JP2014066568A - Storage battery system and charge amount calculation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily calculate the amount of charge of a storage battery.SOLUTION: Map data is stored in a storage section 15 when the amount of charge in a state in which different types of storage batteries (lead acid battery Pb and nickel hydrogen battery Ni) are interconnected in parallel is calculated. In this map data, charge amount data of the storage battery when a predetermined amount of current flows in response to charge/discharge of the storage battery is associated with time data until the direction of the current flowing between the storage batteries in a non-load state after the predetermined amount of current flows changes. In the non-load state after charge or after discharge, a time measurement section 16 measures the time until the direction of the current flowing between the storage batteries changes. A control section 14 calculates the amount of charge of the storage battery on the basis of the time and map data.

Description

  The present invention relates to a storage battery system having a calculation unit that calculates the charge amounts of a plurality of storage batteries connected in parallel, and a charge amount calculation method thereof.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a storage battery that stores electric power supplied to an electric motor (motor) serving as a prime mover of the vehicle. As a method for calculating the charge amount (SOC) of the storage battery, for example, the charge rate estimation method of Patent Document 1 is known. The charging rate estimation method disclosed in Patent Document 1 measures a voltage when the vehicle is in a no-load state at every predetermined time, and uses the measured voltage to approximate a time characteristic of an open circuit voltage to an exponential decay function of the fourth or higher order. And the charging rate is estimated from the convergence value of the open circuit voltage calculated based on the coefficient.

JP 2005-43339 A

  In the charging rate estimation method of Patent Document 1, it is impossible to estimate the charging rate of the storage battery unless the voltage is measured for a long time (for example, about 6 hours). That is, the charging rate estimation method of Patent Document 1 requires complicated processing to estimate the charging rate, such as long-time voltage measurement and reflecting the result in a calculation formula.

  The present invention has been made paying attention to such problems existing in the prior art, and an object thereof is to easily calculate the charge amount of the storage battery.

  In order to solve the above problems, the invention described in claim 1 is a battery unit in which different types of storage batteries are connected in parallel, a current measurement unit that measures a current flowing between the storage batteries, and a measurement by the current measurement unit. Based on the results, a time measurement unit that measures the time until the direction of the current flowing between the storage batteries changes in a no-load state after charging or discharging, and calculation information for calculating the charge amount of the storage battery And a calculation unit that calculates the charge amount of the storage battery based on the measurement time measured by the time measurement unit and the calculation information.

  According to this, since the charge amount of the storage battery is calculated based on the time measured by the time measuring unit and the calculation information, the charge amount of the storage battery can be easily calculated. That is, the amount of charge is calculated by measuring the time until the direction of the current changes, so that the processing can be simplified.

  According to a second aspect of the present invention, in the storage battery system according to the first aspect, the calculation information includes charge amount data of the storage battery when a predetermined amount of current flows along with charge / discharge of the storage battery, and Map data that correlates time data until the direction of the current flowing between the storage batteries changes in a no-load state after a predetermined amount of current flows, and the calculation unit calculates the measurement time from the map data The gist is to calculate the charge amount of the storage battery by extracting the charge amount data associated with the time data corresponding to.

  Moreover, the invention according to claim 3 is the power storage system according to claim 2, further comprising a voltage measuring unit that measures a voltage between the storage batteries, and the map data further includes the charge amount data in relation to the charge amount data. Voltage data between the storage batteries when the direction of current changes is associated, and the calculation unit measures the voltage when the time data corresponding to the measurement time and the direction of the current change from the map data. The gist is to calculate a charge amount of the storage battery by extracting charge amount data associated with voltage data corresponding to the voltage measured by the unit.

  According to the invention of claim 2 or claim 3, map data is stored in advance as calculation information in the storage unit, and the charge amount of the storage battery is calculated based on the map data. It can be easily calculated. That is, since it is not necessary to acquire a large amount of information for complicated calculation processing or the calculation, the processing can be simplified.

  The invention according to claim 4 is a charge amount calculation method for calculating a charge amount of different types of storage batteries connected in parallel, and after charging or after discharging based on a measurement result of a current flowing between the storage batteries. Measure the time until the direction of the current flowing between the storage batteries changes in the no-load state, and calculate the charge amount of the storage battery using the measured time and the calculation information for calculating the charge amount of the storage battery. The gist is to calculate. According to this, the same effect as the invention of the first aspect can be obtained.

  According to a fifth aspect of the present invention, in the charge amount calculation method according to the third aspect, the calculation information includes charge amount data of the storage battery when a predetermined amount of current flows along with charge / discharge of the storage battery. , Map data that correlates time data until the direction of the current flowing between the storage batteries changes in a no-load state after the predetermined amount of current flows, and corresponds to the time measured from the map data The gist is to calculate the charge amount of the storage battery by extracting the charge amount data associated with the time data. Accordingly, the same effect as that attained by the 2nd aspect can be attained.

  The invention according to claim 6 is the charge amount calculation method according to claim 5, wherein the map data includes voltage data between the storage batteries when the direction of the current further changes with respect to the charge amount data. Is measured, and the voltage between the storage batteries when the current changes along with the time until the direction of the current changes, and the time data corresponding to the measurement time and the voltage data corresponding to the voltage are measured. The gist is to calculate the charge amount of the storage battery by extracting the associated charge amount data. According to this, the effect similar to the invention of Claim 2 and 3 can be acquired.

  According to the present invention, the charge amount of the storage battery can be easily calculated.

The block diagram which shows the structure of the storage battery system in 1st Embodiment. Explanatory drawing explaining the charge amount of each storage battery after charge. Explanatory drawing explaining the time when the direction of an electric current changes. The graph which shows the electric current amount which flows into each storage battery during charge. The graph which shows the electric current amount which flows into each storage battery during charge. The graph which shows the electric current amount which flows into each storage battery during charge. The graph which shows the electric current amount of the reflux current which flows after charge. The graph which shows the electric current amount of the reflux current which flows after charge. The graph which shows the electric current amount of the reflux current which flows after charge. Explanatory drawing explaining the map data for calculating charge amount. The flowchart which shows the calculation process of charge amount. The block diagram which shows the structure of the storage battery system in 2nd Embodiment. The graph which shows the electric current amount of the reflux current which flows after charge. The graph which shows the electric current amount of the reflux current which flows after charge. (A), (b) is explanatory drawing explaining the map data for calculating charge amount.

(First embodiment)
A first embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, a vehicle 10 such as an EV or a PHV is equipped with a storage battery system 13 having a battery unit 12 that stores power supplied to a load 11 that is a power supply target mounted on the vehicle 10. . The load 11 is an electric motor (motor) that becomes a prime mover of the vehicle 10, auxiliary machines, and the like. The battery unit 12 of the present embodiment is configured by connecting a plurality of storage batteries in parallel. More specifically, different types of storage batteries are connected in parallel. In this embodiment, as different types of storage batteries, a lead storage battery Pb serving as a first storage battery and a nickel hydride battery Ni serving as a second storage battery are connected in parallel. In addition, each storage battery which comprises the battery part 12 is what assembled the cell of the same kind into an assembled battery.

  The storage battery system 13 includes a controller 17 having a control unit 14 as a calculation unit, a storage unit 15, and a time measurement unit 16. The control unit 14 is configured by a computer such as an ECU (Electronic Control Unit) that performs predetermined arithmetic processing. The memory | storage part 15 memorize | stores various information, such as a control program for calculating the charge amount of a storage battery, and map data as information for calculation. The time measuring unit 16 includes a timer that measures time.

  Further, the storage battery system 13 includes a charger 19 that converts electric power supplied via a charging plug (not shown) connected to the external power source 18 into electric power for charging and charges the electric power. The charger 19 is connected to the controller 17 and is controlled by the controller 17. In addition, the storage battery system 13 includes an ammeter 20 as a first current measurement unit that measures the current flowing through the lead storage battery Pb, and an ammeter 21 as a second current measurement unit that measures the current flowing through the nickel metal hydride battery Ni. And. The ammeters 20 and 21 are connected to the controller 17 and transmit measurement results to the controller 17.

  In the storage battery system 13 of this embodiment, the charge amount (SOC) of each storage battery after charge / discharge is calculated using the map data MD for charge amount calculation stored in the storage unit 15. The map data MD is created in advance based on the simulation result. The SOC (State Of Charge) represents the amount of charge charged with respect to the capacity of the storage battery as a ratio.

  In the simulation described in the present embodiment, the charge amount of each storage battery when a plurality of types (three types in the present embodiment) of charge currents (corresponding to a predetermined amount of current) is supplied for a predetermined time is calculated. In addition, when calculating charge amount, the charge amount of each storage battery at the time of a charge start is adjusted to a fixed amount. Moreover, in the said simulation, the reflux current which flows between storage batteries in the no-load state after charge is measured. The no-load state is a state where no current is flowing. However, when the storage batteries are connected in parallel, current may flow through the individual storage batteries even if they are electrically unloaded. The current flowing at this time is the reflux current. That is, different types of storage batteries have different internal resistances. For this reason, the amount of current input to and output from each storage battery during charging and discharging also varies depending on the difference in internal resistance. As a result, when the load is electrically unloaded, the above-described reflux current flows between the storage batteries in order to balance the voltage between the storage batteries. This reflux current flows until each storage battery returns to its original potential.

  In the simulation described in the present embodiment, in the measurement of the return current, the time until the direction in which the current flows changes is measured. The direction in which the current flows varies depending on the current that flows immediately before the no-load state. In other words, the reflux current flows from the high-voltage storage battery side to the low-voltage storage battery side in the lead storage battery Pb and the nickel-metal hydride battery Ni when the no-load state occurs. For example, when the internal resistances of the lead storage battery Pb and the nickel metal hydride battery Ni are compared, the internal resistance of the nickel metal hydride battery Ni is smaller than the internal resistance of the lead storage battery Pb. For this reason, the charging current that flows during charging tends to flow toward the nickel metal hydride battery Ni. As a result, in a no-load state after charging, a reflux current flows from the nickel metal hydride battery Ni toward the lead storage battery Pb. The direction of the reflux current changes when the voltages of the lead storage battery Pb and the nickel metal hydride battery Ni are balanced. In the present embodiment, map data MD as shown in FIG. 10 is created in advance and stored in the storage unit 15 based on the simulation results described above.

Hereinafter, specific examples of simulation results will be described.
The charge amount of each storage battery (lead storage battery Pb and nickel metal hydride battery Ni) after charging can be calculated from the current accumulated amount. The accumulated current amount can be calculated by integrating the amount of current flowing to the storage battery during charging and time.

  As shown in FIG. 2, when the charging current is Ia, Ib, Ic [A], the respective charge amounts of the lead storage battery Pb are PD1, PD2, and PD3. The charging current has a larger Ib than Ia and a larger Ic than Ib. Then, the amount of current flowing to the lead storage battery Pb increases in proportion to the magnitude of the charging current, as shown by the alternate long and short dash line with the sign “Pb” in FIGS. As a result, when different charging currents are supplied to the lead storage battery Pb for the same time, the charge amount of the lead storage battery Pb increases as the charging current increases. That is, the charge amount of the lead storage battery Pb shown in FIG. 2 is more PD2 than PD1 and more PD3 than PD2. Thereby, the charge current and charge amount in the lead storage battery Pb can be associated. The charging currents Ia, Ib, and Ic are set to 100 [A], 150 [A], and 200 [A], for example.

  Further, as shown in FIG. 2, when the charging currents are Ia, Ib, and Ic [A], the respective charge amounts of the nickel metal hydride battery Ni are ND1, ND2, and ND3. The amount of current flowing to the nickel metal hydride battery Ni increases in proportion to the magnitude of the charging current, as shown by the solid line with the sign “Ni” in FIGS. As a result, when different charging currents are supplied to the nickel metal hydride battery Ni for the same time, the charge amount of the nickel metal hydride battery Ni increases as the charging current increases. That is, the amount of charge shown in FIG. 2 is larger than ND1 and more than ND2. Thereby, the charge current and charge amount in the nickel metal hydride battery Ni can be associated.

  The internal resistance of the lead storage battery Pb and the nickel metal hydride battery Ni is smaller in the nickel metal hydride battery Ni than in the lead storage battery Pb. That is, the nickel-metal hydride battery Ni flows more easily than the lead storage battery Pb. For this reason, as shown in FIGS. 4-6, even if it is a case where it is set as the same charging current, the electric current amount which the nickel hydride battery Ni flows rather than the lead acid battery Pb becomes large. Thereby, when the time which flows charging current is made into the same time, the amount of charge of lead acid battery Pb and nickel metal hydride battery Ni in that time becomes larger in nickel metal hydride battery Ni than lead acid battery Pb.

  And if it will be in a no-load state after charge of a storage battery, a reflux current will flow between storage batteries. The time for which the direction of the reflux current changes varies depending on the magnitude of the charging current supplied to each storage battery during charging and the time for which the charging current is supplied. That is, as shown in FIG. 3, the time [s] during which the direction of the reflux current changes becomes time T1, T2, T3 for each charging current Ia, Ib, Ic.

  The time [s] during which the direction of the reflux current changes varies depending on the charging currents Ia, Ib, and Ic as shown in FIGS. 7 to 9, the alternate long and short dash line with the symbol “Pb” indicates the transition of the reflux current on the lead storage battery Pb side, and the solid line with the symbol “Ni” indicates the transition of the reflux current on the nickel metal hydride battery Ni side. . As can be understood from these figures, after charging, a reflux current flows from the nickel metal hydride battery Ni to the lead storage battery Pb. The direction of the reflux current changes in the direction of flowing from the lead storage battery Pb toward the nickel metal hydride battery Ni as time elapses. Moreover, as shown in FIGS. 7 to 9, the time [s] for changing the direction of the reflux current becomes longer as the charging current is larger. That is, the times T1 to T3 shown in FIG. 3 are longer than the time T1 and longer than the time T2. The times T1, T2, and T3 are about 90 [s], 150 [s], and 180 [s].

  By summarizing such simulation results, the map data MD shown in FIG. 10 can be created. In the above simulation results, when the charging current is changed for the storage battery, the amount of charge of each storage battery is calculated for each charging current, and the time for the direction of the return current to change for each charging current is calculated. Has been. For this reason, since the time when the direction of the reflux current changes corresponds to the charging current, it also corresponds to the charge amount of each storage battery when the charging current flows. Therefore, as shown in FIG. 10, for each storage battery, map data MD in which the charge amount shown in FIG. 2 is associated with the time during which the direction of the return current shown in FIG. 3 changes can be created. In the present embodiment, the charge amount shown in FIG. 2 becomes the charge amount data of the storage battery when a predetermined amount of current flows along with the charge of the storage battery. In the present embodiment, the time when the direction of the return current shown in FIG. 3 changes is time data until the direction of the current flowing between the storage batteries changes in a no-load state after a predetermined amount of current flows. .

Hereinafter, the procedure for calculating the charge amount of the storage battery by the control unit 14 will be described with reference to FIG.
After charging and discharging, the control unit 14 causes the time measurement unit 16 to start measuring time. Further, the control unit 14 acquires the current amount on the lead storage battery Pb side and the current amount on the nickel metal hydride battery Ni side as the measurement results of the ammeters 20 and 21, respectively (step S10). Further, the control unit 14 determines whether or not the direction of the return current has changed based on the acquired amount of current (step S11).

  If the control unit 14 detects that the direction of the reflux current has changed, the control unit 14 makes an affirmative determination in step S11 and proceeds to step S12. On the other hand, when it is not detected that the direction of the return current has changed, the control unit 14 makes a negative determination in step S11, proceeds to step S10, and repeats the processing from step S10.

  Control part 14 which shifted to Step S12 acquires time, ie, time when the direction of return current changed, as a measurement result of time measurement part 16. Next, the control unit 14 refers to the map data MD stored in the storage unit 15 (step S13). And the control part 14 acquires the charge amount (SOC) of each storage battery from map data MD based on the time acquired by step S12 (step S14). For example, when acquiring the time T1, the control unit 14 acquires PD1 as the charge amount of the lead storage battery Pb and ND1 as the charge amount of the nickel metal hydride battery Ni from the map data MD. Thus, by acquiring the charge amount from the map data MD based on the time, the control unit 14 calculates the charge amounts of the lead storage battery Pb and the nickel metal hydride battery Ni. That is, the amount of charge of the storage battery is calculated (estimated) by a simple process of measuring time by the above process.

Next, the effect | action of the storage battery system 13 of this embodiment is demonstrated.
The storage unit 15 stores map data MD in which the amount of charge of each storage battery calculated in advance by simulation is associated with the time when the direction of the reflux current changes. For this reason, the control part 14 monitors the electric current which flows between storage batteries based on the measurement result of each ammeter 20,21, when calculating the charge amount of each storage battery. When the control unit 14 detects that the direction of the reflux current has changed based on the measurement results of the ammeters 20 and 21, the control unit 14 acquires time from the time measurement unit 16. That is, the time acquired at this time is the time when the direction of the reflux current is changed. And the control part 14 calculates the charge amount of each storage battery (lead storage battery Pb and nickel metal hydride battery Ni) based on the acquired time and the map data MD of the memory | storage part 15. FIG.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) Since the charge amount of the storage battery (lead storage battery Pb and nickel metal hydride battery Ni) is calculated based on the time measured by the time measuring unit 16 and the calculation information (map data MD), the charge amount of the storage battery can be easily Can be calculated. That is, it is only necessary to measure the time until the current direction changes, and the processing can be simplified.

  (2) Since the map data MD is stored in the storage unit 15 in advance and the charge amount of the storage battery (lead storage battery Pb and nickel metal hydride battery Ni) is calculated based on the map data MD, the charge amount of the storage battery is easy. Can be calculated. That is, since it is not necessary to acquire a large amount of information for complicated calculation processing or the calculation, the processing can be simplified.

  (3) Since the map data MD is used, data can be easily updated or changed. Further, since the charge amount is calculated from the map data MD, it is possible to calculate the charge amount with higher accuracy without being affected by a calculation error or the like that may be caused by the acquired data.

  (4) Even if the storage battery system 13 having the battery unit 12 in which different types of storage batteries are connected in parallel is constructed by using the charge amount calculation method of the present embodiment, the charge amount of each storage battery can be easily and accurately set. Can be calculated. That is, it is possible to configure the battery unit 12 that can flexibly cope with specifications required when the storage battery system 13 is constructed.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to FIGS.
Note that, in the embodiments described below, the same reference numerals are given to the same configurations as those of the embodiments already described, and redundant descriptions thereof are omitted or simplified.

  As shown in FIG. 12, the storage battery system 13 of this embodiment includes a voltmeter 22 as a voltage measurement unit that measures a voltage between the lead storage battery Pb and the nickel metal hydride battery Ni. The voltmeter 22 is connected to the controller 17 and transmits a measurement result to the controller 17.

  As shown in FIGS. 13 and 14, the time Tx until the flow direction of the reflux current flowing between the storage batteries changes in the no-load state after charging is the initial charge amount (initial SOC) of the storage battery before charging, etc. For this reason, even when charging is performed with different charging currents, the same time may occur. For this reason, in this embodiment, it is comprised so that charge amount (SOC) can be calculated even when time Tx becomes the same time as mentioned above.

  In this embodiment, the voltmeter 22 measures the voltage between the storage batteries when the flow direction of the reflux current changes, and the measurement result is added to the calculation of the charge amount. As shown in FIGS. 13 and 14, the voltage between the storage batteries changes depending on the magnitude of the reflux current flowing between the storage batteries. For example, when comparing the voltage V1 when the return current of the maximum current I1 flows as shown in FIG. 13 and the voltage V2 when the return current of the maximum current I2 larger than the maximum current I1 flows as shown in FIG. The voltage becomes larger when the return current of the maximum current I2 flows. For this reason, in this embodiment, focusing on the fact that the voltage changes according to the magnitude of the return current flowing in the no-load state, the amount of charge of each storage battery based on the time when the direction of the return current changes and the voltage at that time The map data MD is constructed so that can be calculated.

  As shown in FIGS. 15A and 15B, the map data MD1 and MD2 of the present embodiment include the times Ta1 to Tan and the time until the flow direction of the return current changes with respect to the charge amount of each storage battery. Are associated with each other. Note that the map data MD1 shown in FIG. 15A is map data indicating the charge amount of the lead storage battery Pb, and the map data MD2 shown in FIG. 15B is map data indicating the charge amount of the nickel metal hydride battery Ni. . These map data MD1 and MD2 are constructed based on the result of a simulation performed in advance. That is, charging is performed by flowing a predetermined charging current in a state where the initial charging amount is different, and the time and voltage at which the direction of the reflux current changes at that time are extracted. Then, the above extraction is performed with a plurality of charging currents, and based on the results, time Ta1 to Tan, voltages V1 to Vn, and charge amounts Pb1-1 to Pbn-n, Ni1-1 to Nin-n are associated. Thus, the map data MD1 and MD2 are constructed. The voltages V1 to Vn in the map data MD1 and MD2 are voltage data.

Hereinafter, the operation of the storage battery system 13 of the present embodiment will be described.
The control unit 14 calculates the charge amount of each storage battery using the map data MD1, MD2 stored in the storage unit 15. That is, the control unit 14 causes the time measurement unit 16 to start measuring time after charging and discharging, and determines whether or not the direction of the reflux current has changed based on the measurement results of the ammeters 20 and 21. . And if the control part 14 detects that the direction of a return current changed, while acquiring the time at that time from the time measurement part 16, it acquires the voltage between the storage batteries at that time from the voltmeter 22. FIG. Thereby, the control part 14 acquires the charge amount (SOC) of each storage battery from map data MD1, MD2 based on the acquired time and voltage. For example, when acquiring the time T1 and the voltage V1, the control unit 14 acquires Pb1-1 as the charge amount of the lead storage battery Pb from the map data MD1, and as the charge amount of the nickel metal hydride battery Ni from the map data MD2. Acquire Ni1-1.

Therefore, according to this embodiment, in addition to the effects (1) to (4) of the first embodiment, the following effects can be obtained.
(5) Even if the time Tx during which the direction of the return current changes is the same, each storage battery is determined from the time when the direction of the return current changes based on the map data MD1, MD2 and the voltage between the storage batteries at that time. The amount of charge can be easily calculated. Therefore, when calculating the charge amount, it is only necessary to measure time and voltage, so that the processing can be simplified. In addition, the calculation accuracy of the charge amount can be improved.

In addition, you may change the said embodiment as follows.
The map data MD described in the embodiment is created based on the simulation result at the time of charging. Similarly, the map data can be created based on the simulation result at the time of discharging. And by storing these map data in the memory | storage part 15, the charge amount of the storage battery after charging / discharging is computable.

The map data MD described in the embodiment is created based on three types of charging currents, but may be created based on four or more types of charging currents.
○ The amount of charge may be calculated using an arithmetic expression using time as a coefficient.

○ The combination of storage batteries may be changed. For example, a lead storage battery Pb and a lithium ion battery may be combined. Moreover, you may combine lead storage battery Pb and a capacitor.
O You may change to the battery part 12 which connected three or more types of storage batteries in parallel. For example, a lead storage battery Pb, a nickel metal hydride battery Ni, and a lithium ion battery may be connected in parallel.

  The storage battery system 13 is not limited to the vehicle 10 such as EV or PHV, but may be mounted on an industrial vehicle such as a forklift that drives the electric motor with the power of the storage battery. Moreover, the storage battery system 13 may be embodied not only for in-vehicle use but for stationary use.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) The storage battery system according to any one of claims 1 to 3, wherein the storage battery system is mounted on a vehicle that drives a load with electric power stored in the storage battery.

  (B) a first storage battery, a second storage battery connected in parallel to the first storage battery, a second storage battery of a type different from the first storage battery, and a current flowing through the first storage battery; Charging based on the measurement results of the first current measurement unit, the second current measurement unit that measures the current flowing to the second storage battery, and the first current measurement unit and the second current measurement unit A time measuring unit for measuring a time until a direction of a current flowing between the first storage battery and the second storage battery changes in a no-load state after or after discharge, the first storage battery, and the second storage A storage unit for storing calculation information for calculating the charge amount of the storage battery, and a calculation for calculating the charge amounts of the first storage battery and the second storage battery based on the time and the calculation information And a storage battery system.

  (C) a first storage battery, a second storage battery connected in parallel to the first storage battery, a second storage battery of a different type from the first storage battery, and a current flowing through the first storage battery; Charging based on the measurement results of the first current measurement unit, the second current measurement unit that measures the current flowing to the second storage battery, and the first current measurement unit and the second current measurement unit A time measuring unit for measuring the time until the direction of the current flowing between the first storage battery and the second storage battery changes in a no-load state after or after discharging, and when the direction of the current changes A voltage measuring unit that measures a voltage between the storage batteries, a storage unit that stores calculation information for calculating a charge amount of the first storage battery and the second storage battery, the time, the voltage, and the Based on the calculation information, the first storage battery and the second storage battery Battery system characterized by comprising a, a calculation unit for calculating an amount of charge.

  (D) a charge amount calculation method for calculating a charge amount of a second storage battery that is connected in parallel to the first storage battery and the first storage battery and is different from the first storage battery, Based on the measurement result of the current flowing through the first storage battery and the second storage battery, the direction of the current flowing between the first storage battery and the second storage battery in the no-load state after charging or discharging is determined. It measures the time until it changes, and calculates the charge amounts of the first storage battery and the second storage battery using the measurement time and information for calculating the charge amount of the storage battery. Charge amount calculation method.

  (E) a charge amount calculation method for calculating a charge amount of a first storage battery and a second storage battery that is connected in parallel to the first storage battery and is different from the first storage battery; Based on the measurement result of the current flowing through the first storage battery and the second storage battery, the direction of the current flowing between the first storage battery and the second storage battery in the no-load state after charging or discharging is determined. Measure the time until change, measure the voltage between the storage batteries when the current changes, and use the calculation information for calculating the measurement time, the voltage and the charge amount of the storage battery, the first A charge amount calculation method for calculating a charge amount of a storage battery and the second storage battery.

  Pb: lead storage battery, Ni: nickel metal hydride battery, T1-T3: time, MD, MD1, MD2 ... map data, 12: battery unit, 13 ... storage battery system, 14 ... control unit, 15 ... storage unit, 16 ... time measurement Part, 20, 21 ... ammeter, 22 ... voltmeter.

Claims (6)

A battery unit in which different types of storage batteries are connected in parallel;
A current measuring unit for measuring the current flowing between the storage batteries;
Based on the measurement result of the current measuring unit, a time measuring unit that measures the time until the direction of the current flowing between the storage batteries changes in a no-load state after charging or discharging, and
A storage unit for storing calculation information for calculating the charge amount of the storage battery;
A storage battery system comprising: a calculation unit that calculates a charge amount of the storage battery based on the measurement time measured by the time measurement unit and the information for calculation. The calculation information includes the charge amount data of the storage battery when a predetermined amount of current flows along with charge / discharge of the storage battery, and the current flowing between the storage batteries in a no-load state after the predetermined amount of current flows. Map data that correlates time data until the direction changes,
The storage battery system according to claim 1, wherein the calculation unit calculates a charge amount of the storage battery by extracting charge amount data associated with time data corresponding to the measurement time from the map data. A voltage measuring unit for measuring the voltage between the storage batteries,
The map data is associated with voltage data between the storage batteries when the direction of the current further changes with respect to the charge amount data,
The calculation unit obtains charge amount data associated with time data corresponding to the measurement time from the map data and voltage data corresponding to the voltage measured by the voltage measurement unit when the direction of the current changes. The storage battery system according to claim 2, wherein the amount of charge of the storage battery is calculated by extraction. A charge amount calculation method for calculating the charge amount of different types of storage batteries connected in parallel,
Based on the measurement result of the current flowing between the storage batteries, measure the time until the direction of the current flowing between the storage batteries changes in the no-load state after charging or discharging, and the measurement time and the charge amount of the storage battery A charge amount calculation method, wherein the charge amount of the storage battery is calculated using calculation information for calculation.   The calculation information includes the charge amount data of the storage battery when a predetermined amount of current flows along with charge / discharge of the storage battery, and the current flowing between the storage batteries in a no-load state after the predetermined amount of current flows. Map data that correlates time data until the direction changes, and by extracting charge amount data associated with time data corresponding to the measurement time from the map data, the charge amount of the storage battery The charge amount calculation method according to claim 4, wherein the charge amount is calculated. The map data is associated with voltage data between the storage batteries when the direction of the current further changes with respect to the charge amount data,
Measure the voltage between the storage batteries when the current changes along with the time until the direction of the current changes, and charge amount data associated with the time data corresponding to the measurement time and the voltage data corresponding to the voltage The charge amount calculation method according to claim 5, wherein the charge amount of the storage battery is calculated by extracting the charge amount.