CN115051446A - Charging and discharging control method, control equipment and power supply system - Google Patents

Abstract

The invention provides a charge and discharge control method, control equipment and a power supply system, wherein the control method is used for controlling charge and discharge of a battery module, the battery module comprises a plurality of batteries connected in parallel, and the charge and discharge control method comprises the following steps: acquiring the residual electric quantity of a plurality of batteries in a charging mode; estimating whether a battery with charging current larger than preset charging current exists when the plurality of batteries are charged together according to the corresponding relation between the residual electric quantity of the plurality of batteries and the preset electric quantity interval; if yes, controlling the battery to be charged independently; if not, controlling the multiple batteries to be charged together, so that the charging current of all the batteries is less than or equal to the preset charging current when the multiple batteries are charged together, and the service life of the batteries is prevented from being influenced by overlarge charging current of the batteries.

Description

A charge and discharge control method, control device and power supply system

technical field

The invention relates to the technical field of battery charging and discharging, in particular to a charging and discharging control method, a control device and a power supply system.

Background technique

With the increase of people's demand for battery capacity, the battery parallel expansion technology is gradually applied to various battery modules. However, under the influence of factors such as manufacturing process differences, the internal resistance of each battery connected in parallel in the battery module will be different, resulting in a difference in the charging current of each battery. , the charging current of some batteries is too large, and even exceeds its charging specifications, affecting the service life of the battery.

SUMMARY OF THE INVENTION

In view of this, the present invention aims to provide a charging and discharging control method, a control device and a power supply system, so as to avoid excessive charging current of some batteries when a plurality of batteries connected in parallel are jointly charged.

In a first aspect, the present invention provides a charge and discharge control method for controlling charge and discharge of a battery module, wherein the battery module includes a plurality of batteries connected in parallel, and the charge and discharge control method includes:

In the charging mode, obtain the remaining power of the plurality of batteries;

According to the corresponding relationship between the remaining power of the plurality of batteries and the preset power interval, it is estimated whether there is a battery with a charging current greater than a preset charging current when the plurality of batteries are jointly charged;

If so, control the battery to be charged separately;

If not, control the plurality of batteries to charge together.

Optionally, the power range includes a minimum power range and a maximum difference power range, and it is estimated that when the plurality of batteries are jointly charged according to the corresponding relationship between the remaining power of the plurality of batteries and the preset power range Whether there is a battery with a charging current greater than the preset charging current includes:

judging whether the remaining power of the plurality of batteries is within the minimum power interval, and judging whether the difference between the remaining powers of any two batteries in the plurality of batteries is within the maximum difference power interval;

If the remaining power of at least one battery is within the minimum power interval, it is estimated that the charging current of at least one battery is greater than the preset charging current when the plurality of batteries are jointly charged;

If the difference between the remaining powers of the at least two batteries is within the maximum difference power interval, it is estimated that the charging current of at least one battery is greater than the preset charging current when the plurality of batteries are jointly charged;

If the remaining power of the plurality of batteries is not within the minimum power range, and the difference between the remaining power of any two batteries in the plurality of batteries is not within the maximum difference power range, then the estimated When the plurality of batteries are jointly charged, there is no battery whose charging current is greater than the preset charging current.

Optionally, the judging whether the remaining power of the plurality of batteries is within the minimum power interval includes: judging whether the remaining power of the battery with the smallest rated capacity among the plurality of batteries is within the minimum power interval; , the remaining power of at least one battery is within the minimum power interval; if not, the remaining power of the plurality of batteries is not within the minimum power interval;

The judging whether the difference between the remaining power of any two batteries in the plurality of batteries is within the maximum difference power interval includes: judging the difference between the remaining power of the battery with the smallest rated capacity among the plurality of batteries and the remaining power of other batteries; Whether the difference is within the maximum difference power range; if so, the difference between the remaining power of at least two batteries is within the maximum difference power range; if not, then any two batteries in the plurality of batteries The difference of the remaining power of , is not within the maximum difference power interval.

Optionally, the controlling the battery to be individually charged includes: controlling the battery to be individually charged with a charging current matched with the battery, where the matched charging current is less than or equal to the preset charging current;

The controlling the plurality of batteries to be jointly charged includes: controlling the plurality of batteries to be jointly charged with a charging current matched with the battery module; the charging current matched with the battery module is equal to the charging current matched with each battery. Sum of charging currents.

Optionally, the minimum electric quantity interval includes: an interval less than or equal to 5%; the maximum difference electric quantity interval includes: an interval greater than or equal to 30%.

Optionally, also include:

According to the maximum discharge power of each battery in the battery module, a plurality of power thresholds and a plurality of remaining power intervals corresponding thereto are determined, and the plurality of power thresholds increase sequentially;

In the discharge mode, obtain the remaining power of the battery module, and determine whether the remaining power of the battery module is within the plurality of remaining power intervals;

If the remaining power of the battery module is within one of the remaining power intervals, the maximum load power of the battery module is controlled not to exceed the power threshold corresponding to the remaining power interval, so that each of the battery modules The discharge current of the battery is less than the preset discharge current.

Optionally, also include:

If the maximum load power of the battery module exceeds the corresponding power threshold, the battery module is controlled to enter a protection state.

Optionally, the maximum power threshold of the multiple power thresholds is equal to the sum of the maximum discharge powers of the respective batteries in the battery module; the minimum power threshold of the multiple power thresholds is equal to the maximum discharge power of the multiple batteries. The smallest of the discharge power.

Optionally, the battery module includes a first battery and a second battery, the plurality of power thresholds include a first power threshold, a second power threshold and a third power threshold, and the first power threshold is equal to the The sum of the maximum discharge power of the first battery and the maximum discharge power of the second battery, the second power threshold is equal to the maximum discharge power of the first battery, and the third power threshold is equal to the maximum discharge power of the second battery. maximum discharge power, the maximum discharge power of the first battery is greater than the maximum discharge power of the second battery;

The remaining power interval corresponding to the first power threshold includes: an interval greater than the lower limit of the remaining power corresponding to the first power threshold; the remaining power interval corresponding to the second power threshold includes: greater than or equal to the first power threshold The lower limit of the remaining power corresponding to the power threshold, and the interval less than or equal to the lower limit of the remaining power corresponding to the second power threshold; the remaining power interval corresponding to the third power threshold includes: the remaining power greater than the second power threshold corresponding to the threshold the lower bound of the interval.

Optionally, the lower limit of the remaining power corresponding to the first power threshold is 40%, and the lower limit of the remaining power corresponding to the second power threshold is 20%.

In a second aspect, the present invention provides a charge and discharge control device, comprising:

memory for storing instructions;

The controller is configured to execute the charging and discharging control method described in any one of the above according to the instructions stored in the memory.

In a third aspect, the present invention provides a power supply system, including a battery module and the above-mentioned charge and discharge control device, the charge and discharge control device is connected to the battery module, and the charge and discharge control device is used to control Charge and discharge of the battery module.

In the charging and discharging control method, control device and power supply system provided by the present invention, the remaining power of multiple batteries is obtained in the charging mode, and according to the corresponding relationship between the remaining power of the battery and the preset power interval, it is estimated that when the multiple batteries are jointly charged Whether there is a battery with a charging current greater than the preset charging current, if not, charge multiple batteries together, if so, charge the batteries individually until the estimated result is that there is no battery with a charging current greater than the preset charging current. , to charge multiple batteries together, so that when multiple batteries are jointly charged, the charging current of all batteries is less than or equal to the preset charging current, so as not to affect the service life of the batteries due to excessive charging current.

Description of drawings

The above and other objects, features and advantages of the present application will become more apparent from the detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present application, constitute a part of the specification, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation to the present application. In the drawings, the same reference numbers generally refer to the same components or steps.

FIG. 1 is a schematic diagram of a connection relationship of a battery module according to an embodiment of the present invention.

FIG. 2 is a flowchart of a charging and discharging control method provided by an embodiment of the present invention.

FIG. 3 is a flowchart of a charging and discharging control method provided by another embodiment of the present invention.

FIG. 4 is a charging parameter curve diagram of battery 1 and battery 2 in various charging stages according to an embodiment of the present invention.

FIG. 5 is a flowchart of a charging/discharging control method provided by another embodiment of the present invention.

FIG. 6 is a graph of charging parameters of battery 1 and battery 2 in various discharge stages according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The embodiment of the present invention provides a charge and discharge control method, and the control method is used to control the charge and discharge of a battery module. As shown in FIG. 1 , FIG. 1 is a schematic diagram of a connection relationship of a battery module according to an embodiment of the present invention. The battery module 10 is connected to a power adapter 11 and a host 12 respectively. The battery module 10 includes a plurality of batteries connected in parallel, namely battery 1 to battery n, where n is a natural number greater than or equal to 2. The host 12 is connected to a plurality of batteries through a plurality of switches, that is, the switch K1 is connected to the battery 1, the switch K2 is connected to the battery 2, ..., the switch Kn is connected to the battery n, and the host 12 controls the battery by controlling the on-off of the switch Charging and discharging of the module 10 .

The working modes of the battery module 10 include a charging mode and a discharging mode. In the charging mode, the power adapter 11 outputs current to the battery module 10 to charge the battery module 10; during the charging process, the host 12 will control the charging and discharging strategy of the battery module 10, for example, according to the remaining power of each battery , to control whether each battery is charged together. In the discharge mode, the battery module 10 outputs current to the host 12 to supply power to the host 12 .

It should be noted that, FIG. 1 shows a connection relationship of a battery module in a notebook computer, and the present invention is only described as an example, and is not limited to this. In the embodiment of the present invention, the battery in the battery module 10 may be a lead-acid battery, or a lithium battery or the like. In addition, each battery in the embodiments of the present invention may include one battery cell, or may include a plurality of battery cells connected in series.

As shown in FIG. 2, FIG. 2 is a flowchart of a charging and discharging control method provided by an embodiment of the present invention. The charging and discharging control method can be applied to the host 12, and the charging and discharging control method includes:

S201: in the charging mode, obtain the remaining power of multiple batteries;

S202: According to the corresponding relationship between the remaining power of the plurality of batteries and the preset power interval, it is estimated whether there is a battery with a charging current greater than the preset charging current when the plurality of batteries are jointly charged; if so, go to S203; if not, go to S204;

S203: control the battery to be charged separately;

S204: Control multiple batteries to be charged together.

The preset charging current may be the maximum charging current that meets the battery charging specification. The power interval is the remaining power interval in which the charging current of the battery is greater than the preset charging current. The battery can be individually charged by controlling the switch corresponding to the battery to be turned on and the other switches to be turned off, and multiple batteries can be jointly charged by controlling all switches to be turned on.

After obtaining the remaining power of the multiple batteries in the charging mode, according to the corresponding relationship between the remaining power of the battery and the preset power interval, it is estimated whether there is a battery with a charging current greater than the preset charging current when the multiple batteries are jointly charged. If it exists, charge multiple batteries together. If it exists, charge the batteries separately. After the estimated result is that there is no battery with a charging current greater than the preset charging current, charge the multiple batteries together, so that the multiple batteries can be jointly charged. When charging, the charging current of all batteries is less than or equal to the preset charging current, so as not to affect the service life of the battery due to the excessive charging current of the battery.

In some embodiments of the present invention, the power range includes a minimum power range and a maximum difference power range. As shown in FIG. 3 , FIG. 3 is a flowchart of a charging and discharging control method provided by another embodiment of the present invention. The charging and discharging control method include:

S301: in the charging mode, obtain the remaining power of multiple batteries;

S302: Determine whether the remaining power of the plurality of batteries is within the minimum power range, and determine whether the difference between the remaining powers of any two batteries in the plurality of batteries is within the maximum difference power range;

S303: If the remaining power of at least one battery is within the minimum power range, it is estimated that the charging current of at least one battery is greater than the preset charging current when multiple batteries are jointly charged;

S304: If the difference between the remaining powers of the at least two batteries is within the maximum difference power interval, it is estimated that the charging current of at least one battery is greater than the preset charging current when the plurality of batteries are jointly charged;

S305: If the remaining power of the multiple batteries is not within the minimum power range, and the difference between the remaining powers of any two batteries in the multiple batteries is not within the maximum difference power range, it is estimated that the multiple batteries will not be charged together. There are batteries with a charging current greater than the preset charging current.

In the embodiment of the present invention, in the charging mode, the remaining power of each battery in the battery module is obtained, and according to whether the remaining power of each battery is within a preset power interval, it is determined that the charging mode of the battery module is the charging management mode Still in battery management mode. In the charging management mode, each battery in the battery module is charged together, and in the battery management mode, some batteries in the battery module are charged separately.

If the charging current of at least one battery is greater than the preset charging current when it is estimated that multiple batteries are charged together, enter the battery management mode, and control the battery whose estimated charging current is greater than the preset charging current to be charged separately until the remaining power of the battery is not the lowest. After the battery is within the power range, the separate charging of the battery ends; wherein, among the two batteries whose remaining power difference is within the maximum difference power range, the charging current of the battery with the smallest remaining power is estimated to be greater than the preset charging current.

If the remaining power of multiple batteries is not within the minimum power range, and the difference between the remaining power of any two batteries in the multiple batteries is not within the maximum difference power range, the charge management mode is entered to control multiple batteries to charge together. .

It should be noted that during the charging process of the battery module, the remaining power of multiple batteries in the battery module is continuously obtained, and the charging strategy is adjusted in real time according to the remaining power, for example, whether to charge separately or jointly charge in real time.

In the embodiment of the present invention, when the battery is charged separately, a charging current within the charging specification can be used, such as a charging current smaller than the preset charging current. Therefore, it is possible to avoid excessive charging current that affects its service life. question. When multiple batteries are charged together, since the remaining power of each battery is greater than the power in the lowest power interval, it can be avoided that the remaining power of the battery is too small, resulting in the charging current of the battery being too large. The difference in power is less than the power in the maximum difference power interval. Therefore, it can avoid that the charging current of the battery with the smallest remaining power is too large due to the large difference in the remaining power of the two batteries, so that the charging current of each battery can be more balanced. , which can not only avoid the problem that the charging current of some batteries will affect their service life, but also avoid the charging time of some batteries being too small, which will affect the charging efficiency of the battery module. question. On this basis, the internal resistance difference between the individual batteries can be ignored, and the assembly requirements of the battery module can be reduced.

In some embodiments of the present invention, judging whether the remaining power of the plurality of batteries is within the minimum power range includes: judging whether the remaining power of the battery with the smallest rated capacity among the plurality of batteries is within the minimum power range; if so, then the remaining power of at least one battery The power is within the minimum power range; if not, the remaining power of the multiple batteries is not within the minimum power range.

Judging whether the difference between the remaining power of any two batteries in the plurality of batteries is within the maximum difference power range includes: judging whether the difference between the remaining power of the battery with the smallest rated capacity and the remaining power of other batteries among the plurality of batteries is within the maximum difference power within the range; if so, the difference between the remaining power of at least two batteries is within the maximum difference power range; if not, the difference between the remaining power of any two of the multiple batteries is not within the maximum difference power range .

Since the rated power of multiple batteries is different, and the higher the rated power of the battery, the more the remaining power, therefore, the remaining power of other batteries can be determined by judging the remaining power of the battery with the smallest rated power. That is to say, if the remaining power of the battery with the smallest rated capacity is within the minimum power range, then the remaining power of at least one of the multiple batteries is within the minimum power range, and if the remaining power of the battery with the smallest rated capacity is not within the minimum power range Within the range, the remaining power of other batteries must not be within the minimum power range. If the difference between the remaining power of the battery with the smallest rated capacity and the remaining power of other batteries is within the maximum difference power range, the difference between the remaining power of at least two of the multiple batteries is within the maximum difference power range. If the rated capacity is the smallest The difference between the remaining power of the battery and other batteries is not within the maximum difference power range, then the difference of the remaining power of the other batteries must not be within the maximum difference power range. Based on this, the number of comparisons of the remaining battery power can be reduced, and the computing efficiency can be improved.

In some embodiments of the present invention, controlling the battery to be individually charged includes: controlling the battery to be individually charged with a charging current matched with the battery, where the matched charging current is smaller than a preset charging current. Optionally, the matching charging current is less than the maximum current within the preset charging current range, so as to realize fast charging of the battery. The controlling of the multiple batteries to be jointly charged includes: controlling the multiple batteries to be jointly charged with a charging current matched with the battery module; the charging current matched with the battery module is equal to the sum of the charging currents matched with the respective batteries.

In some embodiments of the present invention, the minimum electric quantity interval includes: an interval less than or equal to 5%; the maximum difference electric quantity interval includes: an interval greater than or equal to 30%. Of course, the present invention is not limited to this, and the thresholds of each power interval can be set according to the actual parameters of the battery, which will not be repeated here.

The description is given by taking the battery module having two batteries, namely, battery 1 and battery 2 as an example. The rated capacity of the battery 1 is smaller than the rated capacity of the battery 2 . After obtaining the remaining power of battery 1 and battery 2 in charging mode, determine whether the remaining power of battery 1 is less than 5%; if it is less than 5%, enter the battery management mode, and control battery 1 to charge separately until the remaining power of battery 1 is greater than or is equal to 5%; if it is greater than or equal to 5%, judge whether the difference between battery 1 and battery 2 is greater than 30%; if it is less than or equal to 30%, enter the charge management mode, control battery 1 and battery 2 to charge together until battery 1 and Battery 2 is charged to 100%, and the charging is over; if it is greater than 30%, control battery 1 to charge separately until the difference between battery 1 and battery 2 is less than or equal to 30%, enter the charge management mode, and control battery 1 and battery 2 to charge together , until both battery 1 and battery 2 are charged to 100%, charging ends.

Table 1

Table 1 shows the test data during the charging process of battery 1 and battery 2. At the beginning of charging, the remaining power of battery 1 is 8%, and the remaining power of battery 2 is 3%. First, use the matching current of battery 2 to quickly charge them separately , and then charge battery 1 and battery 2 together. During the whole charging process, the monitoring data is shown in Table 1, and the charging current meets the specifications of each battery. As shown in FIG. 4, FIG. 4 is a charging parameter curve diagram of battery 1 and battery 2 in each charging stage provided by an embodiment of the present invention. During the charging process of battery 1 and battery 2, the charging currents are both within the respective charging specifications. , and the charging time is greatly shortened.

It should be noted that, in some embodiments of the present invention, SOC (State of Charge, state of charge) is used to represent the remaining power of the battery, wherein the SOC value is generally represented by a percentage. Of course, in other embodiments, other parameters may also be used to represent the remaining power, which will not be repeated here.

On the basis of any of the above embodiments, as shown in FIG. 5 , FIG. 5 is a flowchart of a charging and discharging control method provided by another embodiment of the present invention, and the charging and discharging control method further includes:

S501: According to the maximum discharge power of each battery in the battery module, determine a plurality of power thresholds and a plurality of remaining power intervals corresponding to them, and the plurality of power thresholds increase sequentially;

S502: In the discharge mode, obtain the remaining power of the battery module, and determine whether the remaining power of the battery module is within a plurality of remaining power intervals;

S503: If the remaining power of the battery module is within a remaining power range, control the maximum load power of the battery module to be less than or equal to the power threshold corresponding to the remaining power range, so that the discharge current of each battery in the battery module is less than the predetermined value. Set the discharge current.

The preset discharge current is the maximum discharge current within the battery discharge specification. On this basis, if the maximum load power of the battery module does not exceed the corresponding power threshold, the battery module is in a normal working state; if the maximum load power of the battery module exceeds the corresponding power threshold, the battery module is controlled to enter the protection state .

In some embodiments of the present invention, the maximum power threshold among the multiple power thresholds is equal to the sum of the maximum discharge powers of the respective batteries in the battery module; the minimum power threshold among the multiple power thresholds is equal to the minimum among the maximum discharge powers of the multiple batteries By.

On this basis, in some embodiments of the present invention, the battery module includes a first battery (eg, battery 1) and a second battery (battery 2), and the multiple power thresholds include a first power threshold, a second power threshold, and a second power threshold. Three power thresholds, the first power threshold is equal to the sum of the maximum discharge power of the first battery and the maximum discharge power of the second battery, the second power threshold is equal to the maximum discharge power of the first battery, and the third power threshold is equal to the maximum discharge power of the second battery Discharge power, the maximum discharge power of the first battery is greater than the maximum discharge power of the second battery;

The remaining power interval corresponding to the first power threshold includes: an interval greater than the lower limit of the remaining power corresponding to the first power threshold; the remaining power interval corresponding to the second power threshold includes: greater than or equal to the lower limit of the remaining power corresponding to the first power threshold, The interval less than or equal to the lower limit of the remaining power corresponding to the second power threshold; the remaining power interval corresponding to the third power threshold includes: the interval greater than the lower limit of the remaining power corresponding to the second power threshold.

That is to say, if the remaining power of the battery module is within an interval greater than the lower limit of the remaining power corresponding to the first power threshold, the maximum load power of the battery module is controlled to be less than or equal to the first power threshold; if the remaining power of the battery module is within In the interval greater than or equal to the lower limit of the remaining power corresponding to the first power threshold and less than or equal to the lower limit of the remaining power corresponding to the second power threshold, the maximum load power of the control battery module is less than or equal to the second power threshold; When the remaining power is greater than the lower limit of the remaining power corresponding to the second power threshold, the control controls the maximum load power of the battery module to be less than or equal to the third power threshold.

On this basis, in some embodiments of the present invention, the lower limit of the remaining power corresponding to the first power threshold is 40%, and the lower limit of the remaining power corresponding to the second power threshold is 20%. Of course, the present invention is not limited to this, and each power threshold can be set according to the actual parameters of the battery module, which will not be repeated here.

Table 2

Table 2 shows the test data during the discharge process of battery 1 and battery 2. The maximum discharge power of battery 1 is 33.12W, and the maximum discharge power of battery 2 is 54W. Battery 1 and Battery 2 are discharged with a first threshold of 87.12W constant power from the remaining power of 100%, to 40% of the remaining power, discharged with a second threshold of 54W constant power, to 20% of the remaining power, with a third threshold of 33.12W Constant power discharge until the remaining power is 0%. As shown in FIG. 6 , FIG. 6 is a charging parameter curve diagram of battery 1 and battery 2 in each discharge stage provided by an embodiment of the present invention. In each stage of discharge, the SOC curve is obtained by discharging with a set power threshold. picture. During the discharge process, both battery 1 and battery 2 are within their own discharge specifications, and obtain similar SOC curves, providing the best performance for the system.

It should be noted that during the discharging process, the remaining power of the battery module will be continuously obtained, and the maximum load power of the battery module will be adjusted in real time according to the corresponding relationship between the remaining power of the battery module and a plurality of predetermined remaining power intervals. .

Based on this, by setting the power threshold corresponding to the remaining power interval in multiple stages with different remaining power of the battery module, and making the maximum load power of the battery module less than the corresponding power threshold, each battery can be discharged evenly, so that each battery can be discharged in a balanced manner. The discharge curves of the batteries are similar, so that the remaining power of each battery reaches 0 at the same time, and does not exceed their respective discharge specifications during the discharge process, thereby avoiding overload or over-discharge of a certain battery, and avoid the difference between the remaining power of the two batteries being too large. Causes one of the batteries to charge the other. On this basis, the difference between the batteries can also be ignored, thereby reducing the assembly requirements of the battery module 10 .

The embodiment of the present invention also provides a charge and discharge control device, including:

memory for storing instructions;

The controller is configured to execute the charging and discharging control method according to any of the above embodiments according to the instructions stored in the memory.

An embodiment of the present invention also provides a power supply system, including a battery module and the above-mentioned charge and discharge control device, the charge and discharge control device is connected to the battery module, and the charge and discharge control device is used to control the charge and discharge of the battery module. In some embodiments of the present invention, referring to FIG. 1 , the charge and discharge control device may be located in the host 12 , and the power supply system may further include a power adapter 10 for supplying power to the battery module 11 .

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method. The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (12)

1. A charge-discharge control method, characterized in that, for controlling the charge-discharge of a battery module, the battery module comprises a plurality of batteries connected in parallel, and the charge-discharge control method comprises: In the charging mode, obtain the remaining power of the plurality of batteries; According to the corresponding relationship between the remaining power of the plurality of batteries and the preset power interval, it is estimated whether there is a battery with a charging current greater than a preset charging current when the plurality of batteries are jointly charged; If so, control the battery to be charged separately; If not, control the plurality of batteries to charge together. 2 . The charge-discharge control method according to claim 1 , wherein the power interval includes a minimum power interval and a maximum difference power interval, and the charge interval is based on the remaining power of the plurality of batteries and a preset power interval. 3 . The corresponding relationship of , it is estimated whether there is a battery whose charging current is greater than the preset charging current when the plurality of batteries are jointly charged, including: judging whether the remaining power of the plurality of batteries is within the minimum power interval, and judging whether the difference between the remaining powers of any two batteries in the plurality of batteries is within the maximum difference power interval; If the remaining power of at least one battery is within the minimum power interval, it is estimated that the charging current of at least one battery is greater than the preset charging current when the plurality of batteries are jointly charged; If the difference between the remaining powers of the at least two batteries is within the maximum difference power interval, it is estimated that the charging current of at least one battery is greater than the preset charging current when the plurality of batteries are jointly charged; If the remaining power of the plurality of batteries is not within the minimum power range, and the difference between the remaining power of any two batteries in the plurality of batteries is not within the maximum difference power range, then the estimated When the plurality of batteries are jointly charged, there is no battery whose charging current is greater than the preset charging current. 3 . The charge-discharge control method according to claim 2 , wherein the judging whether the remaining power of the plurality of batteries is within the minimum power interval comprises: judging the battery with the smallest rated capacity among the plurality of batteries. 4 . Whether the remaining power of the battery is within the minimum power range; if so, the remaining power of at least one battery is within the minimum power range; if not, the remaining power of the plurality of batteries is not within the minimum power range ; The judging whether the difference between the remaining power of any two batteries in the plurality of batteries is within the maximum difference power interval includes: judging the difference between the remaining power of the battery with the smallest rated capacity among the plurality of batteries and the remaining power of other batteries; Whether the difference is within the maximum difference power range; if so, the difference between the remaining power of at least two batteries is within the maximum difference power range; if not, then any two batteries in the plurality of batteries The difference of the remaining power of , is not within the maximum difference power interval. 4 . The charge-discharge control method according to claim 1 , wherein the controlling the battery to be charged independently comprises: controlling the battery to be charged separately with a charging current matched with the battery, wherein the matched charging current is less than or is equal to the preset charging current; The controlling the plurality of batteries to be jointly charged includes: controlling the plurality of batteries to be jointly charged with a charging current matched with the battery module; the charging current matched with the battery module is equal to the charging current matched with each battery. Sum of charging currents. 5 . The charge-discharge control method according to claim 2 , wherein the minimum electric quantity interval includes: an interval less than or equal to 5%; the maximum difference electric quantity interval includes: greater than or equal to 30% range. 6. The charge-discharge control method according to claim 1, further comprising: According to the maximum discharge power of each battery in the battery module, a plurality of power thresholds and a plurality of remaining power intervals corresponding thereto are determined, and the plurality of power thresholds increase sequentially; In the discharge mode, obtain the remaining power of the battery module, and determine whether the remaining power of the battery module is within the plurality of remaining power intervals; If the remaining power of the battery module is within one of the remaining power intervals, the maximum load power of the battery module is controlled not to exceed the power threshold corresponding to the remaining power interval, so that each of the battery modules The discharge current of the battery is less than the preset discharge current. 7. The charge-discharge control method according to claim 6, further comprising: If the maximum load power of the battery module exceeds the corresponding power threshold, the battery module is controlled to enter a protection state. 8 . The charge-discharge control method according to claim 6 , wherein the maximum power threshold value among the multiple power threshold values is equal to the sum of the maximum discharge powers of the respective batteries in the battery module; the multiple power threshold values The smallest power threshold of the thresholds is equal to the smallest of the maximum discharge powers of the plurality of batteries. 9 . The charge-discharge control method according to claim 6 , wherein the battery module includes a first battery and a second battery, and the plurality of power thresholds include a first power threshold, a second power threshold and a third power threshold, the first power threshold is equal to the sum of the maximum discharge power of the first battery and the maximum discharge power of the second battery, the second power threshold is equal to the maximum discharge power of the first battery Discharge power, the third power threshold is equal to the maximum discharge power of the second battery, and the maximum discharge power of the first battery is greater than the maximum discharge power of the second battery; The remaining power interval corresponding to the first power threshold includes: an interval greater than the lower limit of the remaining power corresponding to the first power threshold; the remaining power interval corresponding to the second power threshold includes: greater than or equal to the first power threshold The lower limit of the remaining power corresponding to the power threshold, and the interval less than or equal to the lower limit of the remaining power corresponding to the second power threshold; the remaining power interval corresponding to the third power threshold includes: the remaining power greater than the second power threshold corresponding to the threshold the lower bound of the interval. 10 . The charge-discharge control method according to claim 9 , wherein the lower limit of the remaining power corresponding to the first power threshold is 40%, and the lower limit of the remaining power corresponding to the second power threshold is 20%. 11 . 11. A charge and discharge control device, comprising: memory for storing instructions; The controller is configured to execute the charging and discharging control method according to any one of claims 1-10 according to the instructions stored in the memory. 12. A power supply system, comprising a battery module and a charge and discharge control device according to claim 11, wherein the charge and discharge control device is connected to the battery module, and the charge and discharge control device is used for Control the charging and discharging of the battery module.

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