Optical storage micro-grid operation control method based on centralized and distributed energy storage

Abstract

The invention relates to an optical storage micro-grid operation control method based on centralized and distributed energy storage, and the control method is applied to an optical storage direct-flexible building micro-grid system comprising at least one centralized energy storage system and a plurality of distributed energy storage systems. The method comprises the following steps: monitoring generated power and load demand power of a micro-grid system, and running states of a centralized energy storage system and distributed energy storage systems in real time; judging the running state of the micro-grid system according to the monitoring data; and based on the determined operation state, executing a preset cooperative control strategy corresponding to the state, and dynamically allocating charging and discharging instructions of centralized energy storage and distributed energy storage. According to the invention, efficient balance and dynamic scheduling of micro-grid level energy can be realized by coordinating charging and discharging behaviors of a centralized energy storage system and distributed energy storage in each building.

Description

Technical Field

[0001] This invention relates to the field of microgrid technology, and in particular to a method for operating and controlling a photovoltaic-storage microgrid based on centralized and distributed energy storage. Background Technology

[0002] Photovoltaic-storage-DC-flexible building microgrids are an important technological path to achieving low-carbon and intelligent building practices. Their operation and control strategies are crucial for improving renewable energy absorption capacity and system economics. Current technologies for photovoltaic-storage-DC-flexible microgrids with multiple building subsystems and hybrid energy storage architectures still have limitations in control architecture and strategies for achieving system-level cluster collaborative operation, optimized scheduling of centralized and distributed energy storage resources, and flexible reconfiguration of operational states. These limitations prevent the full realization of the comprehensive efficiency of hybrid energy storage systems.

[0003] Specifically, patent application CN202411503163.1, entitled "A Method and System for a Grid-Interconnected Photovoltaic-Storage-Direct-Flexible Building Power Distribution Structure," focuses on constructing a grid-interconnected power distribution structure to achieve regional autonomy and power sharing. However, this solution emphasizes physical interconnection and regional autonomy, lacking a coordinated optimization scheduling strategy for centralized and distributed energy storage from a global energy management perspective. Its control method does not clearly define the charging and discharging priorities and coordination mechanisms of centralized energy storage and distributed energy storage in various subsystems under different system operating states, making it difficult to optimize the overall efficiency and lifespan of the hybrid energy storage system.

[0004] For example, the patent application CN202410088373.2, "Low-voltage Distribution Area Photovoltaic-Storage Direct-Flexible Interconnection System," provides an interconnection device and control scheme for low-voltage distribution areas, aiming to improve power quality and the operational stability of energy storage equipment. However, this technical solution mainly focuses on the cluster management and equalization control of energy storage equipment of the same specification, without addressing the differentiated design and coordination issues in architecture and function between centralized large-scale energy storage systems and distributed energy storage systems within buildings. Therefore, it cannot meet the complex control requirements of layered, complementary, and coordinated centralized energy storage as a public energy pool and distributed energy storage in various buildings in near-field multi-building scenarios.

[0005] Furthermore, the patent application CN202410547688.9, entitled "A Fault Protection System and Method for Direct-to-Flexible Interconnection of Photovoltaic and Energy Storage," focuses on solving the problem of rapid fault current limiting and protection in dual-connection systems, ensuring the safety of system equipment. However, the core objective of this patent is system protection under fault conditions, and it does not address energy management and optimized scheduling during normal system operation. It lacks a mechanism for sensing the overall operating status of photovoltaic and energy storage power generation, building load, and hybrid energy storage system, and for formulating and executing coordinated control strategies accordingly, thus failing to improve the system's daily operating economy and energy utilization efficiency.

[0006] Furthermore, while both patents CN202211310265.2 ("A Cloud Energy Storage Scheduling Method Combining Distributed and Centralized Systems") and CN201711339210.3 ("A Hierarchical Energy Storage System and Control Method for Combined Centralized and Distributed Applications") propose the concept of combined centralized and distributed energy storage applications, their application scenarios and control objectives differ significantly from those of building microgrids. The former primarily focuses on the commercial scheduling and economic optimization of wide-area "cloud energy storage," while the latter emphasizes a hierarchical response architecture to meet the large-scale scheduling needs of the power grid. Neither of these patents addresses the specific requirements of building-integrated photovoltaic-storage-DC-flexible microgrids, such as high-proportion local renewable energy consumption, flexible power mutual assistance among subsystems, and dynamic priority collaborative control based on real-time operating status (e.g., power generation surplus / deficit), and designs a matching system architecture and refined operation control method. Summary of the Invention

[0007] The purpose of this invention is to provide a photovoltaic-storage microgrid operation control method based on centralized and distributed energy storage, which can achieve efficient energy balance and dynamic scheduling at the microgrid level by coordinating the charging and discharging behavior of centralized energy storage systems and distributed energy storage in various buildings.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a photovoltaic-storage microgrid operation control method based on centralized and distributed energy storage, wherein the control method is applied to a photovoltaic-storage DC-flexible building microgrid system comprising at least one centralized energy storage system and multiple distributed energy storage systems, the method comprising: Real-time monitoring of the microgrid system's power generation, load demand, centralized energy storage system, and the operating status of each distributed energy storage system; The operating status of the microgrid system is determined based on monitoring data; Based on the determined operating status, a preset collaborative control strategy corresponding to the status is executed to dynamically allocate charging and discharging commands for centralized energy storage and distributed energy storage.

[0009] Furthermore, the photovoltaic-storage-DC-flexible building microgrid system includes data acquisition equipment, data processing equipment, photovoltaic power generation units, DC bus, power loads connected to the DC bus, cluster control manager, sub-controllers connected to each unit, at least one centralized energy storage system, and multiple distributed energy storage systems set in each building subsystem. The sub-photovoltaic-storage-DC-flexible system is interconnected with a common cluster bus through a bidirectional power converter with flexible control function. The centralized energy storage system is also connected to the cluster bus. The cluster control manager connects and exchanges information with the local controllers of each sub-photovoltaic-storage-DC-flexible system, the distributed energy storage management system, and the centralized energy storage management system through a communication network. The data acquisition device is used to collect in real time the operating data of each sub-photovoltaic-storage-direct current-flexible system, the status data of the distributed energy storage system, and the status data of the centralized energy storage system within the near-field. The data acquisition device collects and uploads the data to the data processing device. The control device in the data acquisition device includes a processing unit connected to various sensors and metering instruments. The processing unit is responsible for receiving and initially processing the data from various sensors and metering instruments that serve as the collection points, and transmitting it to the data processing device and the cluster control manager. The data processing device receives and integrates real-time operating data from all sub-photovoltaic-storage-DC-flexible systems, distributed energy storage systems, and centralized energy storage systems collected by the data acquisition device, determines the operating status of the microgrid system, performs comprehensive analysis on the data, and generates and outputs centralized optimization instructions for the cluster control manager. The cluster control manager receives optimization instructions from the data processing device and real-time data from the data acquisition device. Based on the preset collaborative optimization strategy, it generates and sends coordinated charging and discharging instructions to the power conversion devices, distributed energy storage systems, and centralized energy storage systems of each sub-photovoltaic-storage-direct current-flexible system.

[0010] Furthermore, the operating states of the microgrid system include at least a surplus generation state and a deficit generation state; the surplus generation state is when the instantaneous value of the total distributed generation power within the microgrid is greater than the total load demand power within the system; the deficit generation state is when the instantaneous value of the total distributed generation power within the microgrid is less than the total load demand power within the system; when the condition is met... When the system is in a state of insufficient power generation, the criterion formula for switching operating states is as follows: ; The operating status is determined by the system's power generation. This represents the power required by the load.

[0011] Furthermore, when the system is in a state of power generation surplus, the coordinated control strategy implemented is as follows: the surplus power is prioritized to charge each distributed energy storage system until all distributed energy storage systems reach full charge or no longer accept charging; after the distributed energy storage system is saturated or cannot fully absorb the surplus power, the remaining surplus power is then used to charge the centralized energy storage system. Let the charging state of the i-th distributed energy storage system be . Its maximum state of charge is Charging power is The charging control logic satisfies the following formula: like ,but: ; in Let i be the maximum charging power of the i-th distributed energy storage system. This is the charging coefficient. Wait until all distributed energy storage systems are charged to... Then, it charges the centralized energy storage system; The centralized energy storage system consists of multiple sub-batteries. Let the state of charge of the j-th sub-battery be . Its maximum state of charge is Charging power is The system's total surplus power Total charging power of centralized energy storage system The allocation formula is obtained by subtracting the total power of distributed energy storage charging from the surplus power generated. ; ; Furthermore, the charging power of each sub-battery is allocated according to the optimization instructions, satisfying the following constraints and limited by the charging capacity of the sub-batteries: .

[0012] Furthermore, when the system is in a state of insufficient power generation, the coordinated control strategy is as follows: firstly, each distributed energy storage system is called upon to discharge in order to make up for the power deficit, until each distributed energy storage system reaches its discharge limit or is unable to provide the required power; after the discharge capacity of the distributed energy storage system is exhausted, the centralized energy storage system discharges to make up for the remaining power deficit. In situations of insufficient power generation, distributed energy storage systems are prioritized for discharge to compensate for the power deficit. Let the power deficit be... The available discharge power of the i-th distributed energy storage system The calculation is as follows: ; in For maximum discharge power, At minimum charge state, Discharge coefficient; the total available discharge power of the distributed energy storage system. ,like Then only the distributed energy storage system discharges, and the discharge power is allocated according to the optimized instructions; if Then, after the distributed energy storage system discharges, the remaining deficit... The discharge is supplemented by a centralized energy storage system; In the discharge control of a centralized energy storage system, let the available discharge power of the j-th sub-battery be... Total available discharge power The discharge power distribution satisfies: ; In addition, to ensure the safe operation of the centralized energy storage system, data acquisition equipment monitors the temperature of each sub-battery in real time. Set the temperature threshold to The safety control logic is implemented through the following formula: like Then, define the set of high-temperature sub-cells: ; from Select one or more sub-batteries with the highest temperature to disconnect. For high-temperature sub-battery assembly The temperature of the k-th sub-battery in the set is disconnected. for: ; After disconnection, the remaining sub-cells are assembled. Continue to maintain the normal operation of the centralized energy storage system. This represents the adjusted total state of charge (SNP) of the centralized energy storage system. This represents the maximum discharge capacity. At this point, the total capacity and power of the centralized energy storage system are adjusted as follows: ; ; This safety control mechanism operates continuously during charging and discharging to ensure the overall safety of the system.

[0013] Furthermore, the operating state of the microgrid system also includes a system self-balancing state. When the system is in the self-balancing state, the distributed generation power and the load demand power are basically balanced. The control strategy of the system self-balancing state is to maintain the existing operating point. Neither centralized energy storage nor distributed energy storage performs charging and discharging operations, or only performs minor power adjustments required to maintain its internal state.

[0014] Furthermore, the generation of the optimization instructions is further described as follows: based on the objective function, the optimization instructions are generated by solving a constrained optimization problem, and the general form of the objective function is: ; in For grid interaction costs, In order to exchange power with the power grid, The energy storage wear coefficient is defined by constraints including power balance, energy storage state limitations, and safe temperature limits.

[0015] Furthermore, when allocating charging and discharging priorities, the collaborative control strategy combines the current state of charge, health status, charging and discharging efficiency, and power limitations of each energy storage unit to perform secondary optimization allocation of the charging and discharging power of each unit within the same type of energy storage unit.

[0016] Furthermore, the centralized energy storage system consists of multiple sub-batteries, and the control method also includes a centralized energy storage system safety management step: monitoring the temperature of each sub-battery in real time through data acquisition equipment; when the temperature of at least one sub-battery is detected to be higher than a set threshold, controlling the centralized energy storage system to disconnect one or more sub-batteries with the highest temperature from the electrical connection, and having the remaining sub-batteries maintain the normal operation of the centralized energy storage system to ensure system safety.

[0017] The beneficial effects of this invention are: 1. Effectively Achieve Coordinated and Optimized Scheduling of Energy Storage Resources: This invention proposes a coordinated operation control method for centralized and distributed energy storage, effectively solving the problem of insufficient resource utilization or increased cycle losses caused by the incoordination of charging and discharging behaviors between the two in traditional control methods. Based on a microgrid operating state intelligent switching control strategy, this method prioritizes the use of distributed energy storage when there is a power generation surplus, and then activates centralized energy storage as the surplus expands; when there is a power generation shortage, it prioritizes the use of distributed energy storage for support, and then supplements the shortfall with centralized energy storage. This achieves optimized allocation and efficient utilization of energy storage resources, improving the overall economic efficiency of the system.

[0018] 2. Improved System Operation Economy and Equipment Lifespan: The tiered charging and discharging strategy of this invention optimizes the scheduling logic of energy storage units, enabling the rational arrangement of the action sequence and depth of different levels of energy storage based on the magnitude of power deficit or surplus. This strategy helps reduce the frequency of high-power operations in centralized energy storage, while mitigating the impact of collective switching of distributed energy storage. Therefore, while ensuring power supply reliability, it effectively delays the performance degradation of each energy storage unit, reducing the overall operation and maintenance costs of the system throughout its lifecycle.

[0019] 3. Enhanced System Dynamic Response and Power Quality: This invention constructs a rapid sensing and decision-making control architecture through hierarchical collaboration among data acquisition devices, data processing devices, and a cluster control manager. This architecture can determine the system's operating status in real time and quickly issue corresponding coordinated charging and discharging commands, ensuring timely response to photovoltaic output and load fluctuations. Therefore, this invention significantly enhances the microgrid's autonomous regulation capability, effectively maintaining system voltage and frequency stability and improving regional power quality.

[0020] 4. Improved System Power Supply Reliability and Operational Resilience: The operating states and corresponding collaborative control strategies defined in this invention provide clear and reliable control plans for the system to cope with various power imbalance scenarios. In extreme operating conditions or when some equipment fails, such as when sub-batteries in centralized energy storage experience excessively high temperatures, this method can monitor and isolate faulty battery cells in real time, relying on the remaining sub-batteries to maintain the operation of centralized energy storage. This allows for dynamic adjustment of the control strategy based on remaining available energy storage resources, achieving functional complementarity and backup support between different energy storage forms. This significantly enhances the resilience of building microgrids to internal disturbances and external shocks, ensuring continuous power supply to critical loads.

[0021] 5. Possesses excellent architectural universality and scalability: The operation control method and system architecture proposed in this invention do not depend on specific equipment models or capacity configurations. Their core lies in strategy partitioning and collaborative logic based on operational status. This clearly defined method can be flexibly applied to various building microgrid scenarios involving both centralized and distributed energy storage in different proportions, and provides a scalable control framework for future access to more diverse distributed resources, demonstrating promising prospects for widespread application. Attached Figure Description

[0022] Figure 1 Architecture diagram of a photovoltaic-storage-DC-flexible building microgrid system; Figure 2 This is a flowchart of the control method of the present invention. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] Please see Figure 1 This invention provides an embodiment: a photovoltaic-storage microgrid operation control method based on centralized and distributed energy storage. The control method is applied to a photovoltaic-storage-DC-flexible building microgrid system comprising at least one centralized energy storage system and multiple distributed energy storage systems. The method includes: Real-time monitoring of the microgrid system's power generation, load demand, centralized energy storage system, and the operating status of each distributed energy storage system; The operating status of the microgrid system is determined based on monitoring data; Based on the determined operating state, a preset coordinated control strategy corresponding to the state is executed to dynamically allocate charging and discharging commands for centralized and distributed energy storage. By coordinating the charging and discharging behavior of centralized and distributed energy storage, the overall operating efficiency of the microgrid system is optimized and the cyclic loss of energy storage resources is reduced. Please continue reading. Figure 1As shown, in one embodiment of the present invention, the photovoltaic-storage-DC-flexible building microgrid system includes data acquisition equipment, data processing equipment, photovoltaic power generation units, a DC bus, and electrical loads connected to the DC bus. Figure 1 The system includes a DC load connected to the DC bus, a cluster control manager, sub-controllers connecting each unit, at least one centralized energy storage system, and multiple distributed energy storage systems installed in each building subsystem. The sub-photovoltaic-storage-DC-flexible system is interconnected with a common cluster bus via a bidirectional power converter with flexible control capabilities. The centralized energy storage system is also connected to the cluster bus. The cluster control manager connects and exchanges information with the local controllers of each sub-photovoltaic-storage-DC-flexible system, the distributed energy storage management system, and the centralized energy storage management system via a communication network. Each sub-photovoltaic-storage-DC-flexible system is... Figure 1 All content within the dashed box is controlled by the corresponding flexible regulator (energy manager) for each subsystem.

[0025] The data acquisition device is used to collect in real time the operating data of each sub-photovoltaic-storage-direct current-flexible system, the status data of the distributed energy storage system, and the status data of the centralized energy storage system within the near-field. The data is then collected and uploaded to the data processing device. The control device within the data acquisition device includes a processing unit connected to various sensors and metering instruments. The processing unit is responsible for receiving and initially processing the data from various sensors and metering instruments that serve as acquisition points, and transmitting it to the data processing device and the cluster control manager. The "distributed energy storage system" refers to the small energy storage devices configured within each sub-photovoltaic-storage-direct current-flexible system, while the "centralized energy storage system" refers to the large energy storage devices configured separately outside the sub-systems.

[0026] The data processing device receives and integrates real-time operating data from all sub-photovoltaic-storage-DC-flexible systems, distributed energy storage systems, and centralized energy storage systems collected by the data acquisition device, determines the operating status of the microgrid system, performs comprehensive analysis on the data, and generates and outputs centralized optimization instructions for the cluster control manager. The cluster control manager receives optimization instructions from the data processing device and real-time data from the data acquisition device. Based on a preset collaborative optimization strategy, it generates and sends coordinated charging and discharging instructions to the power conversion devices, distributed energy storage systems, and centralized energy storage systems of each sub-photovoltaic-storage-DC-flexible system. The power conversion device can specifically be a DC / DC converter. Please continue reading. Figure 1As shown, in one embodiment of the present invention, the operating states of the microgrid system include at least a power surplus state and a power shortage state; the power surplus state is a state in which the instantaneous value of the total distributed generation power in the microgrid is greater than the total load demand power in the system; the power shortage state is a state in which the instantaneous value of the total distributed generation power in the microgrid is less than the total load demand power in the system; when the condition is met... At that time, the system is in a state of power generation surplus; when the condition is met... When the system is in a state of insufficient power generation, the criterion formula for switching operating states is as follows: ; The operating status is determined by the system's power generation. This represents the power required by the load.

[0027] Please continue reading. Figure 1 As shown, in one embodiment of the present invention, when the system is in a state of power generation surplus, the coordinated control strategy executed is as follows: the surplus power is preferentially used to charge each distributed energy storage system until all distributed energy storage systems reach full charge or no longer accept charging; after the distributed energy storage system is saturated or cannot fully absorb the surplus power, the remaining surplus power is then used to charge the centralized energy storage system. Let the charging state of the i-th distributed energy storage system be . Its maximum state of charge is Charging power is The charging control logic satisfies the following formula: like ,but: ; in Let i be the maximum charging power of the i-th distributed energy storage system. This is the charging coefficient. Wait until all distributed energy storage systems are charged to... Then, it charges the centralized energy storage system; The centralized energy storage system consists of multiple sub-batteries. Let the state of charge of the j-th sub-battery be . Its maximum state of charge is Charging power is The system's total surplus power Total charging power of centralized energy storage system The allocation formula is obtained by subtracting the total power of distributed energy storage charging from the surplus power generated. ; ; Furthermore, the charging power of each sub-battery is allocated according to the optimization instructions, satisfying the following constraints and limited by the charging capacity of the sub-batteries: .

[0028] Please continue reading. Figure 1 As shown, in one embodiment of the present invention, when the system is in a state of insufficient power generation, the coordinated control strategy is as follows: each distributed energy storage system is preferentially called to discharge in order to make up for the power shortage, until each distributed energy storage system reaches the discharge lower limit or cannot provide the required power; after the discharge capacity of the distributed energy storage system is exhausted, the centralized energy storage system discharges to make up for the remaining power shortage. In situations of insufficient power generation, distributed energy storage systems are prioritized for discharge to compensate for the power deficit. Let the power deficit be... The available discharge power of the i-th distributed energy storage system The calculation is as follows: ; in For maximum discharge power, At minimum charge state, Discharge coefficient; the total available discharge power of the distributed energy storage system. ,like Then only the distributed energy storage system discharges, and the discharge power is allocated according to the optimized instructions; if Then, after the distributed energy storage system discharges, the remaining deficit... The discharge is supplemented by a centralized energy storage system; In the discharge control of a centralized energy storage system, let the available discharge power of the j-th sub-battery be... Total available discharge power The discharge power distribution satisfies: ; In addition, to ensure the safe operation of the centralized energy storage system, data acquisition equipment monitors the temperature of each sub-battery in real time. Set the temperature threshold to The safety control logic is implemented through the following formula: like Then, define the set of high-temperature sub-cells: ; from Select one or more sub-batteries with the highest temperature to disconnect. For high-temperature sub-battery assembly The temperature of the k-th sub-battery in the set is disconnected. for: ; After disconnection, the remaining sub-cells are assembled. Continue to maintain the normal operation of the centralized energy storage system. This represents the adjusted total state of charge (SNP) of the centralized energy storage system. This represents the maximum discharge capacity. At this point, the total capacity and power of the centralized energy storage system are adjusted as follows: ; ; This safety control mechanism operates continuously during charging and discharging to ensure the overall safety of the system.

[0029] Please continue reading. Figure 1 As shown, in one embodiment of the present invention, the operating state of the microgrid system also includes a system self-balancing state. When the system is in the system self-balancing state, the distributed generation power and the load demand power are basically balanced. The control strategy of the system self-balancing state is to maintain the existing operating point. Neither centralized energy storage nor distributed energy storage performs charging and discharging actions, or only performs small power adjustments required to maintain its internal state.

[0030] Please continue reading. Figure 1 As shown, in one embodiment of the present invention, the generation of the optimization instruction further comprises: based on the objective function, the optimization instruction is generated by solving a constraint optimization problem, and the general form of the objective function is: ; in For grid interaction costs, In order to exchange power with the power grid, Let be the energy storage wear coefficient. Constraints include power balance, energy storage state limitations, and safe temperature limits. The optimization instruction is to obtain the solution that minimizes this objective function.

[0031] Please continue reading. Figure 1 As shown, in one embodiment of the present invention, the method of the present invention also considers the current state of charge, health status, charge / discharge efficiency, and power limitations of each energy storage unit during the control process; when allocating charge / discharge priorities, the collaborative control strategy combines the current state of charge, health status, charge / discharge efficiency, and power limitations of each energy storage unit to perform secondary optimization allocation of the charge / discharge power of each unit within the same type of energy storage unit. In the present invention, the determination of the above operating status and the execution of the collaborative control strategy is a continuous dynamic process; the cluster control manager continuously receives data uploaded by the acquisition device, determines the status, and generates charge / discharge commands, realizing seamless collaboration and mode switching between centralized and distributed energy storage in different operating scenarios. The charge / discharge priority allocation of the collaborative control strategy includes secondary optimization allocation of the charge / discharge power of each unit within the same type of energy storage unit; wherein, the secondary optimization allocation combines the current state of charge, health status, charge / discharge efficiency, and power limitations of each energy storage unit.

[0032] Please continue reading. Figure 1 As shown, in one embodiment of the present invention, the centralized energy storage system comprises multiple sub-batteries. The control method further includes a centralized energy storage system safety management step: real-time monitoring of the temperature of each sub-battery using data acquisition equipment; when the temperature of at least one sub-battery is detected to be higher than a set threshold, the centralized energy storage system is controlled to disconnect one or more sub-batteries with the highest temperature from the electrical connection, allowing the remaining sub-batteries to maintain the normal operation of the centralized energy storage system and ensure system safety. The centralized energy storage system comprises multiple sub-batteries. Specific Implementation

[0033] 1. Architecture of Building Microgrid Operation and Control System Based on Centralized Energy Storage and Distributed Energy Storage (PV-Storage-DC-Flexible) This invention discloses a photovoltaic-storage-DC-flexible building microgrid operation and control system based on centralized and distributed energy storage, comprising data acquisition equipment, data processing equipment, a cluster control manager, and a cluster DC bus connection control device, such as... Figure 1 As shown, the cluster DC bus connection control device can be a DC / DC converter, which controls the connection and disconnection between each subsystem and the cluster bus.

[0034] The data acquisition equipment is used to collect real-time operational data of each sub-PV-Storage-DC-Flexible system, status data of distributed energy storage systems, and status data of centralized energy storage systems within the near-field area. The collected data includes, but is not limited to, building load data for each sub-PV-Storage-DC-Flexible system, distributed PV power generation data, charge / discharge status and remaining capacity data of distributed energy storage systems, and charge / discharge status, remaining capacity, and health status data of centralized energy storage systems. This data is collected by the data acquisition equipment and uploaded to the data processing equipment, providing a basis for the system's overall energy management and coordinated control of centralized and distributed energy storage.

[0035] In this system, each sub-PV-Storage-DC-Flexible system is interconnected with a common cluster DC bus via a bidirectional power converter with flexible control capabilities. The centralized energy storage system is also connected to this cluster DC bus, serving as a common energy buffer for the entire microgrid. The cluster control manager connects and exchanges information with the local controllers of each sub-PV-Storage-DC-Flexible system, the distributed energy storage management system, and the centralized energy storage management system via a communication network.

[0036] The control unit within the data acquisition equipment includes a processing unit, such as a microprocessor or programmable logic controller, that connects to various sensors and meters. This processing unit is responsible for receiving and initially processing data from each acquisition point and transmitting it to the data processing equipment and the cluster control manager.

[0037] The cluster control manager receives optimization instructions from the data processing equipment and real-time data from the data acquisition equipment. Based on the preset collaborative optimization strategy, it generates and sends coordinated charging and discharging instructions to the power conversion equipment, distributed energy storage system, and centralized energy storage system of each sub-photovoltaic-storage-direct current-flexible system, so as to achieve flexible mutual assistance and optimized allocation of power.

[0038] 2. Data processing equipment and its control device The data processing equipment receives and integrates real-time operational data from all sub-PV-storage-DC-flexible systems, distributed energy storage systems, and centralized energy storage systems obtained from the data acquisition equipment. This data forms the basis for system-level energy management, formulating coordinated scheduling strategies for centralized and distributed energy storage, and achieving flexible interconnection control among the various sub-PV-storage-DC-flexible systems. The data processing equipment includes, but is not limited to, servers, network devices, and databases.

[0039] Through a collaborative operation control method, the data processing equipment performs comprehensive analysis, optimization calculations, and status assessments on the collected data. Based on this, it generates and outputs centralized optimization instructions for the cluster control manager. These instructions include the expected power exchange values ​​for each sub-photovoltaic-storage-DC-flexible system, the charging and discharging plans for the distributed energy storage system, and the charging and discharging plans for the centralized energy storage system, thus providing a decision-making basis for the cluster control manager to execute collaborative operation control strategies.

[0040] 3. The use of connectors between subsystems and the cluster bus within the cluster system and the methods for coordinated operation control. The use and coordinated operation control method of the connectors (DC / DC converters) between subsystems and the cluster bus within the cluster system is as follows: When a subsystem needs planned maintenance, experiences an internal fault, or responds to a centralized charging / discharging command, the cluster control manager controls the bidirectional power converter of that subsystem to switch its connection with the cluster DC bus to a controllable disconnect state or a current-limiting operation state. This flexible connection mechanism ensures that changes in the state of a single subsystem will not impact the stable operation of other subsystems and the centralized energy storage system within the cluster, while also supporting flexible reconfiguration of the system operating topology.

[0041] The core of this invention lies in the operational control method that coordinates the data processing device and the cluster control manager, such as... Figure 2 As shown, this method defines different operating states of a microgrid and uses an intelligent switching control strategy based on these states. The operating state is determined by the system's power generation. With load demand power The comparison determines the outcome. When the conditions are met... At that time, the system is in a state of power generation surplus; when the condition is met... At this time, the system is in a state of insufficient power generation. The criterion formula for switching operating states is as follows: ; The method comprises two core collaborative control modes. In a surplus generation state, priority is given to charging the distributed energy storage systems of each sub-photovoltaic-storage-DC-flexible system. Let the charging state of the i-th distributed energy storage system be... Its maximum state of charge is Charging power is The charging control logic satisfies the following formula: like ,but: ; in Let i be the maximum charging power of the i-th distributed energy storage system. This is the charging coefficient. Wait until all distributed energy storage systems are charged to... Then, it charges the centralized energy storage system. The centralized energy storage system consists of multiple sub-batteries. Let the charging state of the j-th sub-battery be... Its maximum state of charge is Charging power is The system's total surplus power Total charging power of centralized energy storage system The allocation formula is obtained by subtracting the total power of distributed energy storage charging from the surplus power generated. ; ; Furthermore, the charging power of each sub-battery is allocated according to the optimization instructions, satisfying the following constraints and being limited by the charging capacity of the sub-batteries.

[0042] ; In situations of insufficient power generation, distributed energy storage systems are prioritized for discharge to compensate for the power deficit. Let the power deficit be... The available discharge power of the i-th distributed energy storage system The calculation is as follows: ; in For maximum discharge power, At minimum charge state, This represents the discharge coefficient. The total available discharge power of the distributed energy storage system. .like Then only the distributed energy storage system discharges, and the discharge power is allocated according to the optimized instructions; if Then, after the distributed energy storage system discharges, the remaining deficit... The discharge is supplemented by a centralized energy storage system.

[0043] In the discharge control of a centralized energy storage system, let the available discharge power of the j-th sub-battery be... Total available discharge power The discharge power distribution satisfies: ; In addition, to ensure the safe operation of the centralized energy storage system, data acquisition equipment monitors the temperature of each sub-battery in real time. Set the temperature threshold to... The safety control logic is implemented using the following formula: like Then, define the set of high-temperature sub-cells: ; from Select one or more sub-batteries with the highest temperature to disconnect. For high-temperature sub-battery assembly The temperature of the k-th sub-battery in the set is disconnected. for: ; After disconnection, the remaining sub-cells are assembled. Continue to maintain the normal operation of the centralized energy storage system. This represents the adjusted total state of charge (SNP) of the centralized energy storage system. This represents the maximum discharge capacity. At this point, the total capacity and power of the centralized energy storage system are adjusted as follows: ; ; This safety control mechanism operates continuously during charging and discharging to ensure the overall safety of the system.

[0044] Based on optimization instructions issued by the data processing equipment and combined with real-time operating status, the cluster control manager dynamically executes the aforementioned charging and discharging priority control and safety control. This effectively coordinates the charging and discharging behaviors of centralized and distributed energy storage, improves the overall utilization rate of energy storage resources, and optimizes the cycle life of each energy storage unit. The optimization instructions are generated by solving a constraint optimization problem based on objective functions such as minimizing operating costs or maximizing lifespan. Their general form is: ; in For grid interaction costs, In order to exchange power with the power grid, The energy storage wear coefficient is defined by constraints including power balance, energy storage state limitations, and safe temperature limits.

[0045] This invention addresses the problem that existing photovoltaic-storage-DC-flexible systems mostly adopt a single distributed energy storage mode, which makes it difficult to achieve global energy optimization and redundancy backup in near-field multi-building scenarios. This invention aims to establish a hierarchical collaborative control mechanism by coordinating the charging and discharging behavior of centralized energy storage systems and distributed energy storage in each building, thereby ensuring the independent operation capability of each sub-building system while achieving efficient energy balance and dynamic scheduling at the microgrid level.

[0046] To construct an optimized scheduling architecture for hybrid energy storage systems that adapts to the needs of multiple scenarios.

[0047] This invention presents an innovative operation control architecture that dynamically formulates joint operation strategies for centralized and distributed energy storage based on real-time electricity prices, load demand, and photovoltaic power generation forecasts. This architecture overcomes the spatial and functional limitations of various energy storage resources, enabling flexible configuration and complementary advantages across multiple services such as power support, energy transfer, and backup power, thereby improving overall economic efficiency and power supply reliability.

[0048] Improve the overall operating efficiency and economy of building microgrids with photovoltaic, energy storage, direct current and flexible power generation.

[0049] Through the aforementioned collaborative control method and optimized scheduling architecture, this invention can effectively mitigate renewable energy fluctuations, reduce peak grid interaction power, and decrease operating costs. Simultaneously, by establishing bidirectional support capabilities between centralized and distributed energy storage, it enhances the system's resilience to internal faults and external grid anomalies, thereby extending the lifespan of energy storage devices and improving the overall energy utilization efficiency and long-term operational economy of the microgrid.

[0050] In summary, this invention defines different operating states of a microgrid and implements an intelligent switching control strategy based on these states. It includes two core control modes: when the system generates surplus power, it prioritizes charging distributed energy storage, which is then used to charge centralized energy storage after being fully charged; when power generation is insufficient, it prioritizes discharging distributed energy storage, followed by supplementation by centralized energy storage. Furthermore, the centralized energy storage employs a modular structure composed of multiple sub-batteries and features a temperature-monitored safety disconnection mechanism. When the temperature of one or more sub-batteries exceeds the limit, the high-temperature unit is automatically isolated from the system, while the remaining units maintain operation, thus ensuring system safety. Based on the real-time status and demand of the microgrid, the optimal control mode is dynamically selected, and the optimal charging and discharging sequence for centralized and distributed energy storage is determined. This invention not only achieves hierarchical and efficient utilization of energy storage resources but also significantly enhances the system's ability to cope with load fluctuations and intermittent renewable energy generation. It effectively improves the overall operating efficiency and autonomy of the photovoltaic-storage-DC-flexible building microgrid, extends the service life of key equipment, and reduces dependence on and impact on the upper-level power grid while ensuring local power supply reliability.

[0051] The above description is only a preferred embodiment of the present invention and should not be construed as a limitation of this application. All equivalent changes and modifications made in accordance with the scope of the patent application of the present invention should be covered by the present invention.

Claims

1. A method for operation control of a micro-grid based on centralized and distributed energy storage, characterized in that, The control method is applied to a photovoltaic energy storage direct flexible building micro-grid system comprising at least one centralized energy storage system and a plurality of distributed energy storage systems, and the method comprises: Real-time monitoring of power generation, load demand, operation state of the centralized energy storage system and each distributed energy storage system of the micro-grid system; Determining the operation state of the micro-grid system according to the monitoring data; Based on the determined operation state, a preset cooperative control strategy corresponding to the state is executed to dynamically allocate the charge and discharge instructions of the centralized energy storage and the distributed energy storage. 2.The operation control method of the centralized and distributed energy storage based optical storage micro-grid according to claim 1, characterized in that: The photovoltaic energy storage direct flexible building micro-grid system comprises a data acquisition device, a data processing device, a photovoltaic power generation unit, a direct current bus, an electrical load connected to the direct current bus, a cluster control manager, a sub-controller connected to each unit, at least one centralized energy storage system, and a plurality of distributed energy storage systems arranged in each building subsystem; The sub-photovoltaic energy storage direct flexible system is interconnected through a bidirectional power converter with flexible control function and a public cluster bus, the centralized energy storage system is also connected to the cluster bus, and the cluster control manager is connected and information is exchanged with the local controller of each sub-photovoltaic energy storage direct flexible system, the distributed energy storage management system and the centralized energy storage management system through a communication network; The data acquisition device is used to collect the operation data of each sub-photovoltaic energy storage direct flexible system, the state data of the distributed energy storage system and the state data of the centralized energy storage system in the near field in real time, and the data acquisition device collects and uploads the data to the data processing device; The control device in the data acquisition device comprises a processing unit connected to various sensors and meters, which is responsible for receiving and preliminarily processing data from various sensors and meters as collection points, and transmitting them to the data processing device and the cluster control manager; The data processing device receives and integrates all real-time operation data of the sub-photovoltaic energy storage direct flexible system, the distributed energy storage system and the centralized energy storage system collected by the data acquisition device, determines the operation state of the micro-grid system, and comprehensively analyzes the data to generate and output centralized optimization instructions for the cluster control manager; The cluster control manager receives the optimization instructions from the data processing device and the real-time data from the data acquisition device, generates and sends coordinated charge and discharge instructions to the power conversion device of each sub-photovoltaic energy storage direct flexible system, the distributed energy storage system and the centralized energy storage system according to the preset cooperative optimization strategy. 3.The operation control method of the centralized and distributed energy storage based optical storage micro-grid according to claim 1, characterized in that: The operation state of the micro-grid system comprises at least a power generation surplus state and a power generation deficiency state; the power generation surplus state is a state that the total power of the distributed power generation in the micro-grid is greater than the total load demand power in the system; the power generation deficiency state is a state that the total power of the distributed power generation in the micro-grid is less than the total load demand power in the system; when the condition is met, the system is in the power generation surplus state; when the condition is met, the system is in the power generation deficiency state, and the criterion formula of the operation state switching is as follows: ； Psystem is the system generation power, Pload is the load demand power. 4.The operation control method of the centralized and distributed energy storage based optical storage micro-grid according to claim 3, characterized in that, When the system is in a power generation surplus state, the cooperative control strategy executed is to preferentially charge the surplus power to each distributed energy storage system until all distributed energy storage systems reach a full charge state or no longer accept charging; After the distributed energy storage system is fully charged or cannot completely consume the surplus power, the remaining surplus power is charged to the centralized energy storage system; Let the state of charge of the ith distributed energy storage system be , the maximum state of charge be , the charging power be , and the charging control logic satisfy the following equation: If then: ； wherein is the maximum charging power of the ith distributed energy storage system, is the charging coefficient. After all distributed energy storage systems are charged to the centralized energy storage system is charged. The centralized energy storage system is composed of multiple sub-batteries, the state of charge of the jth sub-battery is SOCj , the maximum state of charge is SOCmax , the charging power is Pj , the total surplus power of the system is Psurplus ; the total charging power of the centralized energy storage system is Ptotal obtained by subtracting the total charging power of the distributed energy storage from the power generation surplus power, and the distribution formula is: ； ； And the charging power of each sub-battery is allocated according to the optimization instructions, meets the following constraints, and is limited by the charging capacity of the sub-battery: 。 5. The operation control method of the centralized and distributed energy storage based optical storage micro-grid according to claim 3, characterized in that, When the system is in the power generation insufficient state, the cooperative control strategy executed is: preferentially calling each distributed energy storage system to discharge to make up for the power shortage until each distributed energy storage system reaches the lower limit of discharge or cannot provide the required power; after the discharge capacity of the distributed energy storage system is exhausted, the centralized energy storage system is discharged to make up for the remaining power shortage; In the insufficient power generation state, the distributed energy storage system is preferentially called to discharge to make up for the power shortage, and the power shortage is , the available discharge power of the i th distributed energy storage system is calculated as follows: ； wherein is the maximum discharge power, is the minimum state of charge, is the discharge coefficient; total available discharge power of the distributed energy storage system if only discharge by the distributed energy storage system, the discharge power is distributed according to the optimization instruction; if after discharging by the distributed energy storage system, the remaining shortage is supplemented by the centralized energy storage system; In the discharge control of the centralized energy storage system, the available discharge power of the jth sub-battery is , the total available discharge power ; the discharge power distribution satisfies: ； In addition, in order to ensure the safe operation of the centralized energy storage system, the data acquisition device monitors the temperature of each sub-battery in real time , the temperature threshold is set to , and the safety control logic is realized by the following formula: If then define the high temperature sub-battery set: ； The temperature of the highest one or several of the sub-batteries is selected from the set and disconnected, The set of sub-batteries at high temperature is disconnected, The temperature of the kth sub-battery in the set of sub-batteries at high temperature is disconnected, is ； remaining sub-battery set after disconnection Continuing to maintain normal operation of the centralized energy storage system, for the centralized energy storage system to adjust the total state of charge, for the maximum discharge capacity, at this time the total capacity and power of the centralized energy storage system are adjusted as follows: ； ； The safety control mechanism continuously runs in the charging and discharging process to ensure the overall safety of the system. 6.The operation control method of the centralized and distributed energy storage based optical storage micro-grid according to claim 1, characterized in that: The operating state of the micro-grid system further includes a system self-balancing state, when in the system self-balancing state, the distributed power generation power and the load demand power are basically balanced; the control strategy of the system self-balancing state is to maintain the existing operating point, and the centralized energy storage and the distributed energy storage do not perform charging and discharging actions, or only perform a small power adjustment required to maintain the internal state. 7.The operation control method of the centralized and distributed energy storage based optical storage micro-grid according to claim 2, characterized in that, The generation of the optimization instruction is further based on an objective function, and the optimization instruction is generated by solving a constrained optimization problem, and the general form of the objective function is: ； wherein is the grid interaction cost, is the power exchanged with the grid, is the energy storage wear coefficient, the constraints include power balance, energy storage state limits, and safe temperature limits. 8.The centralized and distributed energy storage based optical storage micro-grid operation control method according to any one of claims 1 to 7, characterized in that: When the cooperative control strategy performs charging and discharging priority allocation, the charging and discharging power of each unit in the same type of energy storage unit is secondarily optimized and allocated in combination with the current state of charge, health state, charging and discharging efficiency and power limit of each energy storage unit. 9.The centralized and distributed energy storage based optical storage micro-grid operation control method according to any one of claims 1 to 7, characterized in that, The centralized energy storage system is composed of a plurality of sub-batteries, and the control method further includes a centralized energy storage system safety management step: the temperature of each sub-battery is monitored in real time through a data acquisition device; when it is monitored that the temperature of at least one sub-battery is higher than a set threshold, the centralized energy storage system is controlled to disconnect the sub-battery or sub-batteries with the highest temperature from electrical connection, and the remaining sub-batteries maintain the normal operation of the centralized energy storage system, ensuring the safety of the system.

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