CN102232261B - A lithium battery balance control device and method - Google Patents

Abstract

The invention discloses a lithium battery equalization control device and a lithium battery equalization control method, belongs to the field of electric energy storage, and is designed for solving the problem that electronic equipment is abnormal due to overheating of a shunt unit in the lithium battery equalization process in the prior art. A lithium battery equalization control device comprises a battery pack, a scheduling unit, a shunt unit and a voltage acquisition unit, wherein the voltage acquisition unit is arranged on one side of a single battery in the battery pack; the single battery is connected with a shunt circuit in the shunt unit in parallel; the shunt unit and the voltage acquisition unit are respectively connected with the scheduling unit; a temperature acquisition unit is arranged on one side of the flow dividing unit; the temperature acquisition unit is connected with the scheduling unit.

Description

A lithium battery balance control device and method

technical field

The invention relates to a lithium battery charging device and method, in particular to a lithium battery equalization control device and method.

Background technique

Lithium batteries are widely used in electronic devices due to their high energy, long cycle life, high energy density and stable working voltage. When multiple lithium batteries are connected in series to form a battery pack, it is necessary to prevent over-discharging and over-charging of single cells due to the safety and cycle performance of lithium batteries. Therefore, the capacity of the battery pack depends on the capacity of each single battery, wherein the capacity of the lithium battery is related to its voltage value. In the process of charging the battery pack, in order to make the battery pack reach the rated voltage, each single battery needs to reach the rated voltage. When a single battery has a low capacity, its voltage is also lower than other single batteries. At this time, in order to reach the rated voltage of the battery pack, other single batteries may be overcharged, which may easily cause lithium battery explosion. .

In order to avoid the occurrence of the above situation, in the prior art, a lithium battery balance control device, as shown in Figure 1, includes a battery pack, a shunt unit, a voltage detection unit and a control unit; each single battery in the battery pack is connected to a shunt The circuits are connected in parallel, and the shunt circuit is provided with energy-consuming elements; the shunt circuit is connected with the control unit; the control unit is connected with the voltage detection unit; the voltage detection unit is connected with the single cells in the battery pack.

When charging the battery pack in the electronic equipment, the voltage of each single battery is detected by the voltage acquisition unit; when the difference between the voltage of one single battery and the voltage of other single batteries is greater than the set value, the through the shunt circuit. For example, when the voltage of the single battery 1 and the voltage of the single battery 4 differ by 20 millivolts, the control unit connects the shunt circuit 4 corresponding to the single battery 4, and the energy-consuming element shunts the charging current of the single battery 4, The charging speed of the single battery 4 decreases, while the single battery 1 maintains the original charging speed; when the difference drops to 5 millivolts, the shunt circuit 4 is disconnected, and the charging speed of the single battery 4 recovers, achieving a balanced effect.

During the above process, heat is generated by consuming electric energy on the shunt unit. When multiple shunt circuits are turned on at the same time, the generated heat increases and cannot be dissipated in time, which will lead to abnormal function of electronic equipment.

Contents of the invention

Embodiments of the present invention provide a lithium battery equalization control device and method for preventing electronic equipment from overheating during the lithium battery equalization process.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

A lithium battery balance control device, comprising a battery pack, a scheduling unit, a shunt unit and a voltage acquisition unit, a voltage acquisition unit is arranged on one side of a single battery in the battery pack; the shunt circuit in the single battery and the shunt unit parallel connection; the shunt unit and the voltage acquisition unit are respectively connected to the dispatch unit; a temperature acquisition unit is arranged on one side of the shunt unit; the temperature acquisition unit is connected to the dispatch unit;

The battery pack is composed of at least two single cells connected in series;

The shunt unit is used to shunt the charging current to reduce the charging speed of the single battery. The shunt unit includes at least two shunt circuits, and the shunt circuits include energy-consuming elements;

The voltage acquisition unit is used to acquire the voltage value of the single battery;

The temperature collection unit is used to collect the temperature value of the flow distribution unit;

The scheduling unit is used to control the on-off of the shunt circuit in the shunt unit according to the collected voltage value and temperature value, so as to realize the balance of the capacity of the single battery and prevent the shunt unit from overheating.

A lithium battery balance control method, comprising:

Set the overheating temperature value of the shunt unit in the scheduling unit;

The temperature acquisition unit acquires the current temperature value of the flow distribution unit;

The scheduling unit judges whether the current temperature value of the branching unit is greater than the set overheating temperature value;

If the scheduling unit judges that the current temperature of the shunt unit is greater than the set overheating temperature value, it disconnects the shunt circuit, reduces the heat generated by the shunt circuit in the shunt unit, and lowers the temperature of the shunt unit.

A lithium battery balance control device and method provided in an embodiment of the present invention collects the temperature of the shunt unit through the temperature acquisition unit. When the temperature exceeds the preset overheating temperature value, the shunt circuit corresponding to the single battery is disconnected to reduce the number of shunt units. The generated heat prevents the electronic equipment from overheating when the single battery is balanced, and improves the stability of the electronic equipment.

Description of drawings

Fig. 1 is a schematic structural view of a lithium battery balance control device in the background technology of the present invention;

2 is a schematic structural diagram of a lithium battery balance control device according to an embodiment of the present invention;

3 is a flow chart of a lithium battery balancing control method according to an embodiment of the present invention;

FIG. 4 is a flow chart of controlling a shunt circuit by a lithium battery balance control method according to an embodiment of the present invention;

5 is a flow chart of disconnecting the shunt circuit when the temperature is too high in a lithium battery equalization control method according to an embodiment of the present invention;

FIG. 6 is a flow chart of a lithium battery balance control method for recovering shunt according to an embodiment of the present invention.

Detailed ways

A lithium battery balance control device and method of the present invention will be described in detail below in conjunction with the accompanying drawings.

A lithium battery balance control device, as shown in Figure 2, includes a battery pack, a scheduling unit, a shunt unit and a voltage acquisition unit, and a voltage acquisition unit is arranged on one side of the single battery in the battery pack; the single battery and The shunt circuit in the shunt unit is connected in parallel; the shunt unit and the voltage acquisition unit are respectively connected to the dispatch unit; a temperature acquisition unit is arranged on one side of the shunt unit; the temperature acquisition unit is connected to the dispatch unit;

The battery pack is composed of at least two single cells connected in series;

The shunt unit is used to shunt the charging current to reduce the charging speed of the single battery. The shunt unit includes at least two shunt circuits, and the shunt circuits include energy-consuming elements;

The voltage acquisition unit is used to acquire the voltage value of the single battery;

The temperature collection unit is used to collect the temperature value of the flow distribution unit;

The scheduling unit is used to control the on-off of the shunt circuit in the shunt unit according to the collected voltage value and temperature value, so as to realize the balance of the capacity of the single battery and prevent the shunt unit from overheating.

The voltage acquisition unit collects the voltage value of each single battery in the battery pack, and sends the voltage value to the dispatching unit; the temperature acquisition unit collects the temperature of the shunt unit, and sends the temperature value to the dispatching unit; the dispatching unit The voltage value and temperature value control the shunt unit, balance the battery pack during the charging process, prevent the overheating of the electronic equipment caused by the excessive heat generated by the shunt unit during the equalization process, and improve the stability of the electronic equipment when charging.

Corresponding to the above-mentioned lithium battery balance control device, the present invention also provides a lithium battery balance control method, as shown in Figure 3, including:

Step 300, setting the overheating temperature value of the diversion unit in the scheduling unit

Set the overheating temperature value of the shunt unit in the scheduling unit. In order to prevent damage to the electronic equipment due to excessive temperature, the temperature value is generally set within the safe temperature range of the electronic equipment. For example, the overheating temperature value can be set to 80 degrees.

In order to balance the capacity of the single cells, it is necessary to judge which single cells need to be shunted according to the voltage difference between the single cells to slow down the charging speed, as shown in Figure 4.

Step 400, setting the voltage difference for shunting the single battery in the dispatching unit, which is called the shunt voltage difference

In order to balance the capacity of the battery pack of electronic equipment, it is necessary to judge whether to open the shunt circuit to shunt the single cells in the battery pack according to the voltage value of the single cells in the battery pack collected by the voltage acquisition unit.

Set the voltage difference of the single cells when the shunt circuit is turned on. This voltage difference is called the shunt voltage difference. For example, the shunt voltage difference is set to 20 millivolts.

Step 401, the voltage acquisition unit obtains the voltage value of each single battery, and determines the single battery corresponding to the minimum voltage value, which is called a short board single battery

The dispatching unit obtains the voltage value of each single battery collected by the voltage acquisition unit, and determines the single battery corresponding to the minimum voltage value, which is called a short-board single battery. According to the short-board single battery, other single batteries are Shunting, to achieve the balance of the capacity of the single battery, as shown in Figure 2, for example, the single battery 1 is the short board single battery, and its voltage value is 3000 millivolts.

Step 402, the scheduling unit judges whether the voltage difference between the single battery and the short-board single battery is greater than the shunt voltage difference

According to the voltage value collected by the voltage acquisition unit, it is judged whether there is a single battery whose voltage difference with the short-board single battery is greater than the shunt voltage difference. For example, the voltage value of the single battery 2 is 3300 millivolts, and the single battery The voltage value of 3 is 3027 millivolts, the voltage value of single battery 4 is 3001 millivolts, and the voltage value of single battery 5 is 3203 millivolts.

Step 403, if the voltage difference between the single battery and the short-board single battery is greater than the shunt voltage difference, turn on the shunt circuit corresponding to the single battery, shunt the single battery, and reduce the charging speed of the single battery

According to the voltage value of the single battery, determine the single battery that is greater than the shunt voltage difference, for example, the voltage difference between the single battery 2, the single battery 3 and the single battery 5 and the short-board single battery is greater than 20 millivolts, so The dispatching unit controls the shunt circuit corresponding to the single battery to be turned on, that is, the shunt circuit 2, the shunt circuit 3 and the shunt circuit 5 are turned on, so as to shunt the single battery and reduce the charging speed of the corresponding single battery. At this time, in the shunt circuit, because the energy consuming element shunts the charging current, heat is generated on the energy consuming element, and the temperature rises.

Step 301, the temperature acquisition unit acquires the current temperature value of the distribution unit

After splitting, the temperature acquisition unit collects the current temperature on one side of the splitting unit at regular intervals, for example, 82 degrees.

Step 302, the scheduling unit judges whether the current temperature value of the distribution unit is greater than the set overheating temperature value

The scheduling unit compares the current temperature value with the superheated temperature value, and determines that 82 degrees is greater than the set superheated temperature value of 80 degrees.

Step 303, if the scheduling unit judges that the current temperature value of the shunt unit is greater than the set overheating temperature value, then disconnect the shunt circuit, reduce the heat generated by the shunt circuit in the shunt unit, and lower the temperature of the shunt unit

When the collected current temperature value is greater than the overheating temperature value, in order to prevent damage to electronic equipment due to excessive temperature, it is necessary to control the shunt circuit to reduce the heat generated by the shunt circuit, as shown in Figure 5.

Step 500, the scheduling unit compares the voltage difference between the short board single battery and the single battery connected to the shunt circuit according to the voltage value of the single battery collected by the voltage acquisition unit

According to the obtained voltage value of the single battery, compare the voltage difference between the short board single battery and the single battery connected by multiple shunt circuits, for example, the voltage difference between the single battery 2 and the short board single battery is 300 millivolts, the voltage difference between the unit battery 3 and the short-board unit battery is 27 millivolts, and the voltage difference between the unit battery 5 and the short-board unit battery is 203 volts.

Step 501. Determine the single battery with the smallest voltage difference with the short board single battery

The single battery with the smallest voltage difference, that is, the single battery 3 is determined according to the voltage difference.

Step 502, disconnect the shunt circuit of the single battery to reduce the heat generated by the shunt unit

Because the voltage difference between the single battery 3 and the short-board single battery is the smallest, it can be determined that the capacity gap between the single battery 3 and the short-board single battery is small, then the shunt circuit 3 of the single battery 3 is disconnected, In order to reduce the heat generated in the shunt circuit, at this time, the temperature on one side of the shunt unit will gradually drop due to the reduction of energy-consuming elements that generate heat.

After a period of time, such as two minutes, the temperature of the shunt unit is collected again. If the temperature still does not reach a preset value, the shunt circuit of a single battery is disconnected according to the above steps.

Further, in order to improve the balance effect among the single cells, when the temperature drops to a preset value, the shunt circuit is reconnected to shunt the single cells, as shown in Figure 6, including:

Step 600, set the temperature value at which the shunt circuit in the shunt unit is reconnected in the dispatching unit, which is called the restart temperature value

After step 300, set a temperature preset value that can reconnect the shunt circuit in the shunt circuit, the preset value is called restart temperature value, for example, the restart temperature value is 60 degrees.

If the scheduling unit judges that the current temperature value of the shunt unit is greater than the set overheating temperature value, disconnect the shunt circuit, reduce the heat generated by the shunt circuit in the shunt unit, and reduce the temperature of the shunt unit, further comprising:

Step 601, judging whether the current temperature value of the diversion unit is less than the restart temperature value

The temperature collection unit collects the current temperature value of the branching unit, for example, the current temperature value is 58 degrees, and judges whether the collected temperature value is lower than the restart temperature value.

Step 602: If the current temperature value of the shunt unit is lower than the restart temperature value, compare the voltage difference between the short board single battery and the single battery that is not connected to the shunt circuit

If the collected temperature of 58 degrees is less than the set minimum temperature value of 60 degrees, then compare the voltage difference between the short-board single battery and the single battery that is not connected to the shunt circuit, for example, the temperature of the single battery 3 in the shunt unit When the value is greater than the overheating temperature value, the branching unit 3 corresponding to the single battery 3 has been disconnected.

Step 603, determine the single battery whose voltage difference with the short-board single battery is greater than the shunt voltage difference

According to the comparison of the voltage difference, the voltage of the single battery 3 is 3027 millivolts, which is 27 millivolts different from the 3000 millivolts of the short board single battery, which is 20 millivolts greater than the shunt voltage difference.

Step 604, connect the shunt circuit corresponding to the single battery, and re-shunt the single battery in the battery pack

The shunt circuit 3 corresponding to the single battery 3 is reconnected to re-shunt the single battery 3 to balance the capacity of the single battery.

When there are multiple single cells in the battery pack that need to be shunted, and the temperature value of the shunt unit is lower than the restart temperature value, the single battery whose voltage difference with the short-board single battery is greater than the shunt voltage difference will be compared with the single battery. The corresponding shunt circuits are all turned on, and the shunt is continued to balance the capacities of the single cells in the battery pack and the short board single cells.

A lithium battery balance control device and method provided in an embodiment of the present invention collects the temperature of the shunt unit through the temperature acquisition unit. When the temperature exceeds the preset overheating temperature value, the shunt circuit corresponding to the single battery is disconnected to reduce the number of shunt units. The generated heat prevents the electronic equipment from overheating when the single battery is balanced, and improves the stability of the electronic equipment.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (5)

1. A lithium battery balance control device, comprising a battery pack, a scheduling unit, a shunt unit and a voltage acquisition unit, and a voltage acquisition unit is arranged on one side of the single battery in the battery pack; the single battery and the shunt unit The shunt circuit is connected in parallel; the shunt unit and the voltage acquisition unit are respectively connected to the dispatch unit, and it is characterized in that a temperature acquisition unit is arranged on one side of the shunt unit; the temperature acquisition unit is connected to the dispatch unit; The battery pack is composed of at least two single cells connected in series; The shunt unit is used to shunt the charging current to reduce the charging speed of the single battery. The shunt unit includes at least two shunt circuits, and the shunt circuits include energy-consuming elements; The voltage acquisition unit is used to collect the voltage value of each single battery, and determine the single battery corresponding to the minimum voltage value, which is called a short board single battery; The temperature collection unit is used to collect the current temperature value of the flow distribution unit; The voltage difference for shunting the single battery is set in the dispatching unit, which is called the shunt voltage difference; the overheating temperature value of the shunting unit is set in the dispatching unit; The scheduling unit is used to judge whether the current temperature value of the shunt unit is greater than the set overheating temperature value; if it is judged that the current temperature value of the shunt unit is greater than the set overheating temperature value, then disconnect the shunt circuit and reduce the flow rate in the shunt unit. The heat generated by the circuit reduces the temperature of the shunt unit; The temperature value at which the shunt circuit in the shunt unit is reconnected is set in the dispatching unit, which is called the restart temperature value; The scheduling unit is also used to judge whether the current temperature value of the shunt unit is less than the restart temperature value; if the current temperature value of the shunt unit is less than the restart temperature value, then compare the short-board single battery with the single battery that is not connected to the shunt circuit Determine the voltage difference between the single battery and the short-board single battery that is greater than the shunt voltage difference; connect the shunt circuit corresponding to the single battery, and re-shunt the single battery in the battery pack. 2. A lithium battery balance control device according to claim 1, characterized in that, The dispatching unit is also used to judge whether the voltage difference between the single battery and the short-board single battery is greater than the shunt voltage difference; if the voltage difference between the single battery and the short-board single battery is greater than The shunt voltage difference is connected to the shunt circuit corresponding to the single battery to shunt the single battery and reduce the charging speed of the single battery. 3. A lithium battery equalization control method, characterized in that, comprising: Set the overheating temperature value of the shunt unit in the scheduling unit; The voltage difference for shunting the single battery is set in the dispatching unit, which is called the shunt voltage difference; The voltage acquisition unit obtains the voltage value of each single battery, and determines the single battery corresponding to the minimum voltage value, which is called a short board single battery; The temperature acquisition unit acquires the current temperature value of the flow distribution unit; The scheduling unit judges whether the current temperature value of the branching unit is greater than the set overheating temperature value; If the scheduling unit judges that the current temperature value of the shunt unit is greater than the set overheating temperature value, then disconnect the shunt circuit, reduce the heat generated by the shunt circuit in the shunt unit, and reduce the temperature of the shunt unit; The temperature value at which the shunt circuit in the shunt unit is reconnected is set in the dispatching unit, which is called the restart temperature value; Judging whether the current temperature value of the shunt unit is less than the restart temperature value; If the current temperature value of the shunt unit is less than the restart temperature value, then compare the voltage difference between the short board single battery and the single battery that is not connected to the shunt circuit; Determine the single battery whose voltage difference with the short-board single battery is greater than the shunt voltage difference; Connect the shunt circuit corresponding to the single battery, and re-shunt the single battery in the battery pack. 4. A lithium battery balance control method according to claim 3, wherein if the scheduling unit judges that the current temperature value of the shunt unit is greater than the set overheating temperature value, then disconnect the shunt circuit and reduce the number of shunt units The heat generated by the shunt circuit reduces the temperature of the shunt unit, including: The dispatching unit compares the voltage difference between the short board single battery and the single battery connected to the shunt circuit according to the voltage value of the single battery collected by the voltage acquisition unit; Determine the single battery with the smallest voltage difference with the short board single battery; Disconnect the shunt circuit of the single battery to reduce the heat generated by the shunt unit. 5. A lithium battery balance control method according to claim 3, further comprising: The dispatching unit judges whether the voltage difference between the single battery and the short board single battery is greater than the shunt voltage difference; If the voltage difference between the single battery and the short-board single battery is greater than the shunt voltage difference, turn on the shunt circuit corresponding to the single battery, shunt the single battery, and reduce the charge of the single battery speed.

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