the rotation angle of the crankshaft, and the like. The information from the battery ECU 1 includes the upper limit value (output limit value) of the discharge power of the secondary battery 40 in addition to the information such as the SOC of the secondary battery 40 described above. Further, the operation amount of the accelerator pedal 37, the operation amount of the brake pedal 36, the shift range selected by the shift lever 35, and the like are also input to the vehicle ECU 20, and these pieces of information are also used for controlling the inverter 22.

  Further, the vehicle ECU 20 closes the relays 30 to 32 by supplying the starting voltage (minimum operating voltage) to the relays 30 to 32, and opens the relays 30 to 32 by stopping the supply of the starting voltage. Specifically, when the vehicle ECU 20 detects the ignition (IG) 34 being turned on, the vehicle ECU 20 first closes the relay 30 and the relay 32. As a result, the smoothing capacitor of the inverter 22 is precharged. When the precharge is completed, the vehicle ECU 20 closes the relay 31 so that electric power is supplied from the secondary battery 40 to the motor 26 via the inverter 22. Further, when the vehicle ECU 20 detects that the ignition (IG) 34 is turned off, the vehicle ECU 20 stops supplying the starting voltage.

  Further, when the vehicle ECU 20 detects that the ignition 34 is turned on, the vehicle ECU 20 transmits a signal notifying that to the battery ECU 1 before supplying the activation voltage. On the other hand, when the vehicle ECU 20 detects that the ignition 34 is turned off, the vehicle ECU 20 stops supplying the starting voltage and simultaneously transmits a signal notifying the fact to the battery ECU 1.

  The secondary battery 40 is configured by connecting battery blocks B1 to B20 in series. Battery blocks B <b> 1 to B <b> 20 are accommodated in a battery case 42. Each of the battery blocks B1 to B20 is configured by electrically connecting two battery modules in series, and each battery module electrically connects six unit cells 11 in series. Configured. As each single battery 11, a nickel metal hydride battery can be used. In addition, the number of battery blocks, battery modules, and single cells 11 is not particularly limited. The configuration of the secondary battery 40 is not limited to the above example.

  A plurality of temperature sensors 43 are disposed in the battery case 42. The arrangement of the plurality of temperature sensors 43 is such that a plurality of battery blocks having relatively close temperatures are grouped as one group, or one battery block having a relatively different temperature from any of the battery blocks is grouped as one group. This is done by arranging two temperature sensors 43. The grouping is performed by measuring the temperature of each battery block by a prior experiment or the like.

  Next, the configuration of the battery ECU 1 will be specifically described with reference to FIG.

  FIG. 2 is a block diagram showing a configuration of battery ECU 1 shown in FIG. As shown in FIG. 2, the battery ECU 1 mainly includes a current measurement unit 2, a temperature measurement unit 3, a voltage measurement unit 4, a calculation unit 5, and a storage unit 6.

  The current measuring unit 2 measures the current value I of the current when the secondary battery 40 is charged / discharged. That is, the current measuring unit 2 converts the analog signal output from the current sensor 44 into a digital signal, and based on this, the current value I of the current input to the secondary battery 40 during charging and the secondary battery during discharging. Current data I (n) for specifying the current value I of the current output from 40 is generated and output to the computing unit 5. Further, the current measuring unit 2 generates current data I (n) with the charge time being negative and the discharge time being positive. The output of the current data I (n) to the calculation unit 5 by the current measurement unit 2 is performed at a preset cycle, and the calculation unit 5 also stores the current data I (n) in the storage unit 6.

  The temperature measuring unit 3 measures the battery temperature of the secondary battery 40. That is, the temperature measurement unit 3 converts the analog signal output from each temperature sensor 43 installed for each group into a digital signal, and generates temperature data T (n) for specifying the battery temperature for each group based on the analog signal. This is output to the calculation unit 5. Further, the output of the temperature data T (n) to the calculation unit 5 by the temperature measurement unit 3 is also performed at a preset cycle, and the calculation unit 5 also stores the temperature data T (n) in the storage unit 6.

  The voltage measuring unit 4 measures the voltage value V of the terminal voltage of the secondary battery 40. That is, the voltage measuring unit 4 measures the terminal voltages Vu1 to Vu20 of the battery blocks B1 to B20. In addition, the voltage measuring unit 4 generates voltage data V (n) that specifies the terminal voltages Vu <b> 1 to Vu <b> 20 and outputs this to the computing unit 5. The output of the voltage data V (n) to the calculation unit 5 by the voltage measurement unit 4 is also performed at a preset cycle, and the calculation unit 5 stores the voltage data V (n) in the storage unit 6.

  The calculation unit 5 includes a zero current voltage calculation unit 7, a zero current voltage change amount calculation unit 8, an estimated charge / discharge amount calculation unit 9, an integrated charge / discharge amount calculation unit 10, an electromotive force calculation unit 11, a polarization voltage calculation unit 12, and a memory. A state determination unit 13 and an SOC estimation unit 14 are provided. With this configuration, the calculation unit 5 determines whether or not the memory state is generated in the secondary battery 40 and the degree thereof, and obtains the SOC of the secondary battery 40 by reflecting the determination result. Charge / discharge (input / output) control is substantially performed.

  The zero current voltage calculation unit 7 calculates a zero current voltage Vb (voltage value V−intercept of an approximate current value I) corresponding to the current 0 (zero) of the secondary battery 40 and stores it in the storage unit 6. The zero current voltage calculation unit 7 includes a no-load voltage calculation unit 7a and an open-circuit voltage calculation unit 7b. The no-load voltage Vsep calculated by the no-load voltage calculation unit 7a or the open-circuit voltage calculation unit 7b The open circuit voltage Voc calculated by is stored in the storage unit 6 as the zero current voltage Vb.

  The no-load voltage calculator 7a acquires a plurality of set data of the current value I and the corresponding voltage value V, and calculates the no-load voltage Vsep based on the acquired set data. Specifically, the no-load voltage calculation unit 7a is based on the voltage data V (n) output from the voltage measurement unit 4 and the current data I (n) output from the current measurement unit 2 within the set period. For each battery block, a plurality of set data of the current value I of the current at the time of charging / discharging and the voltage value of the terminal voltage corresponding thereto are acquired. The acquired set data is stored in the storage unit 6 as a charge / discharge history. The voltage value V of the corresponding terminal voltage refers to the voltage value of the terminal voltage when the current value I is measured.

  Further, the no-load voltage calculation unit 7a determines whether or not the acquired set data is valid data based on a specific selection condition set in advance, and determines the no-load voltage Vsep from the set data determined to be valid. calculate. That is, the no-load voltage calculation unit 7a has the current data I (n) in the charging direction (−) and the discharging direction (+) within a predetermined current range (for example, ± 50 A), and in the charging direction and the discharging direction. It is determined whether or not the number of current data I (n) is equal to or greater than a predetermined number (for example, 10 out of 60 samples). Furthermore, when the current data I (n) is within the current range and a predetermined number or more, the no-load voltage calculation unit 7a determines that the charge / discharge amount of the secondary battery 40 when the set data is acquired is within a predetermined power range. (For example, when it is within 0.3 Ah), when the charge / discharge amount is within a predetermined power range, the set data of the voltage data V (n) and current data I (n) Is determined to be effective. Then, the no-load voltage calculation unit 7a obtains an approximate straight line of the primary voltage value V-current value I from the effective set data by statistical processing such as regression analysis using a method such as the least squares method. Is calculated as the no-load voltage Vsep and stored in the storage unit 6 as the zero current voltage Vb.

  The open-circuit voltage calculation unit 7b uses a specific current condition (for example, the absolute value of the current data I (n) is less than 10A) or a voltage condition (for example, the amount of change in the voltage data V (n) is less than 1V). Is continuously satisfied for a predetermined time (for example, 10 seconds), the open circuit voltage Voc is calculated for each battery block. That is, the open-circuit voltage calculation unit 7b refers to the storage unit 6 to obtain the average value Vave of the voltage data V (n) and the average value Iave of the current data I (n) in each battery block. Then, the open-circuit voltage calculation unit 7b multiplies the average value Iave of the obtained current data I (n) by the preset component resistance value Rcom of the secondary battery 40 to correct the voltage drop due to the component resistance. The open circuit voltage Voc (= Vave + Rcom × Iave) is calculated and stored in the storage unit 6 as the zero current voltage Vb. When the calculation units 7a and 7b of both the no-load voltage calculation unit 7a and the open circuit voltage calculation unit 7b cannot calculate the zero current voltage Vb, the voltage data V (n) and the current data I (n) The set data is acquired again.

  The zero current voltage change amount calculation unit 8 refers to the storage unit 6 to calculate the change amount ΔVb of the zero current voltage Vb (no load voltage Vsep or open circuit voltage Voc) in a predetermined period (for example, 1 minute), It is held in the storage unit 6.

  The estimated charge / discharge amount calculation unit 9 calculates the estimated charge / discharge amount ΔQv for each battery block based on the change amount ΔVb of the zero current voltage Vb calculated by the zero current voltage change amount calculation unit 8. Specifically, the estimated charge / discharge amount calculation unit 9 obtains an estimated charge / discharge amount ΔQv due to a voltage change in each battery block using the following equation (1), and stores it in the storage unit 6.

ΔQv = kb × (ΔVb + ΔVbc) / (Kk + Kpol) (1) Equation In the above equation (1), kb and ΔVbc are an adjustment coefficient and an adjustment constant for the change amount ΔVb of the zero current voltage Vb, respectively. It varies depending on the polarization characteristics and the voltage decay characteristics determined by the charge / discharge (use) state. In addition, with these adjustment coefficient kb and adjustment constant ΔVbc, for example, a reference table using the temperature of the secondary battery 40 as a parameter is stored in advance in the storage unit 6, and the estimated charge / discharge amount calculation unit 9 The adjustment coefficient kb and the adjustment constant ΔVbc corresponding to the temperature data T (n) when ΔVb is calculated are acquired from the corresponding reference table and substituted into the equation (1).

  In the above equation (1), Kk and Kpol are the electromotive force change constant and the polarization voltage generation constant with respect to the amount of charge (or discharge) in the SOC usage region (for example, the range of SOC from 30% to 70%), respectively. It varies depending on the polarization characteristics of the secondary battery 40 and the voltage attenuation characteristics determined by its charge / discharge (use) state. In addition, in these electromotive force change constant Kk and polarization voltage generation constant Kpol, for example, a two-dimensional map (characteristic curve) using the temperature of the secondary battery 40 as a parameter is stored in advance in the storage unit 6, and estimated charge The discharge amount calculation unit 9 acquires the electromotive force change constant Kk and the polarization voltage generation constant Kpol corresponding to the temperature data T (n) when the change amount ΔVb is calculated from the corresponding two-dimensional map, and (1) It is designed to be assigned to an expression.

  The accumulated charge / discharge amount calculation unit 10 calculates the accumulated charge / discharge amount ΔQi of the secondary battery 40 based on the current value I measured by the current measurement unit 2. In the first embodiment, the integrated charge / discharge amount calculation unit 10 reads out current data I (n) from the storage unit 6 in the same predetermined period as the estimated charge / discharge amount ΔQv calculated by the estimated charge / discharge amount calculation unit 9. Then, using the following equation (2), an accumulated charge / discharge amount ΔQi by current accumulation in each battery block is obtained and stored in the storage unit 6. However, when the current data I (n) is the data (−) at the time of charging, the integrated charge / discharge amount calculation unit 10 calculates the charging efficiency and integrates the multiplication value multiplied by the current data I (n). It is supposed to be.

ΔQi = ∫I (n) dt (2) The electromotive force calculation unit 11 calculates the electromotive force Vk of the secondary battery based on the integrated charge / discharge amount ΔQi calculated by the integrated charge / discharge amount calculation unit 10. In the first embodiment, the electromotive force calculation unit 11 adds the integration from the integration charge / discharge amount calculation unit 10 to a characteristic curve, formula, or map (table) indicating the relationship between the electromotive force Vk and the integration charge / discharge amount ΔQi. The electromotive force Vk is obtained by applying the charge / discharge amount ΔQi. Further, the characteristic curves, mathematical formulas, and maps showing the relationship between the electromotive force Vk and the accumulated charge / discharge amount ΔQi use temperature as a parameter. Specifically, in the first embodiment, the vertical axis (or horizontal axis) is the integrated charge / discharge amount ΔQi, the horizontal axis (or vertical axis) is the temperature, and the electromotive force corresponding to the intersection of the vertical axis and the horizontal axis. A two-dimensional map in which Vk is recorded is created in advance and stored in the storage unit 6. The electromotive force calculation unit 11 specifies the lowest temperature (minimum battery temperature) from the temperature for each group based on the temperature data T (n), and the integration calculated by the integration charge / discharge amount calculation unit 10. The charge / discharge amount ΔQi is applied to a two-dimensional map to calculate (estimate) the electromotive force Vk.

  The polarization voltage calculation unit 12 calculates the polarization voltage Vpol of the secondary battery based on the integrated charge / discharge amount ΔQi calculated by the integrated charge / discharge amount calculation unit 10. In the first embodiment, the polarization voltage calculation unit 12 adds the integration charge from the integration charge / discharge amount calculation unit 10 to a characteristic curve, formula, or map (table) indicating the relationship between the polarization voltage Vpol and the integration charge / discharge amount ΔQi. The polarization voltage Vpol is obtained by applying the charge / discharge amount ΔQi. Further, the characteristic curves, mathematical formulas, and maps showing the relationship between the polarization voltage Vpol and the accumulated charge / discharge amount ΔQi use temperature as a parameter. Specifically, in the first embodiment, the vertical axis (or horizontal axis) is the accumulated charge / discharge amount ΔQi, the horizontal axis (or vertical axis) is the temperature, and the polarization voltage corresponding to the intersection of the vertical axis and the horizontal axis. A two-dimensional map in which Vpol is recorded is created in advance and stored in the storage unit 6. The electromotive force calculation unit 11 specifies the lowest temperature (minimum battery temperature) from the temperature for each group based on the temperature data T (n), and the integration calculated by the integration charge / discharge amount calculation unit 10. The charge / discharge amount ΔQi is applied to a two-dimensional map to calculate (estimate) the polarization voltage Vpol.

  The memory state determination unit 13 refers to the storage unit 6 to determine the memory state of the secondary battery 40 for each battery block by comparing the estimated charge / discharge amount ΔQv and the accumulated charge / discharge amount ΔQi. Specifically, the memory state determination unit 13 determines the difference between the accumulated charge / discharge amount ΔQi calculated by the accumulated charge / discharge amount calculation unit 10 and the estimated charge / discharge amount ΔQv calculated by the estimated charge / discharge amount calculation unit 9. And the absolute value A of the difference is obtained. Then, the memory state determination unit 13 compares the obtained absolute value A with a predetermined value α stored in advance in the storage unit 6 and determines that the absolute value A is larger than the predetermined value α. The memory state determination unit 13 determines that the memory state due to the memory effect is occurring in the corresponding battery block. Further, the memory state determination unit 13 determines the level of the memory state based on the absolute value A, acquires the SOC correction coefficient αs according to the determined level of the memory state from the storage unit 6, It outputs to the SOC estimation part 14.

  More specifically, in the first embodiment, by repeating experiments and the like, a memory state is generated in each battery block, and it is determined that the SOC needs to be corrected according to the memory state. The absolute value of the difference between the discharge amount ΔQi and the estimated charge / discharge amount ΔQv is obtained. A predetermined value α greater than the obtained absolute value is determined and stored in advance in the storage unit 6. Further, when a memory state occurs in each battery block, only the estimated charge / discharge amount ΔQv of the estimated charge / discharge amount ΔQv and the accumulated charge / discharge amount ΔQi varies greatly depending on the degree of the generated memory state. It has been confirmed by experiments. Therefore, a characteristic curve, a mathematical expression, or a map (table) indicating the relationship between the correction coefficient αs and the fluctuation value of the estimated charge / discharge amount ΔQv, that is, the absolute value of the difference between the accumulated charge / discharge amount ΔQi is stored. Stored in the unit 6 in advance. Then, the memory state determination unit 13 acquires the correction coefficient αs based on the obtained absolute value A and outputs it to the SOC estimation unit 14.

  The SOC estimation unit 14 estimates the SOC in each battery block using the estimated charge / discharge amount ΔQv calculated by the estimated charge / discharge amount calculation unit 9 or the integrated charge / discharge amount ΔQi calculated by the integrated charge / discharge amount calculation unit 10. To do. Further, the SOC estimation unit 14 is configured to correct the estimated SOC according to the comparison result from the memory state determination unit 13. That is, when the SOC estimation unit 14 receives the correction coefficient αs from the memory state determination unit 13, the SOC estimation unit 14 corrects the estimated SOC using the input correction coefficient αs. Thereby, in the battery ECU 1, the SOC reflecting the degree of the memory state is obtained, and each battery block of the secondary battery 40 can be input / output controlled with high accuracy.

  The storage unit 6 stores a state detection program of the present invention and various programs for causing each unit of the battery ECU 1 to function. In addition, the storage unit 6 appropriately stores measurement data measured by each unit in the battery ECU 1.

  Next, the operation of the first embodiment configured as described above will be specifically described with reference to FIGS.

  FIG. 3 is a flowchart showing the calculation operation of the estimated charge / discharge amount in the battery ECU 1 shown in FIG. 1, and FIG. 4 shows the SOC calculation operation, the memory state determination operation, and the SOC in the battery ECU 1 shown in FIG. It is a flowchart which shows this correction | amendment operation | movement.

  As shown in step S1 of FIG. 3, in the first embodiment, the set data of the current data I (n) and the voltage data V (n) measured by the current measuring unit 2 and the voltage measuring unit 4, respectively, is calculated by the calculating unit 5. In the calculation unit 5, the no-load voltage calculation unit 7a checks whether or not the specific selection condition is satisfied for the set data (step S2). When the set data satisfies the selection condition, the no-load voltage calculation unit 7a obtains an approximate straight line of voltage value V-current value I from the set data, and from the V intercept (value of zero current) of the approximate line. The no-load voltage Vsep is calculated and stored in the storage unit 6 as the zero current voltage Vb (step S3).

  On the other hand, when it is determined in step S2 that the set data does not satisfy the selection condition, the calculation unit 5 causes the open circuit voltage calculation unit 7b to include the current data I (n) and voltage data V ( n) determines whether or not the specific current condition or voltage condition is satisfied continuously for a predetermined time (step S4), and if one of the conditions is satisfied for a predetermined time, it is opened. The voltage calculation part 7b calculates | requires the open circuit voltage Voc which correct | amended the voltage drop by component resistance by calculation, and memorize | stores it in the memory | storage part 6 as zero electric current voltage Vb (step S5). In step S4, when both the specific current condition and the voltage condition are not satisfied continuously for a predetermined time, the process returns to step S1.

  Next, in the calculation unit 5, the zero current voltage change amount calculation unit 8 reads the zero current voltage Vb from the storage unit 6, and calculates the change amount ΔVb of the zero current voltage Vb in a predetermined period (step S6). Thereafter, in the calculation unit 5, the estimated charge / discharge amount calculation unit 9 obtains the change amount ΔVb of the zero current voltage Vb calculated in step S6, and based on the corresponding temperature data T (n) in the predetermined period. To the adjustment coefficient kb, adjustment constant ΔVbc, electromotive force change constant Kk, and polarization voltage generation constant Kpol from the storage unit 6, and by substituting the acquired values into the above equation (1), the estimated charge / discharge amount ΔQv Is stored in the storage unit 6 (step S7).

  Further, as shown in step S8 of FIG. 4, in the calculation unit 5, the integrated charge / discharge amount calculation unit 10 uses the current data I (() used for calculating the no-load voltage Vsep or the open-circuit voltage Voc in step S3 or S5, respectively. The integrated charge / discharge amount ΔQi is calculated based on n) and stored in the storage unit 6 (step S8). Thereafter, in calculation unit 5, SOC estimation unit 14 reads estimated charge / discharge amount ΔQv or integrated charge / discharge amount ΔQi from storage unit 6, and calculates the SOC based on the read estimated charge / discharge amount ΔQv or integrated charge / discharge amount ΔQi. Then, it is held in the storage unit 6 (step S9).

  Subsequently, in the calculation unit 5, the memory state determination unit 13 reads the accumulated charge / discharge amount ΔQi and the estimated charge / discharge amount ΔQv from the storage unit 6, calculates the absolute value A of these differences (step S10), and calculates the absolute It is determined whether or not the value A is larger than a predetermined value α stored in the storage unit 6 (step S11). When the absolute value A is larger than the predetermined value α, the memory state determination unit 13 determines that a memory state has occurred (step S12), and acquires the correction coefficient αs from the storage unit 6 based on the absolute value A. To the SOC estimation unit 14. Thereafter, the SOC estimation unit 14 corrects the estimated SOC with the correction coefficient αs, and stores the new SOC in the storage unit 6 (step S13).

  On the other hand, if it is determined in step S11 that the absolute value A is equal to or less than the predetermined value α, the memory state determination unit 13 determines that no memory state has occurred, and the determination result is stored in the storage unit 6. (Step S14).

  As described above, in the first embodiment, the estimated charge / discharge amount calculation unit 9 and the accumulated charge / discharge amount calculation unit 10 in each battery block of the secondary battery 40 have the estimated charge / discharge amount ΔQv and the accumulated charge / discharge in a predetermined period. Each amount ΔQi is calculated. In addition, the memory state determination unit 13 obtains an absolute value A of the difference between the estimated charge / discharge amount ΔQv and the accumulated charge / discharge amount ΔQi, and compares it with a predetermined value α to determine whether or not a memory state has occurred in each battery block. Is judged. Further, when the memory state determination unit 13 determines that the memory state is occurring, the memory state determination unit 13 determines the degree of the memory state according to the absolute value A, and obtains a correction coefficient αs for correcting the SOC. . Thereby, in this Embodiment 1, the presence or absence and generation | occurrence | production degree of the memory state in each battery block of the secondary battery 40 can be determined with high precision and easily.

  In the first embodiment, since the SOC estimation unit 14 corrects the estimated SOC using the correction coefficient αs from the memory state determination unit 13, in the first embodiment, the occurrence of a memory state occurs. It becomes possible to easily estimate and obtain a high-accuracy SOC reflecting the presence and absence and the degree thereof, and input / output control of each battery block of the secondary battery 40 can be performed with high accuracy.

  The battery ECU 1 according to the first embodiment also installs a state detection program that implements various processes shown in FIGS. 3 and 4 in the microcomputer and executes the state detection program to implement the present embodiment. The state detection method of aspect 1 can be realized. In this case, a CPU (Central Processing Unit) of the microcomputer functions as the calculation unit 5. In addition, the voltage sensor connection circuit and the CPU function as the voltage measurement unit 4, the current sensor connection circuit and the CPU function as the current measurement unit 2, and the temperature sensor 43 connection circuit and the CPU measure the temperature. It functions as part 3. Further, various memories provided in the microcomputer function as the storage unit 6.

  Furthermore, in the field of HEV, a mode in which the vehicle ECU also functions as a battery ECU can be considered. In this aspect, the battery ECU 1 according to the first embodiment installs a state detection program that embodies various processes shown in FIGS. 3 and 4 in the microcomputer that constitutes the vehicle ECU 20, and executes the state detection program. This can be realized.

[Embodiment 2]
FIG. 5 is a block diagram showing a configuration of the battery ECU 1 according to the second embodiment of the present invention. In the figure, the main difference between the second embodiment and the first embodiment is that an SOC range discriminating unit for discriminating whether or not the SOC in a predetermined period is within a predetermined range and an SOC estimating unit are provided. The point is that the estimated SOC is corrected according to the determination result from the SOC range determination unit. In addition, about the element which is common in the said Embodiment 1, the same code | symbol is attached | subjected and the duplicate description is abbreviate | omitted.

  That is, as shown in FIG. 5, in the second embodiment, the battery ECU 1 is provided with an SOC range determination unit 15, and the SOC in the predetermined period when the memory state determination unit 13 determines the memory state is calculated. It is configured to determine whether or not it is within a predetermined range. Specifically, the SOC range determination unit 15 reads the SOC estimated by the SOC estimation unit 14 from the storage unit 6. Then, the SOC range determination unit 15 determines whether or not the read SOC is within a range of, for example, 5% ≦ SOC ≦ 30% or 70% ≦ SOC ≦ 95%, and the determination result is a memory state determination unit. 13 and the SOC estimation unit 14. Thereby, in the second embodiment, the memory state determination unit 13 has a memory state called a discharge memory generated when the secondary battery 40 is discharged and a memory state called a charge memory generated when the secondary battery 40 is charged. It becomes possible to discriminate. Furthermore, in the second embodiment, the SOC estimation unit 14 can estimate the SOC with higher accuracy by correcting the SOC estimated using the determination result of the SOC range determination unit 15 (details will be described later). ).

  In Embodiment 2, the electromotive force calculation unit 11 refers to the storage unit 6 so that the memory state determination unit 13 determines the memory state, and the change amount ΔVk of the electromotive force Vk in the predetermined period. (Hereinafter, referred to as “electromotive force change amount ΔVk”) is calculated. That is, the electromotive force calculation unit 11 applies the integrated charge / discharge amount ΔQi calculated by the integrated charge / discharge amount calculation unit 10 to the two-dimensional map in the storage unit 6, and the electromotive force Vk obtained this time, Is calculated by calculating the difference from the electromotive force Vk ′ before a predetermined period held in the storage unit 6 and is stored in the storage unit 6.

  In the second embodiment, the polarization voltage calculation unit 12 refers to the storage unit 6 so that the memory state determination unit 13 determines the memory state, and the change amount ΔVpol of the polarization voltage Vpol in the predetermined period. (Hereinafter referred to as “polarization voltage change amount ΔVpol”) is calculated. That is, the polarization voltage calculation unit 12 applies the accumulated charge / discharge amount ΔQi calculated by the accumulated charge / discharge amount calculation unit 10 to the two-dimensional map in the storage unit 6, and the polarization voltage Vpol obtained this time, The polarization voltage change amount ΔVpol is calculated by calculating the difference from the polarization voltage Vpol ′ held for a predetermined period before and stored in the storage unit 6.

  Further, in the second embodiment, the estimated charge / discharge amount calculation unit 9 uses the change amount ΔVb, the electromotive force change amount ΔVk, and the polarization voltage change amount ΔVpol of the zero current voltage Vb in the predetermined period to perform integrated charge / discharge. The correction coefficient K for calculating the estimated charge / discharge amount ΔQv ′ by correcting the amount ΔQi is calculated. That is, the estimated charge / discharge amount calculation unit 9 calculates the correction coefficient K using the following equation (3). Further, the estimated charge / discharge amount calculation unit 9 multiplies the accumulated charge / discharge amount ΔQi calculated by the accumulated charge / discharge amount calculation unit 10 by the correction coefficient K, thereby using the estimated charge / discharge amount without using the above equation (1). ΔQv ′ (= ΔQi × K) is obtained and stored in the storage unit 6.

K = ΔVb / (ΔVk + ΔVpol) (3) In the second embodiment, the memory state determination unit 13 refers to the storage unit 6 and compares the estimated charge / discharge amount ΔQv ′ with the accumulated charge / discharge amount ΔQi. By doing so, the memory state in the secondary battery 40 is determined for each battery block. Specifically, the memory state determination unit 13 calculates the cumulative charge / discharge amount ΔQi calculated by the cumulative charge / discharge amount calculation unit 10 and the estimated charge / discharge amount ΔQv ′ calculated by the estimated charge / discharge amount calculation unit 9. The difference is calculated, and the absolute value B of the difference is obtained. Then, the memory state determination unit 13 compares the obtained absolute value B with the predetermined value α ′ stored in advance in the storage unit 6 and determines that the absolute value B is larger than the predetermined value α ′. When it does, the memory state determination part 13 determines with the memory state by the memory effect having generate | occur | produced in the corresponding battery block. Further, when the SOC state determining unit 13 is notified from the SOC range determining unit 15 that the SOC is within the range of 5% ≦ SOC ≦ 30%, the discharge memory is generated in the corresponding battery block. When it is determined that the SOC is in the range of 70% ≦ SOC ≦ 95%, it is determined that the charging memory is generated in the battery block. Then, the memory state determination unit 13 determines the degree of the memory state based on the absolute value B while reflecting the determination result (SOC range) from the SOC range determination unit 15, and the degree of the determined memory state The correction coefficient αs ′ for SOC corresponding to is acquired from the storage unit 6 and output to the SOC estimation unit 14.

  More specifically, in the second embodiment, as in the first embodiment, a memory state is generated in each battery block by repeating experiments and the like, and the SOC is corrected according to the memory state. The absolute value of the difference between the accumulated charge / discharge amount ΔQi determined to be necessary and the estimated charge / discharge amount ΔQv ′ is obtained. A predetermined value α ′ larger than the obtained absolute value is determined and stored in advance in the storage unit 6. In each battery block, when a memory state occurs, only the estimated charge / discharge amount ΔQv ′ of the estimated charge / discharge amount ΔQv ′ and the accumulated charge / discharge amount ΔQi varies greatly depending on the degree of the generated memory state. This has been confirmed by experiments. Therefore, a characteristic curve, formula, or map (table) showing the relationship between the correction coefficient αs ′ and the fluctuation value of the estimated charge / discharge amount ΔQv ′, that is, the absolute value of the difference between the accumulated charge / discharge amount ΔQi. Is stored in advance in the storage unit 6. In addition, these characteristic curves and the like indicate that when the SOC range is 5% ≦ SOC ≦ 30% (when the discharge memory is generated) and when the SOC range is 70% ≦ SOC ≦ 95% (the charge memory is generated). Two cases) are obtained and stored in the storage unit 6 in advance. Then, the memory state determination unit 13 acquires the correction coefficient αs ′ according to the obtained absolute value B and the determination result from the SOC range determination unit 15 and outputs it to the SOC estimation unit 14.

  In the above description, the case where one predetermined value α ′ is used has been described. However, two predetermined values corresponding to the discharge memory and the charge memory are determined in advance and used as a determination criterion for the absolute value B. You can also.

  Further, in the second embodiment, SOC estimation unit 14 estimates the SOC in each battery block using estimated charge / discharge amount ΔQv ′ calculated by estimated charge / discharge amount calculation unit 9. The SOC estimation unit 14 is configured to correct the estimated SOC according to the comparison result from the memory state determination unit 13 and the determination result from the SOC range determination unit 15. That is, the SOC estimation unit 14 inputs the correction coefficient αs ′ from the memory state determination unit 13 and the SOC range determined by the SOC range determination unit 15 is 5% ≦ SOC ≦ 30% or 70% ≦ SOC ≦ When it is 95%, the SOC estimation unit 14 corrects the estimated SOC using the input correction coefficient αs ′. Thereby, the SOC estimation part 14 can estimate more suitable SOC according to the kind of memory state of the said discharge memory and charge memory.

  Next, the operation of the second embodiment configured as described above will be specifically described with reference to FIGS.

  FIG. 6 is a flowchart showing an estimated charge / discharge amount calculation operation and SOC calculation operation in battery ECU 1 shown in FIG. 5, and FIG. 7 is a memory state determination operation and SOC calculation operation in battery ECU 1 shown in FIG. It is a flowchart which shows correction | amendment operation | movement.

  In FIG. 6, in the second embodiment, as in the first embodiment, after the operations shown in steps S1 to S5 in FIG. The zero current voltage Vb is read, and a change amount ΔVb of the zero current voltage Vb in a predetermined period is calculated (step S6). Further, as in the first embodiment, the integrated charge / discharge amount calculation unit 10 performs integration based on the current data I (n) used for calculating the no-load voltage Vsep or the open-circuit voltage Voc in step S3 or S5, respectively. The charge / discharge amount ΔQi is calculated and stored in the storage unit 6 (step S8). Thereafter, in the second embodiment, the electromotive force calculation unit 11 and the polarization voltage calculation unit 12 read the accumulated charge / discharge amount ΔQi from the storage unit 6, and the accumulated charge / discharge amount ΔQi is correspondingly stored in the storage unit 6. By applying to the map, the electromotive force calculation unit 11 and the polarization voltage calculation unit 12 calculate the electromotive force Vk and the polarization voltage Vpol, and store them in the storage unit 6 (step S15).

  Subsequently, the electromotive force calculation unit 11 and the polarization voltage calculation unit 12 respectively read the electromotive force Vk ′ and the polarization voltage Vpol ′ previously calculated from the storage unit 6, and from the electromotive force Vk and the polarization voltage Vpol obtained in step S15. By subtracting the electromotive force Vk ′ and the polarization voltage Vpol ′, the electromotive force change amount ΔVk and the polarization voltage change amount ΔVpol are calculated and stored in the storage unit 6 (step S16).

  Next, the estimated charge / discharge amount calculation unit 9 reads out the change amount ΔVb, the electromotive force change amount ΔVk, and the polarization voltage change amount ΔVpol of the zero current voltage Vb from the storage unit 6 and substitutes them into the above equation (3). Thus, the correction coefficient K is calculated (step S17). Thereafter, the estimated charge / discharge amount calculation unit 9 calculates the estimated charge / discharge amount ΔQv ′ by multiplying the calculated correction coefficient K by the accumulated charge / discharge amount ΔQi read from the storage unit 6, and stores it in the storage unit 6. Hold (step S18). Thereafter, the SOC estimation unit 14 reads the estimated charge / discharge amount ΔQv ′ from the storage unit 6, calculates the SOC based on the estimated charge / discharge amount ΔQv ′, and stores the SOC in the storage unit 6 (step S 19).

  Subsequently, as shown in step S20 of FIG. 7, the memory state determination unit 13 reads the estimated charge / discharge amount ΔQv ′ and the accumulated charge / discharge amount ΔQi from the storage unit 6, and calculates an absolute value B of these differences. Then, it is determined whether or not the calculated absolute value B is larger than a predetermined value α ′ stored in the storage unit 6 (step S21). When the absolute value B is larger than the predetermined value α ′, the memory state determination unit 13 determines that a memory state has occurred (step S12). Further, the memory state determination unit 13 further determines the SOC range determination unit 15 Based on the determination result from, it is ascertained in which range the SOC is (step S22).

  That is, in step S22, when it is determined that the SOC range is 5% ≦ SOC ≦ 30%, the memory state determination unit 13 determines that the discharge memory is generated, and the absolute value calculated in step S21. By referring to the storage unit 6 based on B, the correction coefficient αs ′ corresponding to the discharge memory is acquired and output to the SOC estimation unit 14. After that, the SOC estimation unit 14 corrects the estimated SOC with the correction coefficient αs ′ and stores it in the storage unit 6 as a new SOC (step S23).

  If it is determined in step S22 that the SOC range is any of 0% ≦ SOC <5%, 30% <SOC <70%, and 95% <SOC ≦ 100%, the memory state determination unit 13 determines that almost no memory state has occurred, and notifies the SOC estimation unit 14 of the determination result. Thereafter, the SOC estimation unit 14 determines that the estimated SOC need not be corrected, and does not correct the estimated SOC in the step S19 (step S24).

  In step S22, when it is determined that the SOC range is 70% ≦ SOC ≦ 95%, the memory state determination unit 13 determines that the charging memory is generated, and the absolute value calculated in step S21. By referring to the storage unit 6 based on the value B, the correction coefficient αs ′ corresponding to the charging memory is acquired and output to the SOC estimation unit 14. Thereafter, the SOC estimation unit 14 corrects the estimated SOC with the correction coefficient αs ′, and stores it as a new SOC in the storage unit 6 (step S25).

  On the other hand, if it is determined in step S21 that the absolute value B is equal to or less than the predetermined value α ′, the memory state determination unit 13 determines that no memory state has occurred, and the determination result is stored in the storage unit 6. It is held (step S14).

  As described above, in the second embodiment, the estimated charge / discharge amount calculation unit 9 and the integrated charge / discharge amount calculation unit 10 in each battery block of the secondary battery 40 have the estimated charge / discharge amount ΔQv ′ and the integrated charge / discharge amount in a predetermined period. Each discharge amount ΔQi is calculated. Further, the memory state determination unit 13 obtains the absolute value B of the difference between the estimated charge / discharge amount ΔQv ′ and the accumulated charge / discharge amount ΔQi and compares it with a predetermined value α ′, thereby generating a memory state in each battery block. Whether or not there is. Further, when the memory state determination unit 13 determines that the memory state is occurring, the memory state determination unit 13 determines the degree of the memory state according to the absolute value B, and obtains a correction coefficient αs ′ for correcting the SOC. Yes. Thereby, in this Embodiment 2, the presence or absence and the extent of generation | occurrence | production of the memory state in each battery block of the secondary battery 40 can be determined with high precision and easily.

  In the second embodiment, an SOC range determining unit 15 for determining the SOC range in a predetermined period in which the memory state is determined is provided, and the memory state determining unit 13 sets the correction coefficient αs ′ according to the SOC range. Looking for. Further, since the SOC estimation unit 14 corrects the estimated SOC using the correction coefficient αs ′, the SOC estimation unit 14 corrects the SOC more appropriately according to the SOC range (use state) of the corresponding battery block. Therefore, it is possible to easily estimate and obtain a highly accurate SOC according to the usage state of the battery block.

  Specifically, in each battery block of the secondary battery 40, for example, when the memory state indicated by the solid line 50 in FIG. 8 does not occur and when the memory state indicated by the dotted line 51 occurs in FIG. Therefore, when the SOC range is 5% ≦ SOC ≦ 30% or 70% ≦ SOC ≦ 95%, the difference between the solid line 50 and the dotted line 51 becomes large. That is, when it is in these SOC ranges, the memory state determination unit 13 determines that the SOC needs to be corrected, acquires the correction coefficient αs ′, and outputs it to the SOC estimation unit 14.

  On the other hand, in the SOC range where 0% ≦ SOC <5%, 30% <SOC <70%, and 95% <SOC ≦ 100% in which the difference between the solid line 50 and the dotted line 51 hardly occurs, the memory state determination The unit 13 determines that there is no need to correct the SOC, and has not acquired the correction coefficient αs ′. As described above, in the second embodiment, it is possible to easily estimate and obtain a highly accurate SOC according to the usage state of the battery block.

  The battery ECU 1 according to the second embodiment also installs a state detection program that implements various processes shown in FIGS. 6 and 7 in the microcomputer, and executes the state detection program to implement the present embodiment. The state detection method of aspect 2 can be realized. In this case, the CPU of the microcomputer functions as the calculation unit 5. In addition, the voltage sensor connection circuit and the CPU function as the voltage measurement unit 4, the current sensor connection circuit and the CPU function as the current measurement unit 2, and the temperature sensor 43 connection circuit and the CPU measure the temperature. It functions as part 3. Further, various memories provided in the microcomputer function as the storage unit 6.

  Furthermore, in the field of HEV, a mode in which the vehicle ECU also functions as a battery ECU can be considered. In this aspect, the battery ECU 1 according to the second embodiment installs a state detection program that embodies various processes shown in FIGS. 6 and 7 in the microcomputer constituting the vehicle ECU 20, and executes the state detection program. This can be realized.

  It should be noted that the above embodiments are all illustrative and not restrictive. The technical scope of the present invention is defined by the claims, and all modifications within the scope equivalent to the configurations described therein are also included in the technical scope of the present invention.

  For example, in the above description, the case where the present invention is applied to HEV has been described. However, the present invention is not limited to this, and an electric vehicle such as an electric vehicle or an electric wheelchair in which a power source is configured only by a motor. The present invention can be applied as various power supply sources such as a backup power source for electronic devices such as computers or electric devices used outdoors.

  In the above description, the case where a nickel metal hydride battery is used as a secondary battery has been described. However, the present invention is not limited to this, and a memory state such as a nickel cadmium (nickel) battery is used. The present invention can be suitably applied to a secondary battery in which the above occurs.

  In the above description, the configuration in which the memory state is determined for each battery block has been described. However, the present invention is not limited to this, and the memory state of the entire secondary battery can also be determined. However, the case where the memory state is determined for each battery block as in the above embodiments is preferable in that the memory state can be determined with high accuracy and the SOC can be estimated with high accuracy.

  Since the secondary battery state detection device and the state detection method according to the present invention can easily and accurately determine the memory state of the secondary battery, the secondary battery state detection device is used as a power source for vehicles and the like. Effective for secondary batteries.

It is a figure explaining the principal part structure of the state detection apparatus of the secondary battery concerning Embodiment 1 of this invention, and the vehicle carrying this. FIG. 2 is a block diagram showing a configuration of a battery ECU 1 shown in FIG. 1. 3 is a flowchart illustrating an operation of calculating an estimated charge / discharge amount in battery ECU 1 shown in FIG. 1. 2 is a flowchart showing an SOC calculation operation, a memory state determination operation, and an SOC correction operation in battery ECU 1 shown in FIG. 1. It is a block diagram which shows the structure of battery ECU1 concerning Embodiment 2 of this invention. 6 is a flowchart showing an estimated charge / discharge amount calculation operation and an SOC calculation operation in battery ECU 1 shown in FIG. 5. 6 is a flowchart showing a memory state determination operation and an SOC correction operation in battery ECU 1 shown in FIG. 5. It is a graph which shows an example of the relationship between a memory state, SOC, and zero current voltage.

Explanation of symbols

1 Battery ECU (state detection device)
2 Current measurement unit 4 Voltage measurement unit 7 Zero current voltage calculation unit 7a No-load voltage calculation unit 7b Open voltage calculation unit 8 Zero current voltage change calculation unit 9 Estimated charge / discharge amount calculation unit 10 Integrated charge / discharge amount calculation unit 13 Memory state Determination unit 14 SOC estimation unit 15 SOC range determination unit 40 Secondary battery

Claims (9)

A state detection device for detecting a state of a secondary battery,
A current measuring unit that measures a current value of a current during charging and discharging of the secondary battery;
A voltage measuring unit for measuring a voltage value of a terminal voltage of the secondary battery;
A plurality of set data of the current value and the voltage value corresponding to the current value, and a no-load voltage calculation unit that calculates a no-load voltage based on the acquired set data;
When a specific current condition or voltage condition is continuously satisfied for a predetermined time, an open-circuit voltage calculation unit that calculates an open-circuit voltage from the terminal voltage of the secondary battery;
A zero current voltage change amount calculation unit that calculates a change amount of the no-load voltage or the open-circuit voltage in a predetermined period as a change amount of the zero current voltage of the secondary battery;
An estimated charge / discharge amount calculation unit for calculating an estimated charge / discharge amount of the secondary battery based on the change amount of the zero current voltage;
An integrated charge / discharge amount calculation unit for calculating an integrated charge / discharge amount of the secondary battery by integrating the current value of the current in the predetermined period;
A state detection device for a secondary battery, comprising: a memory state determination unit that determines a memory state in the secondary battery by comparing the estimated charge / discharge amount and the accumulated charge / discharge amount. While using the estimated charge / discharge amount or the accumulated charge / discharge amount, the SOC estimation unit for estimating the remaining battery level of the secondary battery,
2. The secondary battery according to claim 1, wherein the SOC estimation unit corrects the estimated remaining battery level according to a comparison result between the estimated charge / discharge amount from the memory state determination unit and the accumulated charge / discharge amount. State detection device. An SOC range determining unit for determining whether or not the remaining battery level in the predetermined period is within a predetermined range;
The secondary battery state detection device according to claim 2, wherein the SOC estimation unit corrects the estimated remaining battery level according to a determination result from the SOC range determination unit. A state detection method for detecting a state of a secondary battery,
Obtaining a plurality of set data of the current value of the current at the time of charge and discharge of the secondary battery and the voltage value of the terminal voltage of the secondary battery corresponding to the current value;
A step of calculating a no-load voltage based on the acquired set data;
When a specific current condition or voltage condition is continuously satisfied for a predetermined time, a step of calculating an open circuit voltage from the terminal voltage of the secondary battery;
Calculating a change amount of the no-load voltage or the open-circuit voltage in a predetermined period as a change amount of a zero current voltage of the secondary battery;
Calculating an estimated charge / discharge amount of the secondary battery based on a change amount of the zero current voltage;
Calculating an accumulated charge / discharge amount of the secondary battery by integrating the current value of the current in the predetermined period;
A step of determining a memory state of the secondary battery by comparing the estimated charge / discharge amount and the integrated charge / discharge amount. Using the estimated charge / discharge amount or the accumulated charge / discharge amount to estimate the remaining battery level of the secondary battery;
The secondary battery state detection method according to claim 4, further comprising a step of correcting the estimated remaining battery capacity in accordance with a comparison result between the estimated charge / discharge amount and the accumulated charge / discharge amount. Determining whether the remaining battery level in the predetermined period is within a predetermined range;
The method for detecting a state of a secondary battery according to claim 5, further comprising a step of correcting the estimated remaining battery level according to the determination result of the remaining battery level. A state detection program for causing a computer to execute a state detection method for a secondary battery,
The state detection program acquires a plurality of set data of a current value of a current at the time of charge and discharge of the secondary battery and a voltage value of a terminal voltage of the secondary battery corresponding to the current value;
Calculating a no-load voltage based on the acquired set data;
When a specific current condition or voltage condition is continuously satisfied for a predetermined time, calculating an open circuit voltage from the terminal voltage of the secondary battery;
Calculating a change amount of the no-load voltage or the open-circuit voltage in a predetermined period as a change amount of a zero current voltage of the secondary battery;
Calculating an estimated charge / discharge amount of the secondary battery based on a change amount of the zero current voltage;
Calculating an accumulated charge / discharge amount of the secondary battery by integrating the current value of the current in the predetermined period;
A program for detecting a state of the secondary battery by causing the computer to execute a step of determining a memory state of the secondary battery by comparing the estimated charge / discharge amount and the accumulated charge / discharge amount. Estimating the remaining battery level of the secondary battery using the estimated charge / discharge amount or the accumulated charge / discharge amount;
The secondary battery state detection program according to claim 7, wherein the computer executes a step of correcting the estimated battery remaining amount in accordance with a comparison result between the estimated charge / discharge amount and the accumulated charge / discharge amount. Determining whether or not the remaining battery level in the predetermined period is within a predetermined range;
The secondary battery state detection program according to claim 8, wherein the computer executes a step of correcting the estimated remaining battery level in accordance with the determination result of the remaining battery level.

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