TWI552481B - Active charge equalization method with individual charging and controlling system thereof - Google Patents

Description

Battery core active balance charging method and control system thereof

The invention relates to a battery voltage balancing method, in particular to a battery core active balancing charging method and a control system thereof.

Lithium-ion batteries have the advantages of high energy density, power density, extremely low self-discharge rate and zero environmental pollution. In addition, they do not suffer from spontaneous combustion and explosion when overcharged and over-discharged. They are recognized as very safe energy storage. The device is therefore more suitable as a power source for electric vehicles. General lithium-ion battery packs usually need to be managed with a battery management system. The battery management system functions include measuring single-cell voltage and current, over-charge and over-discharge protection mechanisms, and residual power estimation to provide a complete charging mechanism.

In order to solve the problem of single voltage imbalance between the series cells in the lithium-ion battery pack, the battery management system must uniformly balance the lithium-ion battery packs. When the voltages of the batteries are different or the residual power is uneven, The battery with high residual capacity or voltage is charged with less energy, and vice versa for higher energy charging of the lower voltage or residual battery. The purpose of the battery cell voltage is to make each cell in the same state of residual charge.

At present, the evenly balanced battery technology is mainly divided into two types: active technology and passive technology. The passive balancing technology mainly achieves the balance effect by using two methods of long-term overcharging and using the battery to consume energy. Because it does not actively pull the single-cell charge of the lowest voltage or charge in the lithium-ion battery pack, it is called the passive balance method. However, in addition to the long time spent and the waste of the overall electrical energy, the passive balance also reduces the energy of the entire lithium-ion battery pack. Although this method can achieve the balance of each battery core, it sacrifices the energy and valuable of the battery itself. Time, in terms of overall effect, its balance efficiency is not good.

The active balancing rule is to increase the balance of the lowest voltage or the amount of electricity in a lithium-ion battery pack by balancing the charging or charging of the battery with the lowest voltage. Active balancing method can use energy storage components such as capacitors or inductors to transfer electrical energy between cells. The active balancing method is different from the passive balancing method, which requires a long wait, so the efficiency of the active balancing method is higher than that of the passive balancing method.

However, among the currently used adjacent or partially complementary active balancing methods, if the number of cells in the series of lithium-ion battery packs is too high (for example, more than 16 cells are connected in series), there may be an excessive number of power transfer times resulting in a balance. The phenomenon of reduced efficiency, the general active balance method cuts off the charging circuit when the battery is overcharged, but often only some of the batteries reach the overcharge condition and the remaining batteries still have charging space. The unfilled battery will be over-discharged in advance, and then the charging is still the part of the battery. When the battery is overcharged and discharged, some of the cells are still over-discharged. This cycle causes the battery life of the battery pack to be greatly reduced. In addition, high-frequency charge and discharge or charge transfer between small cells with small currents also reduces the life of the cells.

The object of the present invention is to provide a battery core active balance charging method and a control system thereof, which solve the problems of excessive voltage balance time, poor voltage balance efficiency, and overcharge and over discharge of the battery in the balanced battery technology.

Therefore, an embodiment of the present invention provides a battery active balancing charging method that takes into account the charging, and the steps include: a series charging step of providing a balanced power source to charge a battery group. In a switching step, a measuring switch circuit and a balancing switch circuit are provided to control a plurality of cells of the switching cell group. A measuring step provides a voltage measuring circuit and utilizes the opening and closing of the measuring switch circuit to respectively measure the complex voltage values of the cells. In a determining step, a control component is provided to receive the voltage value, so that the control component determines the cell having a minimum voltage value in the cell group. A balancing step of opening and closing the balancing switch circuit enables the balanced power supply to simultaneously charge the battery pack and the minimum voltage of the battery. In a sorting step, each of the cells is sorted according to the voltage value by the control member, and the overcharge voltage must be exceeded in front. And a charging step, so that the control unit sequentially opens and closes the balancing switch circuit according to the order of the cells, so that the balanced power supply sequentially charges the respective batteries.

According to an embodiment of the foregoing embodiment, the measuring step further comprises a pre-judging step, so that the control component determines whether the voltage value of any of the cells is large. For a preset voltage value, if the result is yes, the sorting step is directly performed. The aforementioned preset voltage value may be 3.6 volts. The determining step further comprises a calculating step of causing the control component to discriminate the cell having a maximum voltage value in the cell group, so that the voltage difference between the cell for calculating the maximum voltage and the cell of the minimum voltage is greater than one. The preset voltage difference, if the result is yes, the balancing step. The aforementioned preset voltage difference may be 0.05 volts.

Another embodiment of the present invention provides a battery core active balance charging control system that utilizes both charging and charging, and is applied to the above-mentioned battery core active balancing charging method, and takes into account the charging core active balance charging control system. The utility model is used for an electric vehicle, which comprises a battery core group, a measuring switch circuit, a balance selection circuit, a power converter, a balanced power source and a control member. The battery pack contains those cells, and the cells are connected to each other in series. The measuring switch circuit is electrically connected to the battery core group, and the measuring switch circuit comprises a multi-quantity measuring switch, and two ends of each battery are electrically connected to the two measuring switches. The balance selection circuit is electrically connected to the battery core group, and the balance selection circuit includes a plurality of balance switch switches, and the two ends of each battery core respectively correspond to the two measurement switch switches and are electrically connected to the two balance switch switches. The power converter has an input end and an output end, and the output end is electrically connected to the balance selection circuit. The balanced power supply is electrically connected to the input of the battery pack and the power converter. The control member is electrically connected to the measuring switch circuit and the balance selecting circuit.

According to an embodiment of the foregoing embodiment, the measurement switching switch and the balance switching switch may be optical relays. The balanced power supply can be a charger.

The measurement switching switch mentioned in the foregoing embodiments and embodiments is substantially a high voltage resistant photo relay, and the balance switching switch is capable of withstanding large Current light relay. Therefore, according to the foregoing embodiments and embodiments, the battery active balancing charging method and the charging core active balancing charging control system are also disclosed. The two-stage charging method can be carried out by the active balancing charging method of the charging core and the active balancing charging control system of the charging core, whereby the control unit opens the balance switching switch for the battery to be charged, so that the balance is balanced. When the power cells meet a predetermined voltage difference, the power source simultaneously charges and balances the battery groups through the power converter, and separately charges the batteries when any of the batteries meets a predetermined voltage value.

100‧‧‧Battery active balancing device

200‧‧‧ boards

300‧‧‧Measurement switch circuit

310a~380a, 310b~380b‧‧‧Measurement switch

400‧‧‧balance selection circuit

410a~480a, 410b~480b‧‧‧balance switch

500‧‧‧Power Converter

510‧‧‧ input

520‧‧‧output

600‧‧‧Controls

700‧‧‧balanced power supply

800‧‧‧ batteries group

810~880‧‧‧ batteries

A01‧‧‧String charging step

A02‧‧‧Switching steps

A03‧‧‧Measurement steps

A04‧‧‧ Pre-judging steps

A05‧‧‧ Judgment steps

A06‧‧‧ Calculation steps

A07‧‧‧Equilibrium steps

A08‧‧‧Sorting steps

A09‧‧‧ sub-filling steps

A~I‧‧‧cell end point

I1, I2‧‧‧ electric

FIG. 1 is a flow chart showing a method for actively balancing and charging a battery according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a battery core active balance charging control system according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of the active balance charging control system of the battery according to FIG. 1 .

Please refer to FIG. 1 , which is a flow chart showing a method for actively balancing and charging a battery core according to an embodiment of the present invention. The step of balancing the charging core active balancing charging method comprises: a series charging step A01, providing a balanced power source to charge a battery group I1. a switching step A02, providing a measuring switch circuit and a balancing switch circuit to control the switch battery group Multiple batteries. A measuring step A03 provides a voltage measuring circuit and uses the opening and closing of the measuring switch circuit to respectively measure the complex voltage values of the cells. A pre-judgment step A04 is configured to cause the control unit to determine whether the voltage value of any of the cells is greater than a predetermined voltage value. If the result is yes, the sorting step A08 is directly performed. A determining step A05 provides a control unit receiving the voltage value, so that the control unit discriminates the battery cell having a minimum voltage value in the battery group. A calculating step A06, causing the control component to discriminate the cell having a maximum voltage value in the cell group, so that the voltage difference between the cell for calculating the maximum voltage value and the cell of the minimum voltage value is greater than a preset. The voltage difference, if the result is yes, performs the balancing step A07. A balancing step A07, opening and closing the balance switch circuit, so that the balanced power supply simultaneously charges the battery pack I1 and the minimum voltage of the battery balance charge I2. In a sorting step A08, the control cells are used to sort the cells according to the voltage value. And a charging step A09, so that the control unit sequentially opens and closes the balancing switch circuit according to the order of the cells, so that the balanced power supply sequentially charges the respective cells with a constant voltage I2 until the cells are fully charged and balanced. Thereby, until the cells are fully charged in a balanced manner, the battery active balancing charging method that takes care of the charging is completed.

Before starting to charge, you need to set the data through the software, such as overcharge voltage, number of batteries to be tested, battery preset voltage difference, preset voltage value, power supply voltage and current settings. ...Wait. After starting the charging power supply to start the series charging step A01, the voltage values of the respective batteries in the battery group are respectively measured by the switching step A02 and the measuring step A03, and the pre-judging step A04 is performed at this time, if the voltage value of any of the batteries If it is greater than the preset voltage value, the sorting step A08 is directly performed. If it is predicted that the voltage value of any of the cells in step A04 is less than the preset voltage value, then the determining step A05 is performed. To find the cell with the smallest voltage value. Next, the calculating step A06 determines whether the voltage difference between the maximum voltage value and the minimum voltage value in each of the cells is greater than a preset voltage difference, and if the result is otherwise, returns to the series charging step A01. If the result of the determination in step A05 is YES, the balancing step A07 is performed to allow the balanced power source to perform balanced charging on the minimum voltage value cell until the voltage value of any of the cells in the step A04 is greater than the preset voltage value, and the sorting can be performed. In step A08 and the sub-charging step A09, the voltage values are sorted for each of the cells, and the battery is charged from the battery of the minimum voltage value until the voltage value thereof is greater than the preset voltage value.

Please refer to FIG. 2 and FIG. 3 , wherein FIG. 2 is a block diagram of the battery core active balance charging control system applied to the foregoing charging, and FIG. 3 is a second drawing of the charging core of FIG. 2 The circuit diagram of the active balance charging control system includes a battery active balancing device 100 and a battery pack 800.

In the present embodiment, the battery pack 800 has a plurality of cells 810-880, but the number of cells is not limited to that shown in FIG. 3, and plural numbers are provided at the positive and negative terminals of each of the cells 810-880. Cell end A~I. The cell end points A~I corresponding to the cells 810~880 are as follows:

The battery active balancing device 100 includes a circuit board 200, a measuring switch circuit 300, a balance selecting circuit 400, and a power supply. The converter 500, a control unit 600, and a balanced power supply 700.

The circuit board 200 is electrically connected to the battery pack 800.

The measurement switch circuit 300 is disposed on the circuit board 200 and electrically connected to the battery pack 800. The measurement switch circuit 300 includes a plurality of measurement switch switches 310a, 310b, 320a, 320b, 330a, 330b, 340a, 340b, 350a, 350b, 360a, 360b, 370a, 370b, 380a, 380b electrically connected to the electrical respectively The core terminals A~I of the batteries 810-880 of the core group 800. The above-mentioned measurement switching switches 310a-380a, 310b-380b need to have the following characteristics: small size, simple driving, electrical isolation function and can be directly controlled to be turned on or off by the control unit 600, and the measurement switching switches 310a-380a, 310b-380b It is a high voltage resistant light relay. For example, the cell terminals A, B of the cell 810 are electrically connected to the measurement switch switches 310a, 310b, respectively. The measurement switch switches 310a~380a, 310b~380b connected to the cell terminals A~I of the respective cells 810-880 are as follows:

The balance selection circuit 400 is disposed on the circuit board 200 and electrically connected to the battery group 800. The balance selection circuit 400 includes a plurality of balance switches 410a, 410b, 420a, 420b, 430a, 430b, 440a, 440b, 450a, 450b, 460a, 460b, 470a, 470b, 480a, 480b corresponding to the measurement switching switches 310a, respectively. 380a, 310b~380b are electrically connected to the cell terminals A~I of the cells 810-880 of the cell group 800. The balance switchers 410a, 410b, 420a, 420b, 430a, 430b, 440a, 440b, 450a, 450b, 460a, 460b, 470a, 470b, 480a, 480b need to have the following characteristics: maximum current resistance up to 3 amps, volume Small, simple to drive, electrically isolated and can be turned on or off directly by control unit 600. The balance switches 410a to 480a and 410b to 480b are optical relays that can withstand a large charging current. For example, the cell terminals A, B of the cell 810 are electrically connected to the measurement switch switches 310a, 310b and the balance switch switches 410a, 410b, respectively. The balance switches 410a~480a, 410b~480b connected to the cell terminals A~I of the cells 810-880 are as follows:

The power converter 500 is disposed on the circuit board 200 and has an input terminal 510 and an output terminal 520. The output terminal 520 is electrically connected to the balance selection circuit 400.

The control unit 600 is disposed on the circuit board 200 and electrically connected to the measuring switch circuit 300 and the balance selecting circuit 400. The control unit 600 is configured to control the measuring switch 310a~380a, 310b~380b of the opening and closing measuring switch circuit 300 and The balance switches 410a to 480a, 410b to 480b of the balance selection circuit 400 are balanced.

The balanced power supply 700 is electrically connected to the battery pack 800 and the input terminal 510 of the power converter 500. The balanced power supply 700 can be a charger.

The measuring switch 600 sequentially turns on the measuring switches 310a-380a, 310b-380b connected to each of the cells 810-880 through the measuring switch circuit 300, and measures the cells 810-880 by the control unit 600. After the voltage value is determined by the control unit 600, the voltage difference between the minimum voltage value and the maximum voltage value of each of the batteries 810-880 is greater than 0.05V, and the balance switching switches 410a-480a, 410b-480b of the balance selection circuit 400 are controlled. The battery with the smallest voltage value is balanced and charged. When the voltage value of each of the cells 810-880 is greater than 3.6V, the balance switches 410a-480a, 410b-480b are used to alternately switch the cells 810-880, so that the balanced power supply 700 starts from the cell of the minimum voltage value. Charging, thereby effectively improving the voltage balance efficiency.

In the foregoing embodiment, the battery core active balance charging method and the battery core active balance charging control system taking into account the charging:

1. When the battery pack performs the overall string charging I1, the balance switch circuit is used to balance the charging of the battery with the minimum voltage value I2. When each cell balance is completed, the charging operation of each cell is performed, so that the cell group can reach the highest power storage state and the cells are in a state of balance and do not overcharge.

2. With the external balanced power supply as a balanced source of the battery core group, the balance current can be increased to accelerate the voltage balance of each battery core.

3. At the same time, it is possible to avoid the possibility of overcharging of the battery core. When the battery pack is divided, it can reach the full power of each battery core as much as possible, thereby achieving the purpose of improving the use efficiency and endurance of the battery core group.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

A01‧‧‧String charging step

A02‧‧‧Switching steps

A03‧‧‧Measurement steps

A04‧‧‧ Pre-judging steps

A05‧‧‧ Judgment steps

A06‧‧‧ Calculation steps

A07‧‧‧Equilibrium steps

A08‧‧‧Sorting steps

A09‧‧‧ sub-filling steps

Claims (9)

The utility model relates to a battery core active balance charging method, which comprises: a series charging step, providing a balanced power source for charging a battery core group (I1); a switching step providing a measuring switch circuit and a balancing switch The circuit controls the plurality of cells of the battery group; a measuring step provides a voltage measuring circuit and uses the measuring circuit to open and close the voltage values of the plurality of cells; Providing a control component to receive the voltage values, so that the control component discriminates the battery core having a minimum voltage value in the battery pack; and a balancing step of opening and closing the balance switch circuit to enable the balanced power supply to simultaneously the battery core String charging (I1) and the minimum voltage of the battery balance charging (I2); a sorting step of using the control unit to sort the batteries according to the voltage values; and a charging step to make the The control device sequentially turns on and off the balance switch circuit according to the order of the batteries, so that the balanced power supply sequentially charges the batteries (I2); wherein the balanced power supply, the measurement switch circuit, Balance switch The circuit and the control member are all disposed on a circuit board, thereby effectively improving the voltage balance efficiency, enabling the battery group to reach the highest power storage state and each of the battery cells is in a state of balance of power and does not overcharge. The charging core active balancing charging method according to claim 1, wherein the measuring step further comprises: a pre-judging step, wherein the control component determines that the voltage value of any of the cells is No greater than a preset voltage value, if the result is yes, the sorting step is directly performed. The battery core active balancing charging method according to claim 2, wherein the preset voltage value is 3.6 volts. The charging core active balancing charging method according to claim 1, wherein the determining step further comprises: a calculating step of causing the control component to discriminate the battery cell having a maximum voltage value in the battery group, And causing the control component to calculate whether a voltage difference between the cell of the maximum voltage and the cell of the minimum voltage is greater than a predetermined voltage difference, and if the result is yes, perform the balancing step. The battery core active balancing charging method according to claim 4, wherein the preset voltage difference is 0.05 volts. The utility model relates to a battery core active balance charging control system which is suitable for sub-charging, and is applied to the battery core active balance charging method according to claim 1, wherein the battery core active balance charging control system is used for one electric power The battery core, the active balance charging control system includes: the battery core group, the battery cores, the battery cells are connected to each other in series; the measuring switch circuit is electrically connected to the battery core The measurement switch circuit includes a plurality of measurement switch switches, wherein two ends of each of the cells are electrically connected to the two of the measurement switch switches; the balance selection circuit is electrically connected to the battery group, and the balance selection The circuit includes a plurality of balance switches, and two ends of each of the batteries respectively correspond to the two measurement switches, and two of the balance switches are electrically connected; a power converter having an input terminal and an output terminal, the output terminal being electrically connected to the balance selection circuit; the balanced power source electrically connected to the battery core group and the input end of the power converter; the control And electrically connected to the measurement switch circuit and the balance selection circuit; and the circuit board is configured to set the balanced power supply, the measurement switch circuit, the balance switch circuit and the control component. The battery core active balance charging control system according to claim 6, wherein the measurement switching switches are optical relays. The battery core active balance charging control system according to claim 6, wherein the balance switching switches are optical relays. The battery core active balance charging control system according to claim 6, wherein the balanced power source is a charger.