A regional microgrid system with ultra-large capacity and operation method

Abstract

The present invention discloses a large-capacity regional microgrid system and operation method, wherein the system includes a wind power station, a photovoltaic power station, an energy storage system, a load, a transformer and a distribution equipment, and a microgrid energy management system; the wind power station and the photovoltaic power station are used as the main power sources of the microgrid, and are used to supply power to the load in the microgrid and charge the energy storage system at the same time; the energy storage system is configured on the wind power station side, the photovoltaic power station side, and the 110KV microgrid user station side, and can be used to stabilize power output, shift peaks and fill valleys, adjust power balance, and meet partial power exchange requirements; the load is managed in different levels according to the degree of non-interruptibility; the microgrid energy management system is used to realize integrated management of production scheduling, coordinated control, operation and maintenance management, and comprehensive display. The present invention aims to explore innovative utilization methods and development models of renewable energy, increase the utilization ratio of renewable energy, and promote the nearby consumption of new energy power.

Description

Technical Field

[0001] The present invention relates to the field of microgrid technology, and in particular to an ultra-large capacity regional microgrid system and an operation method thereof. Background Art

[0002] Microgrid is a new type of power network structure, which is a microgrid unit composed of a group of power sources, loads, energy storage systems and control devices. Microgrids integrate advanced information technology, control technology and power electronics technology. While providing reliable power supply and meeting the various needs of users, they can also ensure the maximization of energy benefits, economic benefits and environmental benefits. At the same time, microgrids can provide grid support, improve energy efficiency, save energy and reduce consumption in conventional power grids. Microgrids will be an indispensable and important part of smart grid construction. In my country, vigorously promoting microgrid technology is a concrete manifestation of sustainable development, and a strong support for my country to adjust its energy structure, solve electricity problems in remote areas and protect the environment. However, the existing technology has few designs for regional microgrid systems with ultra-large capacity, and there is no corresponding operation system and operation method for regional microgrid systems with ultra-large capacity.

[0003] Therefore, the prior art has defects and needs to be improved. Summary of the invention

[0004] The purpose of the present invention is to provide an ultra-large capacity regional microgrid system and operation method to explore innovative utilization and development models of renewable energy and improve the scale and technical level of renewable energy utilization.

[0005] An ultra-large capacity regional microgrid system, including a wind power station, a photovoltaic power station, an energy storage system, a load, a power transformation and distribution equipment, and a microgrid energy management system;

[0006] The wind power station is connected to the 35KV collector line in the field after being stepped up by the 35KV box-type substation, and then stepped up by the 110KV transformer and distribution equipment and connected to the power grid; the wind power station is used to supply power to the load in the microgrid and charge the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid;

[0007] When the photovoltaic power generation station is in normal output during the day, it supplies power to the load in the microgrid and charges the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid. When the photovoltaic power generation station is in insufficient output during the day, it supplies power to the load in the microgrid and no longer charges the energy storage system. The photovoltaic module converts solar energy into electrical energy, and the photovoltaic inverter converts the direct current generated by the photovoltaic module into alternating current.

[0008] The energy storage system is a battery energy storage system that outputs electric energy that is boosted to 35KV through a boost transformer. Several energy storage subsystems are connected to the corresponding 110KV transformer and distribution equipment through a 35KV collector line to boost the voltage to one side of the 35KV collector line. At the same time, the battery energy storage system is equipped with a bidirectional meter to measure the charge and discharge of the battery energy storage system. Each group of energy storage batteries is equipped with a battery management system to manage the charge and discharge of the energy storage batteries online. The battery management system and the energy storage converter are connected to the monitoring system through Ethernet to execute the charge and discharge strategy.

[0009] The loads are divided into primary load, secondary load and tertiary load according to the degree of non-interruptibility; the primary load is powered by two stable power supplies, and a backup power supply that only meets the power supply of the primary load can be set; the secondary load is preferably powered by two power supplies, and a backup power supply that only meets the power supply of the primary load can be set, or it can be powered by one power supply; the tertiary load is powered by a single circuit, requiring the distribution system to be simple and reliable, and the number of distribution levels to be minimized;

[0010] The power transformation and distribution equipment includes 110KV photovoltaic substation, 110KV wind power substation, 110KV microgrid user substation, 110KV grid user substation and corresponding 110KV overhead lines;

[0011] The microgrid energy management system adopts a service-oriented architecture and a hierarchical distributed network architecture to realize information modeling, unified data display, unified system management and WEB information release for equipment objects, and adopts standard, mature and open data models and network protocols to provide unified data storage, access, monitoring and early warning functions, and support the modular construction of various business functions; it is used to realize integrated management of production scheduling, coordinated control, operation and maintenance management, and comprehensive display.

[0012] In the above, the wind power station is composed of multiple large-capacity wind turbines and 35KV box-type substations using a one-box-one-transformer unit connection method; after being boosted by the 35KV box-type substation, it is connected to the 35KV collection line in the field, and then boosted by 110KV substations and connected to the power grid.

[0013] In the above, the photovoltaic power station is composed of a plurality of photovoltaic modules and a set of photovoltaic inverters to form a photovoltaic power generation unit. The two photovoltaic power generation units are connected to the 35KV collector line in the field after being stepped up by a box-type substation, and then stepped up by a 110KV photovoltaic substation and connected to the power grid;

[0014] In the above, the battery energy storage system is configured on the wind power station side, the photovoltaic power station side, and the 110KV microgrid user station side, and is used to stabilize power output, shift peaks and fill valleys, and improve the quality of wind power and photovoltaic power generation in an off-grid state. The energy storage station on the wind power station side, the energy storage station on the photovoltaic power station side, and the energy storage station on the 110KV microgrid user station side each include several energy storage subsystems; the energy storage subsystem includes several energy storage converters and at least one group of energy storage batteries.

[0015] In the above, the 110KV photovoltaic substation has 3 outgoing lines, 1 to the 220KV substation, 1 to the 110KV microgrid user substation, and 1 to the 110KV wind power substation; the 110KV wind power substation has 2 outgoing lines, 1 to the 110KV microgrid user substation, and 1 to the 110KV photovoltaic substation; the 110KV microgrid user substation has 2 outgoing lines, 1 to the 110KV wind power substation, and 1 to the 110KV photovoltaic substation; the 110KV power grid user substation has 1 outgoing line to the 220KV substation; a connecting switch is provided between the 110KV busbar of the 110KV microgrid user substation and the 110KV power grid user substation.

[0016] A method for operating a regional microgrid with ultra-large capacity, comprising the following steps:

[0017] Step 1: Joint prediction of wind and photovoltaic power station power. Obtain historical operation data of wind power stations and photovoltaic power stations through data interface scheduling. Use relevant environmental data to build an output power model. Use the model to predict the total wind and photovoltaic power of the next day, and obtain the total power curve of the wind and photovoltaic power stations for the next day.

[0018] Step 2: Power generation plan arrangement, using the wind-solar forecast output curve output by the wind-solar joint forecast model as a reference, combined with the user load curve to formulate the next day's power generation output curve, and provide a variety of optimization control targets for selection. Pre-arrange energy storage and wind-solar power generation units according to the formulated power generation plan.

[0019] Step 3: Real-time power generation control. Based on the actual output of wind and solar power and other real-time monitoring data, the difference between the planned output and the actual output is calculated online. The optimization control target is met as much as possible by adjusting the charging and discharging of energy storage. The unmet part is supplemented by the external power grid.

[0020] In the above, further, step 1: joint prediction of wind and photovoltaic power station power, extract the historical operation data of wind farms and photovoltaic power stations from the database through the data interface, and use the relevant environmental data to construct three neural networks, and integrate the prediction results of the first two networks with the third network to obtain the output power. Network 1, use one-dimensional CNN (1D Convolutional Neural Network) and RNN (Recurrent Neural Network) to construct a deep neural network. Use the sliding window algorithm to process the historical power generation data, generate input vectors and target vectors, and supervise the neural network. The trained network is used to predict the expected total wind and photovoltaic output power from the power generation data. Network 2, construct a fully connected deep neural network. The total radiation, ambient humidity, ambient temperature, radiation intensity, wind speed, wind direction and other environmental historical data are divided and integrated to form an input vector. The total wind and photovoltaic output power in the same period is the target vector, and supervised learning is performed on the constructed fully connected deep neural network. The obtained neural network is used to input environmental parameters to predict the total output power. Network 3, construct a fully connected shallow neural network, use a new set of training data, and obtain two total output powers through the above two networks. The two prediction results are used as input vectors, and the actual wind and solar total output power is used as the target vector to train network 3. The entire trained network is used as a model, and the environmental vectors in the past period are used as the and the power vector As input, the obtained model is used to predict the total wind and solar power of the next day, and the total power curve output by the wind and solar power station of the next day is obtained;

[0021] In the above, further, step 2: power generation plan arrangement, taking the wind-solar power forecast output curve output by the wind-solar power station joint power forecast model as a reference, and combining the user load curve to formulate the next day's power output curve to provide a variety of optimization control targets for selection, such as optimal grid-connected power or optimal power balance, etc. Pre-arrange the power generation plan of the energy storage unit and the wind-solar power generation unit according to the formulated power generation plan;

[0022] In the above, further, step 3: real-time power generation control, according to the actual output of wind and solar power and other real-time monitoring data, the difference Δp(t) between the planned output and the actual output is calculated online, and the optimization control target is met as much as possible by adjusting the energy storage charge and discharge. The unsatisfied part is supplemented by the external power grid. The partial control strategy formula is as follows:

[0023] Optimal power balance: min p cost =p plan (t)+Δp(t)+p ES (t)-p load (t)

[0024] Optimal Internet power consumption: min p cost =p plan (t)+Δp(t)+p ES (t)-p load (t)-p pcc

[0025] Actual and planned difference: Δp(t) = p actual (t)-p plan (t)

[0026] Energy storage system output power:

[0027] Power control of a single energy storage unit:

[0028] Among them, p actual (t) is the actual power generation of photovoltaic and wind power, p plan (t) is the planned total power generation of photovoltaic and wind power at a certain unit time, Δp(t) is the difference between the actual total power generation of photovoltaic and wind power at a certain unit time and the planned total power generation, p ES (t) is the output power of energy storage in a certain unit time, p load (t) is the load power at a certain unit time, p pcc The maximum limit for Internet access power. is the output power of a single energy storage unit at a certain unit time, is the discharge power of a single energy storage unit at a certain unit time, is the charging power of a single energy storage unit at a certain unit time, hold and δ are flags that take 0 and 1. The present invention provides a large-capacity regional microgrid system and operation method, which takes wind power, photovoltaic power generation and other renewable energy power generation as the main body, reasonably optimizes the configuration of the energy storage system, and forms an efficient large-capacity regional microgrid system with integrated generation, transmission and distribution through the microgrid energy management system, which explores the innovative utilization and development mode of renewable energy, improves the utilization ratio of renewable energy, and promotes the local consumption of new energy power. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the networking structure of a microgrid system in an embodiment of the present invention.

[0030] Figure 2 This is a flow chart of a microgrid operation method in an embodiment of the present invention.

[0031] Figure 3 Schematic diagram of wind and solar power station power joint prediction in an embodiment of the method of the present invention. DETAILED DESCRIPTION

[0032] For ease of understanding of the present invention, the present invention will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in this specification in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0033] Embodiment 1

[0034] One embodiment of the present invention is a regional microgrid system with ultra-large capacity, including a wind power station, a photovoltaic power station, an energy storage system, a load, a power transformation and distribution equipment, and a microgrid energy management system.

[0035] The wind power station is composed of multiple large-capacity wind turbines and a 35KV box-type substation using a "one box, one transformer" unit connection method. After being stepped up by the 35KV box-type substation, it is connected to the 35KV collection line in the field, and then stepped up by the 110KV substation and connected to the power grid. The wind power station is used to supply power to the load in the microgrid and charge the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid.

[0036] The photovoltaic power station is composed of a plurality of photovoltaic modules and a set of photovoltaic inverters to form a photovoltaic power generation unit. Two photovoltaic power generation units are connected to the 35KV collector line in the field after being stepped up by a box-type substation, and then stepped up and connected to the power grid by a 110KV photovoltaic substation. When the photovoltaic power station is in normal output during the day, it supplies power to the load in the microgrid and charges the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid. When the photovoltaic output is insufficient during the day, the photovoltaic power station supplies power to the load in the microgrid and no longer charges the energy storage system. The photovoltaic module converts solar energy into electrical energy, and the photovoltaic inverter converts the direct current generated by the photovoltaic module into alternating current.

[0037] The energy storage system is a battery energy storage system that outputs electric energy and is boosted to 35KV through a step-up transformer. Several energy storage subsystems are connected to the corresponding 110KV transformer and distribution equipment through a 35KV collector line to boost the voltage to the side of the 35KV collector line; at the same time, the battery energy storage system is equipped with a bidirectional meter to measure the charging and discharging of the battery energy storage system. Each group of energy storage batteries is equipped with a battery management system to manage the charging and discharging of the energy storage batteries online. The battery management system and the energy storage converter are connected to the monitoring through Ethernet to execute the charging and discharging strategy; the battery energy storage system is configured on the side of the wind power station, the photovoltaic power station, and the 110KV microgrid user station, and is used to stabilize power output, shift peaks and fill valleys, and improve the quality of wind power and photovoltaic power generation in an off-grid state. The energy storage station on the wind power station side, the energy storage station on the photovoltaic power station side, and the 110KV microgrid user station energy storage station each include several energy storage subsystems; the energy storage subsystem includes several energy storage converters and at least one group of energy storage batteries.

[0038] The loads are divided into primary load, secondary load and tertiary load according to the degree of uninterruptibility; the primary load is powered by two stable power supplies, and a backup power supply that only meets the power supply needs of the primary load can be set; the secondary load is preferably powered by two power supplies, and a backup power supply that only meets the power supply needs of the primary load can be set, or it can be powered by one power supply; the tertiary load is powered by a single circuit, requiring the distribution system to be simple and reliable, and the number of distribution levels to be minimized.

[0039] The power transformation and distribution equipment includes a 110KV photovoltaic substation, a 110KV wind power substation, a 110KV microgrid user substation, a 110KV power grid user substation and corresponding 110KV overhead lines; the 110KV photovoltaic substation has 3 outgoing lines, 1 to a 220KV substation, 1 to a 110KV microgrid user substation, and 1 to a 110KV wind power substation; the 110KV wind power substation has 2 outgoing lines, 1 to a 110KV microgrid user substation, and 1 to a 110KV photovoltaic substation; the 110KV microgrid user substation has 2 outgoing lines, 1 to a 110KV wind power substation, and 1 to a 110KV photovoltaic substation; the 110KV power grid user substation has 1 outgoing line to a 220KV substation; a connecting switch is provided between the 110KV busbar of the 110KV microgrid user substation and the 110KV power grid user substation.

[0040] The microgrid energy management system adopts a service-oriented architecture and a hierarchical distributed network architecture to realize information modeling, unified data display, unified system management and WEB information release for equipment objects, and adopts standard, mature and open data models and network protocols to provide unified data storage, access, monitoring and early warning functions, and support the modular construction of various business functions; it is used to realize integrated management of production scheduling, coordinated control, operation and maintenance management, and comprehensive display.

[0041] Based on the above content, the present invention also provides a method for operating a large-capacity regional microgrid, such as Figure 2 As shown, the following steps are included:

[0042] Step 1: Joint prediction of wind and photovoltaic power station power. Obtain historical operation data of wind power stations and photovoltaic power stations through data interface scheduling. Use relevant environmental data to build an output power model. Use the model to predict the total wind and photovoltaic power of the next day, and obtain the total power curve of the wind and photovoltaic power stations for the next day.

[0043] Step 2: Power generation plan arrangement, using the wind-solar forecast output curve output by the wind-solar joint forecast model as a reference, combined with the user load curve to formulate the next day's power output curve, and provide a variety of optimization control targets for selection. Pre-arrange the power generation plan of the energy storage unit and wind-solar power generation unit according to the formulated power generation plan.

[0044] Step 3: Real-time power generation control. Based on the actual output of wind and solar power and other real-time monitoring data, the difference between the planned output and the actual output is calculated online. The optimization control target is met as much as possible by adjusting the charging and discharging of energy storage. The unmet part is supplemented by the external power grid.

[0045] In the above, further, step 1: joint prediction of wind and photovoltaic power station power, extract the historical operation data of wind farms and photovoltaic power stations from the database through the data interface, and use the relevant environmental data to construct three neural networks, and integrate the prediction results of the first two networks with the third network to obtain the output power. Network 1, use one-dimensional CNN (1D Convolutional Neural Network) and RNN (Recurrent Neural Network) to construct a deep neural network. Use the sliding window algorithm to process the historical power generation data, generate input vectors and target vectors, and supervise the neural network. The trained network is used to predict the expected total wind and photovoltaic output power from the power generation data. Network 2, construct a fully connected deep neural network. The total radiation, ambient humidity, ambient temperature, radiation intensity, wind speed, wind direction and other environmental historical data are divided and integrated to form an input vector. The total wind and photovoltaic output power in the same period is the target vector, and supervised learning is performed on the constructed fully connected deep neural network. The obtained neural network is used to input environmental parameters to predict the total output power. Network 3, construct a fully connected shallow neural network, use a new set of training data, and obtain two total output powers through the above two networks. The two prediction results are used as input vectors, and the actual wind and solar total output power is used as the target vector to train network 3. The entire trained network is used as a model, and the environmental vectors in the past period are used as the and the power vector As input, the obtained model is used to predict the total wind and solar power of the next day, and the total power curve output by the wind and solar power station of the next day is obtained;

[0046] In the above, further, step 2: power generation plan arrangement, taking the wind-solar power forecast output curve output by the wind-solar power station joint power forecast model as a reference, and combining the user load curve to formulate the next day's power output curve to provide a variety of optimization control targets for selection, such as optimal grid-connected power or optimal power balance, etc. Pre-arrange the power generation plan of the energy storage unit and the wind-solar power generation unit according to the formulated power generation plan;

[0047] In the above, further, step 3: real-time power generation control, according to the actual output of wind and solar power and other real-time monitoring data, the difference Δp(t) between the planned output and the actual output is calculated online, and the optimization control target is met as much as possible by adjusting the energy storage charge and discharge. The unsatisfied part is supplemented by the external power grid. The control strategy formula is as follows:

[0048] Optimal power balance: min p cost =p plan (t)+Δp(t)+p ES (t)-p load (t)

[0049] Optimal Internet power consumption: min p cost =p plan (t)+Δp(t)+p ES (t)-p load (t)-p pcc

[0050] Actual and planned difference: Δp(t) = p actual (t)-p plan (t)

[0051] Energy storage system output power:

[0052] Power control of a single energy storage unit:

[0053] In the above formula, p actual (t) is the actual power generation of photovoltaic and wind power, p plan (t) is the planned total power generation of photovoltaic and wind power at a certain unit time, Δp(t) is the difference between the actual total power generation of photovoltaic and wind power at a certain unit time and the planned total power generation, p ES (t) is the output power of energy storage in a certain unit time, p load (t) is the load power at a certain unit time, p pcc The maximum limit for Internet access power. is the output power of a single energy storage unit at a certain unit time, is the discharge power of a single energy storage unit at a certain unit time, is the charging power of a single energy storage unit at a certain unit time, hold and δ are flags that take 0 and 1. The present invention provides a large-capacity regional microgrid system and operation method, which takes wind power, photovoltaic power generation and other renewable energy power generation as the main body, reasonably optimizes the configuration of the energy storage system, and forms an efficient large-capacity regional microgrid system with integrated generation, transmission and distribution through the microgrid energy management system, which explores the innovative utilization and development mode of renewable energy, improves the utilization ratio of renewable energy, and promotes the local consumption of new energy power.

[0054] Embodiment 2

[0055] On the basis of the above embodiments, the present invention further provides a large-capacity regional microgrid system, such as Figure 1 As shown, it includes wind power stations, photovoltaic power stations, energy storage systems, loads, power transformation and distribution equipment, and microgrid energy management systems.

[0056] The wind power station consists of 88 wind turbines with a single capacity of 3200 / 4000KW and an export voltage of 690V (not limited and can be optimized) and a 35KV box-type substation using a "one box and one transformer" unit connection method. After being boosted by the box-type substation, it is connected to the 35KV collection line in the field, and then boosted by the 110KV wind power substation and connected to the power grid; the wind power station is used to supply power to the load in the microgrid and charge the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid.

[0057] The photovoltaic power station is composed of a 2000kWp photovoltaic module confluence device and a set of 2000KW photovoltaic inverters to form a photovoltaic power generation unit (not limited, can be optimized), and the direct current is converted into low-voltage alternating current through a centralized inverter. The two photovoltaic power generation units are connected to the 35KV collection line in the field after being stepped up by a 2000kVA double-winding step-up box-type substation, and then stepped up and connected to the power grid through a 110KV photovoltaic substation; when the photovoltaic power station is in normal output during the day, it supplies power to the load in the microgrid and charges the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid; when the photovoltaic output is insufficient during the day, the photovoltaic power station supplies power to the load in the microgrid and no longer charges the energy storage system.

[0058] The energy storage system is a battery energy storage system, which uses a lithium iron phosphate battery pack with a rated capacity of 115Ah and a rated voltage of 3.2V as an energy storage unit, and is connected to the electrical equipment through an energy storage inverter. Four 500kW energy storage inverters and a group of energy storage batteries serve as an energy storage subsystem (not limited and can be optimized). The energy storage subsystem uses an intelligent power distribution system as an external interface, and the output power is boosted to 35KV through a booster transformer. Several energy storage subsystems are connected to the 35KV side of the corresponding 110KV booster station through a 35KV collector line; at the same time, a two-way meter is installed on the battery energy storage system to monitor the charging of the energy storage system. The discharge is metered, and each battery pack is equipped with a battery management system to manage the battery's charge and discharge online. The battery management system and the energy storage converter are connected to the monitor via Ethernet to execute the charge and discharge strategy; the energy storage system includes a 20MW / 40MWh wind farm side energy storage power station (not limited, can be optimized), a 10MW / 20MWh photovoltaic side energy storage power station (not limited, can be optimized), and a 20MW / 20MWh 110KV microgrid user station energy storage power station (not limited, can be optimized), which are used to stabilize power output in an off-grid state, shift peaks and fill valleys, and improve the quality of wind power and photovoltaic power generation.

[0059] The loads are divided into primary load, secondary load and tertiary load according to the degree of uninterruptibility; the primary load is powered by two stable power supplies, and a backup power supply that only meets the power supply needs of the primary load can be set; the secondary load is preferably powered by two power supplies, and a backup power supply that only meets the power supply needs of the primary load can be set, or it can be powered by one power supply; the tertiary load is powered by a single circuit, requiring the distribution system to be simple and reliable, and the number of distribution levels to be minimized.

[0060] The power transformation and distribution equipment mainly includes 110KV photovoltaic substation, 110KV wind power substation, 110KV microgrid user substation, 110KV power grid user substation and corresponding 110KV overhead lines; the 110KV photovoltaic substation has 3 outgoing lines, 1 to 220KV substation, 1 to 110KV microgrid user substation, and 1 to 110KV wind power substation; the 110KV wind power substation has 2 outgoing lines, 1 to 110KV microgrid user substation, and 1 to 110KV photovoltaic substation; 110KV microgrid user substation has 2 outgoing lines, 1 to 110KV wind power substation, and 1 to 110KV photovoltaic substation; 110KV power grid user substation has 1 outgoing line to 220KV substation; a connecting switch is provided between the 110KV busbar of the 110KV microgrid user substation and the 110KV power grid user substation.

[0061] The microgrid energy management system adopts a service-oriented architecture and a hierarchical distributed network architecture to realize information modeling, unified data display, unified system management and WEB information release for equipment objects, and adopts standard, mature and open data models and network protocols to provide unified data storage, access, monitoring and early warning functions, and support the modular construction of various business functions; it is used to realize integrated management of production scheduling, coordinated control, operation and maintenance management, and comprehensive display.

[0062] The present invention provides an ultra-large capacity regional microgrid system and operation method, which takes wind power, photovoltaic power generation and other renewable energy power generation as the main body, reasonably optimizes the configuration of the energy storage system, and forms an efficient ultra-large capacity regional microgrid system with integrated generation, transmission and distribution through the microgrid energy management system. It explores innovative utilization methods and development models of renewable energy, increases the utilization ratio of renewable energy, and promotes the local consumption of new energy electricity.

[0063] It should be noted that the above-mentioned technical features are further combined with each other to form various embodiments not listed above, which are all deemed to be within the scope of the present invention; and, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for operating a large-capacity regional microgrid system, characterized in that: Ultra-large capacity regional microgrid system, including: wind power station, photovoltaic power station, energy storage system, load, power transformation and distribution equipment, microgrid energy management system; The wind power station is connected to the 35KV collector line in the field after being stepped up by the 35KV box-type substation, and then stepped up by the 110KV transformer and distribution equipment and connected to the power grid; the wind power station is used to supply power to the load in the microgrid and charge the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid; When the photovoltaic power generation station is in normal output during the day, it supplies power to the load in the microgrid and charges the energy storage system at the same time. When the energy storage system is full, the excess power is sent to the main grid. When the photovoltaic power generation station is insufficient during the day, it supplies power to the load in the microgrid and no longer charges the energy storage system. The photovoltaic module converts solar energy into electrical energy, and the photovoltaic inverter converts the direct current generated by the photovoltaic module into alternating current. The energy storage system is a battery energy storage system that outputs electric energy that is boosted to 35KV through a boost transformer. Several energy storage subsystems are connected to the corresponding 110KV transformer and distribution equipment through a 35KV collector line to boost the voltage to one side of the 35KV collector line. At the same time, the battery energy storage system is equipped with a bidirectional meter to measure the charge and discharge of the battery energy storage system. Each group of energy storage batteries is equipped with a battery management system to manage the charge and discharge of the energy storage batteries online. The battery management system and the energy storage converter are connected to the monitoring system through Ethernet to execute the charge and discharge strategy. The loads are divided into primary load, secondary load and tertiary load according to the degree of non-interruptibility; the primary load is powered by two stable power supplies, and a backup power supply that only meets the power supply of the primary load can be set; the secondary load is preferably powered by two power supplies, and a backup power supply that only meets the power supply of the primary load can be set, or it can be powered by one power supply; the tertiary load is powered by a single circuit, requiring the distribution system to be simple and reliable, and the number of distribution levels to be minimized; The power transformation and distribution equipment includes 110KV photovoltaic substation, 110KV wind power substation, 110KV microgrid user substation, 110KV grid user substation and corresponding 110KV overhead lines; The microgrid energy management system adopts a service-oriented architecture and a hierarchical distributed network architecture to achieve information modeling, unified data display, unified system management and WEB information release for equipment objects, and adopts standard, mature and open data models and network protocols to provide unified data storage, access, monitoring and early warning functions, and support modular construction of various business functions; it is used to achieve integrated management of production scheduling, coordinated control, operation and maintenance management, and comprehensive display; The operation method of the ultra-large capacity regional microgrid system comprises the following steps: Step 1: Combined power forecasting of wind, solar and storage power stations: Obtain historical operation data of wind farms and photovoltaic power stations from dispatchers through data interfaces. Meanwhile, use relevant meteorological data to establish a certain output power evaluation model, predict the wind power output and photovoltaic power station output for the next day, and obtain the total power curve of the wind, solar and storage power stations output for the next day. Step 2: Power generation plan arrangement, using the wind-solar power forecast output curve output by the wind-solar power storage power station joint power forecasting system as calculation input, providing a variety of optimization control targets for selection, and formulating the planned power generation output curve of the wind-solar power storage power station for the next day; Step 3: Real-time power generation control, based on the actual output of wind and solar power and other real-time monitoring data, online calculate the difference between the planned output and the actual output, so that the actual output of the wind, solar and energy storage power station is as close to the planned output as possible; Step 4: Peak load regulation: the energy storage system is charged when the grid is overloaded and discharged when the grid is underloaded, so as to achieve power supply load matching and reduce the power exchange between the microgrid and the main grid.

2. The operating method according to claim 1, characterized in that: The wind power station is composed of multiple large-capacity wind turbines and 35KV box-type substations using a one-box-one-transformer unit connection method; after being boosted by the 35KV box-type substation, it is connected to the 35KV collection line in the field, and then boosted by 110KV substations and connected to the power grid.

3. The operating method according to claim 2, characterized in that: The photovoltaic power station is composed of a plurality of photovoltaic modules and a set of photovoltaic inverters to form a photovoltaic power generation unit. The two photovoltaic power generation units are connected to the 35KV collection line in the field after being stepped up by a box-type substation, and then stepped up by a 110KV photovoltaic substation and connected to the power grid.

4. The operating method according to claim 3, characterized in that: The battery energy storage system is configured on the wind power station side, the photovoltaic power station side, and the 110KV microgrid user station side, and is used to stabilize power output in an off-grid state, shift peaks and fill valleys, and improve the quality of wind power and photovoltaic power generation; the energy storage station on the wind power station side, the energy storage station on the photovoltaic power station side, and the energy storage station on the 110KV microgrid user station side respectively include several energy storage subsystems; the energy storage subsystem includes several energy storage inverters and at least one group of energy storage batteries.

5. The operating method according to claim 4, characterized in that: The 110KV photovoltaic substation has 3 outgoing lines, 1 to the 220KV substation, 1 to the 110KV microgrid user substation, and 1 to the 110KV wind power substation; the 110KV wind power substation has 2 outgoing lines, 1 to the 110KV microgrid user substation, and 1 to the 110KV photovoltaic substation; the 110KV microgrid user substation has 2 outgoing lines, 1 to the 110KV wind power substation, and 1 to the 110KV photovoltaic substation; the 110KV power grid user substation has 1 outgoing line to the 220KV substation; a connecting switch is provided between the 110KV busbar of the 110KV microgrid user substation and the 110KV power grid user substation.

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