Energy management device and method suitable for distributed energy storage system
Technical Field
The invention relates to the technical field of energy storage energy management, in particular to an energy management device and method suitable for a distributed energy storage system.
Background
For a distributed energy storage system, two EMS (energy management system) architecture modes of local centralized control and cloud centralized control are provided at present, wherein the EMS architecture modes comprise that a front-end controller collects data of a battery cluster, a PCS (personal communication system) and other auxiliary equipment which are dispersedly installed and forwards the data to the local centralized control system, and the local centralized control system is used for carrying out centralized monitoring and energy scheduling and providing an HMI (human-machine interaction interface) for operation control; the data of the battery cluster, the PCS and other auxiliary equipment are collected and forwarded to the cloud platform through the gateway and other Internet of things equipment, and remote monitoring and scheduling are implemented through the cloud platform.
The EMS solution of present distributed energy storage system mainly is two kinds of schemes of local centralized control and high in the clouds centralized control, and the problem that exists includes: 1. the energy storage unit level, particularly the battery cluster level, does not have local monitoring capability, if a local centralized control scheme is generally only provided in a local centralized control center, a monitoring HMI is generally provided in an energy storage plant station level, when the energy storage system enters an installation field for debugging and troubleshooting, information prompt and control of the centralized control center are still relied, and the working efficiency is greatly reduced. Similarly, the cloud centralized control scheme generally only installs communication devices such as gateways on site, and is not equipped with corresponding HMI equipment, so that the cloud centralized control scheme also does not have the local monitoring capability of a battery cluster level. The defect brings great inconvenience to the field debugging, testing and troubleshooting of the energy storage system; 2. at present, a typical mode for configuring and updating the energy strategy of the distributed energy storage system through a cloud is an internet of things protocol level public network communication channel, data loss and other security risks exist due to network quality and security reasons, and the risk of executing an error or invalid strategy exists in the system due to lack of strategy verification at an energy storage system end.
The patent literature in china discloses "an energy storage battery management system", its publication number is CN114006060A, discloses an energy storage battery management system, includes: energy storage unit, energy storage unit group controller and energy management system, wherein: the energy storage unit comprises an energy storage unit controller, a plurality of battery cluster management units and a plurality of battery clusters, the battery clusters are correspondingly connected with the battery cluster management units one by one, and the battery cluster management units are connected in parallel and are in communication connection with the energy storage unit controller through confluence; the energy storage unit group controller is in communication connection with the converged energy storage unit controllers through the Ethernet to form an energy storage unit group; the energy management system is in communication connection with the energy storage unit group controllers after confluence through the Ethernet. However, patent publication No. CN114006060A does not mention in-situ monitoring techniques and verification process of energy policy.
Disclosure of Invention
The invention solves the problems that the existing energy storage unit does not have the in-situ monitoring capability and the strategy verification is lacked at the end of the energy storage system, and provides an energy management device suitable for a distributed energy storage system, wherein a monitoring module and an HMI (human machine interface) are arranged and are arranged on the energy storage unit for in-situ monitoring, and sufficient convenience is provided for the independent debugging, the testing and the troubleshooting of a battery cluster; meanwhile, an energy management method suitable for the distributed energy storage system is provided, energy management strategy verification is carried out locally on the energy storage system, and invalid strategy configuration is alarmed, so that the risk of error or invalid strategy execution is reduced.
In order to achieve the purpose, the invention adopts the following technical scheme: an energy management device suitable for a distributed energy storage system, comprising,
the monitoring module is in communication connection with the HMI, in communication connection with the cloud centralized control system and the local centralized control system, and is also connected with an energy storage unit of the energy storage system;
the HMI is used for providing a local monitoring operation interface and checking the state data information through the HMI;
the monitoring module comprises a monitoring module and a control module,
the data acquisition and forwarding unit acquires and forwards state data information of the energy storage unit;
the state monitoring and alarming unit is used for monitoring the running state of each device of the energy storage system in real time and alarming the abnormal state;
the strategy management checking unit is used for strategy configuration and execution and strategy checking;
the data storage unit is used for storing system operation data in a historical period and verifying the benefit of the energy management strategy;
and the control protection unit is used for managing and executing equipment starting and stopping, relay on-off and system protection logic.
In the invention, the energy management device comprises a monitoring module and an HMI (human machine interface), and is arranged on an energy storage unit; the monitoring module is responsible for data acquisition and forwarding, control protection logic management, energy strategy management, state monitoring, alarming, checking and other functions, the HMI provides a local monitoring operation interface, and local control requirements such as local control, debugging, testing, troubleshooting and the like are met; the method has the advantages that the local monitoring is carried out on the minimum energy storage unit forming the energy storage system, namely the battery cluster level, so that the sufficient convenience is provided for the independent debugging, testing and troubleshooting of the battery cluster; while also supporting in-situ monitoring of energy storage units consisting of multiple battery clusters.
Preferably, the monitoring module is connected with the local centralized control system through the Ethernet, data interaction is performed through an IEC104 protocol, and the monitoring module is in communication connection with the cloud centralized control system through 4G or 5G. In the invention, the monitoring module is provided with communication interfaces such as Ethernet ports (RJ45), RS485, CAN, DI, DO and the like, supports communication protocols such as Modbus, CAN, IEC104, MQTT and the like, and meets the access requirements and cloud communication requirements of mainstream PCS, BMS, air conditioners, fire fighting and other equipment.
Preferably, the energy storage system comprises a plurality of energy storage units, the energy storage units comprise a plurality of battery clusters, the battery clusters are connected with a battery management system, the battery management system is connected with an energy storage converter, and the energy storage converter is connected with a voltage transformation device. The energy storage units are monitoring objects of the invention, and can be flexibly installed and distributed in a distributed or centralized manner, so that the construction requirements of large energy storage systems with different scales and requirements are met.
An energy management method applicable to a distributed energy storage system is applicable to the above energy management device applicable to the distributed energy storage system, and includes an energy management policy verification process, where the verification process includes the following steps:
s1, checking data integrity and validity, including communication check, reverse check, repeat check and conflict check;
s2, protection verification, including explicit parameter verification and simulation operation verification;
and S3, checking the economy.
In the invention, a monitoring module is responsible for managing and verifying an energy scheduling strategy, data integrity and validity verification, protection verification and profit verification are carried out on strategy parameters issued from a cloud, and strategy updating is executed if triple verification is passed; otherwise, the strategy update is abandoned, the strategy abnormal change alarm is recorded and generated, and the strategy abnormal change alarm is reported to the cloud or the local centralized control system, so that the aim of protecting the energy storage system and the income is fulfilled.
Preferably, S11, performing communication check on the received data packet, checking the integrity and correctness of the data packet by using a cyclic redundancy check method, if the data packet is complete and correct, temporarily writing the policy contained in the data packet into the memory of the energy management device, and performing step S12; otherwise, abandoning the write strategy, recording the log and returning data error information to the strategy issuing end;
s12, the energy management device sends the received strategy to the strategy issuing end, and the strategy issuing end performs reverse correction; the strategy issuing end displays the strategy read from the energy management device, and compares the strategy with the original data for confirmation; if the strategy issuing end confirms through the reverse correction and issues confirmation information, the step S13 is entered, otherwise, strategy updating is abandoned;
s13, checking repetition and conflict, searching the historical strategy which is saved and is in the starting state by the energy management device, comparing the historical strategy with the existing strategy, judging whether the strategy is repeated or not according to the charging and discharging time period and whether the time period is overlapped or not, if so, judging the strategy to be conflict, recording the log and returning conflict error information; if not, the process proceeds to step S2. In the invention, the strategy issuing end can be a cloud centralized control system, a local centralized control system or an own HMI; specifically, the strategy issuing end has automatic comparison and calculation capability and carries out automatic comparison and confirmation.
Preferably, the step S2 includes the steps of:
s21, verifying the out-of-limit and deviation states of the explicitly set parameters in the strategy; the out-of-limit checking mode is that the out-of-limit judgment is carried out according to the preset upper and lower limit values of the parameter, the set strategy parameter (P _ set) should meet the condition that P _ min is less than or equal to P _ set and less than or equal to P _ max, wherein P _ min and P _ max are respectively the preset minimum value and the preset maximum value of the strategy parameter, and an out-of-limit error is generated when P _ set is greater than the maximum value or less than the minimum value, and the protection checking is not passed; the deviation state verification is to compare the set strategy parameter (P _ set) with a preset reference value (P _ ref), and if the deviation between the strategy parameter (P _ set) and the preset reference value (P _ ref) is too large, the deviation state verification does not pass through protection verification, and a deviation alarm is generated;
and S22, verifying model operation, namely verifying the possible damage to the energy storage protection constraint generated by the strategy through simulation operation under the condition that the strategy adopts default parameters, wherein the verification content comprises daily charge-discharge cycle times and SOC. In the invention, the parameters supported and verified by the dominant parameter verification comprise a charge and discharge time interval, charge and discharge multiplying power, floating charge voltage, termination voltage, conversion voltage, SOC, depth of discharge (DOD) and charge and discharge power.
Preferably, the step S3 is specifically: all strategies after the new strategy is added in the simulated operation are combined with economic benefits generated by daily charging and discharging, and the calculation method comprises the following steps: and (3) the daily income is daily charging electric quantity and charging electricity price-daily discharging electricity price, if the daily income is increased relative to the original strategy combination, the strategy is applied, and otherwise, an income abnormity prompt is returned. In the invention, after passing the protection verification, the economy verification is carried out; the economic check is to determine whether executing a new policy can yield more revenue than the current policy.
Preferably, the step S22 includes the steps of:
s221, the daily charge and discharge frequency is obtained by calculating all charge and discharge strategies in a starting state on the energy management device, if the daily charge and discharge frequency exceeds a preset value, a log is recorded, and error information that the daily charge and discharge frequency is out of limit is returned;
s222, checking the SOC; as the battery capacity decays during use, the remaining SOC (SOC) is determined under the same remaining capacity requirement residual ) Should be compared to the initial SOC (SOC) min ) Has a large minimum value, considering capacity fade, according to the current SOH,The SOC limit is calculated as follows:
the energy management device calculates the actual remaining SOC according to the discharge duration and the discharge rate of the discharge strategy, and if the actual remaining SOC is smaller than the SOC residual Then log is recorded and a protection error message is returned. In the invention, SOC verification comprehensively considers the battery state of health (SOH) and SOC limit requirements, simulates an operation strategy, and calculates the residual SOC after the operation of a discharge strategy so as to meet the minimum SOC requirement generated by standby power and the like.
The beneficial effects of the invention are:
1. the system has the minimum energy storage unit, namely the local monitoring capability of the battery cluster level, and can provide convenience for field debugging, testing and troubleshooting of the battery cluster;
2. carrying out data integrity and validity check, protection check and profit check on the strategy parameters issued from the cloud centralized control system, and if the triple checks pass, executing strategy updating; otherwise, the strategy update is abandoned, the strategy abnormal change alarm is recorded and generated, and the strategy abnormal change alarm is reported to the cloud centralized control system or the local centralized control system, so that the aim of protecting the energy storage system and the income is fulfilled; 3. the invention simultaneously supports the on-site monitoring and the cloud remote monitoring of the battery cluster level and the station control level, and also supports the continuous sending of the operation data to the cloud centralized control system for the continuous updating of the energy management strategy, thereby meeting the technical requirements of the energy management of the distributed energy storage system.
Drawings
FIG. 1 is a schematic diagram of an energy management apparatus and method for a distributed energy storage system according to the present invention;
fig. 2 is a schematic structural diagram of an energy management device and method for a distributed energy storage system according to the present invention;
fig. 3 is a schematic diagram illustrating connection between an energy management apparatus and an energy storage unit, a local centralized control system, and a cloud centralized control system according to an embodiment of the present invention;
fig. 4 is a flowchart of a method of an energy management apparatus and method for a distributed energy storage system according to the present invention.
Detailed Description
Example (b):
the embodiment provides an energy management device suitable for a distributed energy storage system, and referring to fig. 1, fig. 2, and fig. 3, the energy management device includes a monitoring module and an HMI, wherein the monitoring module is communicatively connected to the HMI, the monitoring module is communicatively connected to a cloud centralized control system and a local centralized control system, and the monitoring module is further connected to an energy storage unit of the energy storage system; the HMI can provide an in-place monitoring operation interface and can view status data information through the HMI; specifically, the monitoring module comprises a data acquisition forwarding unit, a state monitoring and alarming unit, a strategy management checking unit, a data storage unit and a control protection unit; the data acquisition forwarding unit is connected with the state monitoring and alarming unit, the state monitoring and alarming unit is connected with the strategy management checking unit, and the strategy management checking unit is connected with the data storage unit. In the embodiment, the HMI provides an interface for monitoring and operating the battery cluster on site, and can check system state data (such as current, voltage, power, temperature and the like), alarm, charge and discharge amount and other data through the HMI, and perform field control such as system start and stop, relay switch and the like, and energy management strategy configuration and test operation; HMI supports graphical display and supports the display of wiring diagrams and data charts.
Specifically, in the monitoring module, a data acquisition and forwarding unit acquires and forwards state data information of the energy storage unit; in this embodiment, the data collecting and forwarding unit collects and forwards battery, PCS, and other device information, such as battery state data of current, voltage, temperature, and the like, to the cloud centralized control system or the local centralized control system; meanwhile, strategy parameters sent by a cloud centralized control system are received; in addition, the strategy configuration and the control instruction issuing are also supported by the local centralized control system.
The state monitoring and alarming unit is used for monitoring the running state of each device of the energy storage system in real time and alarming the abnormal state; in the embodiment, the abnormal state alarm carries out alarm according to a preset alarm rule; the condition monitoring and warning unit also supports warning of abnormal changes to the energy management strategy.
The strategy management checking unit is used for strategy configuration and execution and strategy checking; in this embodiment, the policy configuration and execution specifically include: supporting strategy and strategy group configuration, configuring one or more peak clipping and valley filling charging and discharging control strategies according to a peak and valley electricity price list, and supporting the combination of a plurality of strategies to form a charging and discharging combination strategy for acquiring the maximum peak clipping and valley filling income for the peak and valley electricity price list with seasonal or time-interval change; the strategy verification specifically comprises the following steps: the method comprises the steps that triple verification of data integrity and validity verification, protection verification and income verification is supported for strategies issued by a local centralized control center or a cloud, and strategy updating is carried out only when the triple verification is passed; otherwise, the strategy updating is abandoned, and the strategy abnormal change alarm is generated.
The data storage unit is used for storing system operation data in a historical period and verifying the benefit of the energy management strategy; in this embodiment, the data storage unit stores data of the last week; in addition, the unit also supports temporary storage of the acquired data so as to realize the function of breakpoint transmission.
And the control protection unit is used for managing and executing equipment starting and stopping, relay on-off and system protection logic.
Referring to fig. 2 and fig. 3, the monitoring module is connected to the local centralized control system through an ethernet, and performs data interaction through an IEC104 protocol, and the monitoring module is connected to the cloud centralized control system in a 4G or 5G communication manner. In the embodiment, the HMI and the monitoring module can adopt a separated installation mode, so that the installation position can be flexibly selected, and the HMI and the monitoring module are not limited by space. The HMI and the monitoring module are communicated through RS485, and the HMI and the monitoring module are respectively provided with corresponding communication interfaces; specifically, the monitoring module has communication interfaces such as ethernet port (RJ45), RS485, CAN, DI, DO, supports communication protocols such as Modbus, CAN, IEC104, MQTT, satisfies the access demand and the high in the clouds communication demand of equipment such as mainstream PCS, BMS and air conditioner, fire control.
Referring to fig. 1, the energy storage system includes a plurality of energy storage units, each energy storage unit includes a plurality of battery clusters, each battery cluster is connected to a battery management system, each battery management system is connected to an energy storage converter, and each energy storage converter is connected to a voltage transformation device. Auxiliary equipment such as fire fighting equipment, air conditioners and the like can be added to form an energy storage unit; the energy storage units are monitoring objects of the invention, and can be flexibly installed and distributed in a distributed or centralized manner, so that the construction requirements of large energy storage systems with different scales and requirements are met.
In the invention, the energy management device comprises a monitoring module and an HMI (human machine interface), and is arranged on an energy storage unit; the monitoring module is responsible for data acquisition and forwarding, control protection logic management, energy strategy management, state monitoring, alarming, checking and other functions, the HMI provides a local monitoring operation interface, and local control requirements such as local control, debugging, testing, troubleshooting and the like are met; the minimum energy storage unit, namely the battery cluster level, forming the energy storage system is monitored in situ, and sufficient convenience is provided for independent debugging, testing and troubleshooting of the battery cluster; while also supporting in-situ monitoring of energy storage units consisting of multiple battery clusters.
In the invention, the configuration management of the energy management strategy is carried out through the cloud centralized control system or the local centralized control system in consideration of the region dispersion characteristic of the distributed energy storage system.
Referring to fig. 4, the present invention mainly includes an energy management policy verification process, which includes a plurality of steps, step S1, data integrity and validity verification, including communication verification, reverse verification, repetition and conflict verification; specifically, the method includes the following three steps, step S11, of performing communication check on a received data packet, specifically, using a cyclic redundancy check method to check the integrity and correctness of the data packet, if the data packet is complete and correct, temporarily writing a policy in the data packet into a memory of the energy management device, and performing the check of step S12; and if the data packet is incomplete or incorrect, abandoning the write strategy, recording the log, and returning data error information to the strategy issuing end.
Then, step S12 is performed, where the energy management device sends the received policy to the policy issuing end to perform reverse calibration; the method comprises the following specific steps: the strategy issuing end (which can be a cloud centralized control system, a local centralized control system or an own HMI) displays the strategy sent and read from the energy management device, compares the strategy with the original data for confirmation, if the strategy issuing end passes the anti-correction confirmation and issues the confirmation information, the verification step of the step S13 is carried out, and if the strategy does not pass the anti-correction confirmation, the strategy updating is abandoned. The strategy issuing end can be a cloud centralized control system, a local centralized control system or an own HMI; specifically, the strategy issuing end has automatic comparison and calculation capacity and carries out automatic comparison and confirmation.
And step S13, finally, carrying out repeat and conflict check, wherein the energy management device retrieves the saved historical strategy in the enabled state, compares the historical strategy with the existing strategy, judges whether the historical strategy is repeated with the existing strategy or not according to the charging and discharging time periods and whether the time periods are overlapped or not, judges that the strategy conflicts if the historical strategy is repeated or overlapped, records logs and returns conflict error information, and judges that the strategy successfully enters step S2 if the historical strategy is not overlapped or overlapped.
Step S2, protection and verification; the method comprises the steps of explicit parameter verification and simulation operation verification; specifically, the method comprises two substeps, step S21, specifically, verifying out-of-limit and deviation states of explicitly set parameters in the strategy, wherein the parameters for verification include a charge and discharge time period, a charge and discharge rate, a floating charge voltage, a termination voltage, a conversion voltage, an SOC, a depth of discharge (DOD), and a charge and discharge power; the specific way of the out-of-limit check is as follows: judging by preset upper and lower parameter limits, setting a strategy parameter (P _ set) to satisfy that P _ min is more than or equal to P _ set and more than or equal to P _ max, wherein P _ min and P _ max are preset minimum and maximum values of the strategy parameter, if the maximum and minimum values of SOC are respectively set to be 90% and 30%, and if the maximum and minimum values of SOC exceed 90% and 30%, an out-of-limit error is generated, and the protection check is not passed; the deviation state check compares the set strategy parameter (P _ set) with a preset reference value (P _ ref), and if the deviation between the strategy parameter (P _ set) and the preset reference value (P _ ref) is too large, such as exceeding 50%, the protection check is not passed, and a deviation alarm is generated. In this embodiment, the preset reference value (P _ ref) is usually set according to the optimal operation experience of the distributed energy storage system, and represents the optimal operation state of the energy storage system, so that usually, P _ set should not generate a large deviation from P _ ref, and the large deviation represents that a policy generates a large change, which greatly affects the operation safety or the operation economy of the energy storage system.
And step S22, the operation verification content of the model mainly comprises daily charge-discharge cycle times and SOC, and the operation verification of the model is the verification of possible damage to the energy storage protection constraint generated by the strategy through simulation operation under the condition that the strategy adopts default parameters. Specifically, the method comprises a step S221 and a step S222, wherein in the step S221, daily charge and discharge cycle number verification is carried out, the daily charge and discharge cycle number verification is obtained by calculating all charge and discharge strategies in an enabled state on the energy management device, if the daily charge and discharge number exceeds a preset value, a log is recorded, and daily charge and discharge number out-of-limit error information is returned; and if the daily charge and discharge times do not exceed a preset value, carrying out the next verification.
And step S222, finally, carrying out SOC verification, wherein the SOC verification comprehensively considers the battery state of health (SOH) and the SOC limit requirements, simulates an operation strategy, and calculates the residual SOC after the operation of a discharge strategy so as to meet the minimum SOC requirements generated by power backup and the like. The battery capacity decays in use, so that under the same requirement of the residual capacity (such as the requirement of standby power), the residual SOC (SOC) residual ) Than initial SOC (SOC) min ) The minimum limit value of (2) is large, the capacity attenuation should be considered, the calculation is carried out by the current SOH and SOC limit values, and the calculation formula is as follows:
the energy management device calculates the actual residual SOC according to the discharge duration and the discharge multiplying power of the discharge strategy, and if the residual SOC is smaller than the SOC residual If so, the log is required to be recorded and protection error information is returned; if the remaining SOC is greater than or equal to the SOC residual Then, the process proceeds to step S3.
Finally, carrying out step S3, and checking the economy; specifically, after passing the protection verification, carrying out the economy verification; the economic verification is to judge whether the new strategy is executed to obtain the income exceeding the current strategy, and the specific mode is as follows: and (3) performing simulation operation on economic benefits generated by daily charge and discharge of all strategy combinations after the new strategy is added, wherein the formula is as follows: and (3) the daily income is daily charging electric quantity and charging electricity price and daily discharging electricity price, if the daily income is increased relative to the original strategy combination, the measurement is applied, and otherwise, an income abnormity prompt is returned.
In the invention, a monitoring module is responsible for managing and verifying an energy scheduling strategy, data integrity and validity verification, protection verification and profit verification are carried out on strategy parameters issued from a cloud end, and strategy updating is executed if triple verification is passed; otherwise, the strategy update is abandoned, the strategy abnormal change alarm is recorded and generated, and the strategy abnormal change alarm is reported to the cloud or the local centralized control system, so that the aim of protecting the energy storage system and the income is fulfilled.
The above embodiments are further illustrated and described in order to facilitate understanding of the invention, and no unnecessary limitations are to be understood therefrom, and any modifications, equivalents, and improvements made within the spirit and principle of the invention should be included therein.