A multi-objective collaborative control device and method for a low-voltage distribution area energy storage system

Abstract

This application discloses a multi-objective collaborative control device and method for a low-voltage distribution area energy storage system. The device includes: a data acquisition module, a single-phase energy storage module group, a collaborative control module, a communication module, and a safety protection module. The output terminals of the data acquisition module and the safety protection module are connected to the input terminal of the collaborative control module. The output terminal of the collaborative control module is connected to the single-phase energy storage module group. The communication module communicates bidirectionally with the collaborative control module to achieve data interaction. The data acquisition module is used to collect low-voltage distribution area operating parameters and identify electricity price periods. The single-phase energy storage module group is used to achieve differentiated charging and discharging regulation. The collaborative control module is used to generate charging and discharging control commands. The communication module is used to ensure real-time data transmission. The safety protection module is used to achieve system anomaly protection.

Description

Technical Field

[0001] This application relates to the field of low-voltage distribution network operation control technology, and in particular to a multi-objective collaborative control device and method for a low-voltage distribution area energy storage system. Background Technology

[0002] Currently, low-voltage distribution area energy storage is mainly based on pilot demonstrations, with insufficient large-scale applications. Its core purpose is to address distributed photovoltaic (PV) grid integration, low voltage / heavy overload, power supply protection, and power quality management. The mainstream technology is lithium iron phosphate (LFP), while emerging technologies (semi-solid-state, sodium-ion batteries, and flow batteries) are gradually being implemented. Profitability and operation and maintenance are the main bottlenecks. Large-scale commercial applications have not yet been achieved; projects are mostly in the hundreds of kW / kWh range, dispersed in rural areas, PV-rich areas, and areas with weak end-point distribution. Furthermore, traditional three-phase imbalance regulation relies heavily on passive compensation devices, and traditional peak-shaving and valley-filling solutions lack linkage control with the load characteristics of the distribution area.

[0003] Existing energy storage applications cannot simultaneously address three-phase imbalance regulation, transformer load optimization, and peak-valley arbitrage, resulting in low resource utilization. Regulation effects are poor; traditional passive compensation devices have slow response times and cannot flexibly adapt to load fluctuations. Traditional peak-shaving and valley-filling schemes have low control precision, making it difficult to match the dynamic operating needs of distribution areas. Equipment utilization is insufficient, with significant peak-valley fluctuations in transformer load rates, and the problems of overload operation during peak hours and low load rates during off-peak hours remain unresolved. At the technical design level, existing solutions lack a multi-objective collaborative control concept and have not established a linkage mechanism of "power quality optimization - equipment load regulation - economic benefit improvement." At the device structure level, existing energy storage systems are mostly monolithic designs, unable to achieve differentiated regulation based on three-phase load differences. At the control logic level, there is a lack of intelligent algorithms adapted to the load characteristics and electricity pricing policies of low-voltage distribution areas, resulting in rigid control strategies that cannot dynamically respond to changes in the operating status of distribution areas. Summary of the Invention

[0004] This application proposes a multi-objective collaborative control device and method for low-voltage distribution area energy storage systems. The purpose is to overcome the shortcomings of existing technologies and solve problems such as the single function of existing low-voltage distribution area energy storage applications, low resource utilization, long investment payback period, poor regulation effect, and excessive transformer load rate fluctuation. The application provides a collaborative control device and method for low-voltage distribution area energy storage, which achieves the coordinated operation of three objectives: three-phase imbalance regulation, transformer load optimization, and peak-valley electricity price arbitrage. This improves the power supply quality of low-voltage distribution areas, reduces grid operation losses, and increases the return on investment of energy storage systems.

[0005] On one hand, this application provides a multi-objective collaborative control device for a low-voltage distribution area energy storage system. The device includes: a data acquisition module, a single-phase energy storage module group, a collaborative control module, a communication module, and a safety protection module. The output terminals of the data acquisition module and the safety protection module are connected to the input terminal of the collaborative control module. The output terminal of the collaborative control module is connected to the single-phase energy storage module group. The communication module communicates bidirectionally with the collaborative control module to achieve data interaction. The data acquisition module is used to collect low-voltage distribution area operating parameters and identify electricity price periods. The single-phase energy storage module group is used to achieve differentiated charging and discharging regulation. The collaborative control module is used to generate charging and discharging control commands. The communication module is used to ensure real-time data transmission. The safety protection module is used to achieve system anomaly protection.

[0006] In one implementation of this application, the data acquisition module comprises a three-phase current sensor, a three-phase voltage sensor, a transformer load rate monitoring terminal, and an electricity price period identification unit; the three-phase current sensor and the three-phase voltage sensor are installed at the low-voltage side outgoing line of the transformer, the transformer load rate monitoring terminal calculates the load rate by collecting transformer operating parameters and feeds back the equipment operating status; the electricity price period identification unit pre-stores peak-valley-flat electricity price period division data and receives electricity price update instructions from the power grid dispatching platform.

[0007] In one implementation of this application, the single-phase energy storage module group consists of three independent single-phase energy storage modules, which are respectively connected to the three-phase output terminals A, B, and C of the low-voltage distribution area. Each energy storage module is equipped with an independent charge and discharge controller. The energy storage medium of the energy storage module is a lithium iron phosphate battery.

[0008] In one implementation of this application, the core of the collaborative control module is an embedded controller with a built-in multi-objective collaborative control algorithm. The collaborative control module can receive monitoring data from the data acquisition module, determine the operating status of the distribution area, generate charging and discharging control commands for each single-phase energy storage module, and interact with the power grid dispatching platform and the intelligent distribution box of the distribution area through the communication module.

[0009] In one implementation of this application, the core of the collaborative control module is an embedded controller with a built-in multi-objective collaborative control algorithm. The collaborative control module can receive monitoring data from the data acquisition module, determine the operating status of the distribution area, generate charging and discharging control commands for each single-phase energy storage module, and interact with the power grid dispatching platform and the intelligent distribution box of the distribution area through the communication module.

[0010] In one implementation of this application, the safety protection module integrates an overcurrent protection unit, an overvoltage protection unit, an overload protection unit, and a temperature monitoring unit. When the energy storage module or the power grid of the distribution area experiences overcurrent, overvoltage, overload, or abnormal temperature, the safety protection module immediately sends an alarm signal to the collaborative control module and triggers the energy storage module to shut down, ensuring the safe and stable operation of the system.

[0011] On the other hand, this application also provides a multi-objective coordinated control method for a low-voltage distribution area energy storage system, the method comprising: Step S1: Collect three-phase current, three-phase voltage, and transformer load rate data of the low-voltage distribution area in real time through the data acquisition module, identify whether the current electricity price period is a low-valley period, peak period, or flat period, and determine whether there is a problem of excessive three-phase imbalance or transformer overload in the distribution area by combining the preset threshold. Step S2: Generate differentiated charging instructions based on the three-phase load difference, control the energy storage modules corresponding to lighter loads to charge first, and reduce the charging power or stop charging of the energy storage modules corresponding to heavier loads, and all energy storage modules complete full charging during off-peak hours. Step S3: Generate discharge commands according to the priority of first adjusting three-phase imbalance, then optimizing transformer load rate, and finally realizing peak-valley arbitrage, and complete current compensation, load rate regulation and grid-connected discharge of remaining power in sequence; Step S4: Control the energy storage unit to standby mode and monitor the operating parameters in real time. If abnormal fluctuations occur, start short-term charge and discharge auxiliary regulation.

[0012] In one implementation of this application, in step S2, the energy storage module with a lighter load is charged with higher power according to the load difference, while the energy storage module with a heavier load reduces the charging power or suspends charging, thereby initially adjusting the three-phase load balance through differentiated charging.

[0013] In one implementation of this application, in step S3, when the three-phase imbalance exceeds a preset threshold, the collaborative control module calculates the current compensation value of each phase through an algorithm, controls the corresponding phase energy storage module to discharge to compensate for the current difference, until the three-phase imbalance drops to within the threshold range; after the three-phase imbalance meets the standard, if the transformer load rate exceeds the preset safety range, the energy storage module is controlled to continue discharging to regulate the transformer input power and control the load rate within the safety range; when the energy storage module still has residual power, it is controlled to discharge to the grid, and economic benefits are obtained by utilizing the peak-valley electricity price difference.

[0014] In one implementation of this application, in step S4, the operating parameters of the transformer substation are continuously monitored during the flat period. When the three-phase imbalance or transformer load rate fluctuates abnormally, the energy storage module is immediately activated for short-term charging and discharging to assist in the adjustment and maintain the stable operation of the transformer substation.

[0015] The multi-objective collaborative control device and method for a low-voltage distribution area energy storage system provided in this application have the following beneficial effects: 1. By adopting the design of 3 independent single-phase energy storage modules and embedded multi-objective collaborative algorithm, a linkage mechanism of "three-phase leveling - load optimization - peak-valley arbitrage" is constructed, which realizes the technical effects of significantly improving the utilization rate of energy storage resources, accurately controlling the three-phase imbalance, greatly reducing the fluctuation of transformer load rate, and effectively reducing the line loss of distribution area, thus ensuring stable power supply quality.

[0016] 2. By adopting the peak-valley arbitrage model of charging during off-peak hours and discharging during peak hours, combined with the cost savings in operation and maintenance and replacement brought about by reduced line losses and extended equipment lifespan, the energy storage system has achieved the goals of broadening the channels for generating benefits, significantly shortening the investment payback period, reducing project investment risks, and significantly improving economic benefits.

[0017] 3. Through modular structural design and automated control logic, it does not require large-scale transformation of the existing low-voltage distribution area power grid, nor does it require manual intervention in daily operation and maintenance. It achieves practical effects such as low construction difficulty, low operation and maintenance cost, low failure rate, adaptability to different low-voltage distribution area scenarios, and wide application value. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a diagram illustrating the composition of a multi-objective collaborative control device for a low-voltage distribution area energy storage system, provided in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] This application provides a multi-objective collaborative control device and method for a low-voltage distribution area energy storage system. The technical solution proposed in this application will be described in detail below with reference to the accompanying drawings.

[0021] Example 1, Figure 1 This is a diagram illustrating the composition of a multi-objective collaborative control device for a low-voltage distribution area energy storage system, provided as an embodiment of this application. Figure 1As shown, the device includes: a data acquisition module, a single-phase energy storage module group, a collaborative control module, a communication module, and a safety protection module.

[0022] The data acquisition module consists of a three-phase current sensor, a three-phase voltage sensor, a transformer load rate monitoring terminal, and an electricity price period identification unit. The three-phase current / voltage sensor is installed at the low-voltage side of the transformer to collect three-phase current and voltage data in real time, providing a basis for determining three-phase imbalance. The transformer load rate monitoring terminal calculates the load rate by collecting transformer operating parameters (such as winding temperature and output power) and provides feedback on the equipment's operating status. The electricity price period identification unit pre-stores peak-valley-flat-rate electricity price period segmentation data and receives real-time electricity price update instructions from the power grid dispatching platform to accurately determine the current period type (valley, peak, flat).

[0023] The single-phase energy storage module group consists of three independent single-phase energy storage modules, which are respectively connected to the A, B, and C phase output terminals of the low-voltage distribution area. Each energy storage module is equipped with an independent charge and discharge controller, enabling precise adjustment of charge and discharge power. The energy storage medium uses lithium iron phosphate batteries, which feature fast charge and discharge response speed (response time ≤50ms) and long cycle life (10,000-15,000 cycles), enabling rapid response to coordinated control commands and adapting to the dynamic regulation needs of the distribution area. The collaborative control module, with its core being an embedded controller (model: STM32H743), incorporates a multi-objective collaborative control algorithm and serves as the control core of this invention. Its core functions include: receiving monitoring data from the data acquisition module; determining the current operating status of the distribution area (whether there are issues such as excessive three-phase imbalance or transformer overload) through the algorithm; generating charging and discharging control commands for each single-phase energy storage module based on the time period and the distribution area's operating status; and interacting with the power grid dispatching platform and the intelligent distribution box in the distribution area through the communication module to achieve information uploading and command reception.

[0024] The communication module adopts power line carrier communication technology (communication rate ≥1Mbps, communication distance ≥1000m) to realize bidirectional data transmission between the collaborative control module, data acquisition module, single-phase energy storage module group, and power grid dispatching platform, ensuring real-time and stable interaction between control commands and monitoring data, and avoiding control lag caused by signal delay.

[0025] The safety protection module integrates an overcurrent protection unit (protection threshold: 1.2 times the rated current), an overvoltage protection unit (protection threshold: 0.45kV), an overload protection unit (protection threshold: 1.1 times the rated power), and a temperature monitoring unit (monitoring range: -20℃~60℃). When the energy storage module or the power grid experiences overcurrent, overvoltage, overload, or abnormal temperature, the safety protection module immediately sends an alarm signal to the coordination control module and triggers the energy storage module to shut down, ensuring the safe and stable operation of the system. Example 2, a multi-objective collaborative control method for low-voltage distribution area energy storage based on the above-mentioned device, includes the following steps and key parameters: Data Acquisition and Status Determination. The data acquisition module collects real-time data on three-phase current, three-phase voltage, and transformer load rate in the low-voltage distribution area at a sampling frequency of 10Hz. The electricity price period identification unit determines whether the current period is a low-peak, peak, or flat period (preset period: set according to different seasons). All data is transmitted to the collaborative control module via the communication module. The collaborative control module determines whether there are problems such as excessive three-phase imbalance or transformer overload in the distribution area based on preset thresholds (three-phase imbalance threshold of 5%, transformer load rate upper limit of 80%).

[0026] Differentiated charging control during off-peak hours. When an off-peak period (low electricity price period) is identified, the collaborative control module calculates the load difference between each phase based on the collected three-phase load data and generates differentiated charging instructions: Energy storage modules with lighter loads are prioritized for charging, with charging power dynamically adjusted according to the load difference (adjustment range: 0~50kW), initially adjusting the three-phase load balance during charging; energy storage modules with heavier loads reduce their charging power (to 0~10kW) or suspend charging to avoid exacerbating the three-phase imbalance. Simultaneously, all energy storage modules are controlled to complete full charging during off-peak hours, reserving energy for peak-hour discharge. Multi-objective discharge control during peak hours. When a peak-hour period (peak electricity price period) is identified, the collaborative control module generates discharge control instructions according to the priority of "prioritizing the adjustment of three-phase imbalance → optimizing transformer load rate → finally achieving peak-valley arbitrage." Specific steps are as follows: Step 1: If the three-phase imbalance exceeds the 5% threshold, the collaborative control module calculates the current compensation value of each phase through the algorithm, controls the corresponding phase energy storage module to discharge at the set power (0~50kW), quickly compensates the current difference, until the three-phase imbalance drops to the threshold range (adjustment response time ≤100ms). Step 2: After the three-phase imbalance meets the standard, if the transformer load rate exceeds the upper limit of 80%, control the energy storage module to continue discharging, reduce the transformer input power, and control the load rate within the safe range of 65%~80%. Step 3: After the above two conditions are met, if the energy storage module still has residual power (residual power ≥ 20%), control it to discharge to the grid and obtain economic benefits by taking advantage of the peak-valley electricity price difference.

[0027] Standby and auxiliary adjustment during flat periods. When a flat period is identified, the coordinated control module keeps the energy storage unit in standby mode and monitors the operating parameters of the transformer substation in real time (monitoring frequency 5Hz). If abnormal fluctuations occur in the three-phase imbalance or transformer load rate (three-phase imbalance briefly rises to 5%~6%, or load rate exceeds 65%~80%), the energy storage module is immediately activated for short-term charging and discharging to perform auxiliary adjustment (adjustment duration 1~5 minutes) to maintain stable operation of the transformer substation.

[0028] This solution enables multi-objective collaborative control, improving resource utilization by over 30%. The reason for this is that the device employs a design with three independent single-phase energy storage modules, allowing for differentiated regulation based on three-phase load variations. The control method utilizes an embedded multi-objective collaborative algorithm to construct a linkage mechanism of "three-phase leveling - load optimization - peak-valley arbitrage," breaking through the limitations of existing single-function technologies and fully tapping the potential of energy storage resources.

[0029] Applying this solution can significantly improve power quality, stably controlling three-phase imbalance within 5% and transformer load rate fluctuation within 15%. Reasons for this: The data acquisition module enables real-time and accurate collection of operating parameters for the distribution area, providing reliable data support for regulation; a tiered regulation strategy of "priority leveling" is adopted during peak periods, combined with the fast response characteristics of the energy storage module (≤50ms), which can quickly compensate for current differences; load rate regulation precisely controls the transformer input power by dynamically adjusting the charging and discharging power of the energy storage, avoiding overload or underload operation.

[0030] Applying this solution can reduce line losses in the transformer substation by 8%-12% and extend equipment lifespan. The reasons are: precise control of three-phase imbalance reduces neutral current and lowers line losses; stable control of transformer load rate avoids insulation aging caused by overload, reduces the probability of equipment failure, and extends transformer lifespan (estimated to be extended by 3-5 years).

[0031] This solution shortens the investment payback period by 2-3 years. The reasons are twofold: firstly, it directly captures the electricity price difference through a peak-valley arbitrage model of charging during off-peak hours and discharging during peak hours; secondly, the reduction in line losses and the extension of equipment lifespan reduce grid maintenance costs and equipment replacement investment, indirectly improving economic efficiency. This dual revenue stream significantly shortens the investment payback period (existing technologies have a payback period of 5-7 years, while this invention can shorten it to 2-4 years).

[0032] This device features a simple structure, low construction difficulty, and low operation and maintenance costs, making it widely applicable. Reasons for its suitability: The device adopts a modular design, allowing direct installation in existing low-voltage distribution areas without large-scale modifications to the power grid infrastructure; the control method utilizes embedded algorithms for automated regulation, eliminating the need for manual intervention and reducing operation and maintenance costs; each module employs mature power electronics technology, ensuring high reliability and a low failure rate.

[0033] The various embodiments in this application are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0034] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0035] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A multi-objective collaborative control device for a low-voltage distribution area energy storage system, characterized in that, The device includes: a data acquisition module, a single-phase energy storage module group, a collaborative control module, a communication module, and a safety protection module. The output terminals of the data acquisition module and the safety protection module are connected to the input terminal of the collaborative control module. The output terminal of the collaborative control module is connected to the single-phase energy storage module group. The communication module communicates bidirectionally with the collaborative control module to achieve data interaction. The data acquisition module is used to collect low-voltage distribution area operating parameters and identify electricity price periods. The single-phase energy storage module group is used to realize differentiated charging and discharging regulation. The collaborative control module is used to generate charging and discharging control commands. The communication module is used to ensure real-time data transmission. The safety protection module is used to realize system anomaly protection.

2. The multi-objective collaborative control device for a low-voltage distribution area energy storage system according to claim 1, characterized in that, The data acquisition module consists of a three-phase current sensor, a three-phase voltage sensor, a transformer load rate monitoring terminal, and an electricity price period identification unit. The three-phase current sensor and the three-phase voltage sensor are installed at the low-voltage side outgoing line of the transformer. The transformer load rate monitoring terminal calculates the load rate by collecting transformer operating parameters and feeds back the equipment operating status. The electricity price period identification unit pre-stores peak-valley-flat electricity price period division data and receives electricity price update instructions from the power grid dispatching platform.

3. The multi-objective collaborative control device for a low-voltage distribution area energy storage system according to claim 1, characterized in that, The single-phase energy storage module group consists of 3 independent single-phase energy storage modules, which are respectively connected to the A, B, and C phase output terminals of the low-voltage distribution area. Each energy storage module is equipped with an independent charge and discharge controller. The energy storage medium of the energy storage module is a lithium iron phosphate battery.

4. The multi-objective collaborative control device for a low-voltage distribution area energy storage system according to claim 1, characterized in that, The core of the collaborative control module is an embedded controller with a built-in multi-objective collaborative control algorithm. The collaborative control module can receive monitoring data from the data acquisition module, determine the operating status of the transformer area, generate charging and discharging control commands for each single-phase energy storage module, and interact with the power grid dispatching platform and the intelligent distribution box of the transformer area through the communication module.

5. The multi-objective collaborative control device for a low-voltage distribution area energy storage system according to claim 1, characterized in that, The core of the collaborative control module is an embedded controller with a built-in multi-objective collaborative control algorithm. The collaborative control module can receive monitoring data from the data acquisition module, determine the operating status of the transformer area, generate charging and discharging control commands for each single-phase energy storage module, and interact with the power grid dispatching platform and the intelligent distribution box of the transformer area through the communication module.

6. The multi-objective collaborative control device for a low-voltage distribution area energy storage system according to claim 1, characterized in that, The safety protection module integrates an overcurrent protection unit, an overvoltage protection unit, an overload protection unit, and a temperature monitoring unit. When the energy storage module or the power grid in the distribution area experiences overcurrent, overvoltage, overload, or temperature abnormalities, the safety protection module immediately sends an alarm signal to the collaborative control module and triggers the energy storage module to shut down, ensuring the safe and stable operation of the system.

7. A multi-objective collaborative control method for a low-voltage distribution area energy storage system, characterized in that, The method includes: Step S1: Collect three-phase current, three-phase voltage, and transformer load rate data of the low-voltage distribution area in real time through the data acquisition module, identify whether the current electricity price period is a low-valley period, peak period, or flat period, and determine whether there is a problem of excessive three-phase imbalance or transformer overload in the distribution area by combining the preset threshold. Step S2: Generate differentiated charging instructions based on the three-phase load difference, control the energy storage modules corresponding to lighter loads to charge first, and reduce the charging power or stop charging of the energy storage modules corresponding to heavier loads, and all energy storage modules complete full charging during off-peak hours. Step S3: Generate discharge commands according to the priority of first adjusting three-phase imbalance, then optimizing transformer load rate, and finally realizing peak-valley arbitrage, and complete current compensation, load rate regulation and grid-connected discharge of remaining power in sequence; Step S4: Control the energy storage unit to standby mode and monitor the operating parameters in real time. If abnormal fluctuations occur, start short-term charge and discharge auxiliary regulation.

8. The multi-objective cooperative control method for a low-voltage distribution area energy storage system according to claim 7, characterized in that, In step S2, the energy storage module with a lighter load is charged with higher power according to the load difference, while the energy storage module with a heavier load reduces the charging power or stops charging. The three-phase load balance is initially adjusted through differentiated charging.

9. A multi-objective cooperative control method for a low-voltage distribution area energy storage system according to claim 7, characterized in that, In step S3, when the three-phase imbalance exceeds the preset threshold, the collaborative control module calculates the current compensation value of each phase through an algorithm and controls the corresponding phase energy storage module to discharge to compensate for the current difference until the three-phase imbalance drops to within the threshold range. After the three-phase imbalance meets the standard, if the transformer load rate exceeds the preset safety range, the energy storage module is controlled to continue discharging to regulate the transformer input power and control the load rate within the safety range. When the energy storage module still has residual power, it is controlled to discharge to the grid, and economic benefits are obtained by utilizing the peak-valley electricity price difference.

10. A multi-objective cooperative control method for a low-voltage distribution area energy storage system according to claim 7, characterized in that, In step S4, the operating parameters of the transformer substation are continuously monitored during the flat period. When the three-phase imbalance or transformer load rate fluctuates abnormally, the energy storage module is immediately activated for short-term charging and discharging to assist in the adjustment and maintain the stable operation of the transformer substation.

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