Balancing control circuit and control method of battery system, battery system and storage medium

Abstract

The invention discloses an equalization control circuit and control method of a battery system, the battery system and a storage medium, the equalization control circuit comprises at least two equalization loops, the equalization loops are formed by connecting switch tubes, resistors and battery cells in series, and the equalization control circuit further comprises a battery management system BMS connected with the switch tubes and used for controlling on and off of the switch tubes, presetting an equalization opening voltage difference and an equalization closing voltage difference of the battery cell; the battery management system BMS is used for detecting the voltage difference of the battery cells in real time, and when the voltage difference of the battery cells is larger than the equalization starting voltage difference, the battery management system BMS controls the switch tube to be switched on, and the equalization loop is powered on to work; and when the voltage difference of the battery cells is smaller than the equalization closing voltage difference, the battery management system BMS controls the switch tube to be switched off, and the equalization loop is powered off and stops working. The voltage difference between the battery cells can be reduced, and the service life of the battery can be prolonged.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a balancing control circuit, a control method, a battery system and a storage medium for a battery system. Background Art

[0002] Batteries are devices used to store electrical energy so that they can be released when needed. Batteries play an important role in modern energy systems, promoting the flexibility and sustainability of energy systems. In household energy storage systems, batteries are an important component, and their use will directly affect the user experience.

[0003] As the battery is used for a longer time, the voltage of some cells inside it will gradually become lower than that of other cells, causing a large voltage difference. There are many reasons for the voltage difference, including uneven internal structure of the cells, different discharge depths, different usage environments, and other innate internal and external factors that cannot be eliminated. The voltage difference will cause the battery to be unable to charge due to the presence of high-voltage cells, and unable to discharge due to the presence of the lowest cell voltage.

[0004] Therefore, how to artificially reduce the voltage difference to extend the service life of the battery is a technical problem that urgently needs to be solved in this field. Summary of the invention

[0005] In view of the above problems, an object of the present invention is to provide a battery system balancing control circuit, a control method, a battery system and a storage medium, which can reduce the voltage difference between battery cells and extend the service life of the battery.

[0006] According to one aspect of the present invention, there is provided a balancing control circuit for a battery system, comprising at least two balancing loops connected in series with each other;

[0007] The balancing circuit is formed by connecting a switch tube, a resistor, and a battery cell in series, and also includes a battery management system BMS connected to the switch tube for controlling the switching on and off of the switch tube.

[0008] The battery cell is provided with a balanced opening pressure difference and a balanced closing pressure difference; the battery management system BMS is set as follows:

[0009] Used to detect the pressure difference of the battery cell in real time. When the pressure difference of the battery cell is greater than the equalization start-up pressure difference, the battery management system BMS controls the switch tube to turn on, and the equalization circuit is energized to work; when the pressure difference of the battery cell is less than the equalization close-down pressure difference, the battery management system BMS controls the switch tube to turn off, and the equalization circuit is powered off and stops working.

[0010] Preferably, in some embodiments of the present invention, the voltage difference of the battery cell is obtained according to the following formula:

[0011] ; , ······, ; = voltage of the nth cell},

[0012] in, is the voltage difference of the battery cell, Take the highest voltage for all cells in the balanced control circuit. Take the lowest voltage for all cells in the balancing control circuit.

[0013] Preferably, in some embodiments of the present invention, a diode is further connected in series in the balancing loop.

[0014] Preferably, in some embodiments of the present invention, the switch tube is configured as a MOS tube.

[0015] Preferably, in some embodiments of the present invention, when the balancing circuits are connected in series, the negative electrode of a battery cell of a preceding balancing circuit is connected to the positive electrode of a battery cell of a succeeding balancing circuit.

[0016] According to another aspect of the present invention, the present application also provides a balancing control method for a battery system, which adopts a balancing control circuit as provided in any one of the above embodiments, including: real-time detection of the voltage difference of the battery cell, when the voltage difference of the battery cell is greater than the balancing start-up voltage difference, the battery management system BMS controls the switch tube to turn on, and the balancing circuit is powered on and works; when the voltage difference of the battery cell is less than the balancing shut-off voltage difference, the battery management system BMS controls the switch tube to turn off, and the balancing circuit is powered off and stops working.

[0017] According to another aspect of the present invention, the present application further provides a battery system, comprising the balancing control circuit provided by any one of the above embodiments.

[0018] According to another aspect of the present invention, the present application further provides a computer-readable storage medium having computer instructions stored thereon. When the computer instructions are executed by a processor, a battery system balancing control method as provided in any one of the above embodiments can be implemented.

[0019] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

[0020] Compared with the prior art, the present invention has the following technical effects:

[0021] The present invention can reduce the voltage difference between battery cells and extend the service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0023] Figure 1 A schematic diagram of a balancing control circuit of a battery system according to an embodiment of the present invention is shown.

[0024] Figure 2 A schematic diagram of the resistance working time of a balancing control circuit of a battery system according to an embodiment of the present invention is shown.

[0025] Reference numerals: 1 battery cell; 2 switch tube; 3 battery management system BMS; 4 resistor; 5 diode. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution, beneficial effects and significant progress of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, all the embodiments described are only partial embodiments of the present invention, not all embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The present invention will be further described below in conjunction with specific implementations. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The phrase appearing in various locations in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments herein may be combined with other embodiments without causing structural conflicts.

[0029] In the description of this article, unless otherwise clearly specified and limited, the technical terms "installed", "connected", "connected" and the like should be understood in a broad sense, and can be a movable connection, a fixed connection or an integral connection, or a connection through a certain connector. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0030] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to have a specific orientation, be installed or operate in a specific orientation, and should not be construed as a limitation on the embodiments in this document.

[0031] In the description of this article, the terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order or primary and secondary relationship of the described technical features. In the description of this article, the meaning of "plurality" is at least two.

[0032] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to represent the same or similar parts.

[0033] Figure 1 FIG. 1 is a schematic diagram showing a balancing control circuit of a battery system according to an embodiment of the present invention. Figure 1 As shown, a balancing control circuit of a battery system of the present invention is used to make the voltages of all cells in the same battery tend to be consistent. The balancing control circuit of the present invention includes at least two balancing circuits connected in series:

[0034] The balancing circuit is formed by connecting the switch tube 2, the resistor 4, and the battery cell 1 in series, and also includes a battery management system BMS3, which is connected to the switch tube 2 and is used to control the on and off of the switch tube 2. After the balancing circuit is turned on, the battery cell 1, the resistor 4 and the switch tube 2 will form a complete circuit. The battery cell 1 acts as a power source, and the resistor 4 acts as a load to slowly consume the power in the battery cell 1 through heat generation, thereby reducing the voltage of the high-power battery cell 1.

[0035] The battery cell 1 is provided with an equalizing opening pressure difference and an equalizing closing pressure difference; the equalizing circuit and the equalizing opening pressure difference and the equalizing closing pressure difference are set when the battery leaves the factory, and when using the battery, there is no need to disassemble the battery casing for a series of operations.

[0036] The battery management system BMS3 is set up as:

[0037] It is used to detect the pressure difference of the battery cell 1 in real time. When the pressure difference of the battery cell 1 is greater than the equalization start-up pressure difference, the battery management system BMS3 controls the switch tube 2 to turn on, and the equalization circuit is energized to work; when the pressure difference of the battery cell 1 is less than the equalization close-down pressure difference, the battery management system BMS3 controls the switch tube 2 to turn off, and the equalization circuit is powered off and stops working.

[0038] Preferably, in some embodiments of the present invention, the voltage difference of the battery cell is obtained according to the following formula:

[0039] ; , ······, ; = voltage of the nth cell},

[0040] in, is the voltage difference of the battery cell, Take the highest voltage for all cells in the balanced control circuit. Take the lowest voltage for all cells in the balancing control circuit.

[0041] Preferably, in some embodiments of the present invention, a diode 5 is further connected in series in the balancing loop.

[0042] Preferably, in some embodiments of the present invention, the switch tube 2 is configured as a MOS tube.

[0043] Preferably, in some embodiments of the present invention, when the balancing circuits are connected in series, the negative electrode of the battery cell 1 of the previous balancing circuit is connected to the positive electrode of the battery cell 1 of the next balancing circuit.

[0044] According to another aspect of the present invention, the present application also provides a balancing control method for a battery system, which adopts a balancing control circuit as provided in any one of the above embodiments, including: real-time detection of the voltage difference of the battery cell 1, when the voltage difference of the battery cell 1 is greater than the balancing start-up voltage difference, the battery management system BMS3 controls the switch tube 2 to turn on, and the balancing circuit is energized to work; when the voltage difference of the battery cell 1 is less than the balancing shut-off voltage difference, the battery management system BMS3 controls the switch tube 2 to turn off, and the balancing circuit is powered off and stops working.

[0045] According to another aspect of the present invention, the present application further provides a battery system, comprising the balancing control circuit provided by any one of the above embodiments.

[0046] According to another aspect of the present invention, the present application further provides a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, a battery system balancing control method provided in any one of the above embodiments can be implemented.

[0047] The principle of the equalization circuit of the present invention is as follows:

[0048] After the battery cells 1 are connected in series, each battery cell 1 is equipped with a balancing circuit, and the switch tube 2 is controlled by the battery management system BMS3. The battery management system BMS3 detects the voltage difference of the battery cell 1 in real time. When the voltage difference of the battery cell 1 is greater than the balancing opening voltage difference, the battery management system BMS3 controls the switch tube 2 to turn on, and the balancing circuit is energized to work; when the voltage difference of the battery cell 1 is less than the balancing closing voltage difference, the battery management system BMS3 controls the switch tube 2 to turn off, and the balancing circuit is powered off and stops working. At the same time, a diode 5 is set in the balancing circuit. As a protective device, the diode 5 can effectively prevent current backflow. The balancing process does not continue all the time, it will be intermittent. After the balancing control circuit is turned on for a period of time, the switch tube 2 will be disconnected for a certain period of time, and then turned on again. After disconnection, the voltage of the battery cell 1 will rebound to a certain extent to prevent the battery cell 1 voltage from dropping suddenly due to continuous discharge and having the opposite effect. At the same time, the voltage borne by the resistor 4 is also intermittent, which prevents the resistor 4 from being continuously heated and causing excessive temperature and damage. The detailed working time of the resistor is as follows Figure 2 shown.

[0049] Compared with the prior art, the present invention has the following technical effects:

[0050] The battery of the present invention has a built-in equalization circuit, and no additional equipment is required. Compared with other active equalization products, the passive equalization control circuit of the present invention is simple and easy to operate, and does not require additional wiring at the positive and negative poles of the battery cell. The battery can be equipped with the circuit when it leaves the factory, and there is no need to disassemble the battery shell for a series of operations.

[0051] The equalization control circuit of the battery system of the present invention can be turned on at any time without waiting. The equalization control circuit can be operated whether the battery is charging, discharging or at rest, and will not be affected. Other equalization devices require that the battery must be at rest. After the equalization control circuit is turned on, the user can continue to use the battery normally, which will not bring a bad experience to the user.

[0052] The equalization control circuit of the battery system of the present invention is safe and reliable and can effectively protect the battery cells. The discharge current of the equalization discharge is small and the discharge is performed intermittently. It can not only not affect the user's daily use of the battery, but also can minimize the battery cell voltage difference and extend the battery cell life.

[0053] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

[0054] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A battery system balancing control circuit, characterized in that: comprising at least two balancing circuits connected in series with each other; The balancing circuit is formed by connecting a switch tube, a resistor, and a battery cell in series, and also includes a battery management system BMS connected to the switch tube for controlling the switching on and off of the switch tube. The battery cell is provided with a balanced opening pressure difference and a balanced closing pressure difference; the battery management system BMS is set as follows: Used to detect the pressure difference of the battery cell in real time. When the pressure difference of the battery cell is greater than the equalization start-up pressure difference, the battery management system BMS controls the switch tube to turn on, and the equalization circuit is energized to work; when the pressure difference of the battery cell is less than the equalization close-down pressure difference, the battery management system BMS controls the switch tube to turn off, and the equalization circuit is powered off and stops working.

2. The equalization control circuit according to claim 1, characterized in that: The voltage difference of the battery cell is obtained according to the following formula: ; , ······, ; = voltage of the nth cell}, in, is the voltage difference of the battery cell, Take the highest voltage for all cells in the balanced control circuit. Take the lowest voltage for all cells in the balancing control circuit.

3. The equalization control circuit according to claim 1, characterized in that: A diode is also connected in series in the balancing loop.

4. The equalization control circuit according to claim 1, characterized in that: The switch tube is configured as a MOS tube.

5. The equalization control circuit according to claim 1, characterized in that: When the balancing circuits are connected in series, the negative electrode of the battery cell of the previous balancing circuit is connected to the positive electrode of the battery cell of the next balancing circuit.

6. A battery system balancing control method, characterized in that: The equalization control circuit according to any one of claims 1 to 5 comprises: The pressure difference of the battery cell is detected in real time. When the pressure difference of the battery cell is greater than the equalization start-up pressure difference, the battery management system BMS controls the switch tube to turn on, and the equalization circuit is powered on and works; when the pressure difference of the battery cell is less than the equalization close-down pressure difference, the battery management system BMS controls the switch tube to turn off, and the equalization circuit is powered off and stops working.

7. A battery system, characterized in that: The device comprises the equalization control circuit as claimed in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: Computer instructions are stored thereon, and when the computer instructions are executed by a processor, the balancing control method for the battery system as claimed in claim 6 can be implemented.

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