TWI412204B - Battery management system and method capable of dynamically allocating charging current - Google Patents

Abstract

A battery management system includes a power converter, a first switch, a second switch and a CPU. The power converter is configured to divide the current of a power supply into two portions, a first portion is provided to power the load, and a second portion is provided to charge a battery. When the current provided by the power supply is equal to a predetermined current threshold value, the CPU turns on both the first switch and the second switch. The first portion of the current is supplied to the load via the first switch, and the second portion of the current charges the battery via the second switch. A related method is also provided.

Description

Battery management system and method with dynamic distribution charging current function

The present invention relates to a battery management system, and more particularly to a battery management system and method having a function of dynamically allocating charging current.

The traditional AC adapter has a limited output current, the system power supply and relatively independent control of the battery charging in the system, the design needs to consider the maximum power consumption of the system, and the remaining current is divided into battery charging. Therefore, these traditional AC adapters may not be able to support fast battery charging when the system load is turned on (running). For example, a conventional charging method uses an AC adapter that can power the system or can charge the battery. This way, the battery cannot be charged while the system is running. Another conventional charging method uses an AC adapter that can power the system while also charging the battery with a large charging current. However, such AC adapters are complex in construction and costly.

However, in practice, the system power consumption is constantly changing, and it will not always work in its maximum power consumption state, so that the battery is charged with the current set current, and the input current capability of the total power source is not fully utilized; on the other hand, the battery is charged. The current is always at a fixed size, resulting in a longer charging time. Moreover, when the input system consumes power, the instantaneous load current exceeds the load capacity of the total input power supply, and cannot be replenished from the battery. This can only increase the load capacity of the total input power supply, thereby increasing the manufacturing of the total input power supply. cost.

In view of this, it is necessary to provide a battery management system and method that can dynamically allocate charging current to maximize input power utilization.

A battery management system includes a power supply, a system load, a battery, and a main control unit. The battery management system further includes: a power converter for dividing the supply current of the power supply into two parts according to the working current required for the normal operation of the system load, a part of which supplies an operating current to the system load, and the remaining part is the battery Provide charging current. a first power switch and a second power switch. The main control unit is configured to turn on the first power switch and the second power switch when the supply current provided by the power source flowing through the power converter meets a predetermined current threshold. The operating current provided for the system load is supplied to the system load via the first power switch, and the charging current provided for battery charging is provided to the battery via the second power switch.

A battery management system implements a method for dynamically distributing a charging current, wherein the battery management system includes: a power source, a battery, a system load, a first power switch, and a second power switch. The method includes: accessing a power source, and detecting whether a power supply current provided by the power source is greater than a preset current threshold.

When the power supply current of the power source is greater than the current threshold, the power supply current of the power supply is divided into two parts according to the requirement of the system load, and a part of the power supply current is supplied to the system load through the first power switch, and the working current supplied to the load Depending on the needs of the load, the remainder is charged by the second power switch.

Compared with the prior art, the present invention provides a power path scheme for dynamically allocating a charging current. The power supply supplies power to the system load and dynamically distributes current for charging the battery. The battery is distributed to the battery as the power consumption of the system load changes. The charging current is also adjusted to achieve maximum use of the power supply current. When the system load is turned off, the entire supply current of the power supply is used to charge the battery for fast charging of the battery. And the power supply structure is simple and the cost is low.

On the other hand, when the system load instantaneous power consumption current increases, exceeding the load capacity of the total input power of the power supply, it can be supplemented from the existing battery to supply the system load, so that the power input load capacity can be improved, thereby reducing the total input power. cost.

100‧‧‧Battery Management System

10‧‧‧Power supply

11‧‧‧System load

12‧‧‧Battery

13‧‧‧Power Converter

14‧‧‧Main control unit

15‧‧‧Power supply current detection unit

16‧‧‧Battery current detection unit

17‧‧‧First power switch

18‧‧‧Second power switch

1 is a block diagram of a battery management system having a power source that can dynamically distribute charging current, in accordance with one embodiment of the present invention.

2 is a flow chart of a method of implementing a dynamic distribution of charging current by a power supply in accordance with an embodiment of the present invention.

The invention will be further described in detail below with reference to the accompanying drawings.

Referring to Figure 1, there is shown a block diagram of a battery management system 100 having a dynamically distributed charging current function in accordance with one embodiment of the present invention. The battery management system 100 includes a power source 10, a system load 11, and a battery 12. The power source 10 can provide an operating current for the system load 11 to operate and a charging current for charging the battery 12. Battery 12 can power system load 11.

The battery management system 100 further includes a power converter 13, a main control unit 14, and a power supply Current detecting unit 15 and battery current detecting unit 16. The power converter 13 is configured to supply a current of a power source 10 (eg, an AC adapter) through the power converter 13 (eg, a step-down DC/DC converter) according to an operating current required for the system load 11 to operate normally. Divided into two parts, one part provides the operating current for the system load 11, and the remainder provides the charging current for the battery 12. The power supply current detecting unit 15 is configured to detect the magnitude of the power supply current supplied from the power source 10 to the power converter 13. The battery current detecting unit 16 is configured to detect the magnitude of the charging current provided by the power source 10 for charging the battery 12.

If the battery management system 100 is operating normally, the system load 11 must obtain the operating current required for its normal operation from the power source 10, that is, actively acquire current, otherwise, the system 100 cannot operate normally. The magnitude of the charging current required to charge the battery 12 is not a certain value, and may be provided by the power source 10 according to the operation of the system 100, that is, the current is passively supplied. Therefore, when the system load 11 is working normally, the power supply current of the power source 10 will preferentially satisfy the operating current of the system load 11 for normal operation. Therefore, when the power supply current of the power source 10 flows through the power converter 13, it will be automatically divided into two parts according to the working current required for the normal operation of the system load 11, a part of which supplies the operating current to the system load 11, and the remaining part is the battery 12 Provide charging current. For example, if the system load 11 has a normal operating current of 40 A and the power supply 10 has a total supply current of 90 A, then the power supply current of the power supply 10 passes through the power converter 13 and preferentially supplies 40 A of operating current to the system load 11, and the remaining 50 A is Battery 12 provides a charging current.

In the battery management system 100, the maximum allowable charging current set to charge the battery 12 is the maximum allowable supply current of the power source 10. As the operating current required to operate the system load 11 changes (e.g., increases or decreases), the charging current supplied to the battery 12 also changes (e.g., decreases or increases). And when the system load 11 is turned off, the power supply 10 The supply current is all charged to the battery 12, ie, charged at its maximum supply current. Thus, the battery management system 100 can achieve dynamic distribution of charging current.

The battery management system 100 also includes a first power switch 17 and a second power switch 18. The second power switch 18 is a double-conducting switch. When the second power switch 18 is conducting, the current supplied by the power source 10 can charge the battery 12; when the second power switch 18 is reverse-conducting, the battery 12 can be The system load 11 is powered; when the second power switch 18 is not turned on in both directions, the second power switch 18 is turned off.

The battery management system 100 pre-sets a current threshold, that is, the power supply current of the power supply 10 can satisfy the current required for the system load 11 to operate normally.

When the power source current detecting unit 15 detects the current flowing through the power source 10 of the power converter 13, and transmits the detection result to the main control unit 14, the main control unit 14 determines whether the detected current is greater than The above current threshold. If greater than the current threshold, the main control unit 14 controls the opening of the first power switch 17, and the power supply 10 provides current to power the system load 11. At the same time, the main control unit 14 controls the second power switch 18 to conduct a forward flow. In addition to supplying the operating current to the system load 11, the remaining current supplies the battery 12 with a charging current. If the current of the power source 10 is less than the current threshold, the main control unit 14 determines that the current of the power source 10 cannot maintain the normal operation of the system, and then controls the first power switch 17 and the second power switch 18 to be turned off.

The power supply current detecting unit 15 and the battery current detecting unit 16 respectively detect the power supply current flowing through the power source 10 of the power converter 13 and the charging current for charging the battery 12, respectively, and charge the battery 12 when charging. The current is less than its charge cut-off current, and the supply current supplied to the power converter 13 is less than the maximum allowable supply of the power source 10. At the time of the flow, the main control unit 14 judges that the charging of the battery 12 is completed, and controls the second power switch 18 to be turned off.

Generally, the criterion for charging the battery 12 is that its charging current is less than a set value, that is, an off current. However, in the battery management system 100, since the charging current supplied to the battery 12 changes as the operating current of the system load 11 changes, there is a case where the operating current required for the system load 11 When it is large, the charging current for charging the battery 12 is reduced, and the magnitude of the supply current flowing through the power converter 13 detected by the power source current detecting unit 15 is still the maximum supply current of the power source 10. At this time, the battery current detecting unit 16 detects that the charging current is smaller than the off current, and the main control unit 14 determines that the charging of the battery 12 is completed, thereby turning off the second power switch 18. However, the actual situation may be that the battery 12 has not been fully charged, but is erroneously judged due to an increase in the operating current supplied to the system load 11. By setting the above conditions, when the magnitude of the charging current of the battery 12 detected by the battery current detecting unit 16 is smaller than the off current, the power supply current detecting unit 15 detects the supply current supplied to the power converter 13. The size of the power supply 10 is smaller than the maximum allowable power supply current of the power supply 10, indicating that the operating current of the system load 11 does not change at this time, but the supply current flowing through the power converter 13 becomes smaller due to the decrease of the charging current of the battery 12, thereby judging The battery 12 is fully charged. Therefore, by setting the supply current of the power source 10 and the charging current of the battery 12 while satisfying the above conditions, it is possible to prevent erroneous determination.

Further, when the main control unit 14 determines that the charging current supplied to the battery 12 is instantaneously reduced to zero by the detection result transmitted by the battery current detecting unit 16, it is determined that the current consumption of the system load 11 is excessive when the current is excessive. Exceeding the maximum allowable power supply of the power supply 10 Current, the main control unit 14 controls the second power switch 18 to reverse conduction, and the battery 12 is no longer charged, but supplies power to the system load 11 (as shown by the dotted line in FIG. 1). When the system load 11 consumes power and the load current exceeds the load capacity of the total input power source, the current is supplemented from the existing battery 12, thereby reducing the cost of the total input power source 10.

Using the battery management system 100 described above, the power supply 10 supplies power to the system load 11 and dynamically charges the battery 12, and as the power consumption of the system load 11 changes, the charging current distributed to the battery 12 is also adjusted. The use of the power supply current of the power source 10 is maximized. When the system load 11 is turned off, all of the power supply current of the power source 10 is used to charge the battery 12, enabling rapid charging of the battery 12. And the power supply structure is simple and the cost is low.

On the other hand, when the system load 11 instantaneously increases the power consumption current and exceeds the load capacity of the total input power of the power source 10, the existing battery 12 can be supplemented with the system load 11 to supply power, so that the power input load capacity can be improved, thereby reducing Total input power cost.

Referring to FIG. 2, a flow chart of a method for dynamically realizing charging current distribution by a power supply in a preferred embodiment of the present invention.

In step S20, the battery management system 100 is connected to the power source 10. The power source current detecting unit 15 detects whether the power supply current provided by the power source 10 is greater than a current threshold. If yes, the process proceeds to step S21; otherwise, the process continues.

The battery management system 100 pre-sets a current threshold, that is, the power supply current of the power supply 10 can satisfy the normal operation of the system load 11. If the current of the power source 10 is less than the current threshold, the main control unit 14 determines that the current of the power source 10 cannot be maintained. When the system is working normally, the first power switch 17 is controlled to be turned off.

In step S21, if the detection result satisfies the current threshold, the main control unit 14 controls to turn on the first power switch 17, while controlling the second power switch 18 to be forwarded.

The second power switch 18 is a double-conducting switch. When the second power switch 18 is conducting, the current supplied by the power source 10 can charge the battery 12; when the second power switch 18 is reverse-conducting, the battery 12 can be The system load 11 is powered; when the second power switch 18 is not turned on in both directions, the second power switch 18 is turned off.

In step S22, the main control unit 14 controls the supply current flowing through the power source 10 of the power converter 13 to be divided into two parts, one part for supplying power to the system load 11, the remaining part for charging the battery 12, and the current for charging the battery 12 with the system load. The power consumption current of 11 is constantly changing.

In step S23, the battery current detecting unit 16 detects whether the charging current of the battery 12 is less than its off current, and if so, proceeds to step S24; otherwise, the step continues.

In step S24, the power supply current detecting unit 15 detects whether the power supply current supplied to the power converter 13 is smaller than the maximum allowable power supply current of the power source 10. If yes, the process goes to step S25; otherwise, the process continues.

In step S25, the main control unit 14 determines that the battery 12 is fully charged, and controls the second power switch 18 to be turned off.

Generally, the criterion for charging the battery 12 is that its charging current is less than a set value, that is, an off current. However, in the battery management system 100, since the charging current supplied to the battery 12 changes as the operating current of the system load 11 changes. There is a case where the charging current for charging the battery 12 is reduced when the operating current required for the system load 11 is large, and the power supply current detecting unit 15 detects the supply to the power converter 13 The magnitude of the supply current is still the maximum allowable supply current of the power supply 10. At this time, the battery current detecting unit 16 detects that the charging current is smaller than the off current, and the main control unit 14 determines that the charging of the battery 12 is completed, thereby turning off the second power switch 18. However, the actual situation is that the battery 12 has not been fully charged, but is erroneously judged due to an increase in the operating current supplied to the system load 11. By setting the above conditions, when the magnitude of the charging current of the battery 12 detected by the battery current detecting unit 16 is smaller than the off current, the power source current detecting unit 15 detects the power supply current supplied to the power converter 13. The size is smaller than the maximum allowable supply current of the power source 10, indicating that the operating current of the system load 11 does not change at this time, but the supply current flowing through the power converter 13 becomes smaller due to the decrease of the charging current of the battery 12, thereby determining the battery. 12 charging is completed. Therefore, by setting the supply current of the power source 10 and the charging current of the battery 12 while satisfying the above conditions, it is possible to prevent erroneous determination.

The power supply current detecting unit 15 detects the power supply current of the power source 10, and further includes the following steps: Step S26, the battery current detecting unit 16 detects whether the charging current of the battery 12 is The moment is reduced to zero, and if so, the process proceeds to step S27; otherwise, the step is continued.

In step S27, the main control unit 14 controls the second power switch 18 to reverse conduction, and the battery 12 supplies power to the system load 11.

When the power consumption of the system load 11 is excessive, the maximum power supply of the power supply 10 is exceeded. When the current is current, the main control unit 14 determines that the charging current of the battery 12 is instantaneously decreased by the detection result transmitted by the battery current detecting unit 16, and when it is reduced to zero, the main control unit 14 controls the second power switch 18 to reverse the conduction. The battery 12 is no longer charged, but supplies power to the system load 11.

Using the above method of dynamic charging current distribution, the power supply 10 supplies power to the system load 11 and dynamically supplies current for charging the battery 12. As the power consumption of the system load 11 changes, the charging current distributed to the battery 12 also follows. Adjustment to achieve maximum use of the power supply current of the power supply 10. When the system load 11 is turned off, all of the power supply current of the power source 10 is used to charge the battery 12, enabling rapid charging of the battery 12. And the power supply structure is simple and the cost is low.

On the other hand, when the system load 11 instantaneously increases the power consumption current and exceeds the load capacity of the total input power source of the power source 10, it can be supplemented from the existing battery 12 to supply the system load 11 so that the power input load capacity can be improved, thereby Reduce total input power costs.

It is to be understood that those skilled in the art can make various other changes and modifications in accordance with the technical concept of the present invention, and all such changes and modifications are intended to fall within the scope of the appended claims.

100‧‧‧Battery Management System

10‧‧‧Power supply

11‧‧‧System load

12‧‧‧Battery

13‧‧‧Power Converter

14‧‧‧Main control unit

15‧‧‧Power supply current detection unit

16‧‧‧Battery current detection unit

17‧‧‧First power switch

18‧‧‧Second power switch

Claims (10)

A battery management system includes a power supply, a system load, a battery, and a main control unit. The improvement is that the battery management system further includes: a power converter for operating current required for normal operation of the system load, The power supply current of the power source is divided into two parts, a part of which provides an operating current for the system load, and a remaining part provides a charging current for the battery; a first power switch; a second power switch; and the main control unit Turning on the first power switch and the second power switch when the supply current provided by the power source flowing through the power converter meets a predetermined current threshold; wherein the operating current provided for the system load is The first power switch is provided to the system load, and the charging current provided for battery charging is provided to the battery via the second power switch. The battery management system according to claim 1, wherein a maximum allowable charging current for charging the battery is set to a maximum allowable supply current of the power source, and an operating current supplied to the system load is required according to a system load. Variations, the remaining portion of the current that is charged by the battery varies with the operating current supplied to the system load. The battery management system of claim 2, further comprising a battery current detecting unit for detecting the charging current provided by the power source for the battery; and a power source current detecting unit for Instantly detecting a power supply current supplied to the power converter; when the battery current detecting unit detects the battery The charging current is less than the charging cut-off current, and the main current control unit determines that the battery charging is completed when the power supply current detecting unit detects that the power supply current flowing through the power converter is less than the maximum allowable power supply current of the power source. And controlling the second power switch to be turned off. The battery management system of claim 3, wherein the main control unit is further configured to: when the power supply current detecting unit detects that the power supply current supplied to the power converter does not satisfy the preset In the current threshold, the first power switch and the second power switch are turned off, wherein the preset current threshold is that the power supply current of the power supply meets the current required for the system load to work normally. The battery management system according to claim 4, wherein the second power switch is a double-conducting switch, and when the second power switch is conducting, the power supply current supplies the battery; when the second power switch When the reverse conduction is performed, the battery supplies power to the system load; when the second power switch is not turned on in both directions, the second power switch is turned off. The battery management system according to claim 5, wherein when the battery current detecting unit detects that the battery current is instantaneously decreased, determining that the power consumption current of the system load exceeds the maximum allowable power supply current of the power source, The main control unit controls the second power switch to reverse conduction, and the battery supplies power to the system load. A battery management system for implementing dynamic charging current distribution, wherein the battery management system comprises: a power source, a battery, a system load, a first power switch, and a second power switch, wherein the method comprises: accessing a power source Detecting whether the power supply current provided by the power source is greater than a preset current threshold; when the power supply current of the power source is greater than the current threshold, according to the system The load needs to immediately divide the supply current of the power supply into two parts, and part of the working current is supplied to the system load through the first power switch, the working current supplied to the load changes according to the needs of the load, and the remaining part is passed through the second power switch. Charging batteries. The method of claim 7, wherein the method further comprises: detecting whether a charging current of the battery is less than a charging cut-off current; detecting whether a power supply current of the power source is less than a maximum allowable power supply current of the power source; The power switch is completed and the battery is fully charged. The method of claim 7, wherein the second power switch is a double-conducting switch, and when the second power switch is conducting, the power supply current supplies the battery; when the second power switch is reversed When the battery is on, the battery supplies power to the system load; when the second power switch is not turned on in both directions, the second power switch is turned off. The method of claim 8, wherein the method further comprises: detecting whether the charging current of the battery is instantaneously reduced to zero; and when the charging current of the battery is instantaneously reduced to zero, the second power is reversely turned on. A switch that uses the battery to power the system load.