TWI463762B - Method of balanced charging for combinational batteries - Google Patents

Description

Static battery balance method for assembled batteries

The invention relates to a static electricity balance method for a combined battery, in particular to a unique static electricity balance method, which can automatically screen an aged battery, can automatically adjust the battery charge and discharge switch conduction rate, and automatically adjust the battery charge and discharge switch during the battery balance process. The static cell balance method of the combination battery with the conductivity and the function of balancing the balance of the plurality of batteries at the same time.

The current battery pack balancing technique focuses on the balance of charging and discharging of individual batteries from an external power source, which is a dynamic balance, that is, the battery pack operates only when there is an external power supply. As for the case where there is no power supply, the battery balance cannot be performed.

On the market, the universal battery balance control unit has an input voltage specification of 110V~220V (in principle, it meets the AC voltage specifications of most countries). As for the output voltage, the internal control circuit automatically senses whether the battery is fully charged. If saturated, only the charging of a single battery can be automatically stopped.

Traditional universal chargers have the following problems:

[1] It is quite inconvenient to charge a single battery at a time. Traditional universal chargers can charge batteries of different rated voltages, but only one type of battery can be charged at a time. This method not only has poor charging efficiency, but also shortens battery life.

[2] Unable to prevent battery overcharge. Although the conventional universal charger has a circuit detecting device, the precision is not high, and the problem of overcharging the battery cannot be avoided. For a period of time, the battery may be overcharged and then the battery is damaged.

[3] No multiple battery dynamics (with external power supply) or static (no external power supply) battery balancing function.

In view of this, it is necessary to develop a technique that can solve the above disadvantages.

The object of the present invention is to provide a static battery balance method for a combined battery, which has a unique static electricity balance method, can automatically screen an aged battery, can automatically adjust the battery charge and discharge switch conduction rate, and automatically adjust the battery charge and discharge process during the battery balance process. The switch conductance has the advantage of balancing the plurality of batteries at the same time. In particular, the problem to be solved by the present invention is that the conventional battery pack cannot perform static power balance without an external power supply, and the universal charger can only charge a single type of battery in the same manner at a time. Convenience and failure to prevent battery overcharge and other issues.

The technical means for solving the above problems is to provide a static battery balancing method for a combined battery, and the method part thereof comprises the following steps: 1. Preparation steps; two. Measuring individual battery internal resistance steps; three. Screening the aging battery step with internal resistance value; Measuring individual battery voltage steps; Differentiate the charging, discharging or stopping operation steps by voltage value; Individual battery charge and discharge switch conduction rate setting steps; Perform a number of battery balancing steps; and eight. Complete the steps.

The above objects and advantages of the present invention will be readily understood from the following detailed description of the preferred embodiments illustrated herein.

The invention will be described in detail in the following examples in conjunction with the drawings:

Referring to the first figure, the present invention is a static battery balancing method for an assembled battery, and the first embodiment includes the following steps: 1. Preparation step 11: Prepare a plurality of batteries ( B _{i , j} , i =1, ... M , j =1, . . . , N ) in parallel with the outline (string) in advance, and the case is drawn by the battery B _1,1 , B _1,2 , B _1,3 , B _1,4 , B _1,5 , B _1,6 , B _2,1 , B _2,2 , B _2,3 , B _2,4 , B _2,5 , B _2,6 , B _3,1 , B _3,2 , B _3,3 , B _3,4 , B _3,5 , B _3,6 constitute a parallel battery pack as an example for explanation), multiple measurements a portion 20, a plurality of cell balancing portions 30 and a control portion 40, each of the measuring portions 20 and each of the cell balancing portions 30 corresponding to each of the battery cells; the measuring portion 20 includes an internal resistance The detecting device 21 and a voltage measuring device 22 each of the battery balancing units 30 have a battery charging and discharging switch C _SW , and the battery charging and discharging switch conduction rate is between 0 and 1; Measure individual battery internal resistance step 12: Measure each corresponding battery with each internal resistance measuring device 21, and obtain an internal resistance value R and return it to the control portion 40; Within the aging resistance of the battery screening Step 13: When the negative threshold internal resistance value R ≧ R ', the battery is deemed to aging of the battery, the control unit 40 to the negative battery for an operation of the power balance; IV. Measuring the individual battery voltages Step 14: The battery remaining after the foregoing steps are excluded, and the corresponding voltage measuring device 22 is measured to obtain a voltage value V _{Bi , j} , and the plurality of cells are sequentially calculated. The plurality of voltage values of the remaining battery are returned to the control unit 40; The charging, discharging or stopping operation is performed according to the voltage value. Step 15: The control unit 40 sorts the corresponding plurality of voltage values V _{Bi , j} of the remaining batteries B _{i , j} after screening the aged battery _, from high to low. And the average voltage value V _average of the plurality of batteries is calculated by the following formula: V _average = ( V _{B 1,1} + V _{B 1,2} +...+ V _{BM , N} )/( M + N ); And the average voltage value V _average +0.05 < V _{Bi , j} determines that the battery should be discharged; and the average voltage value V _average -0.05> V _{Bi , j} determines that the battery should be charged; and the average voltage value V _average - 0.05< V _{Bi , j} <average voltage value V _average +0.05 determines that the battery stops operating (ie, does not charge or discharge, and the error tolerance value of 0.05 can be adjusted according to battery characteristics); Individual battery charge and discharge switch conductance setting step 16: The control unit 40 divides the plurality of batteries into a battery pack to be discharged and a battery pack to be charged; and charges the battery of the plurality of battery balance portions 30 corresponding to the battery pack to be discharged The discharge switch conductance is set to a fixed value (for example, 0.7); and the battery pack to be charged is sorted by the voltage value V _{Bi , j} from low to high, and the plurality of battery balance portions 30 corresponding thereto are sequentially subjected to the battery. The charge-discharge switch conduction ratio is set as follows (the following data can be adjusted according to the battery properties): [a] The top 10% battery charge and discharge switch conductance is set to 0.85; [b] Then 11%~20% battery charge and discharge switch conductance setting 0.75; [c] then 21%~30% battery charge and discharge switch conductance is set to 0.65; [d] then 31%~40% battery charge and discharge switch conductance is set to 0.55; [e] 41% later battery charge The discharge switch conduction rate is always set to 0.5; seven. Performing a plurality of battery balance steps 17: the plurality of batteries to be discharged and the plurality of batteries to be charged are matched with the battery balance portion 30 to perform a balance operation during discharge and charging; Step 18 is completed: the control of the cell balancing unit 30 with different battery charge and discharge switch conductances is performed to bring the plurality of batteries into a state of balance.

In practice, in the preparation step 11, the battery charge and discharge switch conductance is for the battery charge and discharge switch C _{SW to} control each of the batteries ( B _{i , j} , i =1, ... M , j =1,. .., N ) The time of discharge and charging (ie, the duty cycle of a square wave signal in a single cycle at a fixed period).

In the individual battery charge and discharge switch conductance setting step 16, the battery charge and discharge switch conductance ratio of the plurality of battery balance units 30 corresponding to the battery pack to be discharged is 0.7.

Referring to the fifth embodiment, a second embodiment of the present invention is different from the first embodiment, except that the battery balance portion 30 includes: a plurality of the battery charge and discharge switches C _SW , which may be metal-oxide layers - Semiconductor-field effect transistor, referred to as Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), is a field effect transistor (field) that can be widely used in analog circuits and digital circuits. -effect transistor). MOSFETs can be divided into n-type and p-type MOSFETs according to the polarity of their "channels". They are also commonly referred to as NMOSFETs and PMOSFETs. Others include MOSFETs such as NMOS FETs, PMOS FETs, nMOSFETs, and pMOSFETs.

a plurality of diodes 31; at least one capacitive element C; at least one inductive element L; at least one first switch (which may include P _{SW 1} , P _{SW 2} , ..., P _{SW (2 m -1)} , P _{SW (2 m )} ); at least one second switch (which may include S _{SW 1} , ..., S _{SW ( m -1)} ).

In the portion to be described herein, the present invention includes a battery discharge circuit (refer to FIGS. 6A and 6B, which is actually a third embodiment of the present invention, mainly illustrating a discharge path, and some components are slightly increased or decreased and discharged. It is irrelevant, and the battery charging circuit (see the sixth and sixth D diagrams, actually is the third embodiment of the present invention, mainly indicating the charging path, and some components are slightly increased or decreased regardless of the charging path. In the first place, the battery charge and discharge switch C _{SW is} used to control the charging and discharging of the corresponding battery, and the diode 31 is used to control the current flow. The capacitor element C and the inductor element L are used for storing and discharging current (the electronic components of the well-known applications of the diode, the capacitor element and the inductor element are not described in detail).

As for the first switch ( P _{SW 1} , P _{SW 2} , ..., P _{SW (2 m -1)} , P _{SW (2 m )} ) and the second switch ( S _{SW 1} , ..., S _{SW ( m -1 ) )} ) is used to turn on and off the plurality of integrated strings and parallel batteries B _{i , j} .

With regard to the cell balancing process of the present invention, the following steps may be included after the start:

Step A (51): Measure the internal resistance value R of the battery.

Step B (52): Determine whether the internal resistance value R is higher than the exclusion threshold R '? If the determination result is "Yes", proceed to step B '(521): the internal resistance value R is too high, the battery stops operating, and the battery charge and discharge switch conduction ratio is set to zero.

Step C (53): Measure the voltage value and current value of the individual batteries.

Step D (54): The voltage values are sorted sequentially from low to high.

Step E (55): distinguish V _average +0.05< V _{Bi , j} ? V _average -0.05> V _{Bi , j} ? V _average -0.05< V _{Bi , j} < V _average +0.05? If the result of the discrimination is " V _average + 0.05 < V _{Bi , j} ", then step F1 (561) is performed. If the result of the discrimination is " V _average -0.05> V _{Bi , j} ", then step F2 (562) is performed. If the determined result is _{"V average -0.05 <V Bi,} j <V average +0.05", proceeds to step F3 (563).

Regarding step F1 (561): the battery charge and discharge switch conduction ratio is set to a fixed value.

Regarding step F2 (562): according to the low voltage value, the battery charge and discharge switch conduction rate is 0.85, 0.75, 0.65, 0.55, 0.5 in sequence (this data can be adjusted according to the nature of the battery).

Regarding step F3 (563): The operation is stopped.

Step G (57): Determine whether all battery voltage values fall within the stop operation range? If the result of the determination is "NO", then return to step C (53) to re-operate. If the result of the determination is "Yes", the operation ends.

Refer to the second figure to set up 18 batteries B _1,1 , B _1,2 , B _1,3 , B _1,4 , B _1,5 , B _1,6 , B _2,1 , B _2,2 , B _2,3 , B _2,4 , B _2,5 , B _2,6 , B _3,1 , B _3,2 , B _3,3 , B _3,4 , B _3,5 , B _3,6 For example, a battery balance simulation experiment is performed, and the corresponding voltage measuring device 22 is measured to obtain the following 18 battery voltage values V _{Bi , j} : V _{B 1,1} =2.0714, V _{B 1,2} =2.4742 , V _{B 1,3} =2.6694

V _{B 1,4} =2.7881, V _{B 1,5} =2.8172, V _{B 1,6} =2.8587

V _{B 2,1} =2.8648, V _{B 2,2} =2.8845, V _{B 2,3} =2.9002

V _{B 2,4} =3.1881, V _{B 2,5} =3.2252, V _{B 2,6} =3.2852

V _{B 3,1} =3.1432, V _{B 3,2} =3.2419, V _{B 3,3} =3.3408

V _{B 3,4} =3.4399, V _{B 3,5} =3.5409, V _{B 3,6} =3.4441

Battery charge and discharge judgment formula: V _average =3.1190

V _average +0.05=3.1690

V _average -0.05=3.0690

Discharge battery: V _{B 2,4} =3.1881, V _{B 2,5} =3.2252, V _{B 2,6} =3.2852

V _{B 3,1} =3.1432, V _{B 3,2} =3.2419, V _{B 3,3} =3.3408

V _{B 3,4} =3.4399, V _{B 3,5} =3.5409, V _{B 3,6} =3.4441

Rechargeable battery: V _{B 1,1} =2.0714, V _{B 1,2} =2.4742, V _{B 1,3} =2.6694

V _{B 1,4} =2.7881, V _{B 1,5} =2.8172, V _{B 1.6} =2.8587

V _{B 2,1} =2.8648, V _{B 2,2} =2.8845, V _{B 2,3} =2.9002

The voltage obtained after 200 minutes is: V _{B 1,1} =2.8815, V _{B 1,2} =2.8912, V _{B 1,3} =2.9010

V _{B 1,4} =2.9140, V _{B 1,5} =2.9211, V _{B 1,6} =2.9400

V _{B 2,1} =2.9419, V _{B 2,2} =2.9619, V _{B 2,3} =2.9834

V _{B 2,4} =3.0938, V _{B 2,5} =3.1290, V _{B 2,6} =3.2104

V _{B 3,1} =3.0902, V _{B 3,2} =3.1832, V _{B 3,3} =3.1869

V _{B 3,4} =3.3887, V _{B 3,5} =3.4911, V _{B 3,6} =3.3934

Once again, the battery charge and discharge judgment formula: V _average =3.0890

V _average +0.05=3.1390

V _average -0.05=3.0390

Discharge battery: V _{B 2,6} =3.2104, V _{B 3,1} =3.0902, V _{B 3,2} =3.1832

V _{B 3,3} =3.1869, V _{B 3,4} =3.3887, V _{B 3,5} =3.4911

V _{B 3,6} =3.3934

Rechargeable battery: V _{B 1,1} =2.8815, V _{B 1,2} =2.8912, V _{B 1,3} =2.9010

V _{B 1,4} =2.9140, V _{B 1,5} =2.9211, V _{B 1,6} =2.9400

V _{B 2,1} =2.9419, V _{B 2,2} =2.9619, V _{B 2,3} =2.9834

Battery without power change: V _{B 2,4} =3.0938, V _{B 2,5} =3.1290

Finally, after 450 minutes of measurement, the individual battery voltages become: V _{B 1,1} =3.0851, V _{B 1,2} =3.0847, V _{B 1,3} =3.0845

V _{B 1,4} =3.0861, V _{B 1,5} =3.0875, V _{B 1,6} =3.0838

V _{B 2,1} =3.0828, V _{B 2,2} =3.0845, V _{B 2,3} =3.0878

V _{B 2,4} =3.0938, V _{B 2,5} =3.0940, V _{B 2,6} =3.0956

V _{B 3,1} =3.0902, V _{B 3,2} =3.0937, V _{B 3,3} =3.0954

V _{B 3,4} =3.0934, V _{B 3,5} =3.0895, V _{B 3,6} =3.1081

At this time, the battery charge and discharge judgment formula is: V _average =3.0900

V _average +0.05=3.1400

V _average -0.05=3.0400

The voltage variation curve of each of the above battery balancing processes is as shown in the fourth figure (this is the result obtained according to the normal operation of the battery). It is known from the results that after proper control, the individual battery voltages are nearly identical.

The advantages and functions of this creation can be summarized as follows:

[1] Unique static electricity balance method. The invention controls the discharge (the higher voltage) and the charging (the lower voltage) between the plurality of batteries inside the battery pack without any external power supply, so that the voltages of the plurality of batteries are averaged. It is beneficial to charge each battery pack evenly when it is charged by an external power source (dynamic power balance). Therefore, it can be a unique static power Balance method.

[2] Automatic screening of aged batteries. The invention can measure the internal resistance value of each battery. When the internal resistance value is higher than the exclusion threshold, it is determined that the battery is aging (even if charging is not used, this is a well-known technology), and the charging of the aging battery is directly excluded. Improve performance. Therefore, the aging battery can be automatically screened.

[3] can automatically adjust the battery charge and discharge switch conduction rate. The invention can automatically adjust the conduction rate of the battery charge and discharge switch of the battery balance unit corresponding to the battery balancing every time, without manual calculation. Therefore, the battery charge and discharge switch conduction rate can be automatically adjusted.

[4] The battery balance process automatically adjusts the battery charge and discharge switch conduction rate. Since the static battery balance may not achieve the balance of the plurality of batteries at one time, the present invention automatically calculates the average voltage value during the battery balancing process, and automatically adjusts the conduction and discharge rate of the battery charge and discharge switch as long as the battery still meets the condition of the battery balance. Until all batteries are in compliance with the stop operation. Therefore, the battery balance process automatically adjusts the battery charge and discharge switch conduction rate.

[5] The battery can be balanced at the same time. The electric quantity balancing method of the present invention balances the electric quantity by a plurality of batteries at the same time, and is not a one-to-one slow charge-discharge balance of the battery, so that the balance time can be greatly shortened. Therefore, a plurality of batteries can be balanced at the same time.

11‧‧‧Preparation steps

12‧‧‧Measure individual battery internal resistance steps

13‧‧‧Steps to screen aged batteries with internal resistance

14‧‧‧Measure individual battery voltage steps

15‧‧‧Dimensions of charging, discharging or stopping operation by voltage value

16‧‧‧Individual battery charge and discharge switch conductance setting steps

17‧‧‧Multiple battery balancing steps

18‧‧‧Complete steps

20‧‧‧Measurement Department

21‧‧‧Internal resistance detection device

22‧‧‧Voltage measuring device

30‧‧‧Battery Balance Division

40‧‧‧Control Department

51‧‧‧Step A

52‧‧‧Step B

521‧‧‧Step B’

53‧‧‧Step C

54‧‧‧Step D

55‧‧‧Step E

561‧‧‧Step F1

562‧‧‧Step F2

57‧‧‧Step G

B _{i , j} , B _1,1 , B _1,2 , B _1,3 , B _1,4 , B _1,5 , B _1,6 , B _2,1 , B _2,2 , B _2,3 B _2,4 , B _2,5 , B _2,6 , B _3,1 , B _3,2 , B _3,3 , B _3,4 , B _3,5 , B _3,6 , B _{n ,1} , B _{1, m} , B _{2, m} , B _{n , m} ‧‧‧ batteries

R ‧‧‧ internal resistance

R '‧‧‧Exclusion threshold

V _{Bi , j} ‧‧‧ voltage value

The first figure is a flow chart of the method of the present invention

The second drawing is a schematic view of a first embodiment of the present invention.

The third figure is a flow chart of the static electricity of the present invention.

The fourth figure is a graph in which the voltages of the plurality of batteries of the present invention tend to be uniform after the static electricity balance.

Figure 5 is a schematic view of a second embodiment of the present invention

6A, 6B, 6C, and 6D are diagrams showing the flow of charging and discharging currents according to the third embodiment of the present invention, respectively.

11‧‧‧Preparation steps

12‧‧‧Measure individual battery internal resistance steps

13‧‧‧Steps to screen aged batteries with internal resistance

14‧‧‧Measure individual battery voltage steps

15‧‧‧Dimensions of charging, discharging or stopping operation by voltage value

16‧‧‧Individual battery charge and discharge switch conductance setting steps

17‧‧‧Multiple battery balancing steps

18‧‧‧Complete steps

Claims (4)

A static battery balancing method for a combined battery, comprising the following steps: Preparing step: preparing a plurality of batteries, a plurality of measuring sections, a plurality of cell balancing sections, and a control section, wherein each of the measuring sections and each of the cell balancing sections respectively correspond to each of the battery cells; The measuring part comprises an internal resistance detecting device and a voltage measuring device, each of the electric quantity balancing parts has a battery charging and discharging switch, and the charging and discharging switch conduction rate of the battery is between 0 and 1; Measuring individual battery internal resistance steps: measuring each of the corresponding batteries by each internal resistance measuring device to obtain an internal resistance value and returning to the control portion; Screening the aging battery with the internal resistance value: When the internal resistance value ≧ excludes the threshold, the battery is regarded as an aging battery, and the control unit excludes the need for the battery to perform the balancing operation; The step of measuring the individual battery voltages: the remaining battery after the foregoing steps are excluded, and measuring by the corresponding voltage measuring device, to obtain a voltage value, and sequentially calculating the plurality of remaining batteries The voltage value is returned to the control unit; The step of charging, discharging or stopping the operation according to the voltage value: the control unit sorts the corresponding plurality of voltage values V _{Bi , j} of the remaining batteries B _{i , j} after aging the battery _, from high to low, and The average voltage value V _average of the plurality of batteries is calculated by the following formula: V _average = ( V _{B 1,1} + V _{B 1,2} +...+ V _{BM , N} )/( M + N ); Determining that the battery should be discharged according to the average voltage value V _average +0.05< V _{Bi , j} ; and determining that the battery should be charged with the average voltage value V _average -0.05> V _{Bi , j} ; and using the average voltage value V _average -0.05 <V _{Bi, j} <the average voltage value V _average +0.05 operation determines the cell is stopped; VI. Individual battery charge and discharge switch conduction rate setting step: the control unit divides the plurality of batteries into a battery pack to be discharged and a battery pack to be charged; and the battery charge and discharge switch corresponding to the plurality of battery balance portions corresponding to the battery pack to be discharged The conduction rate is set to a fixed value; and the battery pack to be charged is sorted by the voltage value V _{Bi , j} from low to high, and the plurality of battery balance portions corresponding thereto are sequentially turned on. The rate is set as follows: [a] The top 10% of the battery charge and discharge switch conductance is set to 0.85; [b] then 11% to 20% of the battery charge and discharge switch conductance is set to 0.75; [c] then 21%~ 30% of the battery charge and discharge switch conductance is set to 0.65; [d] then 31% ~ 40% of the battery charge and discharge switch conductance is set to 0.55; [e] 41% after the battery charge and discharge switch conductance is uniform Set to 0.5; seven. Performing a plurality of battery balancing steps: the plurality of batteries to be discharged and the plurality of batteries to be charged are matched with the corresponding battery balancing portion to perform a balance balancing operation during discharging and charging; Completion step: controlling the battery balance unit of the different battery charge and discharge switch conduction rate to make the plurality of batteries reach the battery balance state. The static battery balance method of the assembled battery according to claim 1, wherein in the preparing step, the battery charge and discharge switch conductance is for the battery charge and discharge switch to control the discharge and charge time of each battery. . The static battery balance method of the assembled battery according to claim 1, wherein in the preparing step, the charge-discharge relationship of each battery is a metal-oxide layer-semiconductor-field effect transistor. The static battery balance method of the assembled battery according to claim 1, wherein in the individual battery charge and discharge switch conductance setting step, the battery charge of the plurality of battery balance portions corresponding to the battery pack to be discharged The discharge switch conduction rate is 0.7.