High-proportion distributed source load area power supply method based on modular energy storage

Abstract

The invention discloses a modular energy storage-based high-proportion distributed source load district power supply method, which comprises 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. Under the unified coordination of the central control system, the modularized energy storage system and the distributed source load integration system complete the dynamic cooperative power supply work of power generation, power supply and energy storage of the transformer area according to the power supply strategy system, and during the period, the power supply is stabilized through the intelligent fusion terminal; the transformer area can have the functions of transformer area side power out-of-limit control, reverse transmission prevention, voltage reactive power control, source network load storage coordinated optimization and the like, the purposes of improving the transformer area voltage and power factor qualification rate, distributed power supply bearing capacity and load access capacity, reducing the comprehensive line loss rate and the like are achieved, the overall power supply level and quality of the transformer area are improved, and the power supply efficiency is improved. And stable development of the district power grid is ensured.

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, through the controllable power generation system of thermal power, to match the user load, an uncontrollable but basically predictable power consumption system, and adjust it at all times to achieve the purpose of strictly matching electricity production and demand, and ensure the stable operation of the power system.

[0003] 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 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 power supply side of the distribution network has become unstable and lost controllability. At the same time, the rapid growth of the number of electric vehicles has also increased the volatility and randomness of the load side of the distribution network, increasing the difficulty of prediction. Therefore, the traditional "source follows load" method cannot maintain the balance between the production and demand of electricity in the distribution network, and the stability of the power grid cannot be guaranteed. If this problem is not solved, on the premise of ensuring the stability of power supply of the power grid, a large amount of precious electricity produced by new energy can only be abandoned. Therefore, energy storage systems should be configured in distribution network areas with high penetration of distributed new energy access to improve the absorption capacity of new energy in the distribution network, improve the power supply quality, and ensure the stable operation of the power grid. At the same time, the configuration of energy storage systems nearby is conducive to the local absorption of new energy and avoids the loss caused by large-scale long-distance transmission of electricity.

[0005] Compared with centralized energy storage systems, modular energy storage systems have the advantages of standardized products, plug-and-play, more flexible and convenient combination, more convenient installation and maintenance, and good product scalability, so their market applications are becoming increasingly widespread. However, how modular energy storage systems can be connected to high-proportion distributed source-load areas, organically combined with high-proportion distributed new energy, and through mutual cooperation, jointly improve the performance and efficiency of both and the whole, remains to be studied.

[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 prior art and to provide a high-proportion distributed source-load power supply method for the substation based on modular energy storage, which can enable the substation to have the functions of power over-limit control, anti-reverse transmission, voltage reactive power control, source-grid-load-storage coordinated optimization, etc. on the substation side, so as to achieve the purposes of improving the substation voltage and power factor qualification rate, distributed power source 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 power supply method based on modular energy storage, including 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 power generation energy of the distributed energy in the substation area, and discharge it when the power generation in the substation area cannot meet the power supply energy use, to supplement the power supply energy; wherein the distributed source-load integration system is used to integrate all distributed energy and loads in the substation area, convert the direct current generated by each distributed energy into alternating current through an intelligent inverter, and connect it to the substation area power supply network, while real-time monitoring the output power of the distributed energy and 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 various power generation points and load points in the substation; the intelligent fusion terminal is used to stabilize the power supply of the substation; when working, the substation collects real-time data through 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 power generation, power supply and energy storage in the substation according to the power supply strategy system, and the power supply is stabilized through the intelligent fusion terminal during the 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, wherein the PCS module is used to realize the bidirectional conversion of electric energy, wherein the BMS module is used to monitor and manage the status of the rechargeable battery, wherein the SPC module is used for the treatment of three-phase imbalance and harmonics in the power grid, wherein the auxiliary module is used for temperature and humidity control of the battery compartment, and wherein 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 is embedded with a 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 specific content of the power supply strategy system is: 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 powered; 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 of each distributed photovoltaic and local control of reactive power output.

[0017] The intelligent fusion terminal is embedded with a robust optimization method, which is used to cope 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 power grid in the substation area.

[0018] Due to the adoption of the above technical scheme, 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 that the output of the distribution network power supply side becomes unstable and loses controllability due to the access of a large number of distributed new energy power generation devices in the distribution network of the new power system, the modular energy storage technology is used to locally consume excess energy and locally supplement insufficient energy, and the substation can be equipped with the functions of power over-limit control, reverse transmission prevention, voltage reactive power control, source-grid-load-storage coordination optimization, etc., 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, etc., thereby realizing the organic combination of modular energy storage system and high-proportion distributed source-load substation, improving the overall power supply level and quality of the substation, and ensuring the smooth development of the substation 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 substation, and it is flexible and convenient to use; the present invention adopts a distributed source-load integration system, which can monitor the output power of distributed energy and the load demand of the substation in real time according to the substation, optimize energy distribution through integration, and further promote the smooth development of power generation and electricity consumption in the substation power grid; the present invention adopts an intelligent fusion terminal to strengthen the stability monitoring of the substation power, and further ensure the smooth operation of the high-proportion distributed source-load substation. DETAILED DESCRIPTION

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

[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 over-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 over-limit, power over-limit, and reverse transmission on the area side are solved.

[0022] A high-proportion distributed source-load area refers to a local area of ​​the power system that integrates large-scale distributed power generation resources and realizes a high degree of autonomy and coordinated operation of terminal loads. Faced with a high proportion of distributed power generation access, especially the widespread distribution of renewable energy such as photovoltaic power generation, higher requirements are placed on the power quality and operational stability in the area. Therefore, modular energy storage technology is introduced to strengthen the management and distribution of power in complex high-proportion distributed source-load areas, thereby ensuring stable power supply in the 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) 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 realize the bidirectional conversion of electric energy and complete the peak shaving and valley filling function of the substation. The BMS module is used to monitor and manage the status of the rechargeable battery and complete the storage and release of electric energy. The SPC module is used to control the three-phase imbalance and harmonics of the power grid and improve the power quality of the power grid. The auxiliary module is used to control the temperature and humidity of the battery compartment to ensure the safe operation of the battery. The monitoring and control module is used to monitor the various operating states of the entire modular energy storage system, coordinate the work 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. The direct current generated by each distributed energy source is converted into alternating current through an intelligent inverter and connected to the substation area 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 electric energy 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 collects the power parameters of the substation, including voltage, current and power, 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.

[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 for 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 realize automatic power generation control of each distributed photovoltaic and on-site control of reactive power output.

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

[0037] When the present invention is implemented, 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-standing installation 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 and to send relevant information parameters 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 the 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 functions such as power over-limit control, reverse transmission prevention, voltage reactive power control, and source-grid-load-storage coordination optimization on the substation side, 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 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, those skilled in the art should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and 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 in that: It includes modular energy storage system, distributed source-load integration system, power supply strategy system, central control system, real-time monitoring system and intelligent fusion terminal. The modular energy storage system is used to store the excess power generated by distributed energy in the substation area, and discharge it when the power generated in the substation area cannot meet the power supply energy usage to supplement the power supply energy; 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 the intelligent inverter, and connect it to the substation power supply network, while monitoring the output power of distributed energy and the load demand of the substation area in real time to optimize energy distribution; the power supply strategy The 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 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; when working, the substation collects real-time data through 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 power supply strategy system, and the power supply is stabilized through the intelligent fusion terminal.

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 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, wherein the PCS module is used to realize the bidirectional conversion of electric energy, wherein the BMS module is used to monitor and manage the status of the rechargeable battery, wherein the SPC module is used for the treatment of three-phase imbalance and harmonics in the power grid, wherein the auxiliary module is used for temperature and humidity control of the battery compartment, and wherein 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.

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

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 distributed source-load integration system is embedded with a 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.

5. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 4 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.

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 specific content of the power supply strategy system is: 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 powered; in the event of a grid failure or power outage, the modular energy storage system independently provides emergency power for the substation.

7. 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.

8. 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.

9. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 1 is characterized in that: 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 of each distributed photovoltaic and local control of reactive power output.

10. The high-proportion distributed source-load area power supply method based on modular energy storage according to claim 9 is characterized in that: The intelligent fusion terminal is embedded with a robust optimization method, which is used to cope 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 power grid in the substation area.