CN113872301A - Charging and discharging control method and device for energy storage system of series battery pack and energy storage system - Google Patents
Charging and discharging control method and device for energy storage system of series battery pack and energy storage system Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J15/00—Systems for storing electric energy
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
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Abstract
The invention discloses a charge-discharge control method and device for an energy storage system of a series battery pack and the energy storage system, belonging to the field of energy storage systems; firstly, acquiring the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value, and when the maximum pressure difference is greater than the initial pressure difference protection threshold value, adjusting the pressure difference protection threshold value from the initial pressure difference protection threshold value to a target pressure difference protection threshold value, namely increasing the pressure difference protection threshold value; and then controlling the charging and discharging of the energy storage system according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value. According to the scheme, the differential pressure protection threshold value is not a fixed value, when the maximum differential pressure is larger than the initial differential pressure protection threshold value, the charging and discharging of the energy storage system can not be immediately disconnected, the differential pressure protection threshold value is increased firstly, then the charging and discharging of the energy storage system are further controlled according to the size relation between the maximum differential pressure and the target differential pressure protection threshold value, and the utilization efficiency of each battery in the energy storage system is improved on the premise that each battery in the energy storage system can not be overcharged or overdischarged.
Description
Technical Field
The invention relates to the field of energy storage systems, in particular to a charging and discharging control method and device for an energy storage system of a series battery pack and the energy storage system.
Background
The energy storage system plays an important role in the light storage direct current system, and particularly under an off-grid condition, the energy storage system is an indispensable equipment unit. In the conventional energy storage system, batteries are generally connected in series, but the phenomenon of inconsistent internal resistance of the batteries is inevitably caused due to reasons such as control of the production process of the batteries, and the phenomenon of inconsistent voltage among the batteries connected in series is directly reflected in the energy storage system to form battery pressure difference. When the voltage difference of the battery is too large, the overcharge or the overdischarge of the battery can be caused during the charge and the discharge, and the service life of the battery is influenced.
Therefore, the energy storage system is provided with a differential pressure protection threshold value when in use, and when the differential pressure reaches the differential pressure protection threshold value, the energy storage system can disconnect the output contactor, cut off the external electric energy output and start the balance control so as to reduce the battery differential pressure.
The pressure difference protection threshold value is set to be a fixed value in the existing energy storage system, and is unchanged in the use process of the energy storage system, so that the energy storage system can normally work under any condition, the pressure difference protection threshold value is set to be small, under some conditions, even if the pressure difference is greater than the pressure difference protection threshold value, the energy storage system still can normally work, the external electric energy output can be directly disconnected according to the control mode of the existing energy storage system, and the use efficiency of the energy storage system is not high.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a charging and discharging control method and device of an energy storage system of a series battery pack and the energy storage system, and aims to solve the problems that the differential pressure protection threshold is set to be a fixed value and the use efficiency of the energy storage system is not high in the control mode of the prior energy storage system.
The technical scheme adopted by the invention for solving the technical problems is as follows:
in a first aspect,
a charge-discharge control method for an energy storage system of a series battery pack comprises the following steps:
acquiring the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value;
when the maximum differential pressure is larger than the initial differential pressure protection threshold value, adjusting the differential pressure protection threshold value from the initial differential pressure protection threshold value to a target differential pressure protection threshold value, wherein the target differential pressure protection threshold value is larger than the initial differential pressure protection threshold value;
and controlling the energy storage system to charge and discharge according to the magnitude relation between the maximum pressure difference and the target pressure difference protection threshold value.
Further, the obtaining the maximum voltage difference between the batteries of the energy storage system includes:
acquiring the highest voltage value and the lowest voltage value of a battery in the energy storage system;
and obtaining the maximum pressure difference by subtracting the highest voltage value from the lowest voltage value.
Further, when the energy storage system is charged, the adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to the target differential pressure protection threshold comprises:
acquiring a charge cut-off voltage value of the energy storage system;
obtaining a charging difference value by subtracting the highest voltage value from the charging cut-off voltage value;
and obtaining a target differential pressure protection threshold value according to the charging difference value and the initial differential pressure protection threshold value.
Further, the obtaining a target differential pressure protection threshold value according to the charging difference value and the initial differential pressure protection threshold value comprises:
and summing one half of the charging difference value with the initial differential pressure protection threshold value to obtain a target differential pressure protection threshold value.
Further, when the energy storage system is discharged, the adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to the target differential pressure protection threshold includes:
acquiring a discharge cut-off voltage value of the energy storage system;
the discharge cut-off voltage value is differed from the lowest voltage value to obtain a discharge difference value;
and obtaining a target differential pressure protection threshold value according to the discharge difference value and the initial differential pressure protection threshold value.
Further, the obtaining a target differential pressure protection threshold value according to the discharge difference value and the initial differential pressure protection threshold value includes:
and summing one half of the discharge difference value with the initial differential pressure protection threshold value to obtain a target differential pressure protection threshold value.
Further, when the energy storage system is charged, the controlling the charging and discharging of the energy storage system according to the magnitude relation between the maximum differential pressure and the target differential pressure protection threshold value comprises:
when the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the charging power of the energy storage system for charging, and balancing through a BMS (battery management system) of the energy storage system;
and when the maximum pressure difference is greater than the target pressure difference protection threshold value, controlling the energy storage system to stop charging, and balancing through a BMS (battery management system) of the energy storage system.
Further, the reducing the charging power of the energy storage system for charging includes: and reducing the charging power to half for charging.
Further, when the energy storage system discharges, the controlling of charging and discharging of the energy storage system according to the magnitude relation between the maximum differential pressure and the target differential pressure protection threshold value includes:
when the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the discharging power of the energy storage system for discharging, and balancing through a BMS (battery management system) of the energy storage system;
and when the maximum pressure difference is greater than the target pressure difference protection threshold value, controlling the energy storage system to stop discharging, and balancing through a BMS (battery management system) of the energy storage system.
Further, the reducing the discharge power of the energy storage system for discharging includes: and reducing the discharge power to half for discharging.
Further, still include: and after the balancing of the BMS of the energy storage system is finished, adjusting the differential pressure protection threshold value from a target differential pressure protection threshold value to an initial differential pressure protection threshold value.
In a second aspect of the present invention,
a charge-discharge control device for an energy storage system of a series battery pack comprises:
the parameter acquisition module is used for acquiring the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value;
the threshold adjusting module is used for adjusting the pressure difference protection threshold from an initial pressure difference protection threshold to a target pressure difference protection threshold when the maximum pressure difference is larger than the initial pressure difference protection threshold, and the target pressure difference protection threshold is larger than the initial pressure difference protection threshold;
and the system control module is used for controlling the charging and discharging of the energy storage system according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value.
In a third aspect,
an energy storage system, comprising:
a processor;
a memory for storing the processor-executable instructions;
the processor is configured to be used in the method according to the first aspect.
Has the advantages that:
the technical scheme of the application provides a charge-discharge control method, a charge-discharge control device and an energy storage system of a series battery pack energy storage system, wherein the method comprises the steps of firstly obtaining the maximum pressure difference among batteries of the energy storage system and an initial pressure difference protection threshold value, and when the maximum pressure difference is larger than the initial pressure difference protection threshold value, adjusting the pressure difference protection threshold value from the initial pressure difference protection threshold value to a target pressure difference protection threshold value, namely increasing the pressure difference protection threshold value; and then controlling the charging and discharging of the energy storage system according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value. According to the scheme, the differential pressure protection threshold is not a fixed value, and when the maximum differential pressure is not greater than the initial differential pressure protection threshold, the differential pressure protection threshold is the initial differential pressure protection threshold; and when the maximum pressure difference is greater than the initial pressure difference protection threshold value, the pressure difference protection threshold value is increased to become a target pressure difference protection threshold value, and then the energy storage system is controlled to charge and discharge according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value. Therefore, when the maximum pressure difference is larger than the initial pressure difference protection threshold value, the charging and discharging of the energy storage system cannot be immediately disconnected, the pressure difference protection threshold value is increased, the charging and discharging of the energy storage system are further controlled according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value, and the utilization efficiency of each battery in the energy storage system is improved on the premise that each battery in the energy storage system cannot be overcharged or overdischarged.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a flowchart of a charge and discharge control method for an energy storage system of a series battery pack according to an embodiment of the present invention;
fig. 2 is a flowchart of a specific charge-discharge control method for an energy storage system of a series battery pack according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an energy storage system according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a charge and discharge control device of an energy storage system of a series battery pack according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following detailed description of the technical solutions of the present invention is provided with reference to the accompanying drawings and examples. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without making any creative effort, shall fall within the protection scope of the present application.
First, terms appearing in the following examples are explained.
The BMS (Battery MANAGEMENT SYSTEM) BATTERY management system monitors the use state of the BATTERY at any time, relieves the inconsistency of the BATTERY pack through necessary measures and provides guarantee for the use safety of the BATTERY pack.
Equalization, wherein equalization control is divided into active equalization and passive equalization; actively balancing to transfer the electric energy with high voltage to the battery with low voltage; passive equalization generally consumes a part of the energy higher than the battery with high electric energy, so as to achieve the purpose of battery voltage consistency.
Referring to fig. 1, an embodiment of the present invention provides a charge and discharge control method for an energy storage system of a series battery pack, including the following steps:
acquiring the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value;
when the maximum differential pressure is greater than the initial differential pressure protection threshold, adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to a target differential pressure protection threshold, wherein the target differential pressure protection threshold is greater than the initial differential pressure protection threshold;
and controlling the charging and discharging of the energy storage system according to the magnitude relation between the maximum pressure difference and the target pressure difference protection threshold value.
The embodiment of the invention provides a charge-discharge control method for an energy storage system of a series battery pack, which comprises the steps of firstly obtaining the maximum pressure difference among batteries of the energy storage system and an initial pressure difference protection threshold value, and when the maximum pressure difference is larger than the initial pressure difference protection threshold value, adjusting the pressure difference protection threshold value from the initial pressure difference protection threshold value to a target pressure difference protection threshold value, namely increasing the pressure difference protection threshold value; and then controlling the charging and discharging of the energy storage system according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value. According to the scheme, the differential pressure protection threshold is not a fixed value, and when the maximum differential pressure is not greater than the initial differential pressure protection threshold, the differential pressure protection threshold is the initial differential pressure protection threshold; and when the maximum pressure difference is greater than the initial pressure difference protection threshold value, the pressure difference protection threshold value is increased to become a target pressure difference protection threshold value, and then the energy storage system is controlled to charge and discharge according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value. Therefore, when the maximum pressure difference is larger than the initial pressure difference protection threshold value, the charging and discharging of the energy storage system cannot be immediately disconnected, the pressure difference protection threshold value is increased, the charging and discharging of the energy storage system are further controlled according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value, and the utilization efficiency of each battery in the energy storage system is improved on the premise that each battery in the energy storage system cannot be overcharged or overdischarged.
As a supplementary description of the above embodiment, as shown in fig. 2, an embodiment of the present invention provides a method for controlling charging and discharging of an energy storage system of a series battery pack, including the following steps:
acquiring the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value; wherein, obtaining the maximum pressure difference between each battery of the energy storage system comprises: acquiring the highest voltage value and the lowest voltage value of a battery in an energy storage system; obtaining the maximum voltage difference by subtracting the highest voltage value from the lowest voltage value;
and when the maximum differential pressure is not greater than the initial differential pressure protection threshold value, keeping the existing charge-discharge state unchanged.
When the maximum differential pressure is greater than the initial differential pressure protection threshold, adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to a target differential pressure protection threshold, wherein the target differential pressure protection threshold is greater than the initial differential pressure protection threshold; and controlling the charging and discharging of the energy storage system according to the magnitude relation between the maximum pressure difference and the target pressure difference protection threshold value.
Specifically, adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to the target differential pressure protection threshold while the energy storage system is charging comprises: acquiring a charge cut-off voltage value of the energy storage system; obtaining a charging difference value by subtracting the highest voltage value from the charging cut-off voltage value; and obtaining a target differential pressure protection threshold value according to the charging difference value and the initial differential pressure protection threshold value. Preferably, the target differential pressure protection threshold is obtained by summing one-half of the charge differential value with the initial differential pressure protection threshold.
When the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the charging power of the energy storage system for charging, and balancing through a BMS (battery management system) of the energy storage system; and when the maximum pressure difference is greater than the target pressure difference protection threshold value, controlling the energy storage system to stop charging, and balancing through a BMS (battery management system) of the energy storage system. Preferably, the charging power is reduced to half for charging.
In addition, after balancing is carried out by the BMS of the energy storage system, the differential pressure protection threshold value is adjusted to be the initial differential pressure protection threshold value from the target differential pressure protection threshold value.
Adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to the target differential pressure protection threshold when the energy storage system is discharging comprises: acquiring a discharge cut-off voltage value of the energy storage system; the discharge cut-off voltage value is differed from the lowest voltage value to obtain a discharge difference value; and obtaining a target differential pressure protection threshold value according to the discharge difference value and the initial differential pressure protection threshold value. Preferably, the target differential pressure protection threshold is obtained by summing one half of the discharge difference value with the initial differential pressure protection threshold. Preferably, the differential pressure protection threshold is adjusted from the target differential pressure protection threshold to the initial differential pressure protection threshold.
When the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the discharge power of the energy storage system for discharging, and balancing through a BMS (battery management system) of the energy storage system; and when the maximum pressure difference is greater than the target pressure difference protection threshold value, controlling the energy storage system to stop discharging, and balancing through a BMS (battery management system) of the energy storage system.
In addition, after balancing is carried out by the BMS of the energy storage system, the differential pressure protection threshold value is adjusted to be the initial differential pressure protection threshold value from the target differential pressure protection threshold value.
To further illustrate the solution of the present application, the energy storage system shown in fig. 3 is taken as an example, and the energy storage system includes a series battery pack V1, a switch QF1, a battery management system BMS, a 24V power module V2, a DC-DC module U, a Load, DC contactors K1, K2, K3, and K4; the BMS controls the direct current contactors K1, K2, K3 and K4 to be opened and closed, and the DC-DC module realizes the charging and discharging control of the energy storage system.
Setting an initial differential pressure protection threshold value U0, a single battery charging cut-off voltage Ucs and a single battery discharging cut-off voltage Uds according to the type of the energy storage system battery;
the energy storage system is powered on, the BMS detects the monomer voltage of the battery system in real time in the operation process of the energy storage system, and the highest monomer voltage U of the battery is usedHAnd the lowest cell voltage ULCalculating the differential pressure Ut of the current battery, wherein Ut is equal to UH-UL，
When the energy storage system is charged:
if Ut is less than or equal to U0, the energy storage system is charged according to the original charging parameters;
if Ut > U0, the difference DeltaU between the highest cell voltage UH and the charge cut-off voltage Ucs is calculated1And setting a target differential pressure protection thresholdThe value U1 ═ U0+ Δ U1/2；
If U0 is larger than Ut and is not larger than U1, the energy storage system is charged according to half of the original charging power (if the original charging current is 10A, the energy storage system is charged according to 5A), BMS equalization management is started, the battery is equalized, and the differential pressure protection threshold value is set to be U0 after equalization is finished and recovery is carried out;
if Ut is larger than U1, stopping charging the energy storage system, starting BMS equalization management, equalizing the battery, and setting a differential pressure protection threshold value to be U0 after equalization is finished and recovered;
when the energy storage system discharges:
if Ut is less than or equal to U0, the energy storage system discharges according to the original discharge parameters;
if Ut > U0, the difference DeltaU between the lowest cell voltage UL and the discharge cutoff voltage Uds is calculated2And setting the differential pressure protection threshold value to be U1 ═ U0+ delta U2/2；
If U0 is larger than Ut and is not larger than U1, the energy storage system discharges according to half of the original discharge power, BMS balance management is started, the battery is balanced, and the differential pressure protection threshold value is set to be U0 after the balance is finished and recovered;
and if Ut is greater than U1, stopping discharging the energy storage system, and controlling by the BMS to disconnect K2 and K3, starting BMS equalization management, equalizing the battery, setting a differential pressure protection threshold value to be U0 after equalization is finished and recovering, and closing K2 and K3 again.
The embodiment of the invention provides a specific charging and discharging control method for an energy storage system of a series battery pack, which comprises the steps of firstly obtaining the maximum pressure difference, and if the maximum pressure difference is not greater than an initial pressure difference protection threshold value, normally charging and discharging; if the maximum differential pressure is greater than the initial differential pressure protection threshold value, adjusting the differential pressure protection threshold value from the initial differential pressure protection threshold value to a target differential pressure protection threshold value; then controlling the charging and discharging of the energy storage system according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value; if the maximum differential pressure is greater than the target differential pressure protection threshold value, the differential pressure is over-large, and the energy storage system is directly controlled to stop charging and discharging; if the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the charging power or the discharging power to half, and then balancing through the BMS; at the moment, although the maximum differential pressure is greater than the initial differential pressure protection threshold value, the maximum differential pressure is not greater than the target differential pressure protection threshold value, and in the range, charging and discharging are carried out by using half of charging power and discharging power, so that over-discharging or over-charging of the battery in the energy storage system can be prevented, and the service efficiency of the battery can be improved to the maximum extent.
In an embodiment, the present invention further provides a charge and discharge control device for an energy storage system of a series battery, as shown in fig. 4, including:
the parameter obtaining module 41 is configured to obtain a maximum voltage difference between the batteries of the energy storage system and an initial voltage difference protection threshold; specifically, the parameter obtaining module 41 obtains the highest voltage value and the lowest voltage value of the battery in the energy storage system; and obtaining the maximum voltage difference by subtracting the highest voltage value from the lowest voltage value.
A threshold adjusting module 42, configured to adjust the differential pressure protection threshold from the initial differential pressure protection threshold to a target differential pressure protection threshold when the maximum differential pressure is greater than the initial differential pressure protection threshold, where the target differential pressure protection threshold is greater than the initial differential pressure protection threshold;
when the energy storage system is charged, the threshold adjusting module 42 obtains a charging cut-off voltage value of the energy storage system; obtaining a charging difference value by subtracting the highest voltage value from the charging cut-off voltage value; and obtaining a target differential pressure protection threshold value according to the charging difference value and the initial differential pressure protection threshold value. Wherein, obtaining the target differential pressure protection threshold value according to the charging differential value and the initial differential pressure protection threshold value comprises: and summing one half of the charging difference value with the initial differential pressure protection threshold value to obtain a target differential pressure protection threshold value.
When the energy storage system discharges, the threshold adjusting module 42 obtains a discharge cut-off voltage value of the energy storage system; the discharge cut-off voltage value is differed from the lowest voltage value to obtain a discharge difference value; and obtaining a target differential pressure protection threshold value according to the discharge difference value and the initial differential pressure protection threshold value. Obtaining a target differential pressure protection threshold value according to the discharge differential value and the initial differential pressure protection threshold value comprises the following steps: and summing one half of the discharge difference value with the initial differential pressure protection threshold value to obtain a target differential pressure protection threshold value.
And the system control module 43 is configured to control charging and discharging of the energy storage system according to a magnitude relationship between the maximum differential pressure and a target differential pressure protection threshold.
When the energy storage system is charging:
when the maximum differential pressure is not greater than the target differential pressure protection threshold, the system control module 43 reduces the charging power of the energy storage system for charging, and performs equalization through the BMS of the energy storage system; preferably, reducing the charging power of the energy storage system for charging comprises: and reducing the charging power to half for charging.
When the maximum differential pressure is greater than the target differential pressure protection threshold, the system control module 43 controls the energy storage system to stop charging and perform equalization through the BMS of the energy storage system.
When the energy storage system is discharged:
when the maximum pressure difference is not greater than the target pressure difference protection threshold, the system control module 43 reduces the discharge power of the energy storage system to perform discharge, and performs equalization through the BMS of the energy storage system; preferably, reducing the discharge power of the energy storage system for discharging comprises: and reducing the discharge power to half for discharging.
When the maximum differential pressure is greater than the target differential pressure protection threshold, the system control module 43 controls the energy storage system to stop discharging and perform equalization through the BMS of the energy storage system.
As an optional implementation manner of the embodiment of the present invention, after the balancing is completed by the BMS of the energy storage system, the system control module 43 adjusts the differential pressure protection threshold from the target differential pressure protection threshold to the initial differential pressure protection threshold.
According to the charge and discharge control device for the energy storage system of the series battery pack, provided by the embodiment of the invention, the parameter acquisition module acquires the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value; when the maximum differential pressure is larger than the initial differential pressure protection threshold value, the threshold value adjusting module adjusts the differential pressure protection threshold value from the initial differential pressure protection threshold value to a target differential pressure protection threshold value; and the system control module controls the energy storage system to charge and discharge according to the magnitude relation between the maximum pressure difference and the target pressure difference protection threshold value. Firstly, acquiring a maximum pressure difference, and if the maximum pressure difference is not greater than an initial pressure difference protection threshold value, normally charging and discharging; if the maximum differential pressure is greater than the initial differential pressure protection threshold value, adjusting the differential pressure protection threshold value from the initial differential pressure protection threshold value to a target differential pressure protection threshold value; then controlling the charging and discharging of the energy storage system according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value; if the maximum differential pressure is greater than the target differential pressure protection threshold value, the differential pressure is over-large, and the energy storage system is directly controlled to stop charging and discharging; if the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the charging power or the discharging power to half, and then balancing through the BMS; at the moment, although the maximum differential pressure is greater than the initial differential pressure protection threshold value, the maximum differential pressure is not greater than the target differential pressure protection threshold value, and in the range, charging and discharging are carried out by using half of charging power and discharging power, so that over-discharging or over-charging of the battery in the energy storage system can be prevented, and the service efficiency of the battery can be improved to the maximum extent.
In one embodiment, the present invention also provides an energy storage system, comprising:
a processor;
a memory for storing processor-executable instructions;
the processor is configured to perform the specific series battery energy storage system charge-discharge control method provided in the above embodiments.
According to the energy storage system provided by the embodiment of the invention, the executable instruction of the processor is stored through the memory, when the maximum pressure difference is larger than the initial pressure difference protection threshold value, the initial pressure difference protection threshold value is adjusted to be the target pressure difference protection threshold value by the processor, and then the charging and discharging of the energy storage system are controlled according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value. The pressure difference protection threshold value of the energy storage system is not a fixed value, and when the maximum pressure difference is greater than the pressure difference protection threshold value, the pressure difference protection threshold value is adjusted, so that the service efficiency of the battery is improved on the premise of ensuring the safety of the energy storage system.
It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.
It should be noted that, in the description of the present application, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Further, in the description of the present application, the meaning of "a plurality" means at least two unless otherwise specified.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and the scope of the preferred embodiments of the present application includes other implementations in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.
It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.
It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.
In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.
The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc.
In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.
Claims (13)
1. A charge-discharge control method for an energy storage system of a series battery pack is characterized by comprising the following steps:
acquiring the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value;
when the maximum differential pressure is larger than the initial differential pressure protection threshold value, adjusting the differential pressure protection threshold value from the initial differential pressure protection threshold value to a target differential pressure protection threshold value, wherein the target differential pressure protection threshold value is larger than the initial differential pressure protection threshold value;
and controlling the energy storage system to charge and discharge according to the magnitude relation between the maximum pressure difference and the target pressure difference protection threshold value.
2. The method of claim 1, wherein: the acquiring of the maximum voltage difference between the batteries of the energy storage system comprises:
acquiring the highest voltage value and the lowest voltage value of a battery in the energy storage system;
and obtaining the maximum pressure difference by subtracting the highest voltage value from the lowest voltage value.
3. The method of claim 2, wherein: when the energy storage system is charged, the adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to the target differential pressure protection threshold comprises:
acquiring a charge cut-off voltage value of the energy storage system;
obtaining a charging difference value by subtracting the highest voltage value from the charging cut-off voltage value;
and obtaining a target differential pressure protection threshold value according to the charging difference value and the initial differential pressure protection threshold value.
4. The method of claim 3, wherein: the obtaining a target differential pressure protection threshold value according to the charging difference value and the initial differential pressure protection threshold value comprises:
and summing one half of the charging difference value with the initial differential pressure protection threshold value to obtain a target differential pressure protection threshold value.
5. The method of claim 2, wherein: when the energy storage system is discharged, the adjusting the differential pressure protection threshold from the initial differential pressure protection threshold to the target differential pressure protection threshold comprises:
acquiring a discharge cut-off voltage value of the energy storage system;
the discharge cut-off voltage value is differed from the lowest voltage value to obtain a discharge difference value;
and obtaining a target differential pressure protection threshold value according to the discharge difference value and the initial differential pressure protection threshold value.
6. The method of claim 5, wherein: the obtaining of the target differential pressure protection threshold value according to the discharge differential value and the initial differential pressure protection threshold value comprises:
and summing one half of the discharge difference value with the initial differential pressure protection threshold value to obtain a target differential pressure protection threshold value.
7. The method of claim 1, wherein: when the energy storage system is charged, the controlling the charging and discharging of the energy storage system according to the magnitude relation between the maximum differential pressure and the target differential pressure protection threshold value comprises the following steps:
when the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the charging power of the energy storage system for charging, and balancing through a BMS (battery management system) of the energy storage system;
and when the maximum pressure difference is greater than the target pressure difference protection threshold value, controlling the energy storage system to stop charging, and balancing through a BMS (battery management system) of the energy storage system.
8. The method of claim 7, wherein: the reducing the charging power of the energy storage system for charging comprises: and reducing the charging power to half for charging.
9. The method of claim 1, wherein: when the energy storage system discharges, the controlling of charging and discharging of the energy storage system according to the magnitude relation between the maximum differential pressure and the target differential pressure protection threshold value comprises:
when the maximum pressure difference is not greater than the target pressure difference protection threshold value, reducing the discharging power of the energy storage system for discharging, and balancing through a BMS (battery management system) of the energy storage system;
and when the maximum pressure difference is greater than the target pressure difference protection threshold value, controlling the energy storage system to stop discharging, and balancing through a BMS (battery management system) of the energy storage system.
10. The method of claim 9, wherein: the reducing the discharge power of the energy storage system for discharging comprises: and reducing the discharge power to half for discharging.
11. The method of claim 7 or 9, further comprising: and after the balancing of the BMS of the energy storage system is finished, adjusting the differential pressure protection threshold value from a target differential pressure protection threshold value to an initial differential pressure protection threshold value.
12. A series battery energy storage system charge-discharge control device, comprising:
the parameter acquisition module is used for acquiring the maximum pressure difference among the batteries of the energy storage system and an initial pressure difference protection threshold value;
the threshold adjusting module is used for adjusting the pressure difference protection threshold from an initial pressure difference protection threshold to a target pressure difference protection threshold when the maximum pressure difference is larger than the initial pressure difference protection threshold, and the target pressure difference protection threshold is larger than the initial pressure difference protection threshold;
and the system control module is used for controlling the charging and discharging of the energy storage system according to the size relation between the maximum pressure difference and the target pressure difference protection threshold value.
13. An energy storage system, comprising:
a processor;
a memory for storing the processor-executable instructions;
the processor is configured to perform the method of any one of claims 1-11.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116647009A (en) * | 2023-05-05 | 2023-08-25 | 威胜能源技术股份有限公司 | Battery charging protection strategy method in energy storage system |
| CN117318252A (en) * | 2023-11-29 | 2023-12-29 | 深圳市德兰明海新能源股份有限公司 | Battery pack charge and discharge protection method and device |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116647009A (en) * | 2023-05-05 | 2023-08-25 | 威胜能源技术股份有限公司 | Battery charging protection strategy method in energy storage system |
| CN116647009B (en) * | 2023-05-05 | 2024-07-19 | 威胜能源技术股份有限公司 | Battery charging protection strategy method in energy storage system |
| CN117318252A (en) * | 2023-11-29 | 2023-12-29 | 深圳市德兰明海新能源股份有限公司 | Battery pack charge and discharge protection method and device |
| CN117318252B (en) * | 2023-11-29 | 2024-04-09 | 深圳市德兰明海新能源股份有限公司 | Battery pack charge and discharge protection method and device |
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