CN118174414A

CN118174414A - Charge and discharge management method and device

Info

Publication number: CN118174414A
Application number: CN202410338735.9A
Authority: CN
Inventors: 吕伟升; 卢晓; 王四杰; 苏细南
Original assignee: Xiamen Haichen Digital Energy Technology Co ltd
Current assignee: Xiamen Haichen Digital Energy Technology Co ltd
Priority date: 2024-03-22
Filing date: 2024-03-22
Publication date: 2024-06-11

Abstract

The present application discloses a charge and discharge management method and device, the method comprising: collecting BMS monitoring data; determining the charge and discharge management state required by the lithium battery pack according to the BMS monitoring data, the charge and discharge management state comprising any one of the following: charging management state and discharging management state; if the charge and discharge management state is the charging management state, then charging control management is performed on the lithium battery pack according to the DC panel AC/DC switching power supply; if the charge and discharge management state is the discharging management state, then discharging control management is performed on the lithium battery pack. The use of the present application is conducive to improving the life of the lithium battery pack and is conducive to the long-term stable operation of the lithium battery pack.

Description

Charging and discharging management method and device

Technical Field

The application relates to the technical field of lithium batteries, in particular to a charge and discharge management method and a related device.

Background

The direct current screen power supply system in the power industry generally adopts a lead-acid storage battery as a backup energy storage unit thereof, the charging and discharging of the lead-acid storage battery are controlled by a direct current screen AC/DC switch power supply module, the charging and the floating charging are generally carried out after the uniform charging, and the switching between the uniform charging and the floating charging is automatically controlled by a switch power supply monitoring module, so that the charging and discharging of the lead-acid storage battery can be satisfied.

At present, lithium battery energy storage is generally adopted for industrial and commercial energy storage and large container energy storage, but an AC/DC switch power supply module is adopted for a direct current screen charging cabinet, a direct current load of a transformer substation, an opening and closing station and a battery pack are directly hung on a direct current screen charging and discharging bus together, a charging and discharging management method is limited, the charging mode of firstly homogenizing and then floating is not suitable for charging and discharging of the lithium battery, and long-term floating charging can damage the service life and cycle times of the lithium battery.

Disclosure of Invention

The embodiment of the application provides a charge and discharge management method and device, which are beneficial to prolonging the service life of a lithium battery pack and being beneficial to long-term stable operation of the lithium battery pack.

In a first aspect, an embodiment of the present application provides a charge and discharge management method, which is applied to an energy storage battery management system, where the energy storage battery management system is connected to a lithium battery pack for a DC screen, and a charging power supply of the lithium battery pack is an AC/DC switching power supply of the DC screen; the method comprises the following steps:

Collecting BMS monitoring data;

According to the BMS monitoring data, determining a charge and discharge management state required by the lithium battery pack, wherein the charge and discharge management state comprises any one of the following: a charge management state and a discharge management state;

If the charge and discharge management state is the charge management state, carrying out charge control management on the lithium battery pack according to the direct current screen AC/DC switching power supply;

if the charge-discharge management state is the discharge management state, performing discharge control management on the lithium battery pack

In a second aspect, an embodiment of the present application provides a charge and discharge management device, which is applied to an energy storage battery management system, where the energy storage battery management system is connected to a lithium battery pack for a DC screen, and a charging power supply of the lithium battery pack is the DC screen AC/DC switching power supply; the device comprises:

the acquisition unit is used for acquiring BMS monitoring data;

And the determining unit is used for determining a charge and discharge management state required by the lithium battery pack according to the BMS monitoring data, wherein the charge and discharge management state comprises any one of the following: a charge management state and a discharge management state;

the charging management unit is used for carrying out charging control management on the lithium battery pack according to the direct current screen AC/DC switching power supply if the charging and discharging management state is the charging management state;

And the discharging management unit is used for carrying out discharging control management on the lithium battery pack if the charging and discharging management state is the discharging management state.

In a third aspect, an embodiment of the present application provides an electronic device, including a processor, a memory, a communication interface, and one or more programs, where the one or more programs are stored in the memory and configured to be executed by the processor, and the programs include instructions for executing some or all of the steps described in the first aspect of the embodiment of the present application.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium storing a computer program for electronic data exchange, wherein the computer program causes a computer to perform part or all of the steps described in the first aspect of the embodiments of the present application.

In a fifth aspect, embodiments of the present application provide a computer program product, wherein the computer program product comprises a non-transitory computer readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps described in the first aspect of the embodiments of the present application. The computer program product may be a software installation package.

The charge and discharge management method described in the embodiment of the application collects BMS monitoring data; according to BMS monitoring data, determining a charge and discharge management state required by the lithium battery pack, wherein the charge and discharge management state comprises any one of the following: a charge management state and a discharge management state; if the charge and discharge management state is the charge management state, carrying out charge control management on the lithium battery pack according to the direct current screen AC/DC switching power supply; and if the charge and discharge management state is the discharge management state, performing discharge control management on the lithium battery pack. Therefore, the lithium battery pack is adopted in the power direct-current screen power supply, the working mode of the direct-current screen AC/DC switching power supply is not changed, and the charge and discharge management of the direct-current screen is realized according to the direct-current screen AC/DC switching power supply, so that the service life of the lithium battery is prolonged, and the power supply reliability is improved.

Drawings

In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a DC power module according to an embodiment of the present application;

fig. 2 is a schematic diagram of a charge and discharge management system according to an embodiment of the present application;

fig. 3 is a schematic flow chart of a charge and discharge management method according to an embodiment of the present application;

Fig. 4 is a schematic diagram of a relationship between charge and discharge time and voltage of a lithium battery pack according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application;

fig. 6 is a functional unit composition block diagram of a charge and discharge management device according to an embodiment of the present application.

Detailed Description

In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terms first, second and the like in the description and in the claims and in the above-described figures are used for distinguishing between different objects and not necessarily for describing a sequential or chronological order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to the list of steps or elements but may include, in one possible example, other steps or elements not listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

The direct current screen power supply system in the power industry generally adopts a lead-acid storage battery as a backup energy storage unit, the charging and discharging of the lead-acid storage battery are controlled by a direct current screen AC/DC switch power supply (module), the switching between the uniform charging and the floating charging is automatically controlled by a switch power supply monitoring module, the charging and discharging use of the lead-acid storage battery can be met, and the actual service life of the lead-acid storage battery is 4-5 years. The direct current load of the transformer substation, the switching station and the battery pack are directly hung on the direct current screen charging and discharging bus, the charging and discharging management method is limited, and the method can only be applied to the lead-acid battery in a mode of uniformly charging and then floating charging.

At present, lithium Battery energy storage is generally adopted for industrial and commercial energy storage and large container energy storage, and an industrial and commercial energy storage and large container energy storage management system (Battery MANAGEMENT SYSTEM, BMS) can conduct charge and discharge management for 1 time or 2 times each day aiming at an energy storage converter (Power Conversion System, PCS), a direct current screen power supply in the power industry belongs to a standby power supply, and charge and discharge are conducted only when an external power grid is abnormal, and most of time is in a standby power state, so that the BMS management system needs to adjust a management strategy to meet the requirements of a lithium Battery pack of the standby power supply; and the application of the lithium battery of the standby power supply on the direct current screen in the power industry is short in time, no corresponding standard and specification exist, if the management standard and specification of the lead-acid battery screen cabinet are still applied, the charging mode of the lead-acid battery in the original direct current screen is not suitable for charging and discharging of the lithium battery, the service life and the circulation times of the lithium battery are damaged by long-term floating charge, and the lithium battery pack is not beneficial to long-term stable operation.

In order to solve the above problems, the present application provides a charge and discharge management method and apparatus, which are described in detail below.

Referring to fig. 1, fig. 1 is a schematic diagram of a dc power supply module according to an embodiment of the application. The direct current power supply module schematic diagram comprises a lithium battery pack, a charging cabinet AC (alternating current)/DC (direct current), a power supply selection switch, a DC/DC power supply, an energy storage battery management system BMS, a display control module and a 4G communication module.

For example, the BMS is powered by 24V direct current, and is powered by 2 paths from a DC/DC power module, and the main lithium battery pack is always positive and negative (B+ \B-). When the battery in the lithium battery pack is abnormal (the storage time may be too long, the battery is self-discharged, so that the voltage of the battery pack is extremely low, for example, lower than 150VDC, or the battery pack is over-discharged), the battery pack is extremely low, and after the charging cabinet AC/DC is started, a user can manually select the charging cabinet AC/DC power module to supply power through the power selection switch, so that the BMS system works. And the lithium battery pack is charged by forced opening under the abnormal condition, so that the lithium battery pack is charged, and when the voltage of the lithium battery pack is increased to the normal voltage (200V), the battery pack is switched back to the total positive and total negative (B+ \B-) power supply of the lithium battery pack.

Referring to fig. 2, fig. 2 is a schematic diagram of a charge and discharge management system according to an embodiment of the application. The charge and discharge management system can comprise an energy storage battery management system BMS, a lithium battery pack and a direct current screen AC/DC switching power supply.

The energy storage battery management system BMS is connected with the lithium battery pack and the direct current screen AC/DC switching power supply.

Wherein, BMS can be used to gather at least one BMS control data among the charge-discharge management system as follows: the number of charge and discharge cycles, the number of parallel battery packs in the lithium battery pack, the number of module series in the lithium battery pack, the number of battery cell series, the maximum charge voltage value of the lithium battery pack, the maximum charge current value of the lithium battery pack, the minimum discharge voltage value of the lithium battery pack, the maximum discharge current value of the lithium battery pack, the number of battery parallel cabinets, the number of battery module, the number of battery cells/batteries of the lithium battery pack, the total voltage of the lithium battery pack, the total current of the lithium battery pack, the main control temperature, the remaining electric quantity SOC, the state of health SOH, the remaining capacity, the module voltage, the highest cell voltage, the lowest cell voltage, the highest cell voltage number, the lowest cell voltage number, the highest cell temperature, the lowest cell temperature number, the fault code, the electric flag bit, the electric current condition, the sleep time, and the like are not limited herein.

As shown below, the basic state of the lithium battery pack in the present application is briefly explained:

1. sleep state: and the battery is not charged and discharged.

2. State of charge: the battery has a charging current of more than or equal to 100 mA.

3. Homogeneous charge state: when the battery power is low (can set), the even charging zone bit can appear.

4. Floating state: when the battery is charged to a certain voltage (can be set), the even charging zone bit can appear.

5. Discharge state: the battery has a discharge current of not less than 100 mA.

6. Alarm state: the state may not be used as a logical process when the protocol interfaces. The battery system can report an alarm in the states of high temperature, low temperature, high voltage, low voltage, high current, low SOC and the like. But does not affect the system usage, only status event records are made.

7. Protection state: the relay is tripped off and the system is in a protection state due to the occurrence of overvoltage, undervoltage, overtemperature, undertemperature and short circuit of the battery. The protection state is accompanied by alarm information.

8. Fault state: the system detects a fault condition.

9. Standby state: the BMS gets electricity, has no fault and alarm information, and the charging and discharging relays are all disconnected and are not charged or discharged.

Referring to fig. 3, fig. 3 is a flow chart of a charge and discharge management method according to an embodiment of the application; the energy storage battery management system BMS is applied to the energy storage battery management system as shown in fig. 1 or 2, the energy storage battery management system is connected with a lithium battery pack for a direct current screen, and a charging power supply of the lithium battery pack is the direct current screen AC/DC switching power supply; the method comprises the following steps:

And S301, collecting BMS monitoring data.

Wherein, BMS monitoring data that energy storage battery management system gathered includes at least one of: the voltage information, the mains supply condition, the charging current, the total voltage, the highest cell voltage, the lowest cell voltage, and the remaining power SOC parameter of the lithium battery pack, etc., are not limited herein. The BMS monitoring parameters used for determining or evaluating the charge and discharge management states and/or the policies of the charge control management are different.

S302, determining a charge and discharge management state required by the lithium battery pack according to the BMS monitoring data, wherein the charge and discharge management state comprises any one of the following components: a charge management state and a discharge management state.

The energy storage battery management system BMS can determine the charge and discharge management state of the lithium battery pack, and further performs corresponding charge control management or discharge control management on the lithium battery pack according to the charge management state or the discharge management state corresponding to the charge and discharge management state.

And S303, if the charge and discharge management state is the charge management state, carrying out charge control management on the lithium battery pack according to the direct current screen AC/DC switching power supply, wherein the charge control management is used for controlling the lithium battery pack to enter a uniform charge state or a floating charge state or a dormant state.

The lithium battery pack can be subjected to charging control management according to the direct current screen AC/DC switching power supply and part of BMS monitoring data.

The charging control management is used for controlling the lithium battery pack to be in or enter a homogeneous charge state, a float charge state, a dormant state, a charging current limiting state, a charging low-temperature protection state and the like, and is not limited herein.

The lithium battery pack is connected with the direct current screen, and the source of the charging power supply of the lithium battery pack can be a direct current screen AC/DC switching power supply; and the uniform charging or floating charging of the lithium battery pack is determined through the setting of the AC/DC switching power supply of the direct current screen, so that the charging control management of the lithium battery pack is realized.

In specific implementation, the energy storage battery management system BMS can judge the state of the lithium battery pack at this time according to the charging voltage and the charging current, that is, the homogeneous charge state or the float charge state.

And S304, if the charge and discharge management state is the discharge management state, performing discharge control management on the lithium battery pack, wherein the discharge management control is used for controlling the lithium battery pack to enter a low-voltage protection state or a charge prohibition and discharge permission state.

The discharging control management may refer to a strategy that the energy storage battery management system performs discharging management control on the lithium battery pack when the charging and discharging management state is a discharging management state. The above-mentioned charge control management may refer to a policy that the energy storage battery management system performs charge management control on the lithium battery pack when the charge/discharge management state is the charge management state.

The lithium battery pack can be subjected to discharge control management according to the direct current screen AC/DC switching power supply and part of BMS monitoring data.

The above-mentioned discharge management control is used to control the lithium battery pack to be in or enter a low-voltage protection state or allow charge to be forbidden to discharge or discharge to be low-temperature protection state or discharge to limit current, etc., and is not limited herein.

By way of example, the charging process and the discharging process of the lithium battery pack can be managed by controlling the discharging prohibiting MOS tube and the charging prohibiting MOS tube without requiring the action of the charging portion of the direct current screen.

In one possible example, the BMS monitoring data includes voltage information of the lithium battery pack and a utility condition; the method for determining the charge and discharge management state required by the lithium battery pack according to the BMS monitoring data may include the steps of: if the voltage information indicates that the voltage reference value is smaller than or equal to a preset charging voltage value, determining that the charging and discharging management state of the lithium battery pack is the charging management state; and if the commercial power condition indicates that the commercial power is interrupted, determining that the charge and discharge management state of the lithium battery pack is the discharge management state.

The preset charging voltage value may be set by a user or set by the system, which is not limited herein; the voltage reference value may be a minimum single voltage value, or may be a total voltage value, etc., and the setting of the preset charging voltage value is dynamically set according to the voltage information.

For example, when the voltage information in the BMS monitoring data indicates that the voltage reference value (minimum cell voltage value) is less than or equal to a preset charging voltage value corresponding to the minimum cell voltage value, charging of the lithium battery pack is started, and the charge and discharge management state of the lithium battery pack is determined to be the charge management state.

Optionally, the charge and discharge management state may further include a sleep state; for example, if the battery pack is in or enters a sleep state, and if the battery condition in the BMS monitoring data indicates that the battery is interrupted, the charge-discharge management state of the lithium battery may be determined to be a discharge management state; if the commercial power condition in the BMS monitoring data indicates that the commercial power is not interrupted, the charge and discharge management state of the lithium battery can be determined to be a dormant state.

Optionally, after the commercial power is interrupted, when the commercial power condition indicates that the commercial power is recovered, the lithium battery can be controlled to enter a charging management state, namely, the lithium battery pack enters a uniform charging state, a floating charging state and the like according to the direct current screen AC/DC switching power supply.

It can be seen that, in this example, the lithium battery pack is in the charge management state or the discharge management state at this time, so as to implement charge control management or discharge control management for the lithium battery pack, by the BMS monitoring data.

In one possible example, the charging control management of the lithium battery pack according to the DC screen AC/DC switching power supply may include the following steps: controlling the direct current screen AC/DC switching power supply to provide constant current charging for the lithium battery pack, and controlling the lithium battery pack to enter a uniform charging state; if the voltage reference value reaches the set floating charge value of the direct current screen, controlling the direct current screen AC/DC switching power supply to provide constant voltage charge for the lithium battery pack, and controlling the lithium battery pack to enter a floating charge state; acquiring a charging current of the lithium battery pack and a total voltage of the lithium battery pack, which are included in the BMS monitoring data; and if the charging current is 0A and the total voltage is greater than a preset dormant voltage value, controlling the lithium battery pack to enter a dormant state.

The direct current screen setting floating recharging and the preset dormancy voltage value can be set by a user or default by a system, and the direct current screen setting floating recharging and the preset dormancy voltage value are not limited herein; the direct current screen setting floating recharging can be dynamically set according to the setting type of the voltage reference value.

In the specific implementation, when the voltage information in the BMS monitoring data indicates that the voltage reference value (the minimum single voltage value) is smaller than or equal to the preset charging voltage value corresponding to the minimum single voltage value, the direct current screen AC/DC switching power supply can be controlled to provide constant current charging for the lithium battery pack, so that the lithium battery pack is in or enters a uniform charging state; at this time, as the voltage rises at a relatively high speed, when the voltage reference value rises to reach the set floating charging value of the direct current screen, the direct current screen AC/DC switching power supply is controlled to provide constant voltage charging for the lithium battery pack, so that the lithium battery pack is in or enters a floating charging state; at this time, the charging current gradually decreases.

Further, when the charging current is reduced to 0A and the total voltage is greater than the preset sleep voltage value, it indicates that the lithium battery pack reaches the sleep condition, and the lithium battery pack can be further controlled to enter the sleep state.

When the BMS judges that the lithium battery pack is allowed to enter the dormant state, the state is charge inhibition and discharge permission, namely the charging relay is opened, and the discharging relay is closed.

It can be seen that in this example, constant current or constant voltage charging is provided to the lithium battery pack according to the dc screen ACDC, i.e., the lithium battery is caused to be in or enter a transition between a homogeneous charge state and a float charge state. In this way, in the power direct current screen power supply, the working mode of the direct current screen AC/DC switching power supply can not be changed, and the charging control management in the example is adopted, so that the charging management of the direct current screen is improved to meet the management requirement of the lithium battery pack, the service life of the lithium battery pack is prolonged, and the power supply reliability is improved.

In one possible example, the method may further include the steps of: when the lithium battery enters the uniform charge state or the floating charge state, the highest single battery voltage in the lithium battery pack included in the BMS monitoring data is obtained; and if the highest single battery voltage is larger than a preset single overvoltage voltage value or the total voltage is larger than a preset total voltage overvoltage value, controlling the lithium battery pack to enter an overvoltage protection state.

The preset single overvoltage voltage value and the preset total overvoltage value can be set by a user or default by a system, and are not limited herein.

In the specific implementation, if only a single battery cell or a battery is higher than a preset single overvoltage voltage value or the total voltage of the lithium battery pack is higher than the preset total voltage overvoltage value, the lithium battery pack is judged to enter an overvoltage protection state, at the moment, charging is forbidden to allow discharging, namely a charging relay is opened, a discharging relay is closed, and meanwhile, a high-voltage alarm is triggered.

Further, when the highest cell voltage is less than or equal to the preset charging voltage value (for example, may be set to 3.4V), the chargeable state may be restored, the charging relay may be closed, and the high voltage alarm may be released.

It can be seen that, in this example, BMS can further obtain the highest battery cell voltage and the total voltage of lithium cell group in the lithium cell group that BMS monitored data included, when either one of them excessive pressure, then steerable lithium cell group gets into overvoltage protection state to, in electric power direct current screen power, can not change direct current screen AC/DC switching power supply's mode, adopt the charge control management in this example, improve the charge management of direct current screen in order to satisfy the management requirement of lithium cell group, be favorable to improving lithium cell group's life, be favorable to improving the power supply reliability.

In one possible example, the method may further include the steps of: acquiring sleep time included in the BMS monitoring data; and if the sleep time reaches the preset longest sleep time or the total voltage is smaller than the preset wake-up sleep voltage value, controlling the lithium battery to enter a charge-allowing discharge-allowing state and enter the uniform charge state.

The preset maximum sleep time and the preset wake-up sleep voltage value may be set by the user or default by the system, which is not limited herein.

When the BMS monitors that the lithium battery pack enters a floating charge state, the charging current gradually decreases, and when the battery pack reaches a sleep condition, the battery pack is controlled to enter the sleep state; and continuously monitoring the sleep time of the lithium battery pack in or entering the sleep state, when the sleep time reaches the preset longest sleep time or the total voltage is smaller than the preset wake-up sleep voltage value, indicating that the wake-up condition of the lithium battery pack is met, further waking up the lithium battery, controlling the lithium battery to enter a state allowing charge and discharge and enter a state allowing charge and discharge, enabling the duration of the state in charge to be shorter, entering a floating charge again, and repeating the steps.

In this example, when the BMS detects that the sleep time reaches the preset maximum sleep time or the total voltage is smaller than the preset wake-up sleep voltage value, it is determined that the condition of waking up the lithium battery pack is met, and the lithium battery is controlled to enter a state allowing charge and discharge and enter the homogeneous charge state. In this way, in the power direct current screen power supply, the working mode of the direct current screen AC/DC switching power supply can not be changed, and the charging control management in the example is adopted, so that the charging management of the direct current screen is improved to meet the management requirement of the lithium battery pack, the service life of the lithium battery pack is prolonged, and the power supply reliability is improved.

Optionally, in the charge management control process, when the BMS detects that the temperature of the lowest unit cell (or battery) included in the BMS monitoring data is less than or equal to the preset charge lowest unit cell temperature (for example, may be set to 0 ℃), the charging low temperature protection state is entered, that is, the discharging relay is controlled to be turned off, and the charging low temperature alarm is triggered. And releasing the charge low-temperature alarm and controlling the discharge relay to be closed until the lowest monomer temperature is greater than or equal to the preset charge release monomer battery low-temperature alarm temperature (for example, 5 ℃ can be set).

Optionally, in the process of charge management control, two modes of charge current limiting and discharge current limiting can be set; for the charging current limiting mode, the BMS can set the maximum allowable charging current value according to the specification of the battery cell, and set three-level limiting current and time, such as for any battery cell, the primary charging current limiting 145A,30 minutes, the secondary current limiting 145-200A, 10 seconds, and the three-level current limiting is more than 200A for instantaneous protection. For discharge current limiting mode: the BMS sets the maximum allowable discharge current value according to the specification of the battery cell, and sets three-level limiting current and time, such as primary discharge current limiting 145A,30 minutes, secondary discharge current limiting 145-200A, 10 seconds, three-level discharge current limiting > 200A instant protection and the like.

In one possible example, the BMS monitoring data further includes at least one of: the lowest single battery voltage and the residual electric quantity SOC parameter; the method for performing discharge control management on the lithium battery pack comprises the following steps: in the discharging process of the lithium battery pack, if the SOC parameter reaches a first preset value or the lowest single battery voltage reaches a first preset single voltage value, controlling the lithium battery pack to enter a low-voltage protection state; and monitoring the SOC parameter and the lowest single battery voltage until the SOC parameter is greater than or equal to a second preset value or the lowest single battery voltage is greater than or equal to a second preset single voltage value, and controlling the lithium battery pack to enter a charge-allowable discharge-forbidden state, wherein the second preset value is greater than a first preset value, and the second preset single voltage value is greater than the first preset single voltage value.

The first preset value, the second preset value, the first preset single voltage value, and the second preset single voltage value may be set by the user or default by the system, which is not limited herein.

For example, the first preset value may be set to 0%, and the second preset value may be set to 15%; the first preset cell voltage value may be set to 2.65V and the second preset cell voltage value may be set to 3.05V.

In a specific implementation, when the SOC parameter reaches a first preset value, or the lowest cell voltage reaches a first preset cell voltage value, a discharge stopping signal is triggered, and after a preset period (for example, 2s, 3s, 5s, etc.), the discharge relay is opened, and a mortgage protection state is entered, where the state is that charging is allowed to be prohibited, that is, the discharge relay is opened, and the charge relay is closed.

And monitoring the change condition of the SOC parameter and the lowest single battery voltage until the SOC parameter is greater than or equal to a second preset value or the lowest single battery voltage is greater than or equal to the second preset single voltage value, controlling the discharge relay to be closed again, and controlling the lithium battery pack to enter a state allowing charge and discharge, wherein in the process, a low-voltage alarm can be kept.

It can be seen that, in this example, it is possible to determine whether the lithium battery pack needs to enter a low-voltage protection state and whether to release the low-voltage protection state to enter a charge-permitted discharge-prohibited state according to the lowest cell (core) voltage and the remaining capacity SOC parameter included in the BMS monitoring data. Therefore, in the power direct-current screen power supply, the working mode of the direct-current screen AC/DC switching power supply can not be changed, and the discharge control management in the example is adopted, so that the discharge management of the direct-current screen is improved to meet the management requirement of the lithium battery pack, and the service life of the lithium battery pack is prolonged.

In one possible example, the method further comprises the steps of: triggering a low-voltage flag bit and a battery voltage low warning when the SOC parameter reaches a third preset value or the lowest single battery voltage reaches a third preset single voltage value; and stopping the battery voltage low warning when the SOC parameter is greater than or equal to the second preset value or the lowest single battery voltage is greater than or equal to the second preset single voltage value, wherein the third preset single voltage value is smaller than the second preset single voltage value and greater than the first preset single voltage value, and the third preset value is smaller than the second preset value and greater than the first preset value.

The third preset value and the third preset single voltage value may be set by the user or default by the system, which is not limited herein.

For example, the third preset value may be set to 10%, and the third preset cell voltage value may be set to 2.95V.

In the specific implementation, when the SOC parameter, i.e. the residual electric quantity of the lithium battery pack is discharged to a third preset value, or the voltage of the lowest single battery reaches the third preset single voltage value, a low-voltage flag bit and a battery voltage low warning are triggered, and at the moment, under-voltage protection is not achieved yet, only warning is possible to be disabled; and stopping the battery voltage low warning when the SOC parameter is greater than or equal to a second preset value or the lowest single battery voltage is greater than or equal to the second preset single voltage value.

It can be seen that, in this example, the BMS system can determine whether to trigger the low voltage flag bit and the battery voltage low warning, and properly stop the battery voltage low warning through the SOC parameter and the lowest cell voltage battery, which is beneficial to restrict the discharge management of the lithium battery pack. Therefore, in the power direct-current screen power supply, the working mode of the direct-current screen AC/DC switching power supply can not be changed, and the discharge control management in the example is adopted, so that the discharge management of the direct-current screen is improved to meet the management requirement of the lithium battery pack, and the service life of the lithium battery pack is prolonged.

Optionally, in the discharge management control process, when the BMS detects that the temperature of the lowest unit cell (or battery) included in the BMS monitoring data is less than or equal to the preset discharge lowest unit cell temperature (for example, can be set to-20 ℃), the BMS enters a low-temperature protection state, that is, controls the discharge relay to be turned off, and triggers a discharge low-temperature alarm. And (3) until the lowest monomer temperature is greater than or equal to the preset low-temperature warning temperature (for example, -10 ℃) of the discharging releasing monomer battery, releasing the discharging low-temperature warning, and controlling the closing of the discharging relay.

For example, as shown in fig. 4, a schematic diagram of a relationship between charge and discharge time and voltage of a lithium battery pack is shown, and in the above-mentioned charge management control method, when BMS monitoring data such as a highest cell voltage or a total voltage of the lithium battery pack meets a certain condition, the BMS can control the lithium battery pack to enter different states, for example, when a voltage reference value is smaller than a preset charge voltage value (V0), the lithium battery pack can be caused to enter a homogeneous charge state; at the moment, the voltage rises until the voltage is larger than the set floating charging value (V1) of the direct current screen, so that the lithium battery pack can enter a floating charging state; when the total voltage of the lithium battery pack is larger than a preset dormancy voltage value (V2), controlling the lithium battery pack to enter a dormancy state, and when the total voltage value is smaller than a preset awakening dormancy voltage value (V3), awakening the lithium battery pack, uniformly charging the lithium battery pack, and performing floating charging.

Further, as shown in fig. 4, for example, when the total voltage value of the lithium battery pack reaches the preset discharge voltage value (V4), the lithium battery pack may be controlled to enter a discharge state, that is, the discharge control management is performed on the lithium battery pack.

It should be noted that, in the above embodiment, the preset sleep voltage value (V2) is greater than the dc screen set floating recharge value (V1), the preset wake-up sleep voltage value (V3) is less than the preset sleep voltage value (V2), the preset discharge voltage value (V4) is greater than the preset wake-up sleep voltage value (V3), and the preset discharge voltage value (V4) is less than the preset sleep voltage value (V2).

It can be seen that, in the charge and discharge management method described in the embodiment of the present application, BMS monitoring data is collected; according to BMS monitoring data, determining a charge and discharge management state required by the lithium battery pack, wherein the charge and discharge management state comprises any one of the following: a charge management state and a discharge management state; if the charge and discharge management state is the charge management state, carrying out charge control management on the lithium battery pack according to the direct current screen AC/DC switching power supply; and if the charge and discharge management state is the discharge management state, performing discharge control management on the lithium battery pack. Therefore, the lithium battery pack is adopted in the power direct-current screen power supply, the working mode of the direct-current screen AC/DC switching power supply is not changed, and the charge and discharge management of the direct-current screen is realized according to the direct-current screen AC/DC switching power supply, so that the service life of the lithium battery is prolonged, and the power supply reliability is improved.

In accordance with the above embodiment, referring to fig. 5, fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application, where the electronic device is applied to an energy storage battery management system, the energy storage battery management system is connected to a lithium battery pack for a DC screen, and a charging power supply of the lithium battery pack is the DC screen AC/DC switching power supply; as shown in fig. 5, the electronic device includes a processor, a memory, a communication interface, and one or more programs stored in the memory and configured to be executed by the processor, the programs including instructions for performing the steps of:

Collecting BMS monitoring data;

And if the charge and discharge management state is the discharge management state, performing discharge control management on the lithium battery pack.

In one possible example, the BMS monitoring data includes voltage information of the lithium battery pack and a utility condition; in the aspect of determining a charge and discharge management state required for the lithium battery pack according to the BMS monitoring data, the above-described program includes instructions for performing the steps of:

If the voltage information indicates that the voltage reference value is smaller than or equal to a preset charging voltage value, determining that the charging and discharging management state of the lithium battery pack is the charging management state;

and if the commercial power condition indicates that the commercial power is interrupted, determining that the charge and discharge management state of the lithium battery pack is the discharge management state.

In one possible example, the charging control management aspect of the lithium battery pack according to the DC screen AC/DC switching power supply includes instructions for performing the following steps:

Controlling the direct current screen AC/DC switching power supply to provide constant current charging for the lithium battery pack, and controlling the lithium battery pack to enter a uniform charging state;

If the voltage reference value reaches the set floating charge value of the direct current screen, controlling the direct current screen AC/DC switching power supply to provide constant voltage charge for the lithium battery pack, and controlling the lithium battery pack to enter a floating charge state;

Acquiring a charging current of the lithium battery pack and a total voltage of the lithium battery pack, which are included in the BMS monitoring data;

and if the charging current is 0A and the total voltage is greater than a preset dormant voltage value, controlling the lithium battery pack to enter a dormant state.

In one possible example, the above-described program further includes instructions for performing the steps of:

when the lithium battery enters the uniform charge state or the floating charge state, the highest single battery voltage in the lithium battery pack included in the BMS monitoring data is obtained;

and if the highest single battery voltage is larger than a preset single overvoltage voltage value or the total voltage is larger than a preset total voltage overvoltage value, controlling the lithium battery pack to enter an overvoltage protection state.

Acquiring sleep time included in the BMS monitoring data;

And if the sleep time reaches the preset longest sleep time or the total voltage is smaller than the preset wake-up sleep voltage value, controlling the lithium battery to enter a charge-allowing discharge-allowing state and enter the uniform charge state.

In one possible example, the BMS monitoring data further includes at least one of: the lowest single battery voltage and the residual electric quantity SOC parameter; the discharging control management is performed on the lithium battery pack, and the program comprises instructions for executing the following steps:

in the discharging process of the lithium battery pack, if the SOC parameter reaches a first preset value or the lowest single battery voltage reaches a first preset single voltage value, controlling the lithium battery pack to enter a low-voltage protection state;

And monitoring the SOC parameter and the lowest single battery voltage until the SOC parameter is greater than or equal to a second preset value or the lowest single battery voltage is greater than or equal to a second preset single voltage value, and controlling the lithium battery pack to enter a charge-allowable discharge-forbidden state, wherein the second preset value is greater than a first preset value, and the second preset single voltage value is greater than the first preset single voltage value.

Triggering a low-voltage flag bit and a battery voltage low warning when the SOC parameter reaches a third preset value or the lowest single battery voltage reaches a third preset single voltage value;

And stopping the battery voltage low warning when the SOC parameter is greater than or equal to the second preset value or the lowest single battery voltage is greater than or equal to the second preset single voltage value, wherein the third preset single voltage value is smaller than the second preset single voltage value and greater than the first preset single voltage value, and the third preset value is smaller than the second preset value and greater than the first preset value.

It can be seen that the electronic device described in the embodiment of the present application collects BMS monitoring data; according to BMS monitoring data, determining a charge and discharge management state required by the lithium battery pack, wherein the charge and discharge management state comprises any one of the following: a charge management state and a discharge management state; if the charge and discharge management state is the charge management state, carrying out charge control management on the lithium battery pack according to the direct current screen AC/DC switching power supply; and if the charge and discharge management state is the discharge management state, performing discharge control management on the lithium battery pack. Therefore, the lithium battery pack is adopted in the power direct-current screen power supply, the working mode of the direct-current screen AC/DC switching power supply is not changed, and the charge and discharge management of the direct-current screen is realized according to the direct-current screen AC/DC switching power supply, so that the service life of the lithium battery is prolonged, and the power supply reliability is improved.

Fig. 6 is a functional unit block diagram of a charge and discharge management device 600 according to an embodiment of the present application, which is applied to an energy storage battery management system, where the energy storage battery management system is connected to a lithium battery pack for a DC screen, and a charging power supply of the lithium battery pack is the DC screen AC/DC switching power supply; the charge and discharge management apparatus 600 includes: an acquisition unit 601, a determination unit 602, a charge management unit 603 and a discharge management unit 604, wherein,

The collection unit 601 is configured to collect BMS monitoring data;

the determining unit 602 is configured to determine, according to the BMS monitoring data, a charge and discharge management state required by the lithium battery pack, where the charge and discharge management state includes any one of the following: a charge management state and a discharge management state;

The charging management unit 603 is configured to perform charging control management on the lithium battery pack according to the DC screen AC/DC switching power supply if the charging/discharging management state is the charging management state;

the discharge management unit 604 is configured to perform discharge control management on the lithium battery pack if the charge and discharge management state is the discharge management state.

In one possible example, the BMS monitoring data includes voltage information of the lithium battery pack and a utility condition; in the aspect of determining the charge and discharge management state required by the lithium battery pack according to the BMS monitoring data, the determining unit 602 is specifically configured to:

In one possible example, in terms of the charge control management of the lithium battery pack according to the DC-screen AC/DC switching power supply, the charge management unit 603 is specifically configured to:

In one possible example, the above-mentioned charging management unit 603 is specifically further configured to:

Acquiring sleep time included in the BMS monitoring data;

In one possible example, the BMS monitoring data further includes at least one of: the lowest single battery voltage and the residual electric quantity SOC parameter; the discharging control unit 604 is specifically configured to:

In one possible example, the discharge management unit 604 is specifically further configured to:

It can be seen that the charge and discharge management device described in the embodiment of the application collects BMS monitoring data; according to BMS monitoring data, determining a charge and discharge management state required by the lithium battery pack, wherein the charge and discharge management state comprises any one of the following: a charge management state and a discharge management state; if the charge and discharge management state is the charge management state, carrying out charge control management on the lithium battery pack according to the direct current screen AC/DC switching power supply; and if the charge and discharge management state is the discharge management state, performing discharge control management on the lithium battery pack. Therefore, the lithium battery pack is adopted in the power direct-current screen power supply, the working mode of the direct-current screen AC/DC switching power supply is not changed, and the charge and discharge management of the direct-current screen is realized according to the direct-current screen AC/DC switching power supply, so that the service life of the lithium battery is prolonged, and the power supply reliability is improved.

It can be understood that the functions of each program module of the charge and discharge management apparatus of the present embodiment may be specifically implemented according to the method in the foregoing method embodiment, and the specific implementation process may refer to the relevant description of the foregoing method embodiment, which is not repeated herein.

The embodiment of the application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, and the computer program makes a computer execute part or all of the steps of any one of the above method embodiments, and the computer includes an electronic device.

Embodiments of the present application also provide a computer program product comprising a non-transitory computer-readable storage medium storing a computer program operable to cause a computer to perform part or all of the steps of any one of the methods described in the method embodiments above. The computer program product may be a software installation package, said computer comprising an electronic device.

It should be noted that, for simplicity of description, the foregoing method embodiments are all described as a series of acts, but it should be understood by those skilled in the art that the present application is not limited by the order of acts described, as some steps may be performed in other orders or concurrently in accordance with the present application. Further, those skilled in the art will also appreciate that the embodiments described in the specification are all preferred embodiments, and that the acts and modules referred to are not necessarily required for the present application.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, such as the above-described division of units, merely a division of logic functions, and there may be additional manners of dividing in actual implementation, such as multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, or may be in electrical or other forms.

The units described above as separate components may or may not be physically separate, and components shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units described above, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable memory. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a memory, comprising several instructions for causing a computer device (which may be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the above-mentioned method of the various embodiments of the present application. And the aforementioned memory includes: a usb disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Those of ordinary skill in the art will appreciate that all or a portion of the steps in the various methods of the above embodiments may be implemented by a program that instructs associated hardware, and the program may be stored in a computer readable memory, which may include: flash disk, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic disk or optical disk.

The foregoing has outlined rather broadly the more detailed description of embodiments of the application, wherein the principles and embodiments of the application are explained in detail using specific examples, the above examples being provided solely to facilitate the understanding of the method and core concepts of the application; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present application, the present description should not be construed as limiting the present application in view of the above.

Claims

1. The charge and discharge management method is characterized by being applied to an energy storage battery management system, wherein the energy storage battery management system is connected with a lithium battery pack used for a direct current screen, and a charging power supply of the lithium battery pack is an AC/DC switching power supply of the direct current screen; the method comprises the following steps:

Collecting BMS monitoring data, wherein the BMS monitoring data comprises at least one of the following: the lithium battery pack comprises voltage information, a mains supply condition, a charging current, a total voltage, a highest single battery voltage, a lowest single battery voltage and a residual electric quantity SOC parameter;

If the charge and discharge management state is the charge management state, carrying out charge control management on the lithium battery pack according to the direct current screen AC/DC switching power supply, wherein the charge control management is used for controlling the lithium battery pack to enter a uniform charge state or a floating charge state or a dormant state;

And if the charge and discharge management state is the discharge management state, performing discharge control management on the lithium battery pack, wherein the discharge management control is used for controlling the lithium battery pack to enter a low-voltage protection state or a charge permission and discharge prohibition state.

2. The method of claim 1, wherein the BMS monitoring data includes voltage information of the lithium battery pack and a utility condition; the determining the charge and discharge management state required by the lithium battery pack according to the BMS monitoring data includes:

3. The method of claim 2, wherein said performing charge control management on said lithium battery pack according to said direct current screen AC/DC switching power supply comprises:

4. A method according to claim 3, characterized in that the method further comprises:

5. The method according to claim 3 or 4, characterized in that the method further comprises:

Acquiring sleep time included in the BMS monitoring data;

6. The method of claim 2, wherein the BMS monitoring data further comprises at least one of: the lowest single battery voltage and the residual electric quantity SOC parameter; the discharging control management of the lithium battery pack comprises the following steps:

7. The method of claim 6, wherein the method further comprises:

8. The charging and discharging management device is characterized by being applied to an energy storage battery management system, wherein the energy storage battery management system is connected with a lithium battery pack used for a direct current screen, and a charging power supply of the lithium battery pack is an AC/DC switching power supply of the direct current screen; the device comprises:

the acquisition unit is used for acquiring BMS monitoring data;

9. An electronic device comprising a processor, a memory for storing one or more programs and configured to be executed by the processor, the programs comprising instructions for performing the steps in the method of any of claims 1-7.

10. A computer-readable storage medium, characterized in that a computer program for electronic data exchange is stored, wherein the computer program causes a computer to perform the method according to any one of claims 1-7.