TWM541671U - Battery charging system - Google Patents

Description

Battery charging system

This creation is about a battery charging system, especially a battery charging system with battery balancing.

In order to meet the demand for high voltage of rechargeable batteries, rechargeable batteries generally increase the high voltage required for operation in a series connection. For rechargeable batteries, overcharging or over-discharging can cause the battery to age, thus causing the life of the rechargeable battery to decay. Furthermore, due to the different internal resistance or capacity of each rechargeable battery, the problem of different terminal voltages of the respective rechargeable batteries is likely to occur after the charging and discharging process, so that the energy of the rechargeable battery of the series structure cannot be balanced, and the chemistry of each rechargeable battery is destroyed. Features, even causing permanent damage to the rechargeable battery.

When the voltage of the rechargeable battery is unbalanced, it occurs that when one of the rechargeable batteries reaches the rated high voltage (full charge), the remaining rechargeable batteries are not fully charged. Alternatively, when the rechargeable battery is discharged, when one of the rechargeable batteries is discharged to a rated low voltage, the remaining rechargeable batteries have not been completely discharged, and thus, the remaining energy of each of the rechargeable batteries will be different, and thus, the rechargeable battery will be lowered. Operating efficiency, and greatly reducing the service life and charge and discharge safety of the rechargeable battery.

Please refer to FIG. 7 , which is a block diagram of a conventional battery balancing circuit. The battery balancing circuit comprises a charger 91 and a plurality of rechargeable batteries connected in series. In FIG. 7, four rechargeable batteries 921-924 connected in series are used as an example, a battery balancer 93 and a controller 94.

The battery balancer 93 is composed of a plurality of resistors 931-934 and a plurality of switches 935-938, wherein the number of the resistors 931-934 corresponds to the number of the switches 935-938 corresponding to the number of the rechargeable batteries 921-924. That is, the number of the resistors 931-934 and the number of the switches 935-938 are respectively four. Each of the resistors 931-934 is connected in series to each of the switches 935-938, and a series of resistors 931-934 connected in series and the switches 935-938 are connected in parallel to one rechargeable battery 921-924. That is, the resistor 931 is connected in series to the switch 935, and then connected to the rechargeable battery 921 in parallel; the resistor 932 is connected in series to the switch 936, and then connected to the rechargeable battery 922 in parallel, and so on.

The charger 91 is electrically connected to both ends of the rechargeable batteries 921 to 924, and charges the rechargeable batteries 921 to 924. The controller 94 is connected to the charger 91, the rechargeable batteries 921 to 924, and the battery balancer 93, respectively. The controller 94 presets a threshold voltage value. When the charger 91 charges the rechargeable batteries 921 924 924, the controller 94 simultaneously detects the terminal voltage values of the rechargeable batteries 921 924 924, and It is determined whether the terminal voltage value of each of the rechargeable batteries 921 to 924 exceeds the upper threshold voltage value. If the terminal voltage value of any of the rechargeable batteries 921-924 exceeds the upper threshold voltage value, the controller 94 controls the corresponding switches 935-938 to be turned on for voltage balancing. At this time, the other rechargeable batteries 921 to 924 that have not exceeded the upper threshold voltage value continue to be charged by the charging current provided by the charger 91.

For example, when the terminal voltage value of the rechargeable battery 923 exceeds the upper threshold voltage value, it indicates that the rechargeable battery 923 has been fully charged, and therefore, the controller 94 controls the switch 937 to be turned on. At this time, the charging current originally for the rechargeable battery 923 will flow to the resistor 933 connected in series with the switch 937, and the discharge operation is performed through the resistor 933 to stop the charging of the rechargeable battery 923, whereby the rechargeable battery The terminal voltage value of 923 will not increase any more to avoid overcharging of the rechargeable battery 923.

Although the existing battery balancing circuit can perform a discharging operation through the resistive element to avoid overcharging of the rechargeable battery, the resistive element consumes electric energy, so that the efficiency of the charging system is lowered, and the heat energy converted by the consumed electric energy will cause charging. The temperature of the system rises and the performance of the charging system is reduced.

The purpose of the present invention is to provide a battery charging system for solving the voltage imbalance of the rechargeable battery, resulting in lowering the operational efficiency of the rechargeable battery, and greatly reducing the service life and charge and discharge safety of the rechargeable battery. problem.

In order to achieve the foregoing, the battery charging system proposed by the present invention comprises a rechargeable battery pack, a charging unit, a balancing unit and a control unit. The rechargeable battery pack has a plurality of rechargeable batteries connected in series to provide a positive terminal and a negative terminal. The charging unit is electrically connected to the positive terminal and the negative terminal of the rechargeable battery. The balancing unit is electrically connected to the charging unit and the rechargeable battery pack. The control unit is connected to the rechargeable battery pack and the balancing unit, and receives a terminal voltage value of each of the rechargeable batteries, and outputs a complex control signal to control the balancing unit according to the terminal voltage values.

The battery charging system of the present invention controls the balancing unit by the control unit to initiate a voltage balancing operation, thereby maintaining the operating efficiency of the rechargeable battery, and greatly improving the service life and charging and discharging safety of the rechargeable battery.

In order to further understand the techniques, means and functions of this creation for the purpose of achieving the intended purpose, please refer to the following detailed description and drawings of this creation. I believe that the purpose, characteristics and characteristics of this creation can be obtained from this. The detailed description is to be understood as merely illustrative and not restrictive

The technical content and detailed description of this creation are as follows.

Referring to FIG. 1, an embodiment of a rechargeable battery 11 used in the present invention has a positive voltage terminal 111 and a negative voltage terminal 112 for outputting a DC voltage. The rechargeable battery 11 can be a titanate battery, such as a lithium titanate battery or a barium titanate battery, but is not limited by the type of the battery.

Substituting graphite with lithium-grade lithium titanate oxide (nLTO), making lithium titanate oxide a battery electrode material with "zero tension" characteristics, so that when lithium ions enter and leave the particles, they do not change the material. shape. Since the lithium titanate oxide material is a three-dimensional crystal structure, this structure has a space for accommodating lithium atoms, and its size is substantially equivalent to that of atoms. Therefore, no pressure or stress is generated during charging and discharging, and there is no particle fatigue which may cause damage to materials such as graphite, so that lithium titanate oxide as a battery electrode material can be compared with conventional lithium. Ion batteries provide more frequent charging and discharging. In contrast, conventional lithium-ion batteries generally charge and discharge about 1,000 times (about three years) before disposal, while batteries using lithium titanate oxide can reach about 25,000 times of charge and discharge (more than 20 years).

Referring to FIG. 2, the rechargeable battery 11 of the present invention can be connected in series or in parallel to form a rechargeable battery pack structure, and the voltage of the rechargeable battery pack can be increased by connecting in series, and the manner of connecting through parallel connection can be improved. The capacity of the rechargeable battery pack. As shown in FIG. 2, the rechargeable battery pack formed by connecting a plurality of rechargeable batteries 11 to 1n (the connecting wires are not shown in the drawing) is housed in a battery case 100, wherein the battery case 100 can be a A battery case is provided, and a positive joint 101 and a negative joint 102 are disposed on the casing of the battery case 100. Among them, the battery box 100 can be applied to temporary power supply for vehicle and ship loading, mobile stalls, field camping, and the like. The two ends of the parallel charging structure of the plurality of rechargeable batteries are formed at both ends of the rechargeable battery pack, which are respectively a positive terminal and a negative terminal, and are electrically connected, and the positive terminal is electrically connected. The positive terminal 101 of the battery case 100 and the negative electrode end are electrically connected to the negative electrode connector 102 of the battery case 100.

Referring to FIG. 3 and FIG. 4 , the battery charging system of the present invention comprises a rechargeable battery pack 10 , a charging unit 20 , a balancing unit 30 , and a control unit 40 . For example, the rechargeable battery pack 10 has a plurality of rechargeable batteries 11 to 1n connected in series, and the two ends of the rechargeable battery pack 10 are respectively provided with a positive terminal V+ and a negative terminal V-. The terminal voltage values of the respective rechargeable batteries 11 to 1n are V1 to Vn, respectively.

The charging unit 20 is electrically connected to the positive terminal V+ and the negative terminal V- of the rechargeable battery pack 10 to charge the rechargeable batteries 11~1n of the rechargeable battery pack 10.

The balancing unit 30 is electrically connected to the rechargeable battery pack 10, the charging unit 20, and the control unit 40 for providing charging balance for the rechargeable battery pack 10. The control unit 40 detects the voltage values V1 VVn of the terminals of each of the rechargeable batteries 11~1n, and performs charging balance control on the balancing unit 30 according to the detected voltage values V1~Vn of the terminals. The description is as follows.

The balancing unit 30 is electrically connected to the charging unit 10 and the rechargeable battery pack 20 . The balancing unit 30 includes a main energy storage component 31, a first auxiliary energy storage component 321, a second auxiliary energy storage component 322, a first switching switch 331, a second switching switch 332, and a first connection switch 341. a second connection switch 342 and a third connection switch 343.

The main energy storage component 31 has a first end and a second end. The main energy storage component 31 can be a capacitor. The first auxiliary energy storage component 321 has a first end and a second end, wherein the first end of the first auxiliary energy storage component 321 is connected to the first end of the main energy storage component 31. The second auxiliary energy storage component 322 has a first end and a second end, wherein the first end of the second auxiliary energy storage component 322 is connected to the second end of the main energy storage component 31. The first auxiliary energy storage component 321 and the second auxiliary energy storage component 322 can respectively be an inductor or two coupled inductors which are respectively a transformer of a common core.

The first switch 331 has a first end, a second end, and a control end, wherein the first end of the first switch 331 is connected to the first end of the main energy storage component 31 and the first end The first end of the auxiliary energy storage element 321 is. The second switch 332 has a first end, a second end, and a control end, wherein the first end of the second switch 332 is connected to the second end and the second end of the main energy storage component 31 The first end of the auxiliary energy storage element 322. The second end of the second switch 332 is connected to the second end of the first switch 331. The control end of the first changeover switch 331 and the control end of the second changeover switch 332 are electrically connected to the control unit 40 to receive the control signal output by the control unit 40, as described later.

The first connection switch 341 has a first end and a plurality of second ends, wherein the first end of the first connection switch 341 is connected to the second end of the first auxiliary energy storage component 321 , the first connection switch Each of the second ends of the 341 is respectively connected to one of the first polarity ends of each of the rechargeable batteries 11~1n. In this embodiment, the first polarity end is a positive terminal. The second connection switch 342 has a first end and a plurality of second ends, wherein the first end of the second connection switch 342 is connected to the second end of the second auxiliary energy storage component 322, and the second connection switch Each of the second ends of the 342 is respectively connected to one of the second polarity ends of each of the rechargeable batteries 11~1n. In this embodiment, the second polarity end is a negative end opposite to the polarity of the first polarity end.

The third connection switch 343 has a first end and a plurality of second ends, wherein the first end of the third connection switch 343 is connected to the second end of the first switch 331 and the second switch 332 The second end of the third connection switch 343 is connected between the two rechargeable batteries. For example, one of the second ends of the third connection switch 343 is connected between the rechargeable battery 11 and the rechargeable battery 12, the other second end is connected between the rechargeable battery 11 and the rechargeable battery 13, and the other second end is connected. The rechargeable battery 12 and the rechargeable battery 13 are connected, and so on, and the second ends of the third connection switch 343 are respectively between the two rechargeable batteries.

The control unit 40 is electrically connected to the rechargeable battery pack 10 to receive terminal voltage values of the rechargeable batteries 11~1n. The control unit 40 is electrically connected to the balancing unit 30, and outputs a plurality of connection switch control signals, including a first connection switch control signal S1, a second connection switch control signal S2, and a third connection switch control signal S3. The first connection switch control signal S1 controls the first connection switch 341, the second connection switch control signal S2 controls the second connection switch 342, and the third connection switch control signal S3 controls the third connection switch 34. Furthermore, the control unit 40 outputs a plurality of switch control signals including a first switch control signal SS1 and a second switch control signal SS2, wherein the first switch control signal SS1 is transmitted through the first switch 331 The control terminal controls the first switch 331, and the second switch control signal SS2 controls the second switch 332 through the control end of the second switch 332.

The following explains the operation principle and mode of the battery charging system of the present invention through data.

During the charging of the rechargeable battery pack 10 by the charging unit 20, the control unit 40 continuously detects the voltage values V1 VVn of the respective terminals of the rechargeable batteries 11~1n. When there is no voltage imbalance between the rechargeable batteries 11 to 1n, the charging unit 20 charges each of the rechargeable batteries 11 to 1n.

When a voltage imbalance occurs between the rechargeable batteries 11 to 1n, the control unit 40 activates the balancing unit 30 to perform voltage balance adjustment of the voltage unbalanced rechargeable batteries 11 to 1n, which will be specifically described below. The voltage imbalance condition is defined as when the voltage difference between the maximum value of the voltage values of the terminals 11 to 1n and the minimum value of the terminal voltage values exceeds a balanced voltage difference preset by the control unit 40. This indicates a situation in which the rechargeable battery pack 10 experiences a voltage imbalance. Therefore, the sensitivity for starting the balancing unit 30 to perform voltage balance adjustment can be determined according to the voltage value at which the balanced voltage difference is set.

For example, when the voltage difference between the maximum value of the terminal voltage values V1 VVn and the minimum value of the terminal voltage value exceeds the balance voltage difference set to 0.01 volt (10 millivolts), that is, the voltage balance adjustment control is performed. Controls that perform voltage balance adjustment are more sensitive and frequent than when the balance voltage difference is set to 0.02 volts (20 millivolts). Therefore, the following description refers to the voltage difference adjustment between the maximum value of the voltage value of the terminals 11 to 1n and the minimum value of the terminal voltage value when the balancing unit 30 is activated to perform the voltage balance adjustment operation. The preset voltage difference is preset, so it will not be particularly emphasized later.

In the present creation, the balancing unit 30 performs a voltage balancing rule between the rechargeable batteries 11 to 1 n, and has a terminal voltage value higher than the average voltage value based on the average voltage value of the rechargeable battery pack 10 . The rechargeable battery plays the role of releasing electric energy in the operation of voltage balance such that the terminal voltage value thereof is lowered by the operation of releasing the electric energy; conversely, the rechargeable battery having the terminal voltage value lower than the average voltage value, In the operation of voltage balancing, it plays the role of receiving electric energy, so that its terminal voltage value rises by the operation of receiving electric energy, whereby the electric energy of the rechargeable battery having a higher terminal voltage value is released and has a lower end. The electric energy of the rechargeable battery of the voltage value achieves the purpose of voltage balance.

Hereinafter, for convenience of explanation, the terminal battery having a higher terminal voltage value than the average voltage value and the highest terminal voltage value is a power discharging operation, and a terminal voltage value lower than the average voltage value, and The rechargeable battery of the lowest terminal voltage value is described as an example of receiving power operation, however, this creation does not limit the operation of voltage balancing operation only with the rechargeable battery having the highest terminal voltage value and the lowest terminal voltage value. In other words, one or more rechargeable batteries having a terminal voltage value higher than the average voltage value may also function as a discharge of electrical energy, and one or more rechargeable batteries having a terminal voltage value lower than the average voltage value. As a role in receiving electrical energy, to achieve voltage balancing operation.

Referring to FIG. 5 , the rechargeable battery pack 10 has six rechargeable batteries connected in series. The six rechargeable batteries are sequentially the first rechargeable battery 11 , the second rechargeable battery 12 , and the third rechargeable battery 13 . The fourth rechargeable battery 14, the fifth rechargeable battery 15, and the sixth rechargeable battery 16. Further, it is assumed that the balanced voltage difference is 10 millivolts (mV), and at a point in time of charging, the voltage information detected and calculated by the control unit 40 for each of the rechargeable batteries 11-16 is as shown in the following list 1. Table 1         <TABLE border="1" borderColor="#000000" width="_0001"><TBODY><tr><td> </td><td> First rechargeable battery</td><td> Second rechargeable battery </td><td> Third rechargeable battery</td><td> Fourth rechargeable battery</td><td> Fifth rechargeable battery</td><td> Sixth rechargeable battery</td></ Tr><tr><td> terminal voltage value (mV) </td><td> 1854 </td><td> 1868 </td><td> 1866 </td><td> 1834 </td> <td> 1862 </td><td> 1858 </td></tr><tr><td> Set Balanced Voltage Difference (mV) </td><td> 10 </td></tr> <tr><td> Calculated voltage difference between the maximum terminal voltage value and the minimum terminal voltage value (mV) </td><td> 34 </td></tr><tr><td> Calculated average voltage value (mV) </td><td> 1857 </td></tr></TBODY></TABLE>

It can be seen from Table 1 that the balanced voltage difference for starting the voltage balance adjustment by the balancing unit 30 is set to 10 mV, and the maximum terminal voltage value among the rechargeable batteries 11 to 16 is calculated by the control unit 40 (ie, the first The voltage difference between the terminal voltage value of the second rechargeable battery and the minimum terminal voltage value (ie, the terminal voltage value of the fourth rechargeable battery) is 34 mV, that is, V2-V4=1868-1834=34 mV, and the average of the rechargeable battery pack 10. The voltage value, that is, the average voltage value of the terminal voltage measured by the rechargeable batteries 11 to 16 is 1857 mV. Since the voltage difference (34 mV) between the maximum terminal voltage value and the minimum terminal voltage value exceeds the balanced voltage difference (10 mV), the control unit 40 activates the balancing unit 30 to perform voltage balance control.

In this embodiment, since the terminal voltage value (1868 mV) of the second rechargeable battery 12 is greater than the average voltage value (1857 mV), and is the highest terminal voltage among all the rechargeable batteries 11 to 16, the first The second rechargeable battery 12 plays the role of releasing electric energy; in addition, since the terminal voltage value (1834 mV) of the fourth rechargeable battery 14 is smaller than the average voltage value (1857 mV), and has the lowest terminal voltage among all the rechargeable batteries 11 to 16. Therefore, the fourth rechargeable battery 14 plays the role of receiving electric energy.

Referring to FIG. 6A, in the initial stage of the control unit 40 controlling the balancing unit 30 to initiate a voltage balancing operation, the second rechargeable battery 12 having the highest terminal voltage releases the electric energy and the fourth rechargeable battery having the lowest terminal voltage. The first connection switch control signal S1 outputted by the control unit 40 controls the first connection switch 341 to switch, so that the second end of the first auxiliary energy storage element 321 is electrically connected to the first connection switch 341. The positive voltage terminal of the second rechargeable battery 12. At the same time, the second connection switch control signal S2 outputted by the control unit 40 controls the second connection switch 342 to switch, so that the second end of the second auxiliary energy storage element 322 is electrically connected to the fourth rechargeable battery. The negative voltage terminal of 14. Furthermore, the third connection switch control signal S3 outputted by the control unit 40 controls the third connection switch 343 to switch, so that the negative voltage terminal of the second rechargeable battery 12 is directly connected to the positive voltage of the fourth rechargeable battery 14. And the second end of the first changeover switch 331 and the second end of the second changeover switch 332 are connected, and the connected circuit structure is as shown in FIG. 6A.

In addition, the above is only an example. If it is further assumed that the fifth rechargeable battery 15 (having the highest terminal voltage) is to release the electrical energy and the third rechargeable battery 13 (having the lowest terminal voltage) is the received electrical energy, the control unit 40 controls the balancing unit 30 to initiate the voltage balancing operation. In the initial stage, the first connection switch control signal S1 outputted by the control unit 40 controls the first connection switch 341 to switch, so that the second end of the first auxiliary energy storage element 321 is electrically connected to the fifth charging. The positive voltage terminal of the battery 15. At the same time, the second connection switch control signal S2 outputted by the control unit 40 controls the second connection switch 342 to switch, so that the second end of the second auxiliary energy storage element 322 is electrically connected to the third rechargeable battery. The negative voltage terminal of 13. Furthermore, the third connection switch control signal S3 outputted by the control unit 40 controls the third connection switch 343 to switch, so that the negative voltage terminal of the fifth rechargeable battery 15 is directly connected to the positive voltage of the third rechargeable battery 13. The second end of the first changeover switch 331 and the second end of the second changeover switch 332 are connected.

Referring to FIG. 6A, as described above, when the control unit 40 controls the second rechargeable battery 12 (having the highest terminal voltage) and the fourth rechargeable battery 14 (having the lowest terminal voltage) is electrically connected to the balancing unit 30. Then, the control unit 40 further outputs the first switch control signal SS1 and the second switch control signal SS2, and respectively controls the first switch 331 and the second switch 332 to be turned on in a high frequency switching manner ( Turn on) and turn off. The first switch 331 and the second switch 332 are complementary to each other, that is, when the first switch 331 is turned on, the second switch 332 is turned off; When the switch 332 is turned on, the first switch 331 is turned off; thereby, the high-frequency switching is performed to turn on and off the first switch 331 and the second switch 332, so that the balance unit 30 The charging batteries 11 to 16 are controlled to charge balance.

The second rechargeable battery 12 (having the highest terminal voltage) releases electrical energy such that the fourth rechargeable battery 14 (having the lowest terminal voltage) receives power, as detailed below. Referring to FIG. 6B, the control unit 40 outputs the first switch control signal SS1 to control the first switch 331 to be turned on, and outputs the second switch control signal SS2 to control the second switch 332 to be turned off. In the operation mode, the second rechargeable battery 12 discharges electric energy, and the released electric energy is stored in the first auxiliary energy storage element 321, and the electric energy flow direction is as shown in a first loop L1 of FIG. 6B. At the same time, the electric energy stored in the second auxiliary energy storage element 322 and the electric energy stored in the main energy storage element 31 are released, and are transmitted to the fourth rechargeable battery 14, and the electric energy flow direction is a second circuit as shown in FIG. 6B. L2 is shown.

Moreover, as shown in FIG. 6C, the control unit 40 outputs the first switch control signal SS1 to control the first switch 331 to be turned off and output the second switch control signal SS2 to control the second switch 332 to be turned on. In this mode of operation, the second rechargeable battery 12 continuously releases electrical energy, and the released electrical energy is stored in the main energy storage component 31 and the first auxiliary energy storage component 321, and the power flow direction thereof is as shown in FIG. 6C. The three loop L3 is shown. At the same time, the electric energy stored in the second auxiliary energy storage element 322 is released and transmitted to the fourth rechargeable battery 14, and the electric energy flow direction is as shown in a fourth loop L4 of FIG. 6C.

In this manner, when the first switch 331 is turned on and the second switch 332 is turned off, and the first switch 331 is turned off and the second switch 332 is turned on, the main energy storage device 31 and the first auxiliary device are transmitted. The energy storage and discharging operation of the energy storage component 321 and the second auxiliary energy storage component 322, so that the energy of the second rechargeable battery 12 having the highest terminal voltage is transferred to the fourth rechargeable battery 14 having the lowest terminal voltage. Therefore, the terminal voltage of the second rechargeable battery 12 gradually decreases, and at the same time, the terminal voltage of the fourth rechargeable battery 14 gradually rises, and thus, the voltage difference between the maximum terminal voltage value and the minimum terminal voltage value becomes smaller and smaller.

When the control unit 40 controls the balancing unit 30 to perform a voltage balancing operation, the charging unit 20 continuously charges the rechargeable batteries 11 to 1n of the rechargeable battery pack 10. Furthermore, the control unit 40 continuously detects the voltage values V1 VVn of the terminals of each of the rechargeable batteries 11 to 1n. According to the above example, when the voltage difference between the maximum terminal voltage value and the minimum terminal voltage value still exceeds the preset voltage difference, if the second rechargeable battery 12 still has the highest terminal voltage during the release of the power, the second charging The battery 12 plays the role of releasing electric energy. Similarly, if the fourth rechargeable battery 14 still has the lowest terminal voltage during the process of receiving electric energy, the fourth rechargeable battery 14 plays the role of receiving electric energy.

Once the control unit 40 detects that the rechargeable battery having the highest terminal voltage or has the lowest terminal voltage is changed, the control unit 40 controls the output of the first connection switch control signal S1 and the second connection switch control signal S2. And the third connection switch control signal S3 is configured to switch the voltage balancing operation of the corresponding rechargeable battery. According to the above example, if the second rechargeable battery 12 is in the process of releasing the electric energy, the terminal voltage thereof is lower than the terminal voltage of the third rechargeable battery 13, and the fourth rechargeable battery 14 is in the process of receiving the electric energy, and the terminal voltage thereof rises. The first connection switch control signal S1 output by the control unit 40 controls the first connection switch 341 to switch, so that the second end of the first auxiliary energy storage element 321 is maintained. Electrically connecting the positive voltage terminal of the third rechargeable battery 13 while the second connection switch 342 remains unchanged, and the negative voltage terminal of the fourth rechargeable battery 14 is connected to the second auxiliary energy storage component 322. The second end. Moreover, the third connection switch control signal S3 outputted by the control unit 40 controls the third connection switch 343 to switch, so that the negative voltage terminal of the third rechargeable battery 13 is directly connected to the positive voltage of the fourth rechargeable battery 14. The second end of the first changeover switch 331 and the second end of the second changeover switch 332 are connected.

Thereby, the voltage balance principle of the rechargeable battery with the highest terminal voltage and the energy storage of the rechargeable battery having the lowest terminal voltage is maintained, so that the voltage difference between the maximum terminal voltage value and the minimum terminal voltage value becomes smaller and smaller. Once the voltage difference between the maximum terminal voltage value and the minimum terminal voltage value does not exceed the preset balance voltage difference, the balancing unit 30 stops the voltage balancing operation, and only the charging unit 20 charges the rechargeable battery pack 10. operating. If the voltage difference between the maximum terminal voltage of the rechargeable batteries 11 to 16 and the minimum terminal voltage exceeds the preset voltage difference again during the charging operation, the control unit 40 restarts the balancing unit 30. The voltage balancing operation is completed until the charging batteries 11 to 16 of the rechargeable battery pack 10 are completed.

In summary, this creation has the following features and advantages:

1. The high-frequency switch isolation conversion technology controls the first changeover switch 331 and the second changeover switch 332 to operate in a high-frequency switch state, and the isolation conversion technology enables energy transfer between the rechargeable batteries 11~1n, The phenomenon of potential interference occurs.

2. The energy transfer principle is based on the average voltage value of the rechargeable battery pack 10, and the rechargeable battery device that emits the average voltage value releases electrical energy, and the rechargeable battery device that receives the average voltage value receives electrical energy. Therefore, after the voltage balance is reached, the voltage difference between the rechargeable batteries is less than the set balance voltage difference, for example, 10 mV, the efficiency is greater than 90%, and no heat generation occurs in the system.

3. The balance unit 30 is controlled by the control unit 40 to perform voltage balance adjustment to avoid overcharging of the partially charged battery, and the partially charged battery is undercharged (incompletely), so as to maintain the operational performance of the rechargeable battery pack 10, and can greatly The service life and charge and discharge safety of the rechargeable battery pack 10 are improved.

However, the above description is only for the detailed description and the drawings of the preferred embodiments of the present invention, but the features of the present invention are not limited thereto, and are not intended to limit the creation. All the scope of the creation should be as follows. The scope of patents shall prevail, and all embodiments that incorporate the spirit of the patent application scope and similar changes shall be included in the scope of this creation. Anyone familiar with the art may easily think of it in the field of this creation. Variations or modifications may be covered by the patents in this case below.

10‧‧‧Rechargeable battery pack

20‧‧‧Charging unit

30‧‧‧Balance unit

40‧‧‧Control unit

11~1n‧‧‧Rechargeable battery

111‧‧‧ positive voltage terminal

112‧‧‧negative voltage terminal

31‧‧‧Main energy storage components

321‧‧‧First auxiliary energy storage component

322‧‧‧Second auxiliary energy storage component

331‧‧‧First switch

332‧‧‧Second switch

341‧‧‧First connection switch

342‧‧‧Second connection switch

343‧‧‧ Third connection switch

V+‧‧‧ positive end

V-‧‧‧Negative end

V1~Vn‧‧‧ terminal voltage value

S1‧‧‧First connection switch control signal

S2‧‧‧Second connection switch control signal

S3‧‧‧ Third connection switch control signal

SS1‧‧‧First switch control signal

SS2‧‧‧Second switch control signal

L1‧‧‧ first circuit

L2‧‧‧second loop

L3‧‧‧ third circuit

L4‧‧‧ fourth circuit

100‧‧‧ battery box

101‧‧‧ positive joint

102‧‧‧Negative connector

91‧‧‧Charger

921~924‧‧‧Rechargeable battery

93‧‧‧Battery balancer

931~934‧‧‧resistance

935~938‧‧‧Switch

94‧‧‧ Controller

Figure 1: Schematic diagram of the three-dimensional appearance of the rechargeable battery. Figure 2: A perspective view of the assembled rechargeable battery assembly in a battery case. Figure 3 is a block diagram of the circuit of the battery charging system of the present invention. Figure 4 is a detailed circuit block diagram of Figure 3. Figure 5 is a block diagram of the circuit of the embodiment of Figure 4. Figure 6A is a block diagram of a circuit for performing a voltage balancing operation for the inventive battery charging system. FIG. 6B is a circuit block diagram of the voltage balancing operation when the first switching switch of FIG. 6A is turned on. 6C is a circuit block diagram showing a voltage balancing operation when a second switching switch of FIG. 6A is turned on. Figure 7 is a block diagram of an existing battery balancing circuit.

10‧‧‧Rechargeable battery pack

20‧‧‧Charging unit

30‧‧‧Balance circuit

40‧‧‧Control unit

Claims (12)

A battery charging system comprising: a rechargeable battery pack having a plurality of connected rechargeable batteries to provide a positive terminal and a negative terminal; a charging unit electrically connected to the positive terminal and the negative terminal of the rechargeable battery; a balancing unit electrically connected to the charging unit and the rechargeable battery pack; and a control unit connected to the rechargeable battery pack and the balancing unit, receiving terminal voltage values of the rechargeable batteries, and outputting a complex control according to the voltage values of the terminals The signal controls the balancing unit. The battery charging system of claim 1, wherein the balancing unit comprises: a main energy storage component; a first auxiliary energy storage component connected to the primary energy storage component; and a second auxiliary energy storage component connected to the primary storage a first switching switch connecting the main energy storage component and the first auxiliary energy storage component; a second switching switch connecting the primary energy storage component, the second auxiliary energy storage component, and the first switching switch a first connection switch connecting the first auxiliary energy storage component and one of the first polarity ends of each of the rechargeable batteries; a second connection switch connecting the second auxiliary energy storage component and one of the second rechargeable batteries a polarity end, the polarity of the second polarity end is opposite to the polarity of the first polarity end; and a third connection switch connecting the first switch and connecting the two rechargeable batteries; wherein the control unit outputs a plurality of connections The switch control signal respectively controls the first connection switch, the second connection switch and the third connection switch, and the output complex switch control signals respectively control the first switch and the second Toggle switch. The battery charging system of claim 2, wherein: the main energy storage component has a first end and a second end; The first auxiliary energy storage component has a first end and a second end, wherein the first end is connected to the first end of the main energy storage component; the second auxiliary energy storage component has a first end a second end, wherein the first end is connected to the second end of the main energy storage component; the first switch has a first end, a second end, and a control end, wherein the first end is connected to the second end a first end of the main energy storage component; the second switch has a first end, a second end, and a control end, wherein the first end is connected to the second end of the main energy storage component, the first end The second end is connected to the second end of the first switch; the first connection switch has a first end and a plurality of second ends, wherein the first end is connected to the second end of the first auxiliary energy storage component, Each of the second ends is connected to a first polarity end of each of the rechargeable batteries; the second connection switch has a first end and a plurality of second ends, wherein the first end is connected to the second auxiliary energy storage component a second end, each of the second ends is respectively connected to one of the second polarity ends of the rechargeable batteries, the second The polarity of the opposite end is opposite to the polarity of the first polarity end; and the third connection switch has a first end and a plurality of second ends, wherein the first end is connected to the second end of the first switch, each of the The second end is connected between the two rechargeable batteries. The battery charging system of claim 3, wherein: the control unit outputs a first connection switch control signal to control the first connection switch, output a second connection switch control signal to control the second connection switch, and output a third The connection switch control signal controls the third connection switch, and the control unit outputs a first switch control signal and a second switch control signal to respectively control the first switch and the second switch. The battery charging system according to any one of claims 2 to 4, wherein the control unit when the voltage difference between the maximum value of the terminal voltage value of each of the rechargeable batteries and the minimum value of the terminal voltage value exceeds a balanced voltage difference Outputting a plurality of connection switch control signals respectively controlling the first connection switch, the second connection opening And the third connection switch, the output complex switch control signal controls the first switch and the second switch, respectively. The battery charging system of claim 5, wherein the control unit calculates an average value of the terminal voltage values of the rechargeable batteries, and the rechargeable battery having a maximum value of the terminal voltage values greater than the average value is to release the electrical energy Operation, the rechargeable battery having a minimum value of the terminal voltage value less than the average value is a receiving power operation. The battery charging system of any one of claims 2 to 4, wherein the first switching switch and the second switching on relationship are high frequency switching. The battery charging system of claim 7, wherein the duty cycle of the first switch and the second switch is complementary. The battery charging system of any one of claims 2 to 4, wherein the main energy storage component is a capacitor, and the first auxiliary energy storage component and the second auxiliary energy storage component are respectively an inductor. The battery charging system according to any one of claims 2 to 4, wherein the main energy storage component is a capacitor, the first auxiliary energy storage component and the second auxiliary energy storage component are respectively a common core A two-coupled inductor of a transformer. The battery charging system of any one of claims 1 to 4, wherein the rechargeable batteries are connected in series. The battery charging system according to any one of claims 1 to 4, wherein each of the rechargeable batteries is a lithium titanate battery or a barium titanate battery.