Networking structure of energy storage control system and control method

Abstract

The invention relates to the technical field of energy storage control systems, and discloses a networking structure of an energy storage control system and a control method, in the networking structure, a plurality of main control modules are in communication connection in sequence, the first main control module and the last main control module are in communication connection with an EMS system, and hand-in-hand ring network communication is achieved; the plurality of main control modules and the EMS system are respectively connected to the switch through the Ethernet, and Ethernet communication is realized through the switch. According to the control method, a host can carry out sorting and distribution according to the electric quantity and the number of all current battery compartments, charging is started from the battery compartment with the minimum SOC during charging, and discharging is started from the battery compartment with the maximum SOC during discharging. According to the invention, a dual-network dual-redundancy communication mode between the main control module and the EMS system is adopted, the number of control equipment is reduced, the software and hardware cost is reduced, the continuous stability of system operation is ensured through a redundancy communication structure, and the number of operation equipment can be adjusted and the operation loss can be reduced according to full and full discharge conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage control systems, and in particular to a networking structure and a control method of an energy storage control system. Background Art

[0002] The controller system of lithium battery energy storage equipment is a battery management system. The battery management system is an important part of the industrial and commercial lithium battery energy storage control system. It has the functions of equipment status monitoring, equipment status diagnosis and analysis, equipment control and protection, equipment charge and discharge management, equipment communication and information management, and ensures the safe operation of lithium battery energy storage equipment.

[0003] The current battery management system BMS of lithium-ion energy storage equipment mainly adopts a three-level architecture: the first level includes multiple battery PACKs, each battery PACK is equipped with a BMU slave control module; the second level includes multiple battery clusters, each battery cluster is composed of multiple battery PACKs, and each battery cluster is equipped with a BCMU master control module; the third level includes a battery stack, each battery stack is composed of multiple battery clusters, and each battery stack is equipped with a BAMS master control module.

[0004] Some manufacturers use distributed lithium battery energy storage. The main functions of the battery management system BMS of this energy storage equipment are concentrated in the main control module. The master control module is only responsible for coordination and control, and the battery clusters are controlled independently of each other.

[0005] The main problems with the current battery management system BMS and control architecture are: First, the control system is a three-level architecture with a large number of control devices, and the costs of hardware, software, and assembly wiring are all high; second, the control flexibility is insufficient. If the master control module fails, the entire system will shut down and cannot operate normally; third, the equipment is fully charged and discharged. When the load is not full, all devices are running and the loss is high; fourth, when the energy storage system needs to be expanded, the entire control system needs to be reconstructed.

[0006] Based on the above reasons, the control system of the current energy storage system needs to solve the following problems: how to reduce the number of control devices and reduce the cost of software and hardware; how to ensure the normal operation of the system when the master control module or a main control module fails; how to reduce the equipment operation loss when the equipment is fully charged and discharged. Summary of the invention

[0007] The purpose of the present invention is to provide a networking structure and control method of an energy storage control system, which adopts a dual-network dual-redundant communication method between a main control module and an EMS system, reduces the number of control devices, reduces software and hardware costs, ensures the continuous stability of system operation through a redundant communication structure, and can adjust the number of operating devices according to the full and discharge conditions to reduce operating losses.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] A networking structure of an energy storage control system is applied to an energy storage system, each of the energy storage systems comprises a plurality of battery compartments arranged in parallel, each battery compartment is equipped with a main control module; the plurality of main control modules are sequentially connected for communication, wherein the first main control module and the last main control module are respectively connected for communication with an EMS system to realize hand-in-hand bracelet network communication; the plurality of main control modules and the EMS system are respectively connected to a switch via Ethernet, and all the main control modules and the EMS system realize Ethernet communication via the switch.

[0010] Furthermore, a plurality of slave control modules are arranged in the battery compartment, and the plurality of slave control modules are respectively communicatively connected with their corresponding master control modules.

[0011] Furthermore, RS485 communication protocol is used between adjacent main control modules and between the main control modules and the EMS system.

[0012] Furthermore, each master control module performs ID setting and executes different master or slave tasks according to the ID.

[0013] The present invention also provides a control method for an energy storage control system, which is applied to the networking structure of the above energy storage control system and comprises the following steps:

[0014] Each master control module automatically encodes the address and performs ID setting;

[0015] The master control module with the smallest ID address code is defined as the host, and the master control modules other than the host are defined as slaves. The host receives commands from the EMS system, generates power distribution instructions and control commands and sends them to the slaves, and receives all data collected by the slaves and uploads them to the EMS system. The slaves receive the power distribution instructions and control commands from the host to control charging and discharging;

[0016] If the current master is out of operation due to a fault or maintenance, select the slave with the smallest ID address code among the current multiple slaves and redefine it as the master;

[0017] When charging and discharging are required for power output or power distribution, the host will sort the battery compartments according to the number and power of all the battery compartments currently. When charging, it will start from the battery compartment with the smallest power, and when discharging, it will start from the battery compartment with the largest power.

[0018] Furthermore, the data collected by the slave device includes battery data, peripheral data, alarm and protection information.

[0019] Furthermore, when charging and discharging are required for power output or power distribution, the host sorts the battery compartments according to the number and power of all the battery compartments at present. When charging, charging starts from the battery compartment with the smallest power, and when discharging, discharging starts from the battery compartment with the largest power, which specifically includes:

[0020] When charging and discharging are required for power output or power distribution, the EMS system generates a discharge command or a charge command, wherein the discharge command includes a total discharge current, and the charge command includes a total charge current;

[0021] The host receives a discharge command or a charge command and sorts the battery cells according to the total number and power of all the battery cells at present;

[0022] When the host receives a discharge command, if the total discharge current is greater than the total output current of all battery compartments, all battery compartments will start to discharge; if the total discharge current is less than the rated current of a single battery compartment, the battery compartment with the largest power will start to discharge;

[0023] When the host receives a charging command, if the total charging current is greater than the total input current of all battery compartments, all battery compartments will start charging. If the total charging current is less than the rated current of a single battery compartment, the battery compartment with the smallest power will start charging.

[0024] Furthermore, when the host receives a discharge command, if the total discharge current is between the total output current of all battery cells and the rated current of a single battery cell, the number of battery cells to be discharged, n, is calculated according to the following formula: 1 :

[0025]

[0026] In the formula, A d is the total discharge current, A is the rated current of the battery compartment, Indicates rounding up; n 1 ≤N, N is the total number of all current battery compartments;

[0027] Sort by the power level of all battery compartments and select the first n 1 The battery compartments with larger capacity are discharged, among which n 1 Among the battery compartments, the discharge current of the battery compartment with the smallest power is A d -A*n 1 , the discharge current of the remaining battery compartments is the rated current A.

[0028] Furthermore, when the host receives a charging command, if the total charging current is between the total input current of all battery compartments and the rated current of a single battery compartment, the number of battery compartments to be charged, n, is calculated according to the following formula: 2 :

[0029]

[0030] In the formula, A c is the total charging current, A is the rated current of the battery compartment, Indicates rounding up; n 2 ≤N, N is the total number of all current battery compartments;

[0031] Sort by the power level of all battery compartments and select the last n 2 Charge the battery compartments with smaller power, where n 2 Among the battery compartments, the charging current of the battery compartment with the largest power is A c -A*n 2 , the charging current of the remaining battery compartments is the rated current A.

[0032] Furthermore, when the host receives a discharge command, during the discharge process, if the power of a battery compartment reaches the lower limit of discharge, the main control module of the battery compartment controls to stop the discharge of the battery compartment, the total number of all battery compartments is reduced by one, and the remaining battery compartments are re-ordered based on the power;

[0033] When the host receives a charging command, during the charging process, if the power of a battery compartment reaches the charging upper limit, the main control module of the battery compartment will control the charging of the battery compartment to stop, the total number of all battery compartments will be reduced by one, and the remaining battery compartments will be re-sorted based on the power.

[0034] According to the specific embodiments provided by the present invention, the network structure and control method of the energy storage control system provided by the present invention disclose the following technical effects:

[0035] (1) Each battery compartment is equipped with a main control module. A dual-network dual-redundant communication mode is established between the main control module and the EMS system. There is no need to set up a master control module, which reduces the number of control devices. The main control module has the same hardware and software, which reduces the cost of software and hardware, reduces the control links, and improves communication and control efficiency;

[0036] (2) Through dual-network dual-redundant communication, the normal operation of the overall energy storage control system will not be affected when one or more control modules fail, one or more battery compartments fail, or are shut down for maintenance;

[0037] (3) The control method can sort the battery compartments according to the total number and power of the battery compartments, and reasonably arrange the number of battery compartments involved in charging or discharging in combination with the charging or discharging requirements. When the discharging or charging power is small, only some of the battery compartments will be operated, and all battery compartments will not be controlled to operate at the same time. Other battery compartments are in standby state, reducing the power loss of other equipment;

[0038] (4) Expansion is simple and convenient. The communication part only needs to connect the network cable and the custom protocol communication cable, and reconfigure the ID to achieve rapid update of the control logic. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 This is a schematic diagram of the network structure of the energy storage control system according to an embodiment of the present invention;

[0041] Figure 2 Schematic diagram of a control method of an energy storage control system according to an embodiment of the present invention;

[0042] Figure 3 The figure is a flow chart of power distribution and charge-discharge control performed by a host according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The purpose of the present invention is to provide a networking structure and control method of an energy storage control system. By optimizing the design and configuration, a dual-network dual-redundant communication method is adopted between a main control module and an EMS system to reduce the number of control devices and reduce the cost of software and hardware. Through a redundant communication structure, the continuous stability of the system operation is ensured, and the number of operating devices can be adjusted according to the full and discharge conditions to reduce operating losses.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Example 1

[0047] like Figure 1As shown, the networking structure of the energy storage control system provided by the present invention is applied to the energy storage system, each of the energy storage systems includes a plurality of battery compartments arranged in parallel (each battery compartment is a battery cluster), and each battery compartment is equipped with a main control module; the plurality of main control modules are sequentially connected for communication, wherein the first main control module and the last main control module are respectively connected for communication with the EMS system to realize hand-in-hand ring network communication, specifically, the RS485 communication protocol is adopted between adjacent main control modules and between the main control modules and the EMS system to realize hand-in-hand RS485 ring network communication; the plurality of main control modules and the EMS system are respectively connected to the switch via Ethernet, and all the main control modules and the EMS system realize Ethernet communication via the switch.

[0048] The battery compartment is further provided with a plurality of slave control modules, which are respectively connected to the corresponding master control modules for communication. The slave control modules are used to control each battery PACK in the battery compartment.

[0049] Each master control module has an ID setting and executes different master or slave tasks according to the ID.

[0050] For example, the host tasks mainly include battery data aggregation, power allocation, charge and discharge control, demand control of multiple battery compartments, and peripheral control, alarm, protection and control of this battery compartment and other battery compartments. The slave tasks mainly include peripheral control, alarm, protection and control of this battery compartment, and receiving control commands issued by the host.

[0051] Example 2

[0052] like Figure 1 and Figure 2 As shown, the present invention also provides a control method of an energy storage control system, which is applied to the networking structure of the above energy storage control system, and includes the following steps:

[0053] Each main control module automatically encodes the address and sets the ID, and the address range can be 1-65535; the specific encoding method is: the RS485_A communication terminal of the EMS system sends an address setting message to the main control module of battery compartment 1, and the main control module of battery compartment 1 sets the ID to 1 after receiving the message, and then sends the address setting message to the main control module of battery compartment 2 through the RS485_A communication terminal, and the main control module of battery compartment 2 sets the ID to 2 after receiving the message, and sets the ID of the main empty module of each battery compartment in turn. The main control module of the last battery compartment sends the encoding completion message to the RS485_B communication port of the EMS system through the RS485 communication protocol. After the EMS system receives the encoding completion message, the ID setting is completed;

[0054] First, determine whether it is necessary to exit the operation. If yes, continue to wait. If not, define the master control module with the smallest ID address code (for example, ID=1) as the host, and define the master control modules other than the host as slaves. The host receives the command of the EMS system, generates power distribution instructions and control commands and sends them to the slaves, and receives all the data collected by the slaves and uploads them to the EMS system. The slaves receive the power distribution instructions and control commands of the host to perform charge and discharge control. Among them, the host implements the host functions, including battery data aggregation, power distribution, charge and discharge control, demand control, and peripheral control, alarm, protection and control of the battery compartment and other battery compartments of multiple battery compartments. The host can coordinate various controllers; the slave implements the slave functions, including peripheral control, alarm, protection and control of the battery compartment corresponding to the slave, and receiving control commands issued by the host.

[0055] If the current master is out of operation due to a fault or maintenance, the slave with the smallest ID address code among the current multiple slaves is selected and redefined as the master; for example, when one or more battery compartments fail or are out of operation due to maintenance, the slave with the smallest ID among the remaining slaves automatically becomes the master;

[0056] When charging and discharging are required for power output or power distribution, the host will sort the battery compartments according to the number and power of all the battery compartments currently. When charging, it will start from the battery compartment with the smallest power, and when discharging, it will start from the battery compartment with the largest power.

[0057] The data collected by the slave include battery data, peripheral data, alarm and protection information. The peripheral data mainly include refrigeration unit working data, meter data, PCS operation data, insulation detection data, etc. The alarm and protection information include three-level over-voltage and under-voltage alarms, high and low temperature alarms, overcurrent alarms, positive and negative insulation resistance alarms, SOC alarms, etc.

[0058] like Figure 3 As shown, when charging and discharging are required for power output or power distribution, the host sorts the battery compartments according to the number and power of all the battery compartments at present. When charging, charging starts from the battery compartment with the smallest power, and when discharging, discharging starts from the battery compartment with the largest power, which specifically includes:

[0059] When charging and discharging are required for power output or power distribution, the EMS system generates a discharge command or a charge command, wherein the discharge command includes a total discharge current, and the charge command includes a total charge current;

[0060] The host receives a discharge command or a charge command and sorts the battery cells according to the total number and power of all the battery cells at present;

[0061] When the host receives a discharge command, if the total discharge current is greater than the total output current of all battery compartments (i.e., the rated current multiplied by the number of battery compartments), all battery compartments will begin to discharge; if the total discharge current is less than the rated current of a single battery compartment, the battery compartment with the largest power will begin to discharge;

[0062] When the host receives a charging command, if the total charging current is greater than the total input current of all battery compartments (also calculated by multiplying the rated current by the number of battery compartments), all battery compartments will start charging. If the total charging current is less than the rated current of a single battery compartment, the battery compartment with the smallest power will start charging.

[0063] In another case, when the host receives a discharge command, if the total discharge current is between the total output current of all battery cells and the rated current of a single battery cell, the number of battery cells to be discharged, n, is calculated according to the following formula: 1 :

[0064]

[0065] In the formula, A d is the total discharge current, A is the rated current of the battery compartment, Indicates rounding up; n 1 ≤N, N is the total number of all current battery compartments;

[0066] Sort by the power level of all battery compartments and select the first n 1 The battery compartments with larger capacity are discharged, among which n 1 Among the battery compartments, the discharge current of the battery compartment with the smallest power is A d -A*n 1 , the discharge current of the remaining battery compartments is the rated current A.

[0067] In another case, when the host receives a charging command, if the total charging current is between the total input current of all battery cells and the rated current of a single battery cell, the number of battery cells to be charged, n, is calculated according to the following formula: 2 :

[0068]

[0069] In the formula, A c is the total charging current, A is the rated current of the battery compartment, Indicates rounding up; n 2 ≤N, N is the total number of all current battery compartments;

[0070] Sort by the power level of all battery compartments and select the last n 2 Charge the battery compartments with smaller power, where n 2 Among the battery compartments, the charging current of the battery compartment with the largest power is Ac -A*n 2 , the charging current of the remaining battery compartments is the rated current A.

[0071] In addition, when the host receives a discharge command, during the discharge process, if the power of a battery compartment reaches the lower limit of discharge, the main control module of the battery compartment will control the battery compartment to stop discharging, the total number of all battery compartments will be reduced by one, and the remaining battery compartments will be re-sorted based on the power; for example, during the discharge operation, when the SOC of a battery compartment is 0, the battery compartment stops discharging and the other battery compartments are re-sorted according to the power.

[0072] When the host receives a charging command, during the charging process, if the power of a battery compartment reaches the charging limit, the main control module of the battery compartment will control the battery compartment to stop charging, the total number of all battery compartments will be reduced by one, and the remaining battery compartments will be re-sorted based on the power. For example, when the SOC charging degree of a battery compartment is ≥100%, the battery compartment will stop charging and the other battery compartments will be re-sorted based on the power.

[0073] In summary, the present invention provides a networking structure and control method of an energy storage control system, which is suitable for industrial and commercial energy storage systems. Multiple battery compartments of the energy storage system are networked in parallel, and a ring network is formed by hand-in-hand. The ID is automatically set, and the master and slave machines are automatically determined according to the ID and the exit situation; and according to the charging and discharging requirements and the SOC of each battery compartment, the host performs power distribution, energy output, charging and discharging control, etc. for all battery compartments. During basic charging and discharging control, the host will sort and distribute according to the power and quantity of all battery compartments. When charging, it starts from the battery compartment with the smallest SOC, and when discharging, it starts from the battery compartment with the largest SOC. The present invention has the advantages of saving software and hardware design and development costs, simple and convenient networking, flexible and intelligent control, and simple expansion.

[0074] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A network structure of an energy storage control system, applied to an energy storage system, characterized in that: Each of the energy storage systems includes a plurality of battery compartments arranged in parallel, and each battery compartment is equipped with a main control module; the plurality of main control modules are communicatively connected in sequence, wherein the first main control module and the last main control module are communicatively connected with the EMS system respectively to realize hand-in-hand bracelet network communication; the plurality of main control modules and the EMS system are connected to the switch via Ethernet respectively, and all the main control modules and the EMS system realize Ethernet communication via the switch.

2. The network structure of the energy storage control system according to claim 1 is characterized in that: A plurality of slave control modules are also arranged in the battery compartment, and the plurality of slave control modules are respectively communicatively connected with their corresponding master control modules.

3. The network structure of the energy storage control system according to claim 1 is characterized in that: RS485 communication protocol is used between adjacent main control modules and between the main control module and the EMS system.

4. The network structure of the energy storage control system according to claim 1, characterized in that: Each master control module has an ID setting and executes different master or slave tasks according to the ID.

5. A control method for an energy storage control system, applied to the network structure of the energy storage control system according to claims 1-4, characterized in that: The following steps are involved: Each master control module automatically encodes the address and performs ID setting; The master control module with the smallest ID address code is defined as the host, and the master control modules other than the host are defined as slaves. The host receives commands from the EMS system, generates power distribution instructions and control commands and sends them to the slaves, and receives data collected by all slaves and uploads them to the EMS system. The slaves receive the power distribution instructions and control commands from the host to control charging and discharging; If the current master is out of operation due to a fault or maintenance, select the slave with the smallest ID address code among the current multiple slaves and redefine it as the master; When charging and discharging are required for power output or power distribution, the host will sort the battery compartments according to the number and power of all the battery compartments currently. When charging, it will start from the battery compartment with the smallest power, and when discharging, it will start from the battery compartment with the largest power.

6. The control method of the energy storage control system according to claim 5, characterized in that: The data collected by the slave includes battery data, peripheral data, alarm and protection information.

7. The control method of the energy storage control system according to claim 5, characterized in that: When charging and discharging are required for power output or power distribution, the host sorts the battery compartments according to the number and power of all the battery compartments at present. When charging, charging starts from the battery compartment with the smallest power, and when discharging, discharging starts from the battery compartment with the largest power, specifically including: When charging and discharging are required for power output or power distribution, the EMS system generates a discharge command or a charge command, wherein the discharge command includes a total discharge current, and the charge command includes a total charge current; The host receives a discharge command or a charge command and sorts the battery cells according to the total number and power of all the battery cells at present; When the host receives a discharge command, if the total discharge current is greater than the total output current of all battery compartments, all battery compartments will start to discharge; if the total discharge current is less than the rated current of a single battery compartment, the battery compartment with the largest power will start to discharge; When the host receives a charging command, if the total charging current is greater than the total input current of all battery compartments, all battery compartments will start charging. If the total charging current is less than the rated current of a single battery compartment, the battery compartment with the smallest power will start charging.

8. The control method of the energy storage control system according to claim 7, characterized in that: When the host receives a discharge command, if the total discharge current is between the total output current of all battery cells and the rated current of a single battery cell, the number of battery cells n1 that need to be discharged is calculated according to the following formula: In the formula, A d is the total discharge current, A is the rated current of the battery compartment, Indicates rounding up; n1≤N, N is the total number of all current battery compartments; According to the power ranking of all battery compartments, the first n1 battery compartments with larger power are selected for discharge. Among the n1 battery compartments, the discharge current of the battery compartment with the smallest power is A. d -A*n1, the discharge current of the remaining battery compartments is the rated current A.

9. The control method of the energy storage control system according to claim 7, characterized in that: When the host receives a charging command, if the total charging current is between the total input current of all battery compartments and the rated current of a single battery compartment, the number of battery compartments that need to be charged, n2, is calculated according to the following formula: In the formula, A c is the total charging current, A is the rated current of the battery compartment, Indicates rounding up; n2≤N, N is the total number of all current battery compartments; According to the power ranking of all battery compartments, the last n2 battery compartments with smaller power are selected for charging. Among the n2 battery compartments, the charging current of the battery compartment with the largest power is A. c -A*n2, the charging current of the remaining battery compartments is the rated current A.

10. The control method of the energy storage control system according to claim 7, characterized in that: When the host receives a discharge command, during the discharge process, if the power of a battery compartment reaches the lower limit of discharge, the main control module of the battery compartment will control the battery compartment to stop discharging, the total number of all battery compartments will be reduced by one, and the remaining battery compartments will be re-sorted based on the power; When the host receives a charging command, during the charging process, if the power of a battery compartment reaches the charging upper limit, the main control module of the battery compartment will control the charging of the battery compartment to stop, the total number of all battery compartments will be reduced by one, and the remaining battery compartments will be re-sorted based on the power.

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