JP2016111875A - Charging device and charging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time for charging.SOLUTION: A charging device includes: a main power supply device which has a first current control circuit for outputting a fixed charging current to be supplied to a secondary battery, and a voltage control circuit for outputting a charging current keeping the fixed battery voltage of the secondary battery; and a sub power supply device which is connected with the main power supply device in parallel, and has a second current control circuit for outputting a fixed charging current to be supplied to the secondary battery. In the main power supply device, first setting voltage which stops the operation of the first current control circuit is set, and in the sub power supply device, second setting voltage which stops the operation of the second current control circuit and has a higher value than the first setting voltage is set.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a charging device and a charging method for charging a secondary battery.

  2. Description of the Related Art Conventionally, as a charging device for charging a secondary battery, a charging device including a master charger and a slave charger connected in parallel with the master charger is known.

  In the conventional charging device, for example, a charging stop voltage is set for each of the master charger and the slave charger so that the slave charger stops charging before the master charger (Patent Document 1).

  In the above conventional technique, after the slave charger is stopped, the secondary battery is charged only by the master charger, and charging takes time.

  The disclosed technology has been made in view of the above circumstances, and aims to shorten the time required for charging.

  The disclosed technology includes a first current control circuit that outputs a constant charging current supplied to a secondary battery, and a voltage control circuit that outputs a charging current that maintains the battery voltage of the secondary battery constant. A main power supply device, and a sub power supply device connected in parallel with the main power supply device and having a second current control circuit that outputs a constant charging current supplied to the secondary battery, The main power supply device is set with a first set voltage for stopping the operation of the first current control circuit, and the sub power supply device stops the operation of the second current control circuit, It is a charging device in which a second set voltage having a value higher than one set voltage is set.

  The time required for charging can be shortened.

It is a figure explaining the charging device of a first embodiment. It is a figure explaining the main power supply device and sub power supply device which a charging device has. It is a figure explaining the battery monitoring circuit of 1st embodiment. It is a flowchart explaining operation | movement of the charging device of 1st embodiment. It is a figure explaining operation | movement of the charging device of 1st embodiment. It is a figure explaining the battery monitoring circuit of 2nd embodiment. It is a 1st flowchart explaining operation | movement of the charging device of 2nd embodiment. It is a 2nd flowchart explaining operation | movement of the charging device of 2nd embodiment.

(First embodiment)
The first embodiment will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a charging device according to the first embodiment.

  The charging device 10 of the present embodiment charges the secondary battery 12 with, for example, a rectified and smoothed voltage (DC power supply voltage) input by the input unit 11 that rectifies and smoothes an AC voltage. The input unit 11 is a rectifying and smoothing circuit, but may be an adapter that converts an AC voltage into a predetermined DC voltage. The secondary battery 12 is a rechargeable battery or capacitor.

  The charging device 10 of the present embodiment includes a main power supply device 20, a main power supply device 20, a sub power supply device 30, a sub power supply device 40, and a sub power supply device 50. The sub power supply devices 30 to 50 are connected to the main power supply device 20 in parallel.

  In the charging device 10 of the present embodiment, the main power supply device 20 charges the secondary battery 12 by a constant current constant voltage method (CC-CV method). That is, the main power supply device 20 of the present embodiment first charges the secondary battery 12 with a constant current value (constant current method), and after the battery voltage of the secondary battery 12 reaches a specified voltage, Continue charging while reducing the current value to maintain the voltage (constant voltage method).

  The sub power supply devices 30 to 50 of the present embodiment charge the secondary battery 12 by a constant current method (CC method).

  In the present embodiment, the charging by the sub power supply devices 30 to 50 is continued until the charging by the constant voltage method in the main power supply device 20 is completed. Therefore, in this embodiment, the value of the charging current supplied to the secondary battery 12 by the sub power supply devices 30 to 50 can be maintained until the charging is completed, and the time required for charging can be shortened.

  In addition, although the charging device 10 of this embodiment was set as the structure which has three sub power supply devices, the number of sub power supply devices is not limited to this. The number of sub power supply devices included in the charging device may be one or four or more.

  Below, with reference to FIG. 2, each charging device which the charging device 10 has is demonstrated. FIG. 2 is a diagram illustrating a main power supply device and a sub power supply device included in the charging device.

  First, the main power supply device 20 will be described. The main power supply device 20 of the present embodiment includes a current control circuit 21, a voltage control circuit 22, a battery monitoring circuit 23, a controller 24, and a latch circuit 25.

  The current control circuit 21 of the present embodiment outputs a constant charging current supplied to the secondary battery 12. The constant charging current is a preset value. In the following description, the constant charging current is referred to as the setting current I1.

  The voltage control circuit 22 according to the present embodiment supplies the secondary battery 12 with a charging current that is controlled so that the battery voltage of the secondary battery 12 is maintained at a specified voltage. The specified voltage of this embodiment is a preset value. In the following description, the specified voltage is referred to as a set voltage V1.

  Further, when the value of the charging current supplied to the secondary battery 12 becomes a specified current, the voltage control circuit 22 of the present embodiment notifies the controller 24 that the specified value has been detected. The prescribed current in the present embodiment is a preset value. In the following description, the specified current is referred to as a set current I2. The value of the set current I2 of the present embodiment may be a value of about 10% of the set current I1, for example.

  The battery monitoring circuit 23 of the present embodiment detects whether or not the battery voltage of the secondary battery 12 is equal to or higher than the set voltage V1. Details of the battery monitoring circuit 23 will be described later.

  The controller 24 controls the operations of the current control circuit 21 and the voltage control circuit 22 based on the battery voltage detected by the battery monitoring circuit 23. The controller 24 of the present embodiment is realized by a combination of an analog circuit and a logic circuit, for example.

  Hereinafter, the controller 24 will be described. When the battery voltage detected by the battery monitoring circuit 23 is smaller than the set voltage V1, the controller 24 of the present embodiment operates the current control circuit 21 to charge the secondary battery 12 by the constant current method to the main power supply device 20. Let it be done.

  Further, the controller 24 of the present embodiment stops the operation of the current control circuit 21 and operates the voltage control circuit 22 when the battery voltage of the secondary battery 12 becomes equal to or higher than the set voltage V1. Then, the controller 24 causes the main power supply device 20 to charge the secondary battery 12 by the constant voltage method.

  Furthermore, the controller 24 of the present embodiment stops the operation of the voltage control circuit 22 and stops charging when the charging current supplied to the secondary battery 12 becomes equal to or less than the set current I2.

  Further, the controller 24 of the present embodiment notifies the controller of each sub power supply device that the main power supply device 20 starts charging and stops charging the secondary battery 12.

The latch circuit 25 stops the operation of the current control circuit 21 and the voltage control circuit 22 when the controller 24 stops the operation of the current control circuit 21 and operates the voltage control circuit 22.
The state of the operation is held for a predetermined time.

  Next, the sub power supply device 30 will be described. The sub power supply device 30 of this embodiment includes a current control circuit 31, a battery monitoring circuit 32, a controller (subcontroller) 33, and a latch circuit 34.

  The current control circuit 31 outputs a set current I1 that is supplied to the secondary battery 12.

The battery monitoring circuit 32 is configured such that the battery voltage of the secondary battery 12 is a preset charging stop voltage V2.
It is detected whether or not the above is reached. The configuration of the battery monitoring circuit 32 is the same as the configuration of the battery monitoring circuit 23.

  When the controller 33 according to the present embodiment receives a charge stop notification from the controller 24 of the main power supply device 20, the controller 33 stops the operation of the current control circuit 32 and stops charging. Further, the controller 33 of the present embodiment stops the operation of the current control circuit 31 when the battery voltage detected by the battery monitoring circuit 32 becomes equal to or higher than the charging stop voltage V2.

  When charging is stopped by the controller 33, the latch circuit 34 of the present embodiment maintains the stop of the operation of the current control circuit 32 for a predetermined time.

  The sub power supply device 40 of this embodiment includes a current control circuit 41, a battery monitoring circuit 42, a controller 43, and a latch circuit 44. The sub power supply device 50 according to the present embodiment includes a current control circuit 51, a battery monitoring circuit 52, a controller 53, and a latch circuit 54. The sub power supply devices 40 and 50 of the present embodiment have the same configuration as the sub power supply device 30 and thus will not be described.

  Next, the battery monitoring circuit 23 of this embodiment will be described with reference to FIG. FIG. 3 is a diagram illustrating the battery monitoring circuit according to the first embodiment.

  The battery monitoring circuit 23 of the present embodiment includes resistors R1 and R2 connected in series, a resistor group 23R connected in series to the resistor R2, and a comparator 27. One end of the resistor R1 is grounded, and the other end of the resistor R2 is connected to one end of the resistor group 23R. A DC voltage Vcc of a DC power supply is applied to the other end of the resistor group 23R.

The inverting input terminal of the comparator 27 is connected to the connection point A between the resistor R1 and the resistor R2, and the battery voltage of the secondary battery 12 is input to the non-inverting input terminal of the comparator 27.

  The voltage at the connection point A between the resistors R1 and R2 is input to the inverting input terminal of the comparator 27 as a reference voltage (set voltage V1), and the comparator 27 compares the set voltage V1 with the battery voltage of the secondary battery 12. When the battery voltage of the secondary battery 12 is equal to or higher than the set voltage V1, an H level signal is output. When the battery voltage is lower than the set voltage V1, an L level signal is output.

The resistor group 23R includes a plurality of resistors Rn1 to Rn4 connected in series and the resistors Rn1 to Rn4.
And the fuse f1 to f4 connected in parallel to each other, and by cutting any of the fuses f1 to f4 with a laser beam, the value of the set voltage V1 can be arbitrarily set.

  In the present embodiment, it is assumed that the reference voltage is set to the set voltage V2 in the battery monitoring circuits 32, 42, and 52 of the sub power supply devices 30, 40, and 50.

  Next, the operation of the charging device 10 of the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart for explaining the operation of the charging device according to the first embodiment.

  When the charging device 10 of the present embodiment detects the start of charging of the secondary battery 12, the charging device 10 supplies a set current I <b> 1 that is a charging current to the secondary battery 12 from the main power supply device 20 and the sub power supply devices 30 to 50. (Step S41).

  Subsequently, the charging device 10 determines whether or not the battery monitoring circuit 23 has detected that the battery voltage of the secondary battery 12 has become equal to or higher than the set voltage V1 by the controller 24 of the main power supply device 20 (step S42). ). In step S42, when the battery voltage is not equal to or higher than the set voltage V1, the charging device 10 continues charging by the constant current method by the main power supply device 20 and the sub power supply devices 30 to 50 as they are.

  In step S42, when the battery voltage becomes equal to or higher than the set voltage V1, the controller 24 of the main power supply device 20 stops the operation of the current control circuit 21 and operates the voltage control circuit 22 (step S43). That is, the main power supply device 20 switches from charging by the constant current method to charging by the constant voltage method.

  Subsequently, the charging device 10 determines whether or not it has been detected that the charging current supplied from the voltage control circuit 22 of the main power supply device 20 to the secondary battery 12 is equal to or less than the set current I2 (step S44). . In step S44, when the charging current becomes equal to or less than the set current I2, the controller 24 of the main power supply device 20 stops charging by the main power supply device 20. In addition, the controller 24 of the main power supply device 20 notifies the controllers 33, 43, and 53 of the sub power supply devices 30 to 50 to stop charging, and stops charging by the sub power supply devices 30 to 50 (step S45).

  Below, with reference to FIG. 5, operation | movement of the charging device 10 of this embodiment is demonstrated concretely. FIG. 5 is a diagram illustrating the operation of the charging device according to the first embodiment. FIG. 5A shows the waveforms of the charging current and charging voltage output from the main power supply device 20, and FIGS. 5B to 5D are output from the sub power supply devices 30, 40, and 50. The waveforms of charging current and charging voltage are shown. FIG. 5E shows the waveforms of the charging current and charging voltage output from the entire charging apparatus 10.

  In this embodiment, when charging by the charging device 10 is started, the main power supply device 20 and the sub power supply devices 30, 40, and 50 each output the set current I1 as a charging current, and the secondary battery 12 of the constant current method is used. Charge the battery.

  When the battery voltage of the secondary battery 12 reaches the set voltage V1, the main power supply device 20 switches to charging by a constant voltage method that maintains the battery voltage of the secondary battery 12 at the set voltage V1. At this time, the sub power supply devices 30, 40, and 50 continue to be charged by the constant current method.

  Then, when the charging current output from the main power supply device 20 decreases to the charging stop current I2, the main power supply device 20 stops charging. In addition, the main power supply device 20 notifies the sub power supply devices 30, 40, and 50 to stop charging, and stops charging by the sub power supply devices 30, 40, and 50.

  In the following description, the period from the start of charging until the battery voltage reaches the set voltage V1 is defined as period T1, and after the battery voltage reaches the set voltage V1, the charge current output from the main power supply device 20 is the charge stop current I2. A period until it falls to is called a period T2.

  Here, the set voltage V1 and the set voltage V2 of this embodiment will be described. In the present embodiment, the set voltage V2 set in the battery monitoring circuit of each sub power supply device is set to a value that does not reach the battery voltage even if charging is performed using the constant current method of the set current I1 during the period T2. The Accordingly, the set voltage V2 is higher than the set voltage V1.

  In other words, the set voltage V2 is set so that the minimum value of the variation in battery voltage detection by the sub power supply devices 30, 40, 50 is larger than the maximum value of the variation in battery voltage detection by the main power supply device 20. Value.

  In the present embodiment, by setting the setting voltage V2 as described above, the sub power supply devices 30, 40, and 50 can continue charging by the constant current method during the period T2, and from the start of charging to the stop of charging. In the meantime, a charging current that is three times or more of the set current I1 can be secured.

  In the charging device 10 of the present embodiment, the set current I1 is output from each of the main power supply device 20 and the sub power supply devices 30, 40, and 50 until the secondary battery 12 reaches the set voltage V1. Therefore, the charging current Ia supplied from the charging device 10 to the secondary battery 12 in the period T1 is the set current I1 × 4.

  In the charging device 10, only the charging current output from the main power supply device 20 decreases in the period T <b> 2 after the secondary battery 12 reaches the set voltage V <b> 1. Therefore, the charging current Ib supplied from the charging device 10 to the secondary battery 12 in the period T2 is the set current I1 × 3 + charging stop current I2 even at the smallest value.

  As described above, in the present embodiment, the charging current output from the sub power supply devices 30, 40, and 50 and the charging current output from the main power supply device 20 until the charging stop is notified by the main power supply device 20. The secondary battery can be charged with the total current. Therefore, according to this embodiment, rapid charging at a high rate is possible, and the time required for charging can be shortened.

(Second embodiment)
The second embodiment will be described below with reference to the drawings. The second embodiment is different from the first embodiment in that the resumption of charging after charging is stopped is considered. In the following description of the second embodiment, only differences from the first embodiment will be described, and those having the same functional configuration as the first embodiment will be used in the description of the first embodiment. The same reference numerals as those used are assigned, and the description thereof is omitted.

  In this embodiment, when charging is stopped in the main power supply device 20 and each sub power supply device, a threshold voltage is set as a threshold value for restarting charging. In the present embodiment, when the battery voltage of the secondary battery 12 becomes equal to or lower than the threshold voltage set in the battery monitoring circuit 23A of the main power supply device 20, charging is resumed.

  FIG. 6 is a diagram illustrating the battery monitoring circuit according to the second embodiment. The battery monitoring circuit 23A of this embodiment includes a resistor R3 and a switch element Q1 in addition to the components included in the battery monitoring circuit 23 of the first embodiment.

  The resistor R3 has one end connected to the resistor R1 and the other end installed, and the switch element Q1 is connected in parallel with the resistor R3.

  In this embodiment, when the reference voltage (set voltage V1) is set by the resistors R1 ′, R2 ′, the resistor R3, etc., and the battery voltage of the secondary battery 12 becomes equal to or higher than the set voltage V1, the switch element Q1 is controlled by the controller 24. Conduct by. When the switch element Q1 is turned on, the voltage at the connection point A ′ between the resistors R1 ′ and R2 ′ decreases, and becomes a threshold voltage Vth1 lower than the set voltage V1.

  In FIG. 6, the battery monitoring circuit 23A of the main power supply device 20 has been described. However, the configuration of the battery monitoring circuit included in each sub power supply device is the same as that of the battery monitoring circuit 23A.

  In the battery monitoring circuit 23A of the present embodiment, the resistor R3 and the switch element Q1 serve as oscillation preventing means. Therefore, the main power supply device 20 of this embodiment does not have to include the latch circuit 25. Also, each sub power supply device does not have to have a latch circuit.

  Below, operation | movement of the charging device 10 of this embodiment is demonstrated. FIG. 7 is a first flowchart illustrating the operation of the charging device according to the second embodiment.

  The processing from step S71 to step S75 in FIG. 7 is the same as the processing from step S41 to step S45 in FIG.

  In the charging device 10, the controller 24 of the main power supply device 20 turns on the switch element Q1, and sets the threshold voltage Vth1. Similarly, the threshold voltage Vth2 is set for each controller of each sub power supply apparatus.

  Next, an operation when the charging device 10 resumes charging while the secondary battery 12 is being discharged will be described with reference to FIG. FIG. 8 is a second flowchart for explaining the operation of the charging device according to the second embodiment.

  The secondary battery 12 starts to be discharged when the charging is stopped. The charging device 10 determines whether or not the battery monitoring circuit 23A of the main power supply device 20 detects that the battery voltage has become equal to or lower than the threshold voltage Vth1 (step S81). If not detected in step S81, charging device 10 waits until it is detected.

  If detected in step S81, the detection is notified to the controller of each sub power supply. The controller 24 of the main power supply device 20 turns off the switch element Q1 of the battery monitoring circuit 23A and switches the set threshold voltage Vth to the set voltage V1. Further, the controller 24 causes the controller of each sub power supply device to set the set voltage V2 in each battery monitoring circuit (step S82).

  Subsequently, the charging apparatus 10 resumes charging (step S83). More specifically, the controller 24 of the main power supply device 20 resumes charging, and further notifies each sub power supply device of resumption of charging. The controller of each sub power supply device receives the notification of resuming charging and resumes charging. The charging apparatus 10 of this embodiment returns to the process of FIG.

  Here, the magnitude relationship between the threshold voltage Vth1 and the threshold voltage Vth2 of this embodiment will be described. In the present embodiment, the threshold voltage Vth1 is set to a value larger than the threshold voltage Vth2 (Vth1> Vth2).

  In the present embodiment, by setting Vth1> Vth2, it is possible to always restart charging from the main power supply device 20 when charging is restarted.

  In this embodiment, Vth2 is set as the threshold voltage for the three sub power supply devices 30, 40, and 50. However, the present invention is not limited to this. The threshold voltage set for the sub power supply devices 30, 40, and 50 may be a value that is larger than the threshold voltage Vth <b> 1, and a different value may be set for each sub power supply device.

  As described above, according to the present embodiment, when charging is stopped, the threshold voltage Vth1 for resuming charging is set. Therefore, when the battery voltage of the secondary battery 12 becomes equal to or lower than the threshold voltage Vth1. Charging can be resumed automatically.

  As mentioned above, although this invention has been demonstrated based on each embodiment, this invention is not limited to the requirements shown in the said embodiment. With respect to these points, the gist of the present invention can be changed without departing from the scope of the present invention, and can be appropriately determined according to the application form.

DESCRIPTION OF SYMBOLS 10 Charging device 20 Main power supply device 21, 31, 41, 51 Current control circuit 22 Voltage control circuit 23, 32, 42, 52 Battery monitoring circuit 24, 33, 43, 53 Controller 25, 34, 44, 54 Latch circuit 30, 40, 50 Sub power supply

JP 2014-197961 A

Claims (6)

A main power supply device comprising: a first current control circuit that outputs a constant charging current supplied to the secondary battery; and a voltage control circuit that outputs a charging current that maintains the battery voltage of the secondary battery constant; ,
A sub power supply device connected in parallel with the main power supply device and having a second current control circuit for outputting a constant charging current supplied to the secondary battery,
The main power supply is
A first set voltage for stopping the operation of the first current control circuit is set,
The sub power supply is
A charging device in which a second set voltage having a value higher than the first set voltage is set to stop the operation of the second current control circuit. The main power supply is
When the battery voltage of the secondary battery is equal to or higher than the first set voltage, the operation of the first current control circuit is stopped, the voltage control circuit is operated,
The charging device according to claim 1, wherein when the charging current output from the voltage control circuit becomes a charging stop current, charging of the secondary battery by the main power supply device and the sub power supply device is stopped. The second set voltage is
After the voltage control circuit starts operating in the main power supply device, until the charging current output from the voltage control circuit becomes a charging stop current,
The charging device according to claim 2, wherein when the charging current output from the second current control circuit is supplied to the secondary battery, the battery voltage of the secondary battery is set to a value larger than a value reached. The main power supply is
A first threshold voltage is set to operate the first current control circuit after stopping charging;
4. The device according to claim 1, wherein the first current control circuit and the second current control circuit are operated when a battery voltage of the secondary battery becomes equal to or lower than the first threshold voltage. 5. The charging device described in 1. The sub power supply is
A second threshold voltage is set for operating the second current control circuit after stopping charging;
The charging device according to claim 4, wherein the second threshold voltage is lower than the first threshold voltage. A charging method using a charging device having a main power supply device and a sub power supply device connected in parallel with the main power supply device,
The main power supply device is set with a first set voltage for stopping the operation of the first current control circuit,
The sub power supply device is set with a second set voltage higher than the first set voltage, which stops the operation of the second current control circuit,
In the main power supply device,
A procedure for outputting a constant charging current to the secondary battery by the first current control circuit;
A procedure for outputting a charging current for maintaining the battery voltage of the secondary battery constant by a voltage control circuit;
In the sub power supply device,
And a procedure for outputting a constant charging current supplied to the secondary battery by the second current control circuit.

Images