JP2012058144A - Battery power feeding capability determination method and battery charging/discharging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine that power feeding from a battery to a system is enabled, in a control circuit for the battery, for charging the battery by shifting from a trickle charge mode to a quick charge mode.SOLUTION: The present invention relates to a battery power feeding capability determination method which is characterized in that, when a battery voltage Vmeets V>V+ΔV+Vin a quick charge mode, it is determined that a battery is capable of power feeding. Here, Vdenotes a battery voltage in trickle charge completion, ΔV=I×r, Idenotes a current in a constant current charge mode, (r) denotes an internal impedance of the battery, and Vdenotes a charging capability detection voltage of the battery.

Description

  The present invention relates to a battery power supply determination method and a battery charging / discharging device that know a predetermined value of power charged in a battery during battery charging before the charging of the battery is completed.

  Conventionally, there is known a method of charging by switching between trickle charging for charging a battery by supplying a low constant current for a certain period and rapid charging for charging a battery by supplying high power after the trickle charging is completed ( For example, see Patent Document 1). When a battery is deeply discharged, even if it is charged rapidly by supplying high power, it does not charge, or even if it is charged, there is a phenomenon that less power is charged than when fully charged before deep discharging . In order to solve this phenomenon, it is necessary to charge enough electric power so that rapid charging can be performed from the deeply discharged state. A method is known in which a constant amount of power is charged by trickle charging in which a low constant current is supplied for a certain period to charge the battery, and then rapidly charged. In addition, there is also known a method of performing trickle charging after the battery is fully charged in order to prevent a decrease in the amount of charged electric power with the passage of time due to spontaneous discharge.

  Fast charging methods include constant current fast charge mode that charges the battery by supplying a constant current higher than the constant current during trickle charge, and constant voltage fast charge that charges the battery by supplying a constant voltage. Modes and combinations thereof.

  In recent years, an increasing number of devices use both a power source obtained from a commercial AC power source and a battery power source. Some of the operations of these devices cannot be performed accurately with a power source obtained from a commercial AC power source, and must be operated with a power source obtained from a battery power source. Therefore, there is a need for a method of knowing the value of the power charged in the battery during battery charging and determining that sufficient power has been accumulated for the battery to supply power to the system.

Japanese Patent Laid-Open No. 08-140281

  However, in the prior art, the method of knowing the value of the electric power charged in the battery during battery charging can be realized by performing current integration calculation during the charging period, but the circuit scale becomes large and complicated processing is required. Necessary. In order to know the value of the electric power charged in the battery while charging the battery by a simple method other than the above, it is actually necessary to wait until the battery is fully charged.

  Accordingly, the present invention provides a method for knowing a predetermined value of power charged in a battery during battery charging before the battery is completely charged and a battery charging / discharging device capable of the determination by a simple method and apparatus. This is the issue.

In order to achieve the above-mentioned object, the present invention provides a control system for a battery that charges a battery by shifting from a trickle charge mode to a quick charge mode. And determining that the battery can be supplied when the battery voltage V _BAT satisfies V _BAT > V _TKL + ΔV + V _ACC in the quick charge mode. , Where V _{TKL is the} battery voltage when the trickle charge is completed, ΔV = I _CC × r, I _{CC is the} constant current charging mode current, r is the internal impedance of the battery, and V _ACC is dischargeable of the battery. This is the detection voltage.

The invention according to claim 2 is a determination method for determining that power can be supplied from the battery to the system in the battery control circuit for charging the battery by shifting from the trickle charge mode to the quick charge mode. In the quick charge mode, when the battery current I _BAT becomes equal to or lower than a predetermined current value I _VAL and V _BAT ≧ V _EOC , it is determined that the battery can supply power.

According to a third aspect of the present invention, there is provided a battery control circuit for charging a battery by shifting from a trickle charge mode to a quick charge mode including a constant current quick charge mode and a constant voltage quick charge mode. A determination method for determining that power supply is possible, where the battery voltage V _BAT satisfies the following formula (1), where V _BAT > V _TKL + ΔV + V _ACC (1), V _TKL : when trickle charging is completed Voltage of the battery, ΔV = I _CC × r, I _CC : current in constant current charging mode, r: internal impedance of the battery, V _ACC : detection voltage for discharge of the battery, or V _BAT ≧ Judging that the battery can supply power when either V _EOC and the battery current I _BAT <I _VAL are satisfied It is characterized by.

  According to a fourth aspect of the present invention, when it is determined by the determination method according to any one of the first to third aspects that the battery is capable of supplying power, power is supplied from the battery to the system. It is characterized by.

According to a fifth aspect of the present invention, there is provided a battery charging / discharging device comprising trickle charging means, constant current quick charging means, first battery power supply determining means, and battery power supply switching means. The battery power supply determining means generates a signal for turning on the battery power supply switching means when the battery voltage V _BAT satisfies V _BAT > V _TKL + ΔV + V _ACC , where V _TKL : completion of trickle charge Voltage of the battery at the time, ΔV = I _CC × r, I _CC : current in constant current charging mode, r: internal impedance of the battery, V _ACC : dischargeable detection voltage of the battery.

A sixth aspect of the present invention is a battery charge / discharge device comprising trickle charging means, constant voltage quick charging means, second battery power supply determining means, and battery power supply switching means, wherein the second battery The power feeding determining means generates a signal for turning on the battery power feeding switching means when the battery current I _BAT becomes a predetermined current value I _VAL or less.

The invention according to claim 7 is a trickle charging means, a constant current rapid charging means, a constant voltage rapid charging means, a rapid charging mode determining means, a first battery power supply determining means, and a second battery power supply determining. And a battery power supply switching means, wherein the first battery power supply determination means, when the battery voltage V _BAT satisfies V _BAT > V _TKL + ΔV + V _ACC , the battery power supply switch means _Is generated, where V _{TKL is} the voltage of the battery when the trickle charge is completed, ΔV = I _CC × r, I _{CC is} the current in the constant current charging mode, and r is the internal impedance of the battery. , V _ACC: a dischargeable detected voltage of the battery, the second battery power supply determination means, the battery current I _BAT becomes less than a predetermined current value I _VAL And if the V _BAT ≧ V _EOC, and generates a signal to turn on the battery power supply switching means.

  According to the present invention, by a simple method and apparatus, it is possible to know a predetermined value of the electric power charged in the battery during the battery charging before the charging of the battery is completed. It is possible to determine that power can be supplied at an appropriate timing before the charging of the battery is completed.

It is a circuit diagram which shows the 1st form of the battery charging / discharging apparatus which concerns on embodiment of this invention. It is a circuit diagram which shows the 2nd form of the battery charging / discharging apparatus which concerns on embodiment of this invention. It is a circuit diagram which shows the 3rd form of the battery charging / discharging apparatus which concerns on embodiment of this invention. It is a graph which shows the determination method in the constant current quick charge mode which concerns on embodiment of this invention. It is a graph which shows the determination method in the constant voltage quick charge mode which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a circuit diagram showing a first embodiment of the battery charge / discharge device of the present invention. The present embodiment is a battery charging / discharging device that supplies power to the battery 4 and the system 13 by the trickle charging unit 1 and the constant voltage quick charging unit 2. The trickle charging means 1 and the constant current quick charging means 2 are arranged in parallel, one end is connected to the power source, and the other end is connected to one end of the charging mode switching means 10. The charging mode switching means 10 is a switch for switching which of the trickle charging means 1 and the constant current quick charging means 2 is connected to the battery 4. The other end of the charging mode switching means 10 is connected to the battery 4 and the first battery power feeding determination means 8 via the battery power feeding switching means 11 and the battery terminal 7. The battery 4 is composed of a cell 5 and an internal circuit 6, the cell 5 and the internal circuit 6 are arranged in series, the internal circuit 6 is connected to the charging mode switching means 10, and the cell 5 is grounded. The battery power supply switching means 11 is connected to the system 13 and serves as a connection / disconnection switch between the battery charging / discharging device and the system 13. The first battery power supply determination means 8 is constituted by a grounded reference voltage 14 and a comparator 15. The battery 4 is connected to the positive input terminal of the comparator 15, the cell 5 is connected to the negative input terminal of the comparator 15, and the output of the comparator. The terminals are respectively connected to the battery power supply switching means 11 and instruct the battery power supply switching means 11 to disconnect or connect between the battery charge / discharge device and the system 13.

  Details of the operation method of the first embodiment of the battery charging / discharging device will be described later, and then the configuration of the second embodiment of the battery charging / discharging device shown in FIG. 2 will be described, and then the battery charging / discharging device shown in FIG. A configuration of the third embodiment will be described.

  FIG. 2 is a circuit diagram showing a second embodiment of the battery charge / discharge device of the present invention. This embodiment is different from the first embodiment of the battery charge / discharge device shown in FIG. 1 in that the constant voltage quick charge means 3 is used instead of the constant voltage quick charge means 2 and the second battery power supply determination means 8 is used instead of the first battery power supply determination means 8. The configuration is the same except that the battery power supply determination means 9 is used. The second battery power supply determination means 9 is composed of a grounded constant current source 16 and a comparator 15 so that the battery power supply switching means 11 is disconnected or connected between the battery charge / discharge device and the system 13. Give instructions.

FIG. 3 is a circuit diagram showing a third embodiment of the battery charge / discharge device of the present invention. In this embodiment, the first and second embodiments of the battery charge / discharge device shown in FIGS. 1 and 2 are combined. The charging mode switching means 10, the constant voltage quick charging means 2, and the constant current quick charging means 3 are arranged in parallel. The charging mode switching unit 10 is a switch for switching which of the trickle charging unit 1, the constant voltage quick charging unit 2, or the constant current quick charging unit 3 is connected to the battery 4. The first battery power supply determination unit 8 and the second battery power supply determination unit 9 are connected to the charging mode switching unit 10, the battery power supply switching unit 11, and the battery 4. The output terminals of the comparators 15 of the first battery power supply determination means 8 and the second battery power supply determination means 9 are both connected to the quick charge mode determination means 12, and the quick charge mode determination means 12 is connected to the first battery power supply determination means 12. It is a switch for switching which one of the determination unit 8 and the second battery power supply determination unit 9 is connected to the battery power supply switching unit 11. The switch of the quick charge mode determination means 12 is switched by the voltage V _BAT of the battery terminal 7.

  Next, a method for determining that power can be supplied from the battery to the system using the first, second, and third embodiments of the battery charging / discharging device of the present invention will be described with reference to FIGS. .

FIG. 4 is a graph illustrating a determination method in the operation of changing from the constant current rapid charge mode to the constant voltage rapid charge mode according to the present invention, and FIG. 5 is a graph illustrating the determination method in the constant voltage rapid charge mode. 4 and 5, V _EOC is a charge end determination voltage of battery 4, I _BAT is a current flowing through the battery, I _EOC (not shown) is an eigenvalue that is sufficiently small with respect to a charge current determined to end charging, Actual charge balance conditions are V _BAT > V _EOC and I _BAT <I _EOC .

First, a trickle charge mode in which the battery 4 is charged with a low constant current is executed, electric power is accumulated in the cell 5 of the battery 4, and the voltage V _BAT of the battery terminal 7 gradually increases. The switch of the charging mode switching means 10 is connected to the trickle charging means 1.

Next, when the voltage V _BAT of the battery terminal 7 reaches V _TKL , the charging mode switching means 10 switches to the quick charging mode.

V _{BAT at} the moment of switching to the quick charge mode is approximated by the following equation (1).
V _BAT = V _TKL + ΔV
= V _TKL + I _BAT × r (1)
Here, V _TKL is a reference voltage at which the battery can be rapidly charged, I _BAT is a current flowing through the battery and is determined by the constant voltage fast charging means 2 or the constant current rapid charging means 3, and r is the battery. V _TKL and r are eigenvalues of the charging circuit.

As shown in FIG. 4, when V _{BAT at} the moment of switching to the quick charge mode is smaller than V _E , the switch of the charge mode switching means 10 is connected to the constant current quick charge means 3, and I _BAT = _ICC. The current quick charge mode (Continuous Current, CC) is executed, and V _BAT is gradually increased. Here, I _CC is a current flowing through the battery in the constant current fast charge mode is a unique value of the constant current rapid charging means 3, V _E is constant-voltage fast-charge a battery charging target voltage (not shown) This is a value unique to the means 2. As V _BAT increases, the cell voltage V _CEL also increases. When V _BAT reaches V _E , it is not necessary to further increase V _BAT , so the switch of charge mode switching means 10 is connected to constant voltage quick charge means 2 and constant voltage fast charge mode (V _BAT = V _E ( (Continuous Voltage, CV). In this case, the 1st or 3rd form of the battery charging / discharging apparatus of this invention is used.

As shown in FIG. 5, when V _{BAT at} the moment of switching to the quick charge mode is equal to or larger than V _E , the voltage V _BAT of the battery terminal 7 has reached the maximum value, so There is no need to raise V _BAT . Therefore, the switch of the charge mode switching means 10 is connected to the constant voltage quick charge means 2 to execute a constant voltage quick charge mode (Continuous Voltage, CV) where V _BAT = V _E. In this case, the 2nd or 3rd form of the battery charging / discharging apparatus of this invention is used.

  Next, details of a method for determining that power can be supplied from the battery 4 to the system 13 will be described below.

First, as shown in the graphs of the battery current I _BAT in FIGS. 4 and 5, the power charged in the cell 5 is obtained from the integral value of the current I _BAT that has flowed into the battery from the start of charging.

As shown in FIG. 4, after switching from trickle charge mode to rapid charge mode, assuming that the amount of increase in V _BAT when the amount of power that can be supplied from the battery to the system is charged to the cell is V _ACC , When V _TKL + ΔV + V _ACC is smaller than V _E , it is determined that the amount of charge that can supply power from the battery to the system 13 is reached when the condition expressed by the following equation (2) is satisfied.
V _BAT > V _TKL + ΔV + V _ACC (2)

In FIG. 4, as an example, [Delta] V when the charging rate of the charging power of the cell is switched to V _BAT when the 40% V _BAT1, rapidly charging the battery voltage at the time of trickle charging is completed V _TKL, from trickle charge Is ΔV ₁ . ΔV is a variable that changes depending on r, and V _BAT when switching to rapid charging is measured to obtain ΔV ₁ . r includes an internal resistance that changes depending on the frequency of use of the battery, and the value of r varies depending on the number of times of use, such as increasing due to deterioration. Therefore, it is necessary to determine ΔV ₁ by measuring V _BAT every time switching from trickle charge to quick charge. Since the remaining V _ACC may be set to a constant or a value corresponding to ΔV ₁ , the charging that enables power supply from the battery to the system 13 easily and accurately by the voltage V _{BAT at} the battery terminal 7 from the equation (2). It becomes possible to determine that the amount has been reached. In this case, the 1st or 3rd form of the battery charging / discharging apparatus of this invention is used.

Next, as shown in FIG. 5, when V _TKL + ΔV + V _{ACC at} the moment of switching to the quick charge mode is larger than V _E , I _BAT when the amount of power that can be supplied from the battery to the system is charged to the cell is calculated. I _VAL . At this time, when the battery terminal voltage is equal to or higher than V _EOC and the battery current I _BAT is equal to or lower than I _VAL , it is determined that the amount of charge that can supply power from the battery 4 to the system 13 has been reached. In this case, the 2nd or 3rd form of the battery charging / discharging apparatus of this invention is used.

DESCRIPTION OF SYMBOLS 1 Trickle charge means 2 Constant current quick charge means 3 Constant voltage quick charge means 4 Battery 5 Cell 6 Internal circuit 7 Battery terminal 8 First battery power supply determination means 9 Second battery power supply determination means 10 Charge mode switching means 11 Battery power supply Switching means 12 Quick charge mode determination means 13 System 14 Reference voltage 15 Comparator 16 Constant current source

Claims (9)

A determination method for determining that power can be supplied from the battery to the system in the battery control circuit for charging the battery by shifting from the trickle charge mode to the quick charge mode,
A battery power supply determination method, wherein the battery is determined to be able to supply power when the battery voltage V _BAT satisfies the following formula (1) in the quick charge mode.
V _BAT > V _TKL + ΔV + V _ACC (1)
(V _TKL : the battery voltage when the trickle charge is completed, ΔV = I _CC × r, I _CC : current in constant current charging mode, r: internal impedance of the battery, V _ACC : dischargeable detection voltage of the battery) A determination method for determining that power can be supplied from the battery to the system in the battery control circuit for charging the battery by shifting from the trickle charge mode to the quick charge mode,
A method for determining _whether or not battery power can be supplied when the battery current I _BAT is less than or equal to a predetermined current value I _VAL and V _BAT ≧ V _EOC is determined in the quick charge mode. . Judgment to determine that power can be supplied from the battery to the system in the battery control circuit for charging the battery by shifting from the trickle charge mode to a quick charge mode consisting of a constant current quick charge mode and a constant voltage quick charge mode A method,
If V _BAT ≦ V _EOC and the battery voltage V _BAT satisfies the following formula (1),
V _BAT > V _TKL + ΔV + V _ACC (1)
(V _TKL : voltage of the battery when the trickle charge is completed, ΔV = I _CC × r, I _CC : current in constant current charging mode, r: internal impedance of the battery, V _ACC : dischargeable detection voltage of the battery )
A battery power supply possible determination method, characterized in that it is determined that the battery can supply power when V _BAT ≧ _VEOC and the battery current I _BAT <I _VAL is satisfied.   A battery charge / discharge switching method, comprising: supplying power from the battery to a system when it is determined by the determination method according to any one of claims 1 to 3 that the battery can supply power. . A battery charging / discharging device comprising trickle charging means, constant current rapid charging means, first battery power supply determining means, and battery power supply switching means,
The battery charging / discharging device, wherein the first battery power supply determining means generates a signal for turning on the battery power supply switching means when the battery voltage V _BAT satisfies the following expression (1).
V _BAT > V _TKL + ΔV + V _ACC (1)
(V _TKL : voltage of the battery when the trickle charge is completed, ΔV = I _CC × r, I _CC : current in constant current charging mode, r: internal impedance of the battery, V _ACC : dischargeable detection voltage of the battery ) A battery charging / discharging device comprising trickle charging means, constant voltage rapid charging means, second battery power supply determining means, and battery power supply switching means,
The second battery power supply determining means generates a signal for turning on the battery power supply switching means when the battery current I _BAT becomes equal to or lower than a predetermined current value I _VAL and V _BAT ≧ V _EOC. Battery charge / discharge device. Trickle charging means, constant current rapid charging means, constant voltage rapid charging means, rapid charging mode determination means, first battery power supply determination means, second battery power supply determination means, battery power supply switching means, A battery charge / discharge device comprising:
The first battery power supply determining means generates a signal for turning on the battery power supply switching means when the battery voltage V _BAT satisfies the following formula (1):
V _BAT > V _TKL + ΔV + V _ACC (1)
(V _TKL : voltage of the battery when the trickle charge is completed, ΔV = I _CC × r, I _CC : current in constant current charging mode, r: internal impedance of the battery, V _ACC : dischargeable detection voltage of the battery )
The second battery power feeding determining means generates a signal for turning on the battery power feeding switching means when the battery current I _BAT becomes equal to or lower than a predetermined current value I _VAL and V _BAT ≧ V _EOC. Battery charge / discharge device. 4. The battery power feedable determination according to claim 1, wherein V _TKL + ΔV in the equation (1) is obtained by measuring the battery voltage at the time of switching from the trickle charge mode to the quick charge mode. Method. 8. The battery charge / discharge device according to claim 5, wherein V _TKL + ΔV in the equation (1) is obtained by measuring a battery voltage at the time of switching from trickle charge to rapid charge.

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