TWI635300B - Battery management system - Google Patents

Abstract

A battery management system. The battery management system directly couples a switching circuit between the discharging end and the grounding end, and since the switching circuit is not above the discharging circuit, when the battery pack is discharged, the switching circuit will not be current The flow of water produces high temperatures.

Description

Battery management system

The present invention relates to the field of battery management, and more particularly to a battery management system (BMS).

In general, a battery management system is a system that can be used to provide management of a battery pack. It is typically provided with protection against abnormalities such as overcharging/discharging and overheating of the battery pack. Therefore, in recent years, battery management systems have been widely used in various types of electronic devices and Uninterruptible Power Systems (UPS).

For example, in the existing battery management system, a switching circuit is provided on the discharge circuit, and when an overdischarge abnormality occurs, the existing battery management system controls the switching circuit to cut off the discharge. Loop. Because the switch circuit is connected in series above the discharge circuit, when the battery pack is discharged, the switch circuit generates a high temperature due to a large current flowing.

However, although the conventional implementation has been able to solve the high temperature problem of the switching circuit by adding a heat sink, it also increases the layout area and cost of the existing battery management system. Furthermore, if the switching circuit is removed, even if the layout area can be reduced and no high temperature is generated on the discharge circuit, the existing battery management system is used when the battery pack has an overdischarge abnormality. However, the discharge circuit cannot be cut off to achieve the original over-discharge protection function.

In view of the above, it is an object of the present invention to provide a battery management system that ensures that the battery management system retains both the original over-discharge protection function while avoiding high temperature generation on the discharge circuit.

Based on the above objective, an embodiment of the present invention provides a battery management system for providing management of a battery pack. The battery pack is connected in series between the positive terminal module of the battery management system and the ground terminal. The positive terminal module includes a discharge end and a charging end, and the battery management system includes a control circuit and a first switch circuit. The control circuit is coupled to the battery pack and is used to determine whether the battery pack is abnormal. The first switching circuit is controlled by the control circuit, and one end thereof is coupled to the discharging end, and the other end thereof is coupled to the ground end. In the discharge mode, the control circuit controls to cut off the first switching circuit such that the discharge end, the battery pack and the ground end form a discharge loop, and when determining that the battery pack has an overdischarge abnormality, the control circuit controls to turn on the first switching circuit, thereby further Cut off the discharge circuit.

The detailed description of the present invention and the accompanying drawings are to be understood by the claims The scope is subject to any restrictions.

In the following, the invention will be described in detail by way of illustration of various embodiments of the invention. However, the inventive concept may be embodied in many different forms and should not be construed as being limited to the illustrative embodiments set forth herein. In addition, the same reference numerals may be used in the drawings to represent similar elements.

First, please refer to FIG. 1. FIG. 1 is a functional block diagram of a battery management system according to an embodiment of the present invention. In this embodiment, the battery management system 20 is mainly used to provide management of the battery pack 12, and the battery pack 12 is serially connected between the positive terminal module 210 of the battery management system 20 and the ground GND. The positive terminal module 210 includes a discharging end P1 and a charging end P2, and the battery management system 20 includes a control circuit 200 and switching circuits Q2 and Q3. The control circuit 200 is coupled to the battery pack 12 and is used to determine whether the battery pack 12 is abnormal. In the present embodiment, the control circuit 200 is, for example, a microcontroller (MCU) including an analog front-end (AFE) circuit, but the invention is not limited thereto.

It should be noted that, in practice, the control circuit 200 can be used to detect the voltage, current, and temperature of the battery pack 12, and based on the voltage, the current, and the temperature, determine whether the battery pack 12 is abnormal. However, since the voltage, current and temperature of the battery pack 12 are detected, and based on the voltage, current and temperature of the battery pack 12, the operation principle for judging whether the battery pack 12 is abnormal or not is already known to those of ordinary skill in the art. It is to be understood that the details of the control circuit 200 described above will not be further described herein.

The switch circuit Q3 is controlled by the control circuit 200, and one end thereof is coupled to the discharge terminal P1, and the other end thereof is coupled to the ground terminal GND. Thus, in the discharge mode, the control circuit 200 controls the cut-off switching circuit Q3 such that the discharge terminal P1, the battery pack 12, and the ground GND form a discharge circuit to allow the battery pack 12 to discharge by passing through the discharge circuit. However, since the switching circuit Q3 is not connected in series with the discharge circuit, when the battery pack 12 is discharged, the switching circuit Q3 does not generate a high temperature due to a large current flowing.

Similarly, when it is judged that the battery pack 12 is abnormal, the control circuit 200 controls the conduction switching circuit Q3 to further cut off the discharge circuit. It should be understood that the term "abnormal" as used herein may refer to "overdischarge abnormality", but the present invention is not limited thereto. In fact, since the battery management system 20 can connect the discharge terminal P1 and the ground terminal GND to an external load (not shown), and in the discharge mode, the battery pack 12 can pass the external circuit through the discharge circuit. Since the load is discharged, when the conduction switching circuit Q3 is controlled to further cut off the discharge circuit, the battery management system 20 is designed to prevent the external load from being damaged by the overdischarge abnormality.

It should be noted that the present invention also does not limit the specific implementation manner of the switch circuit Q3. In practice, as long as there is a switch capable of providing a cut-off and turn-on function, it can be used as the switch circuit Q3 of the present invention. Therefore, as shown in FIG. 1, the battery management system 20 of the embodiment of the present invention can further reduce the layout area and cost thereof compared to the existing switching circuit Q2.

In addition, the switch circuit Q2 is also controlled by the control circuit 200, and one end thereof is coupled to the charging terminal P2, and the other end thereof is coupled to the common node A between the positive terminal module 210 and the battery pack 12. Therefore, in the charging mode, the control circuit 200 controls the conduction switch circuit Q2 such that the charging terminal P2, the switching circuit Q2, the battery pack 12, and the ground GND form a charging circuit to allow the battery pack 12 to be charged through the charging circuit. And when it is judged that the battery pack 12 is abnormal, the control circuit 200 controls the cut-off switching circuit Q2 to further cut off the charging circuit.

It should be understood that the term "abnormal" as used herein may refer to "overcharge abnormality", but the present invention is not limited thereto. Because the battery management system 20 can also connect the charging terminal P2 and the grounding terminal GND to an external power source (not shown), and in the charging mode, the external power source can perform the battery pack 12 through the charging circuit. Charging, so when the cut-off switching circuit Q2 is controlled to further cut off the charging circuit, the battery management system 20 is just to prevent the battery pack 12 from being damaged by an overcharge abnormality.

In addition, the control circuit 200 can also be used to determine whether the battery pack 12 has an abnormality in overheating. However, since the above-mentioned overheat abnormality may occur in the charging or discharging mode, in some embodiments, when it is judged that the battery pack 12 is overheated abnormally, the control circuit 200 selectively controls the cut-off switching circuit Q2 or the turn-on switching circuit. Q3 to further cut off the charging circuit or the discharging circuit. In general, the present invention does not limit the specific implementation of the overheat protection function, and those skilled in the art should be able to make related designs according to actual needs or applications.

However, to further illustrate implementation details regarding the battery management system 20, the present invention further provides another embodiment of its battery management system 20. Please refer to FIG. 2. FIG. 2 is a schematic circuit diagram of a battery management system according to another embodiment of the present invention. The components in FIG. 2 that are the same as those in FIG. 1 are denoted by the same reference numerals, and thus the details thereof will not be described in detail.

Compared to the functional block diagram of FIG. 1, the battery management system 30 of FIG. 2 further includes a resistor R. The resistor R is connected in series between the battery pack 12 and the ground GND, and the control circuit 200 is coupled to both ends of the resistor R. The current associated with the battery pack 12 is detected by the resistor R. It should be noted that, in practice, the control circuit 200 uses the current flowing through the resistor R as the charging current or the discharging current of the battery pack 12.

In addition, in the embodiment, the battery management system 30 may further include fuses f1 and f2. The fuse f1 is connected in series between the battery pack 12 and the common node A, and the fuse f2 is connected in series between the discharge terminal P1 and the common node A. In fact, since the fuses f1 and f2 are also connected in series above the discharge circuit, when the battery pack 12 is discharged and an overcurrent abnormality occurs, the fuses f1 and f2 can be caused by the high temperature generated by the overcurrent. It is burned to further ensure the disconnection of the discharge circuit, and the external load will not be damaged by the overcurrent abnormality.

Similarly, when the battery pack 12 has an overdischarge abnormality and the control circuit 200 controls the conduction switch circuit Q3, the battery management system 30 of the present embodiment can be turned on by the switching circuit Q3 (that is, the flow through the fuse is increased). The fuses f1 and f2) blow the fuses f1 and f2 to further ensure the disconnection of the discharge circuit, so that the external load will not be damaged by the overdischarge abnormality. That is to say, the battery management system 30 of the embodiment of the present invention can provide a more dual protection mechanism by the above design of the fuses f1 and f2. However, since the operation principles of the fuses f1 and f2 are well known to those of ordinary skill in the art, the details of the above-described fuses f1 and f2 will not be further described herein.

In this embodiment, the battery pack 12 may be a plurality of battery cells 121 to 12N including a series connection. However, for convenience of the following description, the battery cells 121 to 12N of FIG. 2 are described by using only an example of the number 9 (that is, N is 9), but it is not intended to limit the present invention. In addition, in the embodiment, the battery management system 30 may further include a protection circuit 310. The protection circuit 310 is coupled between the anode of each of the battery cells 121-129, the fuse f1, and the control circuit 200, and is configured to detect the cell voltage (not shown) of each of the battery cells 121-129.

Therefore, when the cell voltage of one of the battery cells 121 to 129 exceeds a normal value, the protection circuit 310 outputs a control signal to the fuse f1, so that a heater (not shown) in the fuse f1 is Activate to further blow the fuse f1. In other words, a heater can be provided in the fuse f1, and the heater is controlled by a control signal transmitted from the outside to further perform a heating action to blow the fuse f1.

In addition, battery management system 30 may further include temperature sensor 320. In this embodiment, the temperature sensor 320 is coupled to the control circuit 200 and configured to detect the cell temperatures of each of the battery cells 121 to 12N, respectively. Therefore, when the cell temperature of one of the battery cells 121 to 12N exceeds a reasonable range (that is, the temperature of the battery cell is too high or too low), the temperature sensor 320 outputs a notification signal. (not shown) to the control circuit 200, so that the control circuit 200 controls the cut-off switching circuit Q2 to further cut off the charging circuit so that the battery pack 12 will not be damaged by the temperature abnormality of the battery cells 121-129. In the present embodiment, the temperature sensor 320 may be composed of a plurality of thermistors (NTC), but the invention is not limited thereto.

In summary, the battery management system provided by the embodiment of the present invention directly couples a switch circuit between the discharge end and the ground end of the battery management system, and because the switch circuit is not connected in series to the discharge circuit. Up, so when the battery pack is discharged, the switch circuit will not generate high temperature due to the flow of current. In addition, the switch circuit can also ensure that the battery management system can maintain the original over-discharge protection function, but can also help reduce the layout area and cost of the battery management system.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the invention.

20, 30‧‧‧Battery Management System

12‧‧‧Battery Pack

P1‧‧‧ discharge end

P2‧‧‧Charging end

GND‧‧‧ ground terminal

200‧‧‧Control circuit

210‧‧‧ positive terminal module

Q2, Q3‧‧‧ switch circuit

A‧‧‧Common node

F1, f2‧‧‧ fuse

121～129‧‧‧ battery unit

310‧‧‧Protection circuit

320‧‧‧temperature sensor

R‧‧‧resistance

1 is a functional block diagram of a battery management system according to an embodiment of the present invention. 2 is a circuit diagram of a battery management system according to another embodiment of the present invention.

Claims (5)

A battery management system for providing management of a battery pack, which is connected in series between a positive terminal module and a ground terminal of the battery management system, wherein the positive terminal module includes a discharge end and a battery management system includes: a control circuit coupled to the battery pack and configured to determine whether an abnormality occurs in the battery pack, wherein the control circuit is configured to detect a voltage and a current of the battery pack And a temperature, and determining whether the abnormality occurs in the battery pack according to the voltage, the current, and the temperature; a first switch circuit controlled by the control circuit, one end of which is coupled to the discharge end, and the other end of which is coupled to the discharge end Coupled in the grounding end, in a discharge mode, the control circuit controls to cut off the first switching circuit, so that the discharging end, the battery pack and the grounding end form a discharge loop, and when determining that the battery pack is abnormal The control circuit controls the first switch circuit to turn off the discharge circuit; and a second switch circuit is controlled by the control circuit, one end of which is coupled to the charge The other end is coupled to a common node between the positive terminal module and the battery pack. In a charging mode, the control circuit controls to turn on the second switch circuit, so that the charging end and the second switch The circuit, the battery pack and the grounding end form a charging circuit, and when it is determined that the abnormality occurs in the battery pack, the control circuit controls to cut off the second switching circuit to further cut off the charging circuit. The battery management system of claim 1, further comprising: a resistor connected in series between the battery pack and the ground, and the control circuit is further coupled to the two ends of the resistor for passing The resistor detects the current of the battery pack. The battery management system of claim 1, further comprising: a first fuse connected in series between the battery pack and the common node; and a second fuse connected in series to the discharge end and the common node between. The battery management system of claim 3, wherein the battery pack comprises a plurality of battery cells connected in series, and the battery management system further comprises: a protection circuit coupled to an anode of each of the battery cells, Between the first fuse and the control circuit, and used to detect a cell voltage of each of the battery cells, when the cell voltage of one of the battery cells exceeds a normal value, the protection circuit outputs A control signal is applied to the first fuse to activate a heater in the first fuse. The battery management system of claim 4, further comprising: a temperature sensor coupled to the control circuit and configured to detect a cell temperature of each of the battery cells when the battery cells are When the temperature of the unit of one of the units exceeds a reasonable range, the temperature sensor outputs a notification signal to the control circuit, so that the control circuit controls to cut off the second switching circuit.