WO2020059952A1

WO2020059952A1 - Battery balancing device and method

Info

Publication number: WO2020059952A1
Application number: PCT/KR2018/014098
Authority: WO
Inventors: 이종현
Original assignee: 주식회사 다음코리아
Priority date: 2018-09-21
Filing date: 2018-11-16
Publication date: 2020-03-26
Also published as: KR101988027B1

Abstract

According to a battery balancing device and method of the present invention, a relay assembly is controlled so that a plurality of serially connected battery cells are converted into parallel battery cells, and thus the voltage of an individual battery cell is detected. Therefore, a separate charging device is used so that supplementary charging is performed for a low-charged battery cell in which a voltage charge state compared to a rated voltage is poor, and when an overcharged battery cell compared to the rated voltage exists, the overcharged battery cell is connected in parallel to the low-charged battery, which is not being supplementarily charged so as to resolve overcharging, and thus damage to the battery cell is prevented, and uncharging of the battery cell is prevented so that the battery use time can be increased with a maximum charge capacity.

Description

Battery balancing device and method

The present invention relates to an apparatus and method for balancing a battery, and more specifically, to detect a voltage of an individual battery cell by converting a plurality of battery cells connected in series in parallel by controlling a relay assembly, thereby charging the voltage relative to the rated voltage. The present invention relates to a battery balancing apparatus and method for performing fast charging by performing supplementary charging using a separate charging device targeting a low-charged battery cell that is in poor condition.

In general, electric vehicles and hybrid vehicles based on battery power are configured to use unit battery packs in a series / parallel combination to meet voltage and current energy required for their operation.

Since a unit battery pack composed of a plurality of battery cells can cause a change in state due to the external environment and characteristics of the battery itself, the battery management system (BMS) is used to constantly monitor and manage the state of the unit battery pack. shall.

Here, one of the very important tasks performed by the battery management system is battery cell balancing, which eliminates voltage imbalance between battery cells.

In order to balance the state of charge (SOC) of the battery energy source, battery cell balancing must be performed. As a method of battery cell balancing, there is a method of regulating voltage by discharging using a resistance.

In general, a battery configured to output a desired voltage by connecting a lithium polymer battery (Li-Polymer battery) in series generates imbalance of each cell voltage while repeatedly charging and discharging. If the imbalance increases, the inefficiency of battery use is reduced. Cause, and cause a decrease in life.

In order to prevent the voltage imbalance of the battery cells, the cell balancing operation is performed in the BMS to prevent the cell voltage imbalance.

1 is a circuit diagram for a conventional battery cell balancing method.

As shown in FIG. 1, in a conventional battery cell balancing circuit device, when a voltage of a specific cell among the battery cells is higher than other cells, a resistor connected in parallel to both ends of the battery cell is connected to consume energy of the corresponding cell through the resistance. The voltage is decreasing.

However, in the conventional cell balancing method, the lowest voltage among the voltages of the battery cells is set as a reference voltage, and a resistor is connected to a cell voltage higher than the reference voltage to open a resistance when the corresponding cell voltage approaches the reference voltage. use.

Such a conventional cell balancing method has a problem in that, by connecting a resistor regardless of the amount of deviation from the reference voltage, only the voltage is rapidly reduced through actual energy consumption, causing inefficiency of cell balancing, and increasing cell balancing time. .

The present invention has been devised to solve the above-described problem, and a plurality of battery cells connected in series is controlled in parallel by controlling a relay assembly to detect voltages of individual battery cells, and accordingly, the voltage charging state compared to the rated voltage is sluggish. By performing a supplementary charging using a separate charging device for the low-charged battery cell, and if there is an overcharged battery cell compared to the rated voltage, it is connected in parallel with the low-charged battery cell that is not under supplementary charging to eliminate overcharging. It is to provide a balancing device and method for a battery that prevents damage to a battery cell and prevents uncharging of the battery cell to improve battery usage time with full capacity charging.

The battery balancing device of the present invention for achieving the above object is installed between each of a plurality of battery cells, the battery pack configured to include a connection switch for connecting each battery cell in series or releasing the series connection state; A cell connection unit for parallel connection of two independent battery cells by driving a connection switch among a plurality of battery cells; A power supply unit including a main charging unit for supplying a main charging power for charging a battery pack and a balancing charging unit for supplying a balancing power for charging a battery cell; It is provided between the balancing charging unit and the battery cell and detects voltages for each of a plurality of battery cells and a charging switch that individually controls on / off that the balancing power output through the balancing charging unit is supplied to each battery cell, and detects a rated voltage. As a reference value, if a battery cell with a voltage below the reference value is present, the balancing power is output through the balancing charging unit so that the battery cell is additionally charged. If a battery cell with a voltage exceeding the reference value is present, a battery cell with a voltage below the reference value that is not being charged is selected. It comprises a balancing control unit that controls the cell connection to be connected in parallel to each other so that overcharge is eliminated.

After detecting the voltage for each of the plurality of battery cells, the balancing control unit may discharge the power of the corresponding battery cell to the balancing charging unit and store it until the reference voltage is reached if only a battery cell having a voltage exceeding the reference value exists.

And, the battery balancing device of the present invention for achieving the above object is installed between each of a plurality of battery cells, each battery cell is connected in series or comprises a connection switch for releasing the series connection state of the battery pack ; A cell connection unit for parallel connection of two independent battery cells by driving a connection switch among a plurality of battery cells; A power supply unit including a main charging unit for supplying a main charging power for charging a battery pack and a balancing charging unit for supplying a balancing power for charging a battery cell; It is provided between the balancing charging unit and the battery cell and calculates an average value by detecting voltages for each of a plurality of battery cells and a charging switch that individually controls on / off that the balancing power output through the balancing charging unit is supplied to each battery cell, and calculates an average value. If the battery cell to be balanced is checked after checking the battery cell to be balanced using the average value as a reference value, the highest voltage battery cell and the lowest voltage battery cell among the balancing battery cells are selected, and the voltage deviation of the two selected battery cells is preset If the voltage is less than the voltage deviation, the balancing power is output through the balancing charging unit so that the battery cells are charged, or when the voltage deviation of the two selected battery cells exceeds a preset voltage deviation, the cell connection is controlled so as to be connected in parallel with each other to achieve cell balancing. Balancing control to be performed Is configured is contained.

The connecting switch can be configured as a relay.

The cell connection part is connected to both ends of a plurality of battery cells, and a first cell connection part that connects both ends of one selected battery cell to a first output terminal, and is connected to both ends of a plurality of battery cells, and connects both ends of one selected battery cell. A second cell connection part connected to the second output terminal is included, and the first output terminal and the second output terminal may be connected to each other.

The balancing control unit provides a driving signal to the connection switch so as to detect the voltage of each battery cell, cuts off the connection state of the battery cells, detects the voltage for each of the plurality of battery cells, and sets the target batteries to be balanced with a preset reference value. After checking, if there are batteries to be balanced, any one of the battery cells to be balanced is selected through the first cell connection, and the other battery cell is selected through the second cell connection to be connected in parallel with each other. have.

The cell connection part is connected with a current limiting resistor between the first output terminal of the first cell connection part and the second output terminal of the second cell connection part, and it can be prevented that an overcurrent flows through the current limiting resistance.

The power supply unit includes: a main charging unit that converts input power supplied from external power into main charging power for charging the battery pack, and stores and outputs the stored power; A balancing charging unit that converts input power supplied from an external power source into a balancing power source for charging a battery cell, and stores and outputs the stored power; A charging unit selecting unit which switches a circuit according to the control of the balancing control unit so that input power supplied from an external power supply is supplied to the main charging unit or is supplied to the balancing charging unit; And an output selector for switching the circuit according to the control of the balancing control unit so that the power output from the main charging unit is supplied to the battery pack or the power output from the balancing charging unit is supplied to the battery cell.

In addition, the battery balancing device of the present invention for achieving the above object is installed between each of a plurality of battery cells, each battery cell is connected in series or comprises a connection switch for releasing the series connection state of the battery pack ; A power supply unit including a main charging unit for supplying a main charging power for charging a battery pack and a balancing charging unit for supplying a balancing power for charging a battery cell; It is provided between the balancing charging unit and the battery cell and detects voltages for each of a plurality of battery cells and a charging switch that individually controls on / off that the balancing power output through the balancing charging unit is supplied to each battery cell, and detects a rated voltage. As a reference value, if a battery cell with a voltage below the reference value is present, the first control unit is configured to output the balancing power through the balancing charging unit so that the battery cell is additionally charged. It is configured to include a balancing control unit including a second control unit that discharges power to the balancing charging unit to be stored so that overcharge is eliminated.

In addition, the method of balancing the battery of the present invention for achieving the above object, (a) by driving a connection switch installed between each of a plurality of battery cells through a balancing control unit to release the serial connection state of each battery cell step; (b) a second step of detecting a voltage for each of the plurality of battery cells through the balancing control unit and checking the battery cells to be balanced using the rated voltage as a reference value; (c) If a battery cell with a voltage lower than a reference value is present through the second step, the balancing control unit outputs the balancing power through the balancing charging unit so that the battery cell is additionally charged. And a third step of selecting a battery cell having a voltage lower than a reference value and controlling the cell connection parts to be connected in parallel with each other so that overcharge is eliminated.

In the third step, the balancing control unit detects a voltage for each of the plurality of battery cells, and if there is only a battery cell exceeding a reference value, discharges the power of the corresponding battery cell to the balancing charging unit until it becomes a reference voltage to be stored. It can contain.

In addition, the method of balancing the battery of the present invention for achieving the above object, (a) by driving a connection switch installed between each of a plurality of battery cells through a balancing control unit to release the serial connection state of each battery cell step; (b) a second step of detecting a voltage for each of the plurality of battery cells through a balancing control unit to calculate an average value and checking the battery cells to be balanced using the average value as a reference value; (c) If there is a battery cell to be balanced through the second step, select the highest voltage battery cell and the lowest voltage battery cell among the battery cells to be balanced, and if the voltage deviation of the two selected battery cells is equal to or less than the preset voltage deviation The third to allow the battery cells to be charged by outputting balancing power through the charging unit, or to control the cell connection units to be connected in parallel to each other when the voltage deviation of the two selected battery cells exceeds a preset voltage deviation. Includes steps.

The balancing control unit may include a step of individually controlling on / off that the balancing power output through the balancing charging unit is supplied to each battery cell by driving a charging switch provided between the balancing charging unit and the battery cell.

The balancing control unit selects the battery cell of the highest voltage among the battery cells to be balanced through the first cell connection unit of the cell connection unit, and selects the battery cell of the lowest voltage through the second cell connection unit of the cell connection unit, The second output terminal of the first output terminal and the second cell connection unit may include the step of being connected in parallel with each other.

The balancing control unit may prevent overcurrent from flowing through a current limiting resistor connected between the first output terminal of the first cell connection unit and the second output terminal of the second cell connection unit.

The balancing control unit may include controlling the charging unit selection unit so that input power supplied from an external power supply is supplied to the main charging unit or supplied to the balancing charging unit; Controlling the main charging unit to convert the input power supplied from external power to the main charging power for charging the battery pack and store and output it, or controlling the balancing charging unit to control the input power supplied from the external power supply for balancing battery cells. Converting the data to be stored and then output; The control may include the step of controlling the output selection unit so that the power output from the main charging unit is supplied to the battery pack or the power output from the balancing charging unit is supplied to the battery cell.

In addition, the battery balancing method of the present invention for achieving the above object is, (a) by driving a connection switch installed between each of a plurality of battery cells through a first control unit to release the serial connection state of each battery cell Stage 1; (b) a second step of detecting a voltage for each of the plurality of battery cells through the first control unit and checking the battery cells to be balanced by using the rated voltage as a reference value; (c) If a battery cell with a voltage lower than a reference value is present through the second step, the first control unit causes the balancing power to be output through the balancing charging unit so that the battery cell is additionally charged, and the second control unit if only a battery cell with a voltage exceeding the reference value exists And a third step of discharging the power of the corresponding battery cell to the balancing charging unit and storing it until the reference voltage is reached, so that overcharge is eliminated.

According to the balancing device and method of the battery of the present invention as described above, the plurality of battery cells connected in series is controlled in parallel by controlling the relay assembly to detect the voltage of the individual battery cells, thereby charging the voltage compared to the rated voltage Replenishment charging is performed using a separate charging device for the low-charged battery cells that are in poor condition, and if there is an overcharged battery cell compared to the rated voltage, the battery is overcharged by parallel connection with the low-charged battery cell that is not charging. The battery cell is prevented from being damaged by being solved, and the battery cell is prevented from being charged, thereby improving the battery usage time by charging the maximum capacity.

1 is a view showing a circuit diagram for a conventional battery cell balancing method,

2 is a block diagram illustrating a battery balancing apparatus according to an embodiment of the present invention,

3 is a circuit diagram for explaining a battery balancing device according to an embodiment of the present invention,

4 is a flowchart illustrating a battery balancing method according to an embodiment of the present invention,

5 is a flowchart illustrating a battery balancing method according to another embodiment of the present invention,

6 is a circuit diagram for explaining a battery balancing device according to another embodiment of the present invention,

7 is an exemplary view showing a battery balancing device according to the present invention.

* Description of code

100: power supply 300: charging selection

500: battery pack 700: cell connection

900: balancing control

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to easily describe those skilled in the art to which the present invention pertains.

First, the present invention detects the voltages of a plurality of batteries provided in an energy storage device used in an electric vehicle, a hybrid vehicle, an electric bicycle, a home, a commercial facility, a building, a transmission facility, and various power plants, and a predetermined number of batteries to be balanced If present, the highest voltage battery and the lowest voltage battery are selected and connected in parallel to each other, so the battery with the highest voltage exceeding the voltage average value is discharged without the need for a separate external power source, and the battery with the lowest voltage that does not reach the voltage average value is charged. There is a technical feature that enables the battery cells to be charged in a balanced manner by performing supplementary charging by using a charging device for cells with poor power charging status when balancing is required and additional balancing is required.

The battery balancing device according to an embodiment of the present invention includes a power supply unit 100, a charging selection unit 300, a battery pack 500, a cell connection unit 700, and a first, as shown in FIGS. 2 and 3. The control unit 900 includes a control unit and a second control unit.

The battery pack 500 is installed between a plurality of

battery cells

510, 530, 550, and 570, and a plurality of

battery cells

510, 530, 550, and 570 to connect each battery cell in series or serially. It comprises a

connection switch

501, 503, 505, 507, 509 to release the state.

The

battery cells

510, 530, 550, and 570 may be ordinary lithium ion batteries, lithium polymer batteries, or equivalents thereof, and the type is not limited thereto.

That is, the plurality of

battery cells

510, 530, 550, and 570 output a predetermined voltage or more, are provided with various types of secondary cells capable of repetitive charging and discharging, and serve to supply driving power.

In the present invention, the number of battery cells constituting the battery pack 500 is configured as four, but the present invention is not limited thereto, and may be appropriately selected from three to twelve or the like depending on the situation.

Connection switch (501, 503, 505, 507, 509) may be configured as a relay.

When all of the connection switches 501, 503, 505, 507, 509 are switched to the ON state by the first control unit control signal S1 of the balancing control unit 900, a plurality of

battery cells

510, 530, 550 , 570 are all connected in series, both ends of the first battery cell 510, the second battery cell 530, the third battery cell 550, and the fourth battery cell 570 connected in series (A) , Ground).

Each end of each of the first battery cell 510, the second battery cell 530, the third battery cell 550, and the fourth battery cell 570 is a, b, c, d, e, f, g , h, the first connection switch 501 is connected to the positive terminal (a) of the first battery cell 510 and connected to the power supply 100, and the negative terminal of the first battery cell 510 ( b) and a second connection switch 503 is connected between the positive terminal (c) of the second battery cell 530, the negative terminal (d) of the second battery cell 530 and the third battery cell 550 A third connection switch 505 is connected between the positive terminal (e) of the, and the fourth between the negative terminal (f) of the third battery cell 550 and the positive terminal (g) of the fourth battery cell 570 The connection switch 507 is connected, and the fifth connection switch 509 is connected to the negative terminal h of the fourth battery cell 570 and connected to the ground.

When all of the connection switches 501, 503, 505, 507, and 509 are turned off by the first control unit control signal S1 of the balancing control unit 900, a plurality of

battery cells

510, 530, 550 , 570) are disconnected in series so that they become independent states.

The cell connection unit 700 is for connecting two independent battery cells in parallel by driving the connection switches 501, 503, 505, 507, and 509 among the plurality of

battery cells

510, 530, 550, and 570, and internally A first cell connection unit connected to both ends of the plurality of

battery cells

510, 530, 550, and 570 and connecting both ends of one selected battery cell to the first output terminal, and a plurality of

battery cells

510, 530, 550, 570) is connected to both ends of the selected one of the battery cell is configured to include a second cell connecting portion connecting the second output terminal.

That is, a, b, c, d, e, f, g, and h of both ends of the plurality of

battery cells

510, 530, 550, and 570 are a, b, and c of the first cell connection part and the second cell connection part , d, e, f, g, and h input terminals.

The first cell connection unit and the second cell connection unit include two input terminals a, b, c, d, e, f, g, and h according to the second control unit selection signals S2 and S3 of the balancing control unit 900 Select a terminal and output it to two output terminals.

Here, the two input terminals may be a positive electrode a and a negative electrode b, a positive electrode c and a negative electrode d, a positive electrode e and a negative electrode f, a positive electrode g and a negative electrode h, respectively. The negative electrode is connected to the output terminal for the negative electrode.

Between the output terminal for the positive electrode of the first cell connection part and the output terminal for the positive electrode of the second cell connection part, a current limiting resistor is further provided to prevent overcurrent from flowing, and the output terminal for the negative electrode and the second cell for the first cell connection part are connected. The output terminal for the cathode of the connection is directly connected.

A, b, c, d, e, f, g, and h of both ends of the plurality of

battery cells

510, 530, 550, and 570 are connected to the balancing control unit 900, and the balancing control unit 900 The voltage of the

battery cells

510, 530, 550, and 570 can be detected.

A temperature sensor for sensing the temperature between the plurality of

battery cells

510, 530, 550, and 570 and the cell connection unit 700 is further provided.

The temperature sensor is between the positive terminal (a) of the first battery cell 510 and the a terminal of the cell connection part 700, between the positive terminal c of the second battery cell 530 and the c terminal of the cell connection part 700. , Between the positive terminal (e) of the third battery cell 550 and the e terminal of the cell connection part 700, the temperature between the positive terminal g of the fourth battery cell 570 and the g terminal of the cell connection part 700 It is provided to detect each.

The power supply unit 100 includes a DC supply unit 110, a charging unit selection unit 130, a main charging unit 150, a balancing charging unit 170, and an output selection unit 190.

The DC supply unit 110 converts AC input power input from the outside into DC input power to allow charging of the battery pack 500 by supplying charging power through two charging units that supply power of different voltages.

The charging unit selection unit 130 is connected to one of the two charging units by the first control unit control signal S0 of the balancing control unit 900 to transmit DC input power to the charging unit, and the DC supply unit 110 Selected control is performed by switching the circuit by switching on / off the switch element so that the converted DC input power is supplied to the main charging unit 150 or supplied to the balancing charging unit 170.

The switching element of the charger selection unit 130 may be a metal oxide field effect transistor (MOSFET), a bipolar junction transistor (BJT), or an insulated gate bipolar transistor (IGBT).

The main charging unit 150 is selected through the charging unit selection unit 130 to receive DC input power and convert it to the main charging power for charging the battery pack 500 to be output.

The balancing charging unit 170 is selected through the charging unit selection unit 130 and receives DC input power, converts it into a balancing power for charging a plurality of

battery cells

510, 530, 550, and 570, and stores and outputs it.

Here, if the charging voltage for charging the battery pack 500 is set to about 20V as one embodiment, the charging voltage for charging each battery cell may be set to about 5V as one embodiment.

Therefore, the main charging unit 150 further includes a configuration of dropping the voltage of the input DC input power to a voltage required for charging the battery pack 500, and the balancing charging unit 170 also inputs the voltage of the input DC power. The

cell

510, 530, 550, 570 may be configured to further include a configuration to drop to a voltage required for charging.

The output selector 190 selects the power output from the main charging unit 150 to be supplied to the battery pack 500 or the power output from the balancing charging unit 170 to the

battery cells

510, 530, 550, 570 Choose to supply.

The charging selection unit 300 is provided between the power supply unit 100 and the balancing charging unit 170 and the battery pack 500, and the power supply unit 100 by the first control unit control signal S4 of the balancing control unit 900 The balancing power output from the balancing charging unit 170 of the

battery cells

510, 530, 550, 570 is supplied to each on / off control individually.

The charging selection unit 300 is connected to the positive terminal (a) of the first battery cell 510 to control on / off that the balancing power supplied from the balancing charging unit 170 is charged in the first battery cell 510. On / off control that the balancing power supplied from the balancing charging unit 170 is charged to the second battery cell 530 by being connected to the positive terminal c of the first charging switch 310 and the second battery cell 530 The second charging switch 330 is connected to the positive terminal (e) of the third battery cell 550, the on / off that the balancing power supplied from the balancing charging unit 170 is charged to the third battery cell 550 It is connected to the positive terminal (g) of the third charging switch 350 and the fourth battery cell 570 to control the on / off that the balancing power supplied from the balancing charging unit 170 is charged to the fourth battery cell 570. A fourth charging switch 370 for controlling off is included and configured.

The first control unit of the balancing control unit 900 detects a voltage for each of the plurality of

battery cells

510, 530, 550, and 570, uses the rated voltage as a reference value, checks whether a battery cell with a voltage below the reference value exists, and then balances When the target battery cell is present, the balancing power is output through the balancing charging unit so that the battery cell is additionally charged, and the second control unit selects a voltage battery cell below the reference value that is not being charged when the voltage cell exceeding the reference value exists. Control the cell connection so that it is connected in parallel so that overcharge is eliminated.

Then, the second control unit of the balancing control unit 900 selects the highest voltage battery cell and the lowest voltage battery cell among the battery cells to be balanced, and controls the cell connection units to be connected in parallel to each other so that cell balancing is performed.

Subsequently, when the temperature sensor detects a value exceeding a predetermined temperature during cell balancing, the cell connection unit 700 is controlled to stop cell balancing, and then the balancing power is output through the power supply unit 100 to display the battery cell ( 510, 530, 550, and 570 are controlled to be charged.

Then, when the second control unit of the balancing control unit 900 is charging the

battery cells

510, 530, 550, 570 with the balancing power output through the power supply unit 100, when a temperature sensor detects a value below a predetermined temperature After stopping the output of the balancing power through the power supply unit 100, the cell connection unit 700 is controlled to connect the highest voltage battery cell and the lowest voltage battery cell in parallel with each other to perform cell balancing again. do.

On the other hand, a voltage is detected for each of the plurality of

battery cells

510, 530, 550, and 570, and the rated voltage is used as a reference value. If there is a battery cell charged with a voltage exceeding the reference value, the battery cell charged with the voltage exceeding the reference value is discharged and stored in the balancing charging unit 170 until the reference voltage is reached, so that overcharge is eliminated. .

Meanwhile, the power supply unit 100, the charging selection unit 300, the cell connection unit 700, and the balancing control unit 900 according to an embodiment of the present invention are manufactured in modularity and connected to a battery pack as shown in FIG. It can be configured as possible.

The balancing method of the battery balancing device configured as described above is as follows.

First, using the main charging power output from the main charging unit 150 of the power supply unit 100 to the energy storage device used in electric vehicles, hybrid vehicles, electric bicycles, homes, commercial facilities, buildings, transmission facilities, various power plants, etc. The provided battery pack 500 is charged.

Subsequently, when charging of the battery pack 500 is completed (S101), connection switches 501 and 503 respectively installed between the plurality of

battery cells

510, 530, 550, and 570 through the first control unit of the balancing

control unit

900 , 505, 507, 509 to release the series connection state of each

battery cell

510, 530, 550, 570.

Subsequently, the voltage of each

battery cell

510, 530, 550, 570 is detected through the first control unit of the balancing control unit 900 (S102).

Subsequently, the first control unit of the balancing control unit 900 checks whether a battery cell having a voltage exceeding the reference value or a battery cell having a voltage below the reference value is present using the rated voltage as a reference value.

Subsequently, if it is determined by the first control unit of the balancing control unit 900 that there is no battery cell having a voltage exceeding the reference value or a battery cell having a voltage below the reference value, it is determined that all battery cells have been balanced and the balancing is terminated.

However, if a voltage battery cell having a voltage lower than a reference value is present through the first control unit, it is determined that balancing is necessary, so that the balancing power is output through the balancing charging unit 170 so that the battery cell is additionally charged.

For a specific example, a battery cell having a voltage lower than a reference value is referred to as a second battery cell 530 and a third battery cell 550, and the circuit is switched to supply the balancing power to the battery cell, thereby being connected to the main charging unit 150. The power supply circuit is connected to the balancing charging unit 170.

Subsequently, the second charging switch 330 and the third charging switch 350 connected to the corresponding battery cell are provided so that the balancing power can be additionally supplied to the second battery cell 530 and the third battery cell 550 that require balancing. Turn it on.

Subsequently, the second battery cell 530 and the third battery cell 550, which need additional balancing, are charged with the balancing power output through the balancing charging unit 170 (S103).

In addition, when a voltage battery cell having a voltage exceeding a reference value is also present together with a battery cell having a voltage lower than the reference value, the battery connection part 700 is selected to be connected in parallel with each other by selecting a battery cell having a voltage below the reference value that is not being additionally charged through the second control part. Let the overcharging of the voltage battery cell be eliminated.

That is, the balancing control unit 900 selects a voltage battery cell exceeding a reference voltage and a voltage battery cell below a reference value that is not being charged in parallel through the cell connection unit 700 to eliminate overcharging of the battery cell having a voltage exceeding the reference value, and is connected in parallel with each other. (S103).

In this case, the battery cell with a voltage exceeding the reference value becomes a battery cell to be discharged, and a battery cell with a voltage below the reference value becomes a battery cell to be charged.

For example, assuming that the battery cell having a voltage exceeding the reference value is the first battery cell 510 and the battery cell having the voltage below the reference value is the fourth battery cell 570, the second control unit of the balancing control unit 900 is subject to discharge. A selection signal S2 is provided to the cell connection unit 700 so that the two input terminals a and b connected to both ends of the first battery cell 510 which is a battery cell are connected to the two output terminals, and the fourth battery that is a battery cell to be charged The selection signal S3 is provided to the cell connection unit 700 such that the two input terminals g and h connected to both ends of the cell 570 are connected to the two output terminals.

Subsequently, by the selection signals S1 and S2, the cell connection unit 700 connects both output terminals a and b of the battery cell 510 to be discharged and two output terminals, and both ends of the battery cell 570 to be charged (g) , h) and two output terminals.

Accordingly, the battery cells 510 to be discharged and the battery cells 570 to be charged are connected in parallel, and as a result, a current flows from the battery cells 510 to be discharged with a relatively high potential for a certain period of time to charge the battery cells 570 to be charged. Will be charged.

By doing this, the overcharged first battery cell 510 may be prevented from being overcharged, thereby preventing fire and prolonging life, and the lowly charged fourth battery cell 570 is additionally charged with power, The life of the battery pack can be extended.

Charging / discharging between the above-referenced voltage battery cell and the below-referenced voltage battery cell continues until the voltages of the two battery cells are balanced, and the second control unit of the balancing control unit 900 during charging / discharging is through a temperature sensor. When the temperature between the battery cell and the cell connection unit 700 is checked, and a value exceeding the allowable temperature is detected, charging / discharging is stopped between the battery cell exceeding the reference voltage and the battery cell below the reference voltage.

Subsequently, when the temperature sensor detects a value below the allowable temperature, the second control unit of the balancing control unit 900 continuously detects the voltage of the

battery cells

510, 530, 550, 570 and goes through the process as described above. Charging / discharging is performed between a battery cell with a voltage exceeding the reference value and a battery cell with a voltage below the reference value until no overcharged voltage battery cells exist.

On the other hand, the second control unit of the balancing control unit 900 detects a voltage for each of the plurality of battery cells, and if there is only a battery cell with a voltage exceeding a reference value, i.e., a battery to be charged by discharging the power of the battery with a voltage exceeding the reference value Since there is no charged battery cell, the discharged power can be recycled by discharging the power of the battery cell exceeding the reference voltage to the balancing charging unit 170 until the reference voltage is reached.

As another embodiment of the battery balancing method according to the present invention, first, the battery pack 500 is charged using the main charging power output from the main charging unit 150 of the power supply unit 100.

Subsequently, when charging of the battery pack 500 is completed (S201), connection switches 501 and 503 respectively installed between the plurality of

battery cells

510, 530, 550, and 570 through the first control unit of the balancing

control unit

900 , 505, 507, 509 to release the series connection state of each

battery cell

510, 530, 550, 570.

Subsequently, the voltage of each

battery cell

510, 530, 550, 570 is detected through the first control unit of the balancing control unit 900 (S202).

Subsequently, when the voltage of each

battery cell

510, 530, 550, or 570 is detected, the first control unit of the balancing control unit 900 calculates a voltage average value therefor (S203).

Subsequently, when the voltage average value is calculated, the first control unit of the balancing control unit 900 sets the balancing target range using the calculated voltage average value as a reference value (S204).

For example, the balancing is performed when it is out of the 10 mV range based on the calculated average voltage value, and the range in which the balancing is performed is called a balancing target range.

Subsequently, when the balancing target range is set, the first control unit of the balancing control unit 900 continues to be a battery cell belonging to the balancing target range among the plurality of

battery cells

510, 530, 550, and 570 measured voltage, that is, calculated It is checked whether there is a battery cell having a voltage value outside the 10 mV range based on the average voltage value (S205).

Subsequently, if it is determined that there is no battery having a voltage value outside the range of 10 mV based on the average voltage value by the first control unit of the balancing control unit 900, it is determined that all battery cells have been balanced and the balancing ends.

However, if it is determined that there are two or more battery cells having a voltage value outside the range of 10 mV based on the average voltage value, which is the target range for balancing, it is determined that balancing is necessary, and among the battery cells to be balanced, the battery cell with the highest voltage and the lowest voltage The deviation of the battery cell is calculated (S206).

Subsequently, if the deviation between the highest voltage battery cell and the lowest voltage battery cell is greater than or equal to a reference set value, the first control unit of the balancing control unit 900 determines a parallel balancing mode (S207).

Subsequently, the second control unit selects a battery cell having the highest voltage and a battery cell having the lowest voltage from among the battery cells to be parallelly connected (S208), determines the battery cell having the highest voltage as the battery cell to be discharged, and has the lowest voltage below the average value of the voltage. The battery cell of the voltage is determined as the battery cell to be charged, so that the parallel balancing process is performed as described above (S209).

On the other hand, if the deviation between the battery cell of the highest voltage and the battery cell of the lowest voltage is less than the reference set value, the first control unit of the balancing control unit 900 determines the charging balancing mode (S210), and as described above, each

battery cell

510 , 530, 550, and 570 are again detected, additionally checking the existence of a battery cell that needs balancing, and then switching a circuit so that the balancing power is supplied to the battery cell to charge the battery cell requiring balancing ( S211).

In the above description, a preferred embodiment of the present invention has been presented and described, but the present invention is not necessarily limited thereto, and a person skilled in the art to which the present invention pertains does not depart from the technical spirit of the present invention. It will be readily apparent that various substitutions, modifications and variations are possible.

Claims

A battery pack which is installed between a plurality of battery cells and includes a connection switch for connecting each battery cell in series or releasing the series connection state;

A cell connection unit for parallel connection of two independent battery cells by driving a connection switch among a plurality of battery cells;

A power supply unit including a main charging unit for supplying a main charging power for charging a battery pack and a balancing charging unit for supplying a balancing power for charging a battery cell;

A charging switch provided between the balancing charging unit and the battery cell to individually control on / off that the balancing power output through the balancing charging unit is supplied to each battery cell; And

A first control unit that detects a voltage for each of the plurality of battery cells, uses a rated voltage as a reference value, and outputs a balancing power through a balancing charging unit to output a balancing power when a battery cell with a voltage below the reference value exists, and a reference value When an excess voltage battery cell is present, a balancing control unit including a second control unit configured to control the cell connection unit so as to be connected in parallel to each other by selecting a battery cell having a voltage lower than a standard value that is not being charged is included. Battery balancing device.
The method according to claim 1, After detecting the voltage for each of the plurality of battery cells, the second control unit discharges the power of the corresponding battery cell to the balancing charging unit until it becomes a reference voltage when only a battery cell having a voltage exceeding a reference value is present to be stored. Battery balancing device characterized in that.
A battery pack which is installed between a plurality of battery cells and includes a connection switch for connecting each battery cell in series or releasing the series connection state;

A cell connection unit for parallel connection of two independent battery cells by driving a connection switch among a plurality of battery cells;

A power supply unit including a main charging unit for supplying a main charging power for charging a battery pack and a balancing charging unit for supplying a balancing power for charging a battery cell;

A charging switch provided between the balancing charging unit and the battery cell to individually control on / off that the balancing power output through the balancing charging unit is supplied to each battery cell; And

When a voltage is detected for each of the plurality of battery cells, an average value is calculated, and the battery cell to be balanced is checked based on the average value, and if a battery cell to be balanced exists, the highest voltage battery cell and the lowest voltage battery cell among the balancing battery cells When the voltage deviation of the selected two battery cells is equal to or less than a preset voltage deviation, a second control unit configured to output the balancing power through the balancing charging unit to charge the battery cell, and the voltage deviation of the two selected battery cells in advance When the set voltage deviation is exceeded, a balancing control unit including a second control unit to control cell connection units to be connected in parallel to each other to perform cell balancing.

Balancing device characterized in that the configuration is included.
The battery balancing device according to claim 1 or 3, wherein the connection switch comprises a relay.
The method according to claim 1 or claim 3, The cell connection unit is connected to both ends of the plurality of battery cells, a first cell connection unit for connecting both ends of any one selected battery cell to the first output terminal, and is connected to both ends of the plurality of battery cells Balancing device of the battery, characterized in that it comprises a second cell connecting portion connecting both ends of the selected one battery cell with the second output terminal, wherein the first output terminal and the second output terminal are connected to each other.
The method according to claim 5, to provide a driving signal to the connection switch to detect the voltage of each battery cell through the first control unit to cut off the connection state of the battery cell, and detect the voltage for each of the plurality of battery cells in advance After checking the batteries to be balanced with the set reference value, if there are batteries to be balanced, any one of the target battery cells is selected through the first cell connection unit through the second control unit, and the other battery cell is the second cell. Balancing device of the battery, characterized in that to be connected in parallel to each other by selecting through the connection.
The method according to claim 1 or claim 3, The cell connection portion is connected to the current limiting resistor between the first output terminal of the first cell connection portion and the second output terminal of the second cell connection portion, and prevents overcurrent from flowing through the current limiting resistance. Battery balancing device characterized in that.
The method according to claim 1 or claim 3, The power supply unit, The main charging unit for converting the input power supplied from the external power supply to the main charging power for charging the battery pack; A balancing charging unit that converts input power supplied from an external power source into a balancing power source for charging a battery cell, and stores and outputs the stored power; A charging unit selection unit for switching the circuit under the control of the first control unit and selecting the input power supplied from the external power source to be supplied to the main charging unit or to be supplied to the balancing charging unit; And an output selector configured to switch circuits under the control of the first control unit so that power output from the main charging unit is supplied to the battery pack or power output from the balancing charging unit is supplied to the battery cell. Battery balancing device.
A battery pack which is installed between a plurality of battery cells and includes a connection switch for connecting each battery cell in series or releasing the series connection state;

A power supply unit including a main charging unit for supplying a main charging power for charging a battery pack and a balancing charging unit for supplying a balancing power for charging a battery cell;

A charging switch provided between the balancing charging unit and the battery cell to individually control on / off that the balancing power output through the balancing charging unit is supplied to each battery cell; And

A first control unit that detects a voltage for each of the plurality of battery cells, uses a rated voltage as a reference value, and outputs a balancing power through a balancing charging unit to output a balancing power when a battery cell with a voltage below the reference value exists, and a reference value If only the excess voltage battery cell is present, the battery is characterized in that it comprises a balancing control unit that includes a second control unit that discharges and stores the power of the corresponding battery cell until the reference voltage is reached, thereby eliminating overcharge. Balancing device.
(a) a first step of releasing a series connection state of each battery cell by driving a connection switch installed between a plurality of battery cells through a first control unit;

(b) a second step of detecting a voltage for each of the plurality of battery cells through the first control unit and checking the battery cells to be balanced by using the rated voltage as a reference value;

(c) When a battery cell with a voltage below a reference value exists through the second step, the first control unit causes the balancing power to be output through the balancing charging unit so that the battery cell is further charged, and the second control unit has a voltage battery cell exceeding the reference value. If it is, the third step of selecting a voltage below the reference battery cell that is not being charged and controlling the cell connection so that they are connected in parallel with each other so that overcharge is eliminated

Balancing method of the battery comprising a.
The method according to claim 10, In the third step, the second control unit detects the voltage for each of the plurality of battery cells, and then discharges the power of the battery cell to the balancing charging unit until the reference voltage when only the battery voltage exceeds the reference value Balancing method of the battery, characterized in that it comprises the step of storing it.
(a) a first step of releasing a series connection state of each battery cell by driving a connection switch installed between a plurality of battery cells through a first control unit;

(b) a second step of detecting a voltage for each of the plurality of battery cells through the first control unit to calculate an average value and checking the battery cells to be balanced using the average value as a reference value;

(c) If a battery cell to be balanced exists through the second step, the highest voltage battery cell and the lowest voltage battery cell among the battery cells to be balanced are selected through the first controller, and the voltage deviation of the two selected battery cells is preset. If the voltage is equal to or less than the voltage deviation, the balancing power is output through the balancing charging unit to charge the battery cell, and when the voltage deviation of the two selected battery cells exceeds the preset voltage deviation through the second control unit, the cell connection unit is controlled to be connected in parallel with each other. Step to ensure cell balancing is performed

Balancing method of the battery comprising a.
The method according to claim 10 or 12, By driving the charging switch provided between the balancing charging unit and the battery cell through the first control unit, the on / off control of the supply of the balancing power output through the balancing charging unit to each battery cell individually Balancing method of the battery comprising the step of.
The method according to claim 10 or claim 12, wherein the battery cell of the highest voltage among the battery cells to be balanced through the second control unit is selected through the first cell connection of the cell connection, the battery cell of the lowest voltage is the second cell connection of the cell connection And selecting the first output terminal of the first cell connection unit and the second output terminal of the second cell connection unit in parallel with each other.
The method according to claim 10 or 12, comprising the step of preventing overcurrent from flowing through a current limiting resistor connected between the first output terminal of the first cell connection portion and the second output terminal of the second cell connection portion through the second control unit. Battery balancing method characterized in that.
The method of claim 10 or 12, further comprising: controlling the charging unit selection unit through the first control unit such that input power supplied from an external power supply is supplied to the main charging unit or supplied to the balancing charging unit; Control the main charging unit to convert the input power supplied from external power to the main charging power for charging the battery pack, or output it, or control the balancing charging unit to convert the input power supplied from the external power to balancing power for charging the battery cell Storing and then outputting; And controlling the output selector to allow power output from the main charging unit to be supplied to the battery pack or to supply power output from the balancing charging unit to the battery cell.
(a) a first step of releasing a series connection state of each battery cell by driving a connection switch installed between a plurality of battery cells through a first control unit;

(b) a second step of detecting a voltage for each of the plurality of battery cells through the first control unit and checking the battery cells to be balanced by using the rated voltage as a reference value;

(c) If a battery cell with a voltage lower than a reference value exists through the second step, the first control unit causes the balancing power to be output through the balancing charging unit so that the battery cell is additionally charged,

The second control unit discharges the power of the corresponding battery cell to the balancing charging unit until it reaches a reference voltage when only a battery cell with a voltage exceeding the reference value exists, so that the overcharge is eliminated.

Balancing method of the battery comprising a.