TWI535145B - Battery balancer and charge device thereof - Google Patents

Description

Battery balancer and charging device thereof

The present invention relates to a balancer, and more particularly to a battery balancer and a charging device therefor.

With the depletion of fossil fuels and the public's emphasis on environmental issues, the development and application of many alternative energy sources has gradually matured. Regardless of the depth of technology or the breadth of applications, the development of green energy products continues to break through, so that green energy products are more competitive in the market.

Today, in order to meet the demand for high voltage, rechargeable batteries (such as lithium ion batteries) are connected in series to provide the high voltage required for operation (for example, 400 volts). However, in the case of a rechargeable battery, overcharging or over-discharging can cause the battery to age and thus reduce the life of the rechargeable battery. Moreover, the internal impedance of the rechargeable battery and the battery capacity also change with time, so that the energy of the serially connected rechargeable batteries cannot be balanced, so that the chemical characteristics of the respective rechargeable batteries are destroyed. Wherein, the energy imbalance of the rechargeable battery occurs when one of the rechargeable batteries reaches a rated high voltage, at which time the charging device stops charging the rechargeable battery, so that the energy of each rechargeable battery (ie, the battery voltage) Not the same. Or drawing, when the rechargeable battery is discharged, discharging one of the rechargeable batteries to a rated low voltage will cause the serially connected rechargeable battery pack to stop discharging early, so that the remaining energy of each battery is different. Therefore, how to solve the problem of battery voltage imbalance after charging and discharging of the rechargeable battery has become a focus of designing the charging device.

The invention provides a battery balancer and a charging device thereof, which can quickly balance the battery voltage of each rechargeable battery.

The battery balancer of the present invention is applicable to a plurality of rechargeable battery modules connected in series, and includes a plurality of power storage units and a power control unit. The power storage unit commonly connects a first rechargeable battery module of the rechargeable battery modules, and the power storage units respectively connect a corresponding one of the rechargeable battery modules, wherein the first rechargeable battery module and the first The two rechargeable battery modules are different from each other. The power control unit is configured to measure a plurality of battery voltages of the rechargeable battery modules, and couple the power storage units. When the battery voltages are different, the power control unit controls the power storage units to perform charging and discharging to perform power balancing at a highest voltage and a lowest voltage among the battery voltages.

The charging device of the present invention is applicable to a plurality of rechargeable battery modules connected in series, and includes a power supply unit and the above-described battery balancer. The power supply unit is configured to provide a charging voltage to the rechargeable battery modules. The battery balancer is coupled to the rechargeable battery modules.

In an embodiment of the invention, when a maximum between these battery voltages When the voltage difference is greater than or equal to a critical value, the power control unit controls the power storage units to perform charging and discharging to perform power transfer in the rechargeable battery modules.

In an embodiment of the invention, when the battery voltage of the first rechargeable battery module is the highest voltage, the power control unit controls one of the power storage units to charge, and discharge, using the battery voltage of the first rechargeable battery module. To the second rechargeable battery module corresponding to the lowest voltage.

In an embodiment of the invention, when the battery voltage of the first rechargeable battery module is the lowest voltage, the power control unit controls one of the power storage units to perform the battery voltage of the first rechargeable battery module corresponding to the highest voltage. Charging, and discharging to the first rechargeable battery module.

When the battery voltage of one of the second rechargeable battery modules is the highest voltage, during a first power transfer, the power control unit controls one of the power storage units to utilize the battery of the second rechargeable battery module corresponding to the highest voltage. The voltage is charged and discharged to the first rechargeable battery module. During a second power transfer, the power control unit controls one of the power storage units to be charged by the battery voltage of the first rechargeable battery module, and discharged to correspond The lowest voltage second rechargeable battery module.

In an embodiment of the invention, the length of time during the first power transfer period and the second power transfer period is the same.

In an embodiment of the invention, each of the power storage units includes an energy storage component and a switch unit. The switch unit is coupled to the storage component, the first rechargeable battery module, and the corresponding second rechargeable battery module. The switch unit is controlled by the power control unit to store energy The component is connected in parallel with the first rechargeable battery module or the corresponding second rechargeable battery module.

In an embodiment of the invention, the energy storage component is a capacitor, and the switch unit includes a first switch and a second switch. The first switch has a first end, a second end, and a third end, wherein the first end is coupled to a first positive voltage end of the first rechargeable battery module, and the second end is coupled to the corresponding second rechargeable battery A second positive voltage terminal of the module, the third end is coupled to one end of the capacitor, and the first switch is controlled by the power control unit to couple the third end to the first end or the second end. The second switch has a fourth end, a fifth end and a sixth end, wherein the fourth end is coupled to a first negative voltage end of the first rechargeable battery module, and the fifth end is coupled to the corresponding second rechargeable battery A second negative voltage terminal of the module, the sixth end is coupled to the other end of the capacitor, and the second switch is controlled by the power control unit to couple the sixth end to the fourth end or the fifth end.

In an embodiment of the invention, the energy storage component is an inductor, and the switch unit includes a third switch and a fourth switch. The third switch has a seventh end, an eighth end, a ninth end, a tenth end and a tenth end, wherein the seventh end is coupled to a first positive voltage end of the first rechargeable battery module, The eighth end is coupled to a first negative voltage end of the first rechargeable battery module, the ninth end is coupled to a second positive voltage end of the corresponding second rechargeable battery module, and the tenth end is coupled to the corresponding second charging end a second negative voltage end of the battery module, the eleventh end is coupled to one end of the inductor, and the third switch is controlled by the power control unit to couple the eleventh end to the seventh end, the eighth end, and the ninth end Or the tenth end. The fourth switch has a twelfth end, a thirteenth end, a fourteenth end, a fifteenth end and a sixteenth end, wherein the twelfth end is coupled to the first of the first rechargeable battery modules a positive voltage end, the thirteenth end is coupled to the first negative voltage end of the first rechargeable battery module, the fourteenth The end is coupled to the second positive voltage end of the corresponding second rechargeable battery module, the fifteenth end is coupled to the second negative voltage end of the corresponding second rechargeable battery module, and the sixteenth end is coupled to the other end of the inductor, And the fourth switch is controlled by the power control unit coupling the sixteenth end to the twelfth, thirteenth, fourteenth or fifteenth end.

In an embodiment of the invention, each rechargeable battery module includes at least one serially connected rechargeable battery.

Based on the above, the battery balancer and the charging device of the embodiment of the present invention have a power storage unit coupled to a rechargeable battery module, and a corresponding rechargeable battery module can quickly balance each other through charging and discharging of the power storage unit. The battery voltage of the rechargeable battery. Thereby, the battery voltage imbalance problem after charging and discharging of the rechargeable battery can be solved, and the service life of the rechargeable battery is improved and the charging efficiency of the charging device is improved.

The above described features and advantages of the invention will be apparent from the following description.

10_1‧‧‧First rechargeable battery module

10_2~10_n‧‧‧Second rechargeable battery module

100‧‧‧Charging device

110‧‧‧Power supply unit

120‧‧‧Battery balancer

121‧‧‧Power Control Unit

123_1~123_p‧‧‧Power storage unit

210, 310‧‧‧ energy storage components

220, 320‧‧‧ switch unit

A1~A6, B1~B10‧‧‧ endpoint

C‧‧‧ capacitor

L‧‧‧Inductance

SCT_1~SCT_p‧‧‧Power control signal

SW11, SW12, SW21, SW22‧‧‧ switch

VBC‧‧‧Charging voltage

VBT_1~VBT_n‧‧‧Battery voltage

1 is a schematic diagram of a system of a charging device in accordance with an embodiment of the present invention.

2 is a circuit diagram of the power storage unit of FIG. 1 according to an embodiment of the invention.

3 is a circuit diagram of the power storage unit of FIG. 1 according to another embodiment of the present invention.

1 is a schematic diagram of a system of a charging device in accordance with an embodiment of the present invention. Referring to FIG. 1 , in the embodiment, the charging device 100 is adapted to charge a plurality of serially connected rechargeable battery modules (eg, 10_1~10_n), and the charging device 100 includes a power supply unit 110 and a battery balancer 120. Where n is a positive integer greater than 1, and each of the rechargeable battery modules (eg, 10_1~10_n) may include a rechargeable battery or a plurality of serially connected rechargeable batteries, which may be set by a person skilled in the art.

The power supply unit 110 is configured to provide a charging voltage VBC to the serially connected rechargeable battery modules (eg, 10_1~10_n). The battery balancer 120 is coupled to the rechargeable battery module (such as 10_1~10_n) for balancing the battery voltage of the rechargeable battery module (such as 10_1~10_n) (such as VBT_1~VBT_n). In other words, when the difference between the battery voltages VBT_1 VVBT_n is too large, the battery balancer 120 performs power transfer between the battery modules 10_1~10_n so that the battery voltages VBT_1~VBT_n are substantially equal. Thereby, the imbalance problem of the battery voltage (such as VBT_1~VBT_n) after charging and discharging of the rechargeable battery can be solved to improve the service life of the rechargeable battery and improve the charging efficiency of the charging device 100.

In the present embodiment, the battery balancer 120 includes a plurality of power storage units 121 (eg, 123_1~123_p), where p is an integer and is equal to n-1. The power storage units 123_1~123_p are connected in parallel to the rechargeable battery module 10_1 (corresponding to the first rechargeable battery module), and the power storage units 123_1~123_p respectively connect the corresponding rechargeable battery modules of the rechargeable battery modules 10_2~10_n (corresponding to the second rechargeable battery) Module). The first rechargeable battery module and the second rechargeable battery module are different from each other, and the rechargeable battery modules that are commonly connected in parallel are exemplified by the rechargeable battery module 10_1, but in other embodiments, the rechargeable battery modules are connected in parallel. The group can be a rechargeable battery module 10_2~10_n One of them, and the remaining rechargeable battery modules (such as 10_1~10_n) are connected in parallel with the corresponding power storage unit (such as 123_1~123_p).

The power control unit 121 is coupled to the rechargeable battery modules 10_1~10_n and the power storage units 123_1~123_p for measuring the battery voltages VBT_1~VBT_n of the rechargeable battery modules 10_1~10_n, and providing a plurality of power control signals SCT_1~SCT_p to power storage. Units 123_1~123_p. When the battery voltages VBT_1 VVBT_n are different, the power control unit 121 performs charging and discharging through the power storage units 123_1~123_p of the control portions of the power control signals SCT_1~SCT_p to balance the highest voltage and the lowest voltage among the battery voltages VBT_1~VBT_n. . In other words, when the maximum voltage difference between the highest voltage and the lowest voltage of the battery voltages VBT_1 VVBT_n is greater than or equal to a critical value (for example, 0.1 volt), the power storage units 121_1 to 123_p of the control portion of the power control unit 121 sequentially charge and discharge. Power transfer is performed in the rechargeable battery modules 10_1 to 10_n.

Further, when the battery voltage VBT_1 of the rechargeable battery module 10_1 is the highest voltage and the battery voltage VBT_3 of the rechargeable battery module 10_3 is the lowest voltage, the power control unit 121 controls the power storage unit 123_2 to utilize the battery voltage of the rechargeable battery module 10_1. VBT_1 performs charging, and controls the electric storage unit 123_2 to discharge to the rechargeable battery module 10_3. When the battery voltage VBT_3 of the rechargeable battery module 10_3 is the highest voltage and the battery voltage VBT_1 of the rechargeable battery module 10_1 is the lowest voltage, the power control unit 121 controls the power storage unit 123_2 to charge using the battery voltage VBT_3 of the rechargeable battery module 10_3. And controlling the electric storage unit 123_2 to discharge to the rechargeable battery module 10_1.

When the battery voltage VBT_3 of the rechargeable battery module 10_3 is the highest voltage and the battery voltage VBT_2 of the rechargeable battery module 10_2 is the lowest voltage, during the first power transfer, the power control unit 121 controls the power storage unit 123_2 to utilize the rechargeable battery module 10_3. The battery voltage VBT_3 is charged, and the control power storage unit 123_2 is discharged to the rechargeable battery module 10_1. Next, during the second power transfer, the power control unit 121 controls the power storage unit 123_1 to perform charging using the battery voltage VBT_1 of the rechargeable battery module 10_1, and controls the power storage unit 123_1 to discharge to the rechargeable battery module 10_1. Thereby, the battery voltages VBT_2 and VBT_3 perform power balance to solve the imbalance problem of the battery voltage (such as VBT_1~VBT_n). The time length of the first power transfer period and the second power transfer period may be set to be the same, but the embodiment of the present invention is not limited thereto.

2 is a circuit diagram of the power storage unit of FIG. 1 according to an embodiment of the invention. Referring to FIG. 1 and FIG. 2, in the present embodiment, the power storage unit (taking 122_p as an example) includes, for example, an energy storage element 210 and a switch unit 220, wherein the same or similar elements use the same or similar reference numerals. Here, it is assumed that the switch unit 220 is coupled to the storage component 210, the rechargeable battery modules 10_1 and 10_n, and the switch unit 220 is controlled by the power control signal SCT_p provided by the power control unit 121 to connect the energy storage component 210 in parallel to the rechargeable battery module 10_1. Or 10_n.

Further, the energy storage element 210 is, for example, a capacitor C, and the switch unit 220 includes, for example, switches SW11 and SW12. The switch SW11 has an end point A1~A3, wherein the end point A1 is coupled to the positive voltage end of the rechargeable battery module 10_1 (corresponding to the first positive voltage end), and the end point A2 is coupled to the positive voltage end of the rechargeable battery 10_n module (corresponding to the first Two positive At the voltage terminal, the terminal A3 is coupled to one end of the capacitor C. And, the switch SW11 is controlled by the power control unit 121 to couple the terminal A3 to the terminals A1, A2 or not. The switch SW12 has an end point A4~A5, wherein the end point A4 is coupled to the negative voltage end of the rechargeable battery module 10_1 (corresponding to the first negative voltage end), and the end point A5 is coupled to the negative voltage end of the rechargeable battery 10_n module (corresponding to the first The second negative voltage terminal), the terminal A6 is coupled to the other end of the capacitor C. And, the switch SW12 is controlled by the power control unit 121 to couple the terminal A6 to the terminals A4, A5 or not.

When the terminal A3 is coupled to the terminal A1 and the terminal A6 is coupled to the terminal A4, the capacitor C is connected in parallel to the rechargeable battery module 10_1. Then, when the voltage across the capacitor C is greater than the battery voltage VBT_1 of the rechargeable battery module 10_1, the capacitor C is discharged to the rechargeable battery module 10_1; otherwise, when the voltage across the capacitor C is less than the battery voltage VBT_1 of the rechargeable battery module 10_1. The capacitor C is charged by the battery voltage VBT_1 of the rechargeable battery module 10_1.

When the terminal A3 is coupled to the terminal A2 and the terminal A6 is coupled to the terminal A5, the capacitor C is connected in parallel to the rechargeable battery module 10_n. Then, when the voltage across the capacitor C is greater than the battery voltage VBT_n of the rechargeable battery module 10_n, the capacitor C is discharged to the rechargeable battery module 10_n; otherwise, when the voltage across the capacitor C is less than the battery voltage VBT_n of the rechargeable battery module 10_n. The capacitor C is charged by the battery voltage VBT_n of the rechargeable battery module 10_n.

3 is a circuit diagram of the power storage unit of FIG. 1 according to another embodiment of the present invention. Referring to FIG. 1 and FIG. 3, in the embodiment, the power storage unit (taking 122_p as an example) includes, for example, an energy storage component 310 and a switch unit 320, wherein the same or similar elements The pieces use the same or similar labels. Here, it is assumed that the switch unit 320 is coupled to the storage component 310, the rechargeable battery modules 10_1 and 10_n, and the switch unit 320 is controlled by the power control signal SCT_p provided by the power control unit 121 to connect the energy storage component 310 in parallel to the rechargeable battery module 10_1. Or 10_n.

Further, the energy storage element 310 is, for example, an inductance L, and the switching unit 320 includes, for example, switches SW21 and SW22. The switch SW21 has the end points B1 B B5, wherein the end point B1 is coupled to the positive voltage end of the rechargeable battery module 10_1, the end point B2 is coupled to the negative voltage end of the rechargeable battery module 10_1, and the end point B3 is coupled to the rechargeable battery 10_n module. The positive voltage terminal, the terminal B4 is coupled to the negative voltage terminal of the rechargeable battery 10_n module, and the terminal B5 is coupled to one end of the inductor L. And, the switch SW21 is controlled by the power control unit 121 to couple the end point B5 to one of the terminals B1 to B4 or not. The switching unit 320 includes, for example, switches SW21 and SW22. The switch SW22 has an end point B6~B10, wherein the end point B6 is coupled to the positive voltage end of the rechargeable battery module 10_1, the end point B7 is coupled to the negative voltage end of the rechargeable battery module 10_1, and the end point B8 is coupled to the rechargeable battery 10_n module. The positive voltage terminal, the terminal B9 is coupled to the negative voltage terminal of the rechargeable battery 10_n module, and the terminal B10 is coupled to the other end of the inductor L. And, the switch SW22 is controlled by the power control unit 121 to couple the end point B10 to one of the terminals B6 to B9 or not.

In an embodiment of the invention, it is assumed that the battery voltage VBT_1 is greater than the battery voltage VBT_n. At this time, the end point B5 can be coupled to the end point B1, and the end point B10 can be coupled to the end point B7 so that the inductor L is connected in parallel to the rechargeable battery module 10_1, and the inductor L utilizes the rechargeable battery module 10_1. The battery voltage VBT_1 is charged. Then, the endpoint B5 can be coupled to the endpoint B4, and the endpoint B10 can be coupled to the endpoint B8. The inductor L is connected in parallel to the rechargeable battery module 10_n, and the inductor L is discharged to the rechargeable battery module 10_n.

In an embodiment of the invention, it is assumed that the battery voltage VBT_n is greater than the battery voltage VBT_1. At this time, the end point B5 can be coupled to the end point B3, and the end point B10 can be coupled to the end point B9 so that the inductor L is connected in parallel to the rechargeable battery module 10_n, and the inductor L utilizes the rechargeable battery module 10_n. The battery voltage VBT_n is charged. Then, the terminal B5 can be coupled to the end point B2, and the end point B10 can be coupled to the end point B6, so that the inductor L is connected in parallel to the rechargeable battery module 10_1, and the inductor L is discharged to the rechargeable battery module 10_1. .

In summary, the battery balancer and the charging device of the embodiment of the present invention, the power storage unit is coupled to a rechargeable battery module, and coupled to a corresponding rechargeable battery module, respectively, through the charging and discharging of the power storage unit. The battery voltage of each rechargeable battery can be quickly balanced. Thereby, the battery voltage imbalance problem after charging and discharging of the rechargeable battery can be solved, and the service life of the rechargeable battery is improved and the charging efficiency of the charging device is improved.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

10_1~10_n‧‧‧Rechargeable battery module

100‧‧‧Charging device

110‧‧‧Power supply unit

120‧‧‧Battery balancer

121‧‧‧Power Control Unit

123_1~123_p‧‧‧Power storage unit

SCT_1~SCT_p‧‧‧Power control signal

VBC‧‧‧Charging voltage

VBT_1~VBT_n‧‧‧Battery voltage

Claims (10)

The utility model relates to a battery balancer, which is suitable for a plurality of rechargeable battery modules connected in series, comprising: a plurality of power storage units, a first rechargeable battery module of the plurality of rechargeable battery modules being connected in parallel, and the plurality of power storage units are respectively connected in parallel a second rechargeable battery module of the plurality of rechargeable battery modules, wherein the first rechargeable battery module and the plurality of second rechargeable battery modules are different from each other; and a power control unit for measuring the a plurality of battery voltages of the plurality of rechargeable battery modules, and coupled to the plurality of power storage units, the power control unit controls the plurality of power storage units to perform charging and discharging when the plurality of battery voltages are different A maximum voltage and a minimum voltage of the battery voltage are used for power balance. The battery balancer of claim 1, wherein the power control unit controls the plurality of power storage units to perform charging and discharging when a maximum voltage difference between the plurality of battery voltages is greater than or equal to a threshold value. To perform power transfer in the plurality of rechargeable battery modules. The battery balancer of claim 1, wherein when the battery voltage of the first rechargeable battery module is the highest voltage, the power control unit controls one of the plurality of power storage units to utilize the first The battery voltage of a rechargeable battery module is charged and discharged to the second rechargeable battery module corresponding to the lowest voltage. The battery balancer of claim 1, wherein when the battery voltage of the first rechargeable battery module is the lowest voltage, the power control unit controls one of the plurality of power storage units to utilize the corresponding The first charge of the highest voltage The battery voltage of the battery module is charged and discharged to the first rechargeable battery module. The battery balancer of claim 1, wherein when the battery voltage of one of the second rechargeable battery modules is the highest voltage, the power control unit controls the current during a first power transfer One of the plurality of power storage units is charged by the battery voltage of the second rechargeable battery module corresponding to the highest voltage, and discharged to the first rechargeable battery module, the power control during a second power transfer The unit controls one of the plurality of power storage units to be charged by the battery voltage of the first rechargeable battery module, and discharged to the second rechargeable battery module corresponding to the lowest voltage. The battery balancer of claim 5, wherein the length of time during the first power transfer period and the second power transfer period is the same. The battery balancer of claim 1, wherein each of the plurality of power storage units comprises: an energy storage component; and a switch unit coupled to the storage component, the first rechargeable battery module, and the corresponding The second rechargeable battery module is controlled by the power control unit to connect the energy storage component in parallel with the first rechargeable battery module or the corresponding second rechargeable battery module. The battery balancer of claim 7, wherein the energy storage component is a capacitor, and the switch unit comprises: a first switch having a first end, a second end, and a third end, The first The end is coupled to a first positive voltage end of the first rechargeable battery module, the second end is coupled to a second positive voltage end of the corresponding second rechargeable battery module, and the third end is coupled to the capacitor One end, wherein the first switch is controlled by the power control unit to couple the third end to the first end or the second end; and a second switch has a fourth end, a fifth end, and a a sixth end, the fourth end is coupled to a first negative voltage end of the first rechargeable battery module, and the fifth end is coupled to a second negative voltage end of the corresponding second rechargeable battery module, the first end The sixth end is coupled to the other end of the capacitor, wherein the second switch is controlled by the power control unit to couple the sixth end to the fourth end or the fifth end. The battery balancer of claim 7, wherein the energy storage component is an inductor, and the switch unit comprises: a third switch having a seventh end, an eighth end, and a ninth end, a tenth end and a tenth end, the seventh end is coupled to a first positive voltage end of the first rechargeable battery module, and the eighth end is coupled to a first negative of the first rechargeable battery module a voltage terminal, the ninth end is coupled to a second positive voltage end of the corresponding second rechargeable battery module, and the tenth end is coupled to a second negative voltage end of the corresponding second rechargeable battery module, The eleventh end is coupled to one end of the inductor, wherein the third switch is controlled by the power control unit coupling the eleventh end to the seventh end, the eighth end, the ninth end or the tenth And a fourth switch having a twelfth end, a thirteenth end, a fourteenth end, a fifteenth end and a sixteenth end, wherein the twelfth end is coupled to the first charging The first positive voltage end of the battery module, the thirteenth end is coupled to the first portion of the first rechargeable battery module a negative voltage end, the fourteenth end is coupled to the second positive voltage end of the corresponding second rechargeable battery module, and the fifteenth end is coupled to the second negative of the corresponding second rechargeable battery module a voltage terminal, the sixteenth end is coupled to the other end of the inductor, wherein the fourth switch is controlled by the power control unit coupling the sixteenth end to the twelfth end, the thirteenth end, the The fourteenth end or the fifteenth end. A charging device, applicable to a plurality of rechargeable battery modules connected in series, comprising: a power supply unit for providing a charging voltage to the plurality of rechargeable battery modules; and as described in claim 1 The battery balancer is coupled to the plurality of rechargeable battery modules.