A high-proportion distributed source and load area power supply method based on modular energy storage

Abstract

The application discloses a kind of high proportion distributed source and load area power supply method based on modular energy storage, the system using this method includes modular energy storage system, distributed source and load integration system, power supply strategy system, central control system, real-time monitoring system and intelligent fusion terminal, first by the real-time data acquisition of real-time monitoring system, then under the unified coordination of central control system, by modular energy storage system and distributed source and load integration system according to the indication of power supply strategy system complete substation power generation, power supply and the dynamic collaborative power supply work of energy storage, during through intelligent fusion terminal stable power supply, can make substation have substation side power over-limit control, prevent reverse sending, voltage reactive power control, source network load storage coordination optimization etc. Function, reach the purposes of improving substation voltage and power factor qualified rate, distributed power load bearing capacity and load access ability, reduce comprehensive line loss rate etc., improve the overall power supply level and power supply quality of substation, guarantee the smooth development of substation power grid.

Description

Technical Field

[0001] The present invention belongs to the technical field of distributed source-load area power supply, and in particular relates to a high-proportion distributed source-load area power supply method based on modular energy storage. Background Art

[0002] The production organization model adopted by the traditional power system is "source follows load", that is, the controllable power generation system of thermal power is used to match the user load, an uncontrollable but basically predictable power consumption system, and it is adjusted at all times to achieve the goal of strictly matching electricity production and demand, thereby ensuring the stable operation of the power system.

[0003] On March 15, 2021, the Ninth Meeting of the Central Financial and Economic Commission made new arrangements for achieving "carbon peak" and "carbon neutrality". The meeting pointed out that it is necessary to build a clean, low-carbon, safe and efficient energy system, control the total amount of fossil energy, focus on improving utilization efficiency, implement renewable energy substitution actions, deepen power system reform, and build a new power system with new energy as the main body. The new power system is defined as a power system with new energy as the main body, which means that new energy such as wind power and photovoltaics will become the main energy source of the new power system, and coal-fired power will be reduced to an auxiliary energy source. The key to new energy becoming the main energy source of the power system is to enhance the power system's ability to absorb new energy and avoid excessive waste.

[0004] In the distribution networks of new power systems, the integration of a large number of distributed renewable energy generation devices has led to unstable power generation and a loss of controllability on the distribution network's power supply side. Furthermore, the rapid growth in the number of electric vehicles has increased the volatility and randomness of the distribution network's load side, making forecasting more difficult. Therefore, the traditional "source follows load" approach cannot maintain a balance between power production and demand in the distribution network, nor can it guarantee grid stability. If this problem is not addressed, while ensuring grid power supply stability, a large amount of valuable renewable energy will be forfeited. Therefore, energy storage systems should be deployed in distribution network substations with high penetration of distributed renewable energy to enhance the network's capacity to absorb renewable energy, improve power supply quality, and ensure stable grid operation. Furthermore, deploying energy storage systems locally facilitates the local absorption of renewable energy, avoiding losses associated with large-scale, long-distance transmission of electricity.

[0005] Compared to centralized energy storage systems, modular energy storage systems offer advantages such as standardized products, plug-and-play functionality, flexible and convenient combination, easier installation and maintenance, and improved scalability. Consequently, they are seeing increasing market adoption. However, research remains to be conducted on how modular energy storage systems can be integrated into high-proportion distributed energy resource and load distribution areas, organically integrate with high-proportion distributed renewable energy sources, and, through mutual collaboration, enhance the performance and efficiency of both systems and their overall performance.

[0006] In order to solve the above problems, it is necessary to develop a high-proportion distributed source-load area power supply method based on modular energy storage. Summary of the Invention

[0007] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a high-proportion distributed source-load power supply method based on modular energy storage, which can enable the substation to have the functions of power over-limit control, anti-backflow, voltage and reactive power control, source-grid-load and storage coordination optimization on the substation side, so as to achieve the purpose of improving the substation voltage and power factor qualification rate, distributed power supply carrying capacity and load access capacity, and reducing the comprehensive line loss rate, thereby realizing the organic combination of modular energy storage system and high-proportion distributed source-load substation, improving the overall power supply level and power supply quality of the substation, and ensuring the smooth development of the substation power grid.

[0008] The purpose of the present invention is achieved as follows: a high-proportion distributed source-load area power supply method based on modular energy storage, the system using this method includes a modular energy storage system, a distributed source-load integration system, a power supply strategy system, a central control system, a real-time monitoring system and an intelligent fusion terminal, wherein the modular energy storage system is used to store the excess generated electricity of the distributed energy in the area, and discharge it when the generated electricity in the area cannot meet the power supply needs, to supplement the power supply; wherein the distributed source-load integration system is used to integrate all distributed energy and loads in the area, convert the DC power generated by each distributed energy into AC power through an intelligent inverter, and connect it to the area power supply network, while monitoring the output power of the distributed energy in real time. The system optimizes energy distribution by combining the power supply rate and load demand of the substation; the power supply strategy system is used to adjust the power supply mode according to the load demand, including peak and valley electricity price response, emergency dispatch and maintenance dispatch; the central control system is used for centralized management and control of the substation; the real-time monitoring system is used for real-time data collection and analysis of each power generation point and load point in the substation; the intelligent fusion terminal is used to stabilize the power supply of the substation; during operation, the substation collects real-time data from the real-time monitoring system, and under the unified coordination of the central control system, the modular energy storage system and the distributed source-load integration system complete the dynamic coordinated power supply of the substation's power generation, power supply and energy storage in accordance with the instructions of the power supply strategy system, and the intelligent fusion terminal is used to stabilize the power supply during this period.

[0009] The modular energy storage system includes a PCS module, a BMS module, an SPC module, an auxiliary module, a monitoring and control module, and multiple rechargeable battery modules. The PCS module is used to realize bidirectional conversion of electric energy, the BMS module is used to monitor and manage the status of the rechargeable battery, the SPC module is used to control three-phase imbalance and harmonics in the power grid, the auxiliary module is used to control the temperature and humidity of the battery compartment, and the monitoring and control module is used to monitor the operating status of the entire modular energy storage system, coordinate the work of each module, and remotely control and manage the modular energy storage system.

[0010] The rechargeable battery module is a liquid flow battery, a sodium flow battery or a lithium titanate battery.

[0011] The distributed source-load integration system has an embedded distributed energy management subsystem for real-time monitoring of the output power of distributed energy and the load demand of the substation area, optimizing energy distribution, and improving the utilization efficiency of each distributed energy in the substation area.

[0012] The distributed energy includes distributed photovoltaic power generation, distributed wind power generation, small gas turbines and fuel cells, and the loads are various electrical equipment and electricity users.

[0013] The power supply strategy system is specifically used to: when the output power of distributed energy is greater than the load demand of the substation, the excess electric energy is stored in the modular energy storage system; when the output power of distributed energy is less than the load demand of the substation, the modular energy storage system and the distributed energy are jointly supplied with power; in the event of a grid failure or power outage, the modular energy storage system independently provides emergency power for the substation.

[0014] The real-time monitoring system collects the power parameters of the substation, including voltage, current and power, in real time through corresponding sensor technology, and feeds back to the central control system in real time. Under the unified arrangement of the central control system, real-time adjustments are made according to the preset control strategy.

[0015] The central control system also has fault diagnosis and early warning functions.

[0016] The intelligent fusion terminal is embedded with photovoltaic direct procurement and supply technology, which is used to obtain the electrical parameters of each distributed photovoltaic in real time and upload these data to the central control system to achieve automatic power generation control and local control of reactive power output of each distributed photovoltaic.

[0017] The intelligent fusion terminal is embedded with a robust optimization method, which is used to deal with the uncertainty of data acquired by the intelligent fusion terminal. Taking the uncertainty of the data into consideration, an optimal solution is found to ensure the reliable operation of the substation power grid.

[0018] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: the present invention adopts a modular energy storage system, a distributed source-load integration system, a power supply strategy system, a central control system, a real-time monitoring system and an intelligent fusion terminal. In view of the problems such as the access of a large number of distributed new energy power generation devices in the distribution network of the new power system, which makes the output of the distribution network power supply side unstable and loses controllability, the modular energy storage technology is used to consume excess energy on-site and supplement insufficient energy on-site, and the substation can be equipped with substation side power over-limit control, anti-backfeed, voltage reactive power control, source-grid-load-storage coordinated optimization and other functions, so as to improve the substation voltage and power factor qualification rate, distributed power supply carrying capacity and load access capacity, The purpose is to reduce the comprehensive line loss rate, thereby realizing the organic combination of modular energy storage system and high-proportion distributed source-load area, improving the overall power supply level and power supply quality of the area, and ensuring the smooth development of the area's power grid; the present invention adopts modular energy storage technology, and the specific performance indicators can be flexibly configured according to the actual situation and needs of the area, and it is flexible and convenient to use; the present invention adopts a distributed source-load integration system, which can monitor the distributed energy output power and the area load demand in real time according to the area, optimize energy distribution through integration, and further promote the smooth development of power generation and electricity consumption in the area's power grid; the present invention adopts intelligent fusion terminals to strengthen the stability monitoring of the area's power, and further ensure the smooth operation of the high-proportion distributed source-load area. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further specifically described below through examples.

[0020] With the continuous development of the economy and society and the green and low-carbon transformation, various new load equipment such as electric vehicles and distributed power sources have brought about a series of power supply quality problems such as three-phase imbalance, voltage exceeding the limit, high harmonic content, voltage fluctuation and flicker.

[0021] In this regard, the present invention provides a high-proportion distributed source-load area power supply method based on modular energy storage. The method is mainly implemented through a modular energy storage system, a distributed source-load integration system, a power supply strategy system, a central control system, a real-time monitoring system and an intelligent fusion terminal. Distributed energy storage areas are installed in distributed energy concentration areas and user terminals. By comprehensively managing the power quality on the energy storage side, problems such as voltage exceeding the limit, power exceeding the limit, and reverse transmission on the area side are solved.

[0022] A high-proportion distributed power grid area refers to a local area of ​​the power system that integrates large-scale distributed generation resources and achieves a high degree of autonomy and coordinated operation of terminal loads. The high proportion of distributed generation access, especially the widespread distribution of renewable energy sources such as photovoltaic power generation, places higher demands on power quality and operational stability within the grid area. Therefore, modular energy storage technology is being introduced to enhance power management and distribution in complex, high-proportion distributed power grid areas, thereby ensuring stable power supply within the grid area.

[0023] Among them, the modular energy storage system is used to store the excess generated electricity of distributed energy in the substation area, and discharge it to supplement the power supply when the generated electricity in the substation area cannot meet the power supply needs.

[0024] Specifically, the modular energy storage system includes a PCS (power conversion) module, a BMS (battery management system) module, an SPC (three-phase imbalance control) module, an auxiliary module, a monitoring and control module, and multiple rechargeable battery modules. The PCS module is used to achieve bidirectional conversion of electrical energy, completing the peak-shaving and valley-filling function of the substation. The BMS module is used to monitor and manage the status of the rechargeable batteries, completing the storage and release of electrical energy. The SPC module is used to control three-phase imbalance and harmonics in the power grid, thereby improving the power quality of the grid. The auxiliary module is used to control the temperature and humidity of the battery compartment to ensure battery safety. The monitoring and control module is used to monitor the operating status of the entire modular energy storage system, coordinate the operation of each module, and remotely control and manage the modular energy storage system.

[0025] Furthermore, the rechargeable battery module adopts a variety of advanced rechargeable batteries such as liquid flow batteries, sodium flow batteries or lithium titanate batteries.

[0026] Among them, the distributed source-load integration system is used to integrate all distributed energy sources and loads in the substation area. It converts the direct current generated by each distributed energy source into alternating current through an intelligent inverter and connects it to the substation power supply network. At the same time, it monitors the output power of distributed energy and the load demand of the substation area in real time to optimize energy distribution.

[0027] Specifically, the distributed source-load integration system has an embedded distributed energy management subsystem, which is used to monitor the output power of distributed energy and the load demand of the substation in real time, optimize energy distribution, and improve the utilization efficiency of each distributed energy in the substation.

[0028] Furthermore, distributed energy includes distributed photovoltaic power generation, distributed wind power generation, small gas turbines and fuel cells, and load refers to various electrical equipment and electricity users.

[0029] Among them, the power supply strategy system is used to adjust the power supply mode according to load demand, including peak and valley electricity price response, emergency dispatch and maintenance dispatch.

[0030] Specifically, the power supply strategy system has the following contents: when the output power of distributed energy is greater than the load demand of the substation, the excess electricity will be stored in the modular energy storage system; when the output power of distributed energy is less than the load demand of the substation, the modular energy storage system and the distributed energy will jointly supply power; in the event of a grid failure or power outage, the modular energy storage system will independently provide emergency power for the substation.

[0031] Among them, the central control system is used for centralized management and control of the substation, and the central control system has fault diagnosis and early warning functions.

[0032] Among them, the real-time monitoring system is used for real-time data collection and analysis of each power generation point and load point in the substation.

[0033] Specifically, the real-time monitoring system uses corresponding sensor technology to collect the power parameters of the substation, including voltage, current and power, and feeds them back to the central control system in real time. Under the unified arrangement of the central control system, real-time adjustments are made according to the preset control strategy.

[0034] Among them, the intelligent fusion terminal is used to stabilize the power supply in the substation. It is installed in the substation and is responsible for intelligent collection and control. It can improve the substation's management capabilities of distributed energy and meet the management and control needs of diversified loads.

[0035] Furthermore, the intelligent fusion terminal is embedded with photovoltaic direct procurement and supply technology, which is used to obtain the electrical parameters of each distributed photovoltaic in real time and upload these data to the central control system to achieve automatic power generation control and on-site control of reactive power output of each distributed photovoltaic.

[0036] Furthermore, the intelligent fusion terminal has an embedded robust optimization method to cope with the uncertainty of data acquired by the intelligent fusion terminal. Taking into account the uncertainty of the data, an optimal solution is found, that is, a solution that is stable to the changes of uncertain parameters, thereby ensuring the reliable operation of the substation power grid.

[0037] During the specific implementation of the present invention, multiple rechargeable battery modules of the modular energy storage system are installed near the substation transformer and arranged on a cement foundation in a floor-mounted manner. Pre-buried pipes for power lines and communication cables are reserved in the cement foundation to facilitate the modular energy storage system to be connected to the low-voltage side of the substation transformer. At the same time, relevant information parameters are sent to the background central control system through the substation intelligent fusion terminal.

[0038] When the present invention is working, the substation collects real-time data through the real-time monitoring system. Under the unified coordination of the central control system, the modular energy storage system and the distributed source-load integration system complete the dynamic coordinated power supply of the substation's power generation, power supply and energy storage in accordance with the power supply strategy system, and the intelligent fusion terminal is used to stabilize the power supply during this period.

[0039] In summary, the present invention uses a modular energy storage system, a distributed source-load integration system, a power supply strategy system, a central control system, a real-time monitoring system and an intelligent fusion terminal to address the problems in the distribution network of the new power system. Due to the access of a large number of distributed new energy power generation devices, the output of the distribution network power supply side becomes unstable and loses controllability. Modular energy storage technology is used to consume excess energy on-site and supplement insufficient energy on-site, and the substation can be equipped with substation-side power over-limit control, anti-backfeed, voltage and reactive power control, source-grid-load-storage coordination optimization and other functions, so as to achieve the purposes of improving the substation voltage and power factor qualification rate, distributed power supply carrying capacity and load access capacity, and reducing the comprehensive line loss rate, thereby realizing the organic combination of the modular energy storage system and the high-proportion distributed source-load substation, improving the overall power supply level and power supply quality of the substation, and ensuring the stable development of the substation power grid.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A high-proportion distributed source-load area power supply method based on modular energy storage, characterized by: The system using this method includes a modular energy storage system, a distributed source-load integration system, a power supply strategy system, a central control system, a real-time monitoring system and an intelligent fusion terminal. The modular energy storage system is used to store the excess generated electricity of the distributed energy in the substation area, and discharge it when the generated electricity in the substation area cannot meet the power supply needs to supplement the power supply; the distributed source-load integration system is used to integrate all distributed energy and loads in the substation area, convert the DC power generated by each distributed energy into AC power through an intelligent inverter, and connect it to the substation power supply network, while monitoring the output power of the distributed energy and the load demand of the substation area in real time to optimize energy distribution; the supply The power strategy system is used to adjust the power supply mode according to load demand, including peak and valley electricity price response, emergency dispatch and maintenance dispatch; the central control system is used for centralized management and control of the substation; the real-time monitoring system is used to collect and analyze real-time data from each power generation point and load point in the substation; and the intelligent fusion terminal is used to stabilize the power supply in the substation. During operation, the substation collects real-time data from the real-time monitoring system. Under the unified coordination of the central control system, the modular energy storage system and the distributed source-load integration system complete the dynamic coordinated power supply of the substation's power generation, power supply and energy storage according to the instructions of the power supply strategy system, and the intelligent fusion terminal is used to stabilize the power supply during this period. The modular energy storage system includes a PCS module, a BMS module, an SPC module, an auxiliary module, a monitoring and control module, and multiple rechargeable battery modules. The PCS module is used to achieve bidirectional conversion of electric energy, the BMS module is used to monitor and manage the status of the rechargeable battery modules, the SPC module is used to control three-phase imbalance and harmonics in the power grid, the auxiliary module is used to control the temperature and humidity of the battery compartment, and the monitoring and control module is used to monitor the operating status of the entire modular energy storage system, coordinate the work of each module, and remotely control and manage the modular energy storage system. The distributed source-load integration system has an embedded distributed energy management subsystem for real-time monitoring of the output power of distributed energy and the load demand of the substation area, optimizing energy distribution, and improving the utilization efficiency of each distributed energy in the substation area. The intelligent fusion terminal has an embedded photovoltaic direct procurement and direct supply technology for real-time acquisition of electrical parameters of each distributed photovoltaic and uploading these data to the central control system to achieve automatic power generation control and local control of reactive power output of each distributed photovoltaic. The intelligent fusion terminal has an embedded robust optimization method for addressing the uncertainty of data obtained by the intelligent fusion terminal. Taking into account the data uncertainty, an optimal solution is found to ensure the reliable operation of the substation area power grid.

2. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 1 is characterized in that: The rechargeable battery module is a liquid flow battery, a sodium flow battery or a lithium titanate battery.

3. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 1 is characterized in that: The distributed energy includes distributed photovoltaic power generation, distributed wind power generation, small gas turbines and fuel cells, and the loads are various electrical equipment and electricity users.

4. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 1 is characterized in that: The power supply strategy system is specifically used to: when the output power of distributed energy is greater than the load demand of the substation, the excess electric energy is stored in the modular energy storage system; when the output power of distributed energy is less than the load demand of the substation, the modular energy storage system and the distributed energy are jointly supplied with power; in the event of a grid failure or power outage, the modular energy storage system independently provides emergency power for the substation.

5. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 1 is characterized in that: The real-time monitoring system collects the power parameters of the substation, including voltage, current and power, in real time through corresponding sensor technology, and feeds back to the central control system in real time. Under the unified arrangement of the central control system, real-time adjustments are made according to the preset control strategy.

6. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 1 is characterized in that: The central control system also has fault diagnosis and early warning functions.