Electric power and electric quantity balance optimization method for electricity-gas coupling system under extreme disasters

Abstract

An electric power and electric quantity balance optimization method for an electricity-gas coupling system under extreme disasters comprises the following steps: firstly, establishing dynamic association between a natural gas system and an electric power system through an electricity-to-gas device and a gas power plant, and building an electricity-gas coupling model; and secondly, aiming at climate resource fluctuation caused by disasters, combining a new energy output model and source-load characteristics during the disasters, utilizing natural gas energy storage to make up an electric quantity gap of new energy output, and ensuring source-load supply and demand balance of the power system. And finally, in combination with the predicted climate data and the load side power demand, establishing a pre-disaster-disaster-time (intra-day) multi-time scale scheduling strategy by taking the maximum generating capacity of the system as a target. According to the method, the advantages of electricity-gas coupling are utilized, resources are effectively scheduled before and after an extreme disaster event occurs, through a multi-time-scale scheduling strategy, the influence of the extreme disaster on the power system source-load supply and demand relationship is reduced, and the power and electric quantity balance of the system is ensured.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and more particularly to the field of power balance technology for power systems under extreme disasters, specifically a method for optimizing the power balance of an electro-electric coupling system under extreme disasters. Background Technology

[0002] In recent years, global warming and frequent extreme weather events have exacerbated the instability risks of power systems, making it difficult to guarantee the power balance requirements. This is especially true in emerging power systems where the penetration rate of renewable energy is constantly increasing. The significant impact of extreme disasters on natural resources such as wind, solar, and hydropower makes the randomness and volatility of renewable energy generation even more difficult to predict and control. As critical energy infrastructure, power systems and natural gas systems are physically interconnected and functionally interdependent. Due to the widespread development of natural gas, gas-fired power generation has become an important, even the largest, source of electricity in many parts of the world. Researching electro-gas coupled systems and improving the resilience of energy systems is an important topic in current development. Furthermore, natural gas systems (underground natural gas pipelines) typically exhibit greater resilience in responding to disasters. In contrast, the power balance of power systems is more susceptible to the impact of extreme disaster events. Therefore, how to ensure the safe and stable operation of power systems under extreme events and meet load demands is a pressing research topic.

[0003] Currently, in integrated energy systems with a high proportion of renewable energy penetration, most research focuses on the resilient recovery of distribution networks after disasters, with limited research on the power system's source-load side. This is particularly problematic when renewable energy output fluctuates, easily leading to source-load power imbalances and frequent power system safety incidents. Using natural gas energy storage devices can effectively mitigate these risks. By integrating natural gas systems with the power system, natural gas can be used as fuel to provide energy storage for renewable energy output on the source side, while simultaneously improving renewable energy absorption capacity through power-to-gas conversion technology.

[0004] Therefore, the applicant proposes a power balance optimization method for electro-electric coupling systems under extreme disasters, which takes into account both the fluctuations in renewable energy output on the source side and the surge in load demand, thereby achieving power balance in the power system. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem of power system supply and demand imbalance caused by insufficient output of new energy sources and excessive load demand under extreme disasters, so as to achieve power balance optimization under extreme disasters. This invention proposes a power balance optimization method for electro-electric coupling systems under extreme disasters.

[0006] To solve the above-mentioned technical problems, the present invention proposes the following technical solution: A method for optimizing the power balance of an electro-electric coupling system under extreme disasters includes the following steps: Step 1: Establish a dynamic correlation system between the natural gas system and the power system through the power-to-gas conversion device and the gas-fired power plant, and construct an electric-gas coupling system that includes a new energy output model and a natural gas energy storage model to characterize the basic relationship between source-side output and load-side demand under extreme disaster conditions; Step 2: Input the climate and load forecast information related to extreme disasters into the new energy output model to obtain the new energy output forecast results for each period, identify the possible power shortage, and use the natural gas energy storage model and gas turbine output to form a pre-disaster dispatching plan to make up for the power shortage under the constraints of the model. Step 3: Based on the pre-disaster scheduling scheme and combined with the climate and load operation information during the extreme disaster, with the goal of maximizing the power generation of the electric-gas coupling system, construct a multi-timescale scheduling strategy for the electric-gas coupling system before and during the extreme disaster, and obtain the multi-timescale scheduling scheme for the electric-gas coupling system. By taking advantage of the electro-pneumatic coupling system through the above steps, resources can be effectively scheduled before and after extreme disaster events. Multi-timescale scheduling strategies are adopted to reduce the impact of extreme disasters on the power system's source-load supply and demand relationship, and to ensure the power balance of the electro-pneumatic coupling system.

[0007] The dynamic correlation system includes hydropower stations, photovoltaic power plants, wind power plants, coal-fired power plants, gas-fired power plants, natural gas storage devices, electricity-to-gas devices, distributed power sources, and the load side; Photovoltaic power plants, wind power plants, and hydropower stations are classified as new energy power plants, while coal-fired power plants and gas-fired power plants are classified as thermal power plants. Both new energy power plants and thermal power plants provide electricity to the power system.

[0008] The power-to-gas conversion unit utilizes the surplus electricity generated from new energy power generation to electrolyze water to produce hydrogen, which is then methanated to produce natural gas, which is then fed into the gas network and natural gas storage devices. The natural gas storage devices, as energy storage devices, will supply energy to the gas turbine units according to the established pre-disaster dispatch strategy during extreme disaster events, enabling the gas turbine units to generate power. At the same time, when no extreme disaster events occur, the natural gas storage devices supply natural gas to the gas network.

[0009] Distributed power sources are located on the load side and are independent power sources. In the event of extreme disasters, they are dispatched according to pre-disaster dispatch strategies. If there is still a supply-demand imbalance on some load sides, distributed power sources can supply power to the load sides to improve the power supply reliability of the power system. The load side is the user side. When extreme disasters (including high temperatures, droughts, cold waves, etc.) occur, the electricity demand on the load side also increases, which can easily lead to a source-load supply imbalance, requiring adjustments according to pre-disaster dispatch strategies.

[0010] The electro-gas coupling system built in step 1 is modeled based on wind power, photovoltaic power, hydropower, gas, and natural gas storage, specifically including a new energy output model and a natural gas energy storage model, wherein: The power output model of the wind turbine is shown in equation (1): (1); In the formula: These represent different time scales, including the pre-disaster time scale and the disaster-time time scale. This is wind speed data; To cut in wind speed; Rated wind speed; To cut off the wind speed; Rated power; The output model of the photovoltaic unit is shown in equation (2): (2); In the formula: is Photovoltaic power station Photovoltaic output during the period; This is the power derating factor; It is time The actual light intensity at that time; It is the power temperature coefficient; time The operating point temperature at that time, in °C; Rated power; This represents the temperature of the photovoltaic cell under standard conditions, which is 25°C. The light intensity under specified standard conditions is 1000 W / m². The normal operating temperature of solar panels is typically 48℃±2℃; for Monitor the temperature constantly; The power output model of the hydropower unit is shown in equation (3): (3); In the formula: It is the hydropower output of the hydropower station during time period t; and These represent the electricity generated by the hydropower station and the electricity that is abandoned, respectively. This refers to the overall power output coefficient of the hydropower station; Indicates that the hydroelectric power station is Power generation flow during a given time period; Indicates that the hydroelectric power station is The amount of water discharged during a given time period; and Hydropower stations Inflow and outflow within a ten-day period; Indicates that the hydroelectric power station is Water head size over a given period; and The hydroelectric power station is located at Average reservoir water level and tailwater level over the period; For the hydroelectric power station Head loss during a given period; and Hydropower stations Storage capacity at the beginning and end of the time period; For the hydroelectric power station Reservoir water level during a specific time period; and These represent the water level-reservoir capacity relationship and the tailrace water level-discharge relationship of the hydropower station, respectively, expressed using function fitting. for Average reservoir capacity at the beginning and end of the time period; The power output model of a thermal power unit is shown in equation (4): (4); In the formula: To provide thermal power output for thermal power plants; Energy consumed for thermal power generation; These are the coefficients used to fit the thermal power generation function; The model of the electro-gas conversion device is shown in equation (5): (5); In the formula: Let be the electrical power of hydrogen electrolysis at time t. and Let be the production rates of hydrogen and natural gas at time t, respectively. It is the rate of hydrogen methanation. It is the output power of natural gas at time t. and These refer to the efficiency of hydrogen production through water electrolysis and the efficiency of natural gas synthesis from hydrogen. and These are the calorific values ​​of natural gas and hydrogen, respectively. The natural gas energy storage model is shown in equation (6): (6); In the formula: and represent and Natural gas energy storage for real-time energy storage; The efficiency of the electrolysis unit; The efficiency of converting hydrogen to natural gas in an electro-gas converter; for The electrical power consumed during the conversion of hydrogen to natural gas over a given period of time; and For the efficiency of gas turbines in gas-fired power plants and Electric power during a given time period.

[0011] The constraints of wind turbines are affected by the wind speed in the climate data. When the wind speed is too high and exceeds the cut-out wind speed, the wind turbine may stop generating electricity to protect the unit's safety. When the wind speed is too low, the wind turbine will also stop generating electricity. Therefore, it is necessary to set constraints for the wind turbine. The constraints of the wind turbine are shown in Equation (7): (7); In the formula: This refers to the output power of the wind turbine. and These are the lower and upper limits of the wind turbine's output, respectively. This refers to the electricity generated by the wind turbine generators and fed into the grid. It is the abandoned electricity generated by wind power.

[0012] The constraints of photovoltaic units are affected by data such as light intensity and temperature in climate data, so there are also maximum and minimum limits on the output. The constraints are shown in equation (8): (8); In the formula: The power output of the photovoltaic unit; and These are the lower and upper limits of the output of the photovoltaic unit, respectively. This refers to the electricity generated by the photovoltaic (PV) generators and fed into the grid. This refers to the abandoned electricity generated by solar power. The constraints of hydropower units are affected by many factors, including reservoir capacity, downstream flow, head, and unit ramp-up, as shown in equation (9): (9); In the formula: and These are the lower and upper limits of the output of the hydropower unit, respectively. and These are the minimum and maximum discharge flows of the hydropower station, respectively. and These represent the minimum and maximum power generation flows of the hydropower station; and These are the minimum and maximum height limits for the water head during hydropower generation. and Minimum and maximum constraints for the reservoir capacity of the hydropower station; This represents the unit's power output during time period t. and These are the unit's uphill and downhill ramp rates, respectively. To provide the maximum lifting force for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running; When a thermal power unit is operating and generating power, the long start-up and shutdown time will cause wear and tear on the unit and shorten its service life. Therefore, it is necessary to impose constraints on the start-up and shutdown time and the ramp-up rate of the unit. The constraints are shown in Equation (10): (10); In the formula: and These are the minimum and maximum output values ​​of a thermal power plant, respectively. and Minimum shutdown and startup time; For the unit The work status; The current time period; and These are the unit's uphill and downhill ramp rates, respectively. This is the maximum lifting force required for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running.

[0013] It also includes constraints on natural gas storage devices; the constraints on natural gas storage devices are mainly limited by the size of the storage capacity, and the constraint conditions are shown in equation (11): (11); In the formula: and These are the minimum and maximum values ​​for the capacity of the natural gas storage device, respectively. The power conversion capacity of the power-to-gas conversion device is mainly constrained by the amount of power curtailment from the wind, solar and hydropower new energy systems. The constraint condition is shown in equation (12): (12); In the formula: This refers to the amount of water wasted and generated by the hydropower station. It is the discharge flow of water from the hydropower station; The sum of the amount of abandoned electricity contributing to the entire new energy sector; , and These are the abandoned power generated by wind power, solar power, and hydropower, respectively. Let be the electrical power used in the electrolysis of hydrogen at time t; for The electrical power consumed during the conversion of hydrogen into natural gas over a given period of time.

[0014] In step 2, the following sub-steps are specifically adopted: Step 2-1) Based on the time scale, before the occurrence of extreme disaster events, new energy power plants predict the impact of extreme disasters on climate data in advance, and input the predicted data into the new energy output model to obtain the new energy output curve under the interference of extreme disasters. Step 2-2) For the power shortage in each period of the curve, reserve the corresponding natural gas energy storage, use gas-fired power generation to supplement the power output gap of new energy sources on the source side, obtain the pre-disaster dispatch curve, and form a pre-disaster dispatch plan. By employing the above pre-disaster dispatch strategies, we can ensure the balance between power source and load supply and demand in the power system.

[0015] In step 3, the objective function of the pre-disaster-disaster multi-timescale strategy is shown in equation (13): (13); In the formula: This is the system's maximum power generation; yes Photovoltaic power output during the period; yes Wind power output during the period; yes Hydropower output during the specified time period; yes Thermal power output during the period; yes Gas-fired power generation using natural gas storage during the specified time period; See Figure 3 In order to achieve the power system's source-load supply and demand balance and maintain the power system's operational safety, it is also necessary to meet the power balance of the power system, as shown in equation (14): (14); In the formula: This refers to the electricity generated by the wind power station and fed into the grid. This refers to the electricity generated by the photovoltaic power station and fed into the grid. This refers to the electricity generated by the hydropower station and fed into the grid. This refers to the electricity generated by thermal power plants connected to the grid. It refers to gas-fired power plants that use natural gas for energy storage and power generation; It is the load-side demand of the power system; according to formula (14), the power system maintains the supply and demand balance between the source and the load, avoids the danger caused by the imbalance between supply and demand, and ensures the stable operation of the power system.

[0016] Compared with the prior art, the present invention has the following technical effects: 1) This invention provides a method for optimizing the power balance of an electric-gas coupled system under extreme disasters. When extreme disasters such as high temperatures, cold waves, typhoons, and droughts occur, the extreme disaster early warning system provides predicted climate data such as wind speed, air pressure, light intensity, and inflow to the renewable energy output model to form a pre-disaster scheduling strategy. Due to the impact of extreme disasters, the relevant climate data changes, causing a decrease in renewable energy output. At the same time, the demand for electric heating or cooling on the load side increases, leading to an imbalance in the power system's source-load supply and demand relationship. Based on the pre-disaster scheduling strategy, a scheduling curve is derived. For periods of supply and demand imbalance, backup energy storage is prepared in advance, and natural gas stored in natural gas storage devices is used for gas-fired power generation to compensate for the power gap caused by the decrease in renewable energy output. When an extreme disaster occurs, an intraday scheduling plan is formulated based on intraday climate data and load demand. For areas with severe power shortages, distributed power sources are used to provide emergency power to the load side or to cut off the load side to ensure power supply balance and avoid power system failures. 2) The electric-gas coupling system provided by this invention for coping with extreme disasters mainly achieves the electric-gas coupling relationship through electric-to-gas technology and gas-fired power plants. The electric-to-gas technology utilizes surplus electricity from renewable energy power generation systems to electrolyze water to produce hydrogen, which is then methanated to produce natural gas. This natural gas is then introduced into the natural gas system and storage facilities, improving the renewable energy utilization capacity. The stored natural gas can be quickly used as fuel during extreme disasters. Based on pre-disaster dispatch strategies, the corresponding natural gas is allocated for power generation by gas-fired power plants. 3) The present invention provides a method for optimizing the power balance of an electric-gas coupled system under extreme disasters. It focuses on the source-load supply balance of the power system and mainly studies the impact of extreme disasters such as high temperature, cold wave, typhoon, and drought on the continuous output of new energy. It establishes pre-disaster scheduling strategies and intraday scheduling strategies during disasters. It also adopts electric-to-gas technology to couple the power system and the natural gas system. It uses the surplus new energy power generation to supply power to the electric-to-gas device, improves the new energy absorption capacity, uses natural gas as backup energy storage for the power system, and uses gas-fired power plants to make up for the shortfall in new energy output. Through multi-time-scale scheduling strategies, the power balance of the electric-gas coupled system is optimized. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 Power system source-load supply and demand relationship diagram under extreme disasters; Figure 2 Power balance diagram of an electro-pneumatic coupling system under extreme disasters; Figure 3 Diagram of scheduling strategy for electro-pneumatic coupling system under extreme disasters. Detailed Implementation

[0018] A method for optimizing the power balance of an electro-electric coupling system under extreme disasters includes the following steps: Step 1: Establish a dynamic correlation system between the natural gas system and the power system through the power-to-gas conversion device and the gas-fired power plant, and construct an electric-gas coupling system that includes a new energy output model and a natural gas energy storage model to characterize the basic relationship between source-side output and load-side demand under extreme disaster conditions; Step 2: Input the climate and load forecast information related to extreme disasters into the new energy output model to obtain the new energy output forecast results for each period, identify the possible power shortage, and use the natural gas energy storage model and gas turbine output to form a pre-disaster dispatching plan to make up for the power shortage under the constraints of the model. Step 3: Based on the pre-disaster scheduling scheme and combined with the climate and load operation information during the extreme disaster, with the goal of maximizing the power generation of the electric-gas coupling system, construct a multi-timescale scheduling strategy for the electric-gas coupling system before and during the extreme disaster, and obtain the multi-timescale scheduling scheme for the electric-gas coupling system. By taking advantage of the electro-pneumatic coupling system through the above steps, resources can be effectively scheduled before and after extreme disaster events. Multi-timescale scheduling strategies are adopted to reduce the impact of extreme disasters on the power system's source-load supply and demand relationship, and to ensure the power balance of the electro-pneumatic coupling system.

[0019] The dynamic correlation system includes a hydropower station 1, a photovoltaic power plant 2, a wind power plant 3, a coal-fired power plant 4, a gas-fired power plant 5, a natural gas storage device 7, an electricity-to-gas device 8, a distributed power source 9, and a load side 10. Among them, photovoltaic power plant 2, wind power plant 3, and hydropower station 1 are new energy power plants, while coal-fired power plant 4 and gas-fired power plant 5 are thermal power plants. New energy power plants and thermal power plants provide electricity to the power system.

[0020] The power-to-gas conversion unit 8 utilizes the surplus electricity generated from new energy power generation to electrolyze water to produce hydrogen, which is then methanated to produce natural gas, and fed into the gas network and the natural gas storage unit 7. The natural gas storage unit 7 serves as an energy storage device, which will supply energy to the gas turbine units according to the established pre-disaster dispatch strategy in the event of an extreme disaster, enabling the gas turbine units to generate power. At the same time, when no extreme disaster event occurs, the natural gas storage unit 7 supplies natural gas to the gas network.

[0021] Distributed power source 9 is located on the load side 10 and is an independent power source. In the event of extreme disasters, it is dispatched according to the pre-disaster dispatch strategy. If there is still a supply-demand imbalance on some load sides, the distributed power source 9 will supply power to the load side to improve the power supply reliability of the power system. The load side is the user side. When extreme disasters (including high temperature, drought, cold wave, etc.) occur, the electricity demand on the load side will also increase, which can easily lead to a source-load supply imbalance, and adjustments need to be made according to the pre-disaster dispatch strategy.

[0022] The electro-gas coupling system built in step 1 is modeled based on wind power, photovoltaic power, hydropower, gas, and natural gas storage, specifically including a new energy output model and a natural gas energy storage model, wherein: The power output model of the wind turbine is shown in equation (1): (1); In the formula: These represent different time scales, including the pre-disaster time scale and the disaster-time time scale. This is wind speed data; To cut in wind speed; Rated wind speed; To cut off the wind speed; Rated power; The output model of the photovoltaic unit is shown in equation (2): (2); In the formula: is Photovoltaic power station Photovoltaic output during the period; This is the power derating factor; It is time The actual light intensity at that time; It is the power temperature coefficient; time The operating point temperature at that time, in °C; Rated power; This represents the temperature of the photovoltaic cell under standard conditions, which is 25°C. The light intensity under specified standard conditions is 1000 W / m². The normal operating temperature of solar panels is typically 48℃±2℃; for Monitor the temperature constantly; The power output model of the hydropower unit is shown in equation (3): (3); In the formula: It is the hydropower output of the hydropower station during time period t; and These represent the electricity generated by the hydropower station and the electricity that is abandoned, respectively. This refers to the overall power output coefficient of the hydropower station; Indicates that the hydroelectric power station is Power generation flow during a given time period; Indicates that the hydroelectric power station is The amount of water discharged during a given time period; and Hydropower stations Inflow and outflow within a ten-day period; Indicates that the hydroelectric power station is Water head size over a given period; and The hydroelectric power station is located at Average reservoir water level and tailwater level over the period; For the hydroelectric power station Head loss during a given period; and Hydropower stations Storage capacity at the beginning and end of the time period; For the hydroelectric power station Reservoir water level during a specific time period; and These represent the water level-reservoir capacity relationship and the tailrace water level-discharge relationship of the hydropower station, respectively, expressed using function fitting. for Average reservoir capacity at the beginning and end of the time period; The power output model of a thermal power unit is shown in equation (4): (4); In the formula: To provide thermal power output for thermal power plants; Energy consumed for thermal power generation; These are the coefficients used to fit the thermal power generation function; The model of the electro-gas conversion device is shown in equation (5): (5); In the formula: Let be the electrical power of hydrogen electrolysis at time t. and Let be the production rates of hydrogen and natural gas at time t, respectively. It is the rate of hydrogen methanation. It is the output power of natural gas at time t. and These refer to the efficiency of hydrogen production through water electrolysis and the efficiency of natural gas synthesis from hydrogen. and These are the calorific values ​​of natural gas and hydrogen, respectively. The natural gas energy storage model is shown in equation (6): (6); In the formula: and represent and Natural gas energy storage for real-time energy storage; The efficiency of the electrolysis unit; The efficiency of converting hydrogen to natural gas in an electro-gas converter; for The electrical power consumed during the conversion of hydrogen to natural gas over a given period of time; and For the efficiency of gas turbines in gas-fired power plants and Electric power during a given time period.

[0023] The constraints of wind turbines are affected by the wind speed in the climate data. When the wind speed is too high and exceeds the cut-out wind speed, the wind turbine may stop generating electricity to protect the unit's safety. When the wind speed is too low, the wind turbine will also stop generating electricity. Therefore, it is necessary to set constraints for the wind turbine. The constraints of the wind turbine are shown in Equation (7): (7); In the formula: This refers to the output power of the wind turbine. and These are the lower and upper limits of the wind turbine's output, respectively. This refers to the electricity generated by the wind turbine generators and fed into the grid. It is the abandoned electricity generated by wind power.

[0024] The constraints of photovoltaic units are affected by data such as light intensity and temperature in climate data, so there are also maximum and minimum limits on the output. The constraints are shown in equation (8): (8); In the formula: The power output of the photovoltaic unit; and These are the lower and upper limits of the output of the photovoltaic unit, respectively. This refers to the electricity generated by the photovoltaic (PV) generators and fed into the grid. This refers to the abandoned electricity generated by solar power. The constraints of hydropower units are affected by many factors, including reservoir capacity, downstream flow, head, and unit ramp-up, as shown in equation (9): (9); In the formula: and These are the lower and upper limits of the output of the hydropower unit, respectively. and These are the minimum and maximum discharge flows of the hydropower station, respectively. and These represent the minimum and maximum power generation flows of the hydropower station; and These are the minimum and maximum height limits for the water head during hydropower generation. and Minimum and maximum constraints for the reservoir capacity of the hydropower station; This represents the unit's power output during time period t. and These are the unit's uphill and downhill ramp rates, respectively. To provide the maximum lifting force for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running; When a thermal power unit is operating and generating power, the long start-up and shutdown time will cause wear and tear on the unit and shorten its service life. Therefore, it is necessary to impose constraints on the start-up and shutdown time and the ramp-up rate of the unit. The constraints are shown in Equation (10): (10); In the formula: and These are the minimum and maximum output values ​​of a thermal power plant, respectively. and Minimum shutdown and startup time; For the unit The work status; The current time period; and These are the unit's uphill and downhill ramp rates, respectively. This is the maximum lifting force required for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running.

[0025] It also includes constraints on natural gas storage devices; the constraints on natural gas storage devices are mainly limited by the size of the storage capacity, and the constraint conditions are shown in equation (11): (11); In the formula: and These are the minimum and maximum values ​​for the capacity of the natural gas storage device, respectively. The power conversion capacity of the power-to-gas conversion device is mainly constrained by the amount of power curtailment from the wind, solar and hydropower new energy systems. The constraint condition is shown in equation (12): (12); In the formula: This refers to the amount of water wasted and generated by the hydropower station. It is the discharge flow of water from the hydropower station; The sum of the amount of abandoned electricity contributing to the entire new energy sector; , and These are the abandoned power generated by wind power, solar power, and hydropower, respectively. Let be the electrical power used in the electrolysis of hydrogen at time t; for The electrical power consumed during the conversion of hydrogen into natural gas over a given period of time.

[0026] In step 2, the following sub-steps are specifically adopted: Step 2-1) Based on the time scale, before the occurrence of extreme disaster events, new energy power plants predict the impact of extreme disasters on climate data in advance, and input the predicted data into the new energy output model to obtain the new energy output curve under the interference of extreme disasters. Step 2-2) For the power shortage in each period of the curve, reserve the corresponding natural gas energy storage, use gas-fired power generation to supplement the power output gap of new energy sources on the source side, obtain the pre-disaster dispatch curve, and form a pre-disaster dispatch plan. By employing the above pre-disaster dispatch strategies, we can ensure the balance between power source and load supply and demand in the power system.

[0027] In step 3, the objective function of the pre-disaster-disaster multi-timescale strategy is shown in equation (13): (13); In the formula: This is the system's maximum power generation; yes Photovoltaic power output during the period; yes Wind power output during the period; yes Hydropower output during the specified time period; yes Thermal power output during the period; yes Gas-fired power generation using natural gas storage during the specified time period; See Figure 3 In order to achieve the power system's source-load supply and demand balance and maintain the power system's operational safety, it is also necessary to meet the power balance of the power system, as shown in equation (14): (14); In the formula: This refers to the electricity generated by the wind power station and fed into the grid. This refers to the electricity generated by the photovoltaic power station and fed into the grid. This refers to the electricity generated by the hydropower station and fed into the grid. This refers to the electricity generated by thermal power plants connected to the grid. It refers to gas-fired power plants that use natural gas for energy storage and power generation; It is the load-side demand of the power system; according to formula (14), the power system maintains the supply and demand balance between the source and the load, avoids the danger caused by the imbalance between supply and demand, and ensures the stable operation of the power system.

[0028] Example: See Figure 1 This invention introduces several scenarios mainly caused by extreme disaster events, including typhoons, droughts, cold, and high temperatures, as well as the impact of each extreme disaster event on the output of new energy sources, such as insufficient sunlight, excessively high / low wind speeds, drought and water shortages, and excessively high / low temperatures. Due to the impact of extreme disasters on climate resources, the output characteristics of new energy units change, resulting in a decrease in new energy output. This leads to a mismatch between the electricity demand on the load side and the power output on the power system source side, resulting in an imbalance between source and load supply.

[0029] See Figure 2 This invention introduces a power balance system diagram of an electro-gas coupling system under extreme disasters. The system diagram includes: 1. Hydropower station; 2. Photovoltaic power plant; 3. Wind power plant; 4. Coal-fired power plant; 5. Gas-fired power plant; 6. Extreme disaster factors; 7. Natural gas storage device; 8. Electricity-to-gas device; 9. Distributed power source; 10. Load side.

[0030] See Figure 2 The functions of each part of the system diagram are as follows: Power plants are divided into new energy power plants (photovoltaic power plants, wind power plants, hydropower stations) and thermal power plants (coal-fired power plants, gas-fired power plants), which provide electricity to the power system; the power-to-gas conversion unit utilizes the waste electricity generated from new energy power generation to electrolyze water to produce hydrogen, which is then methanated to produce natural gas, and fed into the gas network and natural gas storage devices; the natural gas storage devices, as energy storage devices, will supply energy to the gas turbine units according to the established pre-disaster dispatch strategy during extreme disaster events, enabling the gas turbine units to output power. Meanwhile, in the absence of extreme disasters... During disasters, natural gas storage facilities also supply natural gas to the gas grid; distributed power sources are located on the load side and are independent power sources. During extreme disasters, they are dispatched according to pre-disaster dispatch strategies. If there is still a supply-demand imbalance on some load sides, distributed power sources can supply power to the load sides to improve the power supply reliability of the power system. The load side is the user side. When extreme disasters (including high temperatures, droughts, cold waves, etc.) occur, the electricity demand on the load side also increases, which can easily lead to a source-load supply imbalance, requiring adjustments according to pre-disaster dispatch strategies.

[0031] Based on this invention, an electro-gas coupling model with a high proportion of new energy penetration is proposed, which is modeled according to wind power, photovoltaic, hydropower, gas and natural gas storage.

[0032] The power output model of the wind turbine is shown in equation (1): (1); In the formula: These represent different time scales, including the pre-disaster time scale and the disaster-time time scale. This is wind speed data; To cut in wind speed; Rated wind speed; To cut off the wind speed; This is the rated power.

[0033] The output model of the photovoltaic unit is shown in equation (2): (2); In the formula: is Photovoltaic power station Photovoltaic output during the period; This is the power derating factor; It is time The actual light intensity at that time; It is the power temperature coefficient; time The operating point temperature at that time, in °C; Rated power; This represents the temperature of the photovoltaic cell under standard conditions, which is 25°C. The light intensity under specified standard conditions is 1000 W / m². The normal operating temperature of solar panels is typically 48℃±2℃; for Monitor the temperature constantly.

[0034] The power output model of the hydropower unit is shown in equation (3): (3); In the formula: It is the hydropower output of the hydropower station during time period t; and These represent the electricity generated by the hydropower station and the electricity that is abandoned, respectively. This refers to the overall power output coefficient of the hydropower station; Indicates that the hydroelectric power station is Power generation flow during a given time period; Indicates that the hydroelectric power station is The amount of water discharged during a given time period; and Hydropower stations Inflow and outflow within a ten-day period; Indicates that the hydroelectric power station is Water head size over a given period; and The hydroelectric power station is located at Average reservoir water level and tailwater level over the period; For the hydroelectric power station Head loss during a given period; and Hydropower stations Storage capacity at the beginning and end of the time period; For the hydroelectric power station Reservoir water level during a specific time period; and These represent the water level-reservoir capacity relationship and the tailrace water level-discharge relationship of the hydropower station, respectively, expressed using function fitting. for The average reservoir capacity at the beginning and end of the time period.

[0035] The power output model of a thermal power unit is shown in equation (4): (4); In the formula: To provide thermal power output for thermal power plants; Energy consumed for thermal power generation; These are the coefficients used to fit the thermal power generation function.

[0036] The model of the electro-gas conversion device is shown in equation (5): (5); In the formula: Let be the electrical power of hydrogen electrolysis at time t. and Let be the production rates of hydrogen and natural gas at time t, respectively. It is the rate of hydrogen methanation. It is the output power of natural gas at time t. and These refer to the efficiency of hydrogen production through water electrolysis and the efficiency of natural gas synthesis from hydrogen. and These are the calorific values ​​of natural gas and hydrogen, respectively.

[0037] The natural gas energy storage model is shown in equation (6): (6); In the formula: and represent and Natural gas energy storage for real-time energy storage; The efficiency of the electrolysis unit; The efficiency of converting hydrogen to natural gas in an electro-gas converter; for The electrical power consumed during the conversion of hydrogen to natural gas over a given period of time; and For the efficiency of gas turbines in gas-fired power plants and Electric power during a given time period.

[0038] The above model is the basic model of the electro-pneumatic coupling system under extreme disasters. In actual operation, the unit and the electro-pneumatic conversion device will have corresponding constraints.

[0039] The constraints of wind turbines are affected by the wind speed in the climate data. When the wind speed is too high and exceeds the cut-out wind speed, the wind turbine may stop generating electricity to protect the unit's safety. When the wind speed is too low, the wind turbine will also stop generating electricity. Therefore, it is necessary to set constraints for the wind turbine, as shown in equation (7): (7); In the formula: This refers to the output power of the wind turbine. and These are the lower and upper limits of the wind turbine's output, respectively. This refers to the electricity generated by the wind turbine generators and fed into the grid. It is the abandoned electricity generated by wind power.

[0040] The constraints of photovoltaic units are affected by data such as light intensity and temperature in climate data, so there are also maximum and minimum limits on the output. The constraints are shown in equation (8): (8); In the formula: The power output of the photovoltaic unit; and These are the lower and upper limits of the output of the photovoltaic unit, respectively. This refers to the electricity generated by the photovoltaic (PV) generators and fed into the grid. It refers to the abandoned electricity generated by photovoltaic power.

[0041] The constraints of hydropower units are affected by many factors, including reservoir capacity, downstream flow, head, and unit ramp-up, as shown in equation (9): (9); In the formula: and These are the lower and upper limits of the output of the hydropower unit, respectively. and These are the minimum and maximum discharge flows of the hydropower station, respectively. and These represent the minimum and maximum power generation flows of the hydropower station; and These are the minimum and maximum height limits for the water head during hydropower generation. and Minimum and maximum constraints for the reservoir capacity of the hydropower station; This represents the unit's power output during time period t. and These are the unit's uphill and downhill ramp rates, respectively. To provide the maximum lifting force for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running.

[0042] When a thermal power unit is operating, the long start-up and shutdown times can cause wear and tear on the unit, shortening its service life. Therefore, it is necessary to impose constraints on the start-up and shutdown times and ramp-up rates, as shown in equation (10): (10); In the formula: and These are the minimum and maximum output values ​​of a thermal power plant, respectively. and Minimum shutdown and startup time; For the unit The work status; This refers to the current time period. and These are the unit's uphill and downhill ramp rates, respectively. This is the maximum lifting force required for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running.

[0043] The constraints on natural gas storage facilities are mainly limited by the size of the storage capacity, as shown in equation (11): (11); In the formula: and These represent the minimum and maximum capacities of the natural gas storage device, respectively.

[0044] The power conversion capacity of the power-to-gas conversion device is mainly constrained by the amount of power curtailment from the wind, solar and hydropower new energy systems. The constraint condition is shown in equation (12): (12); In the formula: This refers to the amount of water wasted and generated by the hydropower station. It is the discharge flow of water from the hydropower station; The sum of the amount of abandoned electricity contributing to the entire new energy sector; , and These are the abandoned power generated by wind power, solar power, and hydropower, respectively. Let be the electrical power used in the electrolysis of hydrogen at time t; for The electrical power consumed during the conversion of hydrogen into natural gas over a given period of time.

[0045] See Figure 3 This invention provides a scheduling strategy for an electric-gas coupled system under extreme disasters. Based on a time scale, before the occurrence of an extreme disaster event, renewable energy power plants predict the impact of the disaster on climate data and input the predicted data into a renewable energy output model to derive a renewable energy output curve under extreme disaster interference. Simultaneously, for the power shortage in each time period of the curve, corresponding natural gas storage is prepared as backup, and gas-fired power generation is used to supplement the renewable energy output shortage on the source side, resulting in a pre-disaster scheduling curve and achieving overall power balance in the power system, thus formulating a pre-disaster scheduling strategy. Specifically, the goal of the pre-disaster scheduling strategy is to meet the supply and demand balance between the source and load sides of the power system over a long time scale, and to optimize the power balance by utilizing natural gas storage power generation through an electric-gas coupled model.

[0046] See Figure 3 The objective function of the strategy is shown in equation (13): (13); In the formula: This is the system's maximum power generation; yes Photovoltaic power output during the period; yes Wind power output during the period; yes Hydropower output during the specified time period; yes Thermal power output during the period; yes Gas-fired power generation using natural gas storage during a given period.

[0047] See Figure 3 In order to achieve the power system's source-load supply and demand balance and maintain the power system's operational safety, it is also necessary to meet the power balance of the power system, as shown in equation (14): (14); In the formula: This refers to the electricity generated by the wind power station and fed into the grid. This refers to the electricity generated by the photovoltaic power station and fed into the grid. This refers to the electricity generated by the hydropower station and fed into the grid. This refers to the electricity generated by thermal power plants connected to the grid. It refers to gas-fired power plants that use natural gas for energy storage and power generation; It is the load-side demand of the power system; according to formula (14), the power system maintains the supply and demand balance between the source and the load, avoids the danger caused by the imbalance between supply and demand, and ensures the stable operation of the power system.

[0048] See Figure 3 During extreme disasters, the uncertainty of these events and the randomness and uncertainty of climate data changes necessitate higher precision in intraday dispatching. By improving forecast accuracy and reducing the time scale, dispatching strategies can meet the near-real-time supply and demand relationship of sources and loads. New energy power plants can derive more accurate new energy output curves by forecasting near-real-time climate data. They can also consider the capacity of distributed power sources to form an intraday dispatching curve. Based on this, for loads with excessively high electricity demand, they can consider using distributed power sources or load shedding operations to cut off some high-electricity loads, thereby optimizing the power balance of the electric-gas coupling system.

[0049] This invention selects an extreme high-temperature scenario on a summer day as the research scenario to analyze the overall system operation under the scheduling method proposed in this invention. The basic parameters of the electro-pneumatic coupling system are shown in Table 1. Table 1: Basic parameters of electro-electric coupling system

[0050] Table 2 shows the daily power generation of various power sources in the electricity-gas coupling system and the daily gas volume changes of the natural gas storage device from day 1 to day 3 before the disaster, reflecting the characteristics of the electricity-gas joint dispatching of this invention on a multi-day timescale before the disaster. Looking at the daily power generation before the disaster, the hydropower station's daily power generation remained consistently between 7000 MWh and 11000 MWh, undertaking the main power supply throughout the dispatching period, demonstrating the role of hydropower units as the base power source in this embodiment. Wind and photovoltaic power generation fluctuated due to the extreme disaster, reflecting the randomness of wind and solar power output affected by meteorological conditions. The daily power generation of coal-fired power plants gradually decreased from 2473.58 MWh on day 1 to 1800.00 MWh on day 3, showing an overall downward trend; while the daily power generation of gas-fired power plants increased from 547.62 MWh on day 1 to 3000.00 MWh on day 3, and the daily power generation of distributed power sources also increased slightly. This indicates that under the scheduling strategy of this invention, as extreme disasters evolve and pre-disaster operating conditions and load demands change, the system gradually increases the participation of gas-fired power plants and distributed power sources, while moderately reducing the power generation of coal-fired power plants, reserving a certain peak-shaving capacity for the disaster period. On the first and second days, during the night and periods of surplus wind and solar power output, the power-to-gas conversion device converts the curtailed wind and solar power, injecting a portion of the synthetic natural gas into the pipeline network and a portion into the gas storage device, causing the gas storage volume to increase daily. On the third day, the disaster period, load demand increases compared to the previous two days, and gas-fired power plant output increases. The gas storage device releases gas during certain periods of the day to participate in supply, therefore the gas storage volume at the end of the day is slightly lower than on the second day, but still maintains a buffer gas volume of 700.00 m³.

[0051] Table 2: Dispatch Results of the Pre-Disaster Dispatch Plan

[0052] Table 3 shows the time-of-use power output of wind power, photovoltaic power, hydropower, coal-fired power, gas-fired power, and distributed power sources during each 6-hour period during the disaster, as well as the remaining gas storage capacity of natural gas storage devices. During the dispatching process, the extreme high-temperature disaster significantly impacted the output of new energy sources such as wind, solar, and hydropower. Constrained by changes in meteorological conditions, wind and photovoltaic output fluctuated considerably across different time periods, especially during the 12-18 hour period, when wind power output decreased significantly, with only a portion contributed by photovoltaic power, insufficient to cover the continuously rising electricity demand. Although hydropower units maintained high output levels across different time periods, their adjustment space was limited by inflow conditions and reservoir capacity constraints, making it difficult to independently handle the power gap caused by the rapid increase in load and the weakening of wind and solar power output under extreme high-temperature scenarios.

[0053] Gas-fired power plants played a major peak-shaving role in the disaster-time dispatching of this invention. Table 3 shows that from 6-12 hours onwards, with the increase in load and fluctuations in wind and solar power, the output of gas-fired power plants significantly increased, further climbing during the midday and afternoon periods, reaching the highest level of the day during the evening peak period from 18-24 hours, jointly bearing the peak load with hydropower. Natural gas storage devices gradually replenished gas volume through power-to-gas conversion devices during periods of surplus wind and solar power output, and cooperated with gas-fired power plants to release gas during the evening peak period, providing gas source support for the output ramp-up of gas turbine units. Overall, the 24-hour time-sharing dispatching results during disaster times demonstrate that, under conditions where extreme high temperatures limit the output of wind, solar, and hydropower renewable energy sources while maintaining high load levels, this invention, by increasing the time-sharing output of gas-fired power plants and utilizing gaseous gas storage devices for cross-time-sharing buffering, effectively compensated for fluctuations in renewable energy output and provided an orderly response to load peaks.

[0054] Table 3: Time-based Dispatch Results for 24 Hours During Disaster

[0055] Simulation results from pre-disaster and intraday scheduling demonstrate that the proposed power-energy balance optimization method for the electric-gas coupled system under extreme disasters can effectively coordinate the dynamic balance between the output and load demand of wind power, photovoltaic power, hydropower, coal-fired power plants, gas-fired power plants, power-to-gas conversion devices, and gaseous natural gas storage devices under conditions of fluctuating wind, solar, and hydropower output and increased load during disasters. This provides a guarantee for improving the power-energy balance capability and renewable energy utilization level of the electric-gas system under extreme disaster scenarios, and also verifies the applicability and feasibility of the method.

Claims

1. A method for optimizing the power balance of an electro-pneumatic coupling system under extreme disasters, characterized in that, Includes the following steps: Step 1: Establish a dynamic correlation system between the natural gas system and the power system through the power-to-gas conversion device and the gas-fired power plant, and construct an electric-gas coupling system that includes a new energy output model and a natural gas energy storage model to characterize the basic relationship between source-side output and load-side demand under extreme disaster conditions; Step 2: Input the climate and load forecast information related to extreme disasters into the new energy output model to obtain the new energy output forecast results for each period, identify the possible power shortage, and use the natural gas energy storage model and gas turbine output to form a pre-disaster dispatching plan to make up for the power shortage under the constraints of the model. Step 3: Based on the pre-disaster scheduling scheme and combined with the climate and load operation information during the extreme disaster, with the goal of maximizing the power generation of the electric-gas coupling system, construct a multi-timescale scheduling strategy for the electric-gas coupling system before and during the extreme disaster, and obtain the multi-timescale scheduling scheme for the electric-gas coupling system. By taking advantage of the electro-pneumatic coupling system through the above steps, resources can be effectively scheduled before and after extreme disaster events. Multi-timescale scheduling strategies are adopted to reduce the impact of extreme disasters on the power system's source-load supply and demand relationship, and to ensure the power balance of the electro-pneumatic coupling system.

2. The method according to claim 1, characterized in that, The dynamic correlation system includes a hydropower station (1), a photovoltaic power plant (2), a wind power plant (3), a coal-fired power plant (4), a gas-fired power plant (5), a natural gas storage device (7), an electric-to-gas device (8), a distributed power source (9), and a load side (10). Among them, photovoltaic power plants (2), wind power plants (3), and hydropower plants (1) are new energy power plants, while coal-fired power plants (4) and gas-fired power plants (5) are thermal power plants. New energy power plants and thermal power plants provide electricity to the power system.

3. The method according to claim 2, characterized in that, The power-to-gas conversion device (8) uses the waste electricity generated in the new energy power generation to electrolyze water to produce hydrogen, which is then methanated to produce natural gas, and then fed into the gas network and the natural gas storage device (7). The natural gas storage device (7) serves as an energy storage device. In the event of an extreme disaster, it will supply energy to the gas turbine unit according to the established pre-disaster dispatch strategy, so that the gas turbine unit can output power. At the same time, when no extreme disaster occurs, the natural gas storage device (7) supplies natural gas to the gas network.

4. The method according to claim 2 or 3, characterized in that, Distributed power sources (9) are distributed on the load side (10). When extreme disasters occur, they are dispatched according to the pre-disaster dispatch strategy. If there is still a supply-demand imbalance on some load sides, the distributed power sources (9) will supply power to the load side to improve the power supply reliability of the power system. The load side is the user side. When extreme disasters occur, the electricity demand on the load side will also increase, which may lead to a source-load supply imbalance. It is necessary to make adjustments according to the pre-disaster dispatch strategy.

5. The method according to claim 1, characterized in that, The electro-gas coupling system built in step 1 is modeled based on wind power, photovoltaic power, hydropower, gas, and natural gas storage, specifically including a new energy output model and a natural gas energy storage model, wherein: The power output model of the wind turbine is shown in equation (1): （1）； In the formula: This indicates different time scales, including the pre-disaster time scale and the disaster-time time scale. This is wind speed data; To cut in wind speed; Rated wind speed; To cut off the wind speed; Rated power; The output model of the photovoltaic unit is shown in equation (2): （2）； In the formula: is Photovoltaic power station Photovoltaic output during the period; This is the power derating factor; It is time The actual light intensity at that time; It is the power temperature coefficient; time The operating point temperature at that time, in °C; Rated power; This refers to the temperature of the photovoltaic cell under standard conditions. The light intensity under specified standard conditions; This represents the temperature of the solar panel during normal operation. for Monitor the temperature constantly; The power output model of the hydropower unit is shown in equation (3): （3）； In the formula: It is the hydropower output of the hydropower station during time period t; and These represent the electricity generated by the hydropower station and the electricity that is abandoned, respectively. This refers to the overall power output coefficient of the hydropower station; Indicates that the hydroelectric power station is Power generation flow during a given time period; Indicates that the hydroelectric power station is The amount of water discharged during a given time period; and Hydropower stations Inflow and outflow within a ten-day period; Indicates that the hydroelectric power station is Water head size over a period of time; and The hydroelectric power station is located at Average reservoir water level and tailwater level over the period; For the hydroelectric power station Head loss during a given period; and Hydropower stations Storage capacity at the beginning and end of the time period; For the hydroelectric power station Reservoir water level during a given period; and These represent the water level-reservoir capacity relationship and the tailrace water level-discharge relationship of the hydropower station, respectively, expressed using function fitting. for Average reservoir capacity at the beginning and end of the time period; The power output model of a thermal power unit is shown in equation (4): （4）； In the formula: To provide thermal power output for thermal power plants; Energy consumed for thermal power generation; These are the coefficients used to fit the thermal power generation function; The model of the electro-gas conversion device is shown in equation (5): （5）； In the formula: for t The electrical power of hydrogen electrolysis at any given time. and Let be the production rates of hydrogen and natural gas at time t, respectively. It is the rate of hydrogen methanation. yes t Continuously outputting natural gas power, and These refer to the efficiency of hydrogen production through water electrolysis and the efficiency of natural gas synthesis from hydrogen. and These are the calorific values ​​of natural gas and hydrogen, respectively. The natural gas energy storage model is shown in equation (6): （6）； In the formula: and represent and Natural gas energy storage for real-time energy storage; The efficiency of the electrolysis unit; The efficiency of converting hydrogen to natural gas in an electro-gas converter; for The electrical power consumed during the conversion of hydrogen to natural gas over a given period of time; and For the efficiency of gas turbines in gas-fired power plants and Electric power during a given time period.

6. The method according to claim 5, characterized in that, The constraints of wind turbines are affected by the wind speed in the climate data. When the wind speed is too high and exceeds the cut-out wind speed, the wind turbine may stop generating electricity to protect the unit's safety. When the wind speed is too low, the wind turbine will also stop generating electricity. Therefore, it is necessary to set constraints for the wind turbine. The constraints of the wind turbine are shown in Equation (7): （7）； In the formula: This refers to the output power of the wind turbine. and These are the lower and upper limits of the wind turbine's output, respectively. This refers to the electricity generated by the wind turbines and fed into the grid. It is the abandoned electricity generated by wind power.

7. The method according to claim 5, characterized in that, The constraints of photovoltaic units are affected by data such as light intensity and temperature in climate data, so there are also maximum and minimum limits on the output. The constraints are shown in equation (8): （8）； In the formula: The power output of the photovoltaic unit; and These are the lower and upper limits of the output of the photovoltaic unit, respectively. This refers to the electricity generated by the photovoltaic (PV) generators and fed into the grid. This refers to the abandoned electricity generated by solar power. The constraints of hydropower units are affected by many factors, including reservoir capacity, downstream flow, head, and unit ramp-up, as shown in equation (9): （9）； In the formula: and These are the lower and upper limits of the output of the hydropower unit, respectively. and These are the minimum and maximum discharge flows of the hydropower station, respectively. and These represent the minimum and maximum power generation flows of the hydropower station; and These are the minimum and maximum height limits for the water head during hydropower generation. and Minimum and maximum constraints for the reservoir capacity of the hydropower station; This represents the unit's power output during time period t. and These are the unit's uphill and downhill ramp rates, respectively. To provide the maximum lifting force for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running; When a thermal power unit is operating and generating power, the long start-up and shutdown time will cause wear and tear on the unit and shorten its service life. Therefore, it is necessary to impose constraints on the start-up and shutdown time and the ramp-up rate of the unit. The constraints are shown in Equation (10): （10）； In the formula: and These are the minimum and maximum output values ​​of a thermal power plant, respectively. and Minimum shutdown and startup time; For the unit The work status; The current time period; and These are the unit's uphill and downhill ramp rates, respectively. This is the maximum lifting force required for unit startup; For the unit Maximum output reduction during shutdown; When the value is 0, the unit stops. When the value is 1, the unit is running.

8. The method according to any one of claims 5 to 7, characterized in that, It also includes constraints on natural gas storage devices; the constraints on natural gas storage devices are mainly limited by the size of the storage capacity, and the constraint conditions are shown in equation (11): （11）； In the formula: and These are the minimum and maximum values ​​for the capacity of the natural gas storage device, respectively. The power conversion capacity of the power-to-gas conversion device is mainly constrained by the amount of power curtailment from the wind, solar and hydropower new energy systems. The constraint condition is shown in equation (12): （12）； In the formula: This refers to the amount of water wasted and generated by the hydropower station. It is the discharge flow of water from the hydropower station; The sum of the amount of abandoned electricity contributing to the entire new energy sector; , and These are the abandoned power generated from wind power, solar power, and hydropower, respectively. Let be the electrical power of hydrogen electrolysis at time t; for The electrical power consumed during the conversion of hydrogen into natural gas over a given period of time.

9. The method according to any one of claims 1 to 5, characterized in that, In step 2, the following sub-steps are specifically adopted: Step 2-1) Based on the time scale, before the occurrence of extreme disaster events, new energy power plants predict the impact of extreme disasters on climate data in advance, and input the predicted data into the new energy output model to obtain the new energy output curve under the interference of extreme disasters. Step 2-2) For the power shortage in each period of the curve, reserve the corresponding natural gas energy storage, use gas-fired power generation to supplement the power output gap of new energy sources on the source side, obtain the pre-disaster dispatch curve, and form a pre-disaster dispatch plan. By employing the above pre-disaster dispatch strategies, we can ensure the balance between power source and load supply and demand in the power system.

10. The method according to claim 9, characterized in that, In step 3, the objective function of the pre-disaster-disaster multi-timescale strategy is shown in equation (13): （13）； In the formula: This is the system's maximum power generation; yes Photovoltaic power output during the period; yes Wind power output during the period; yes Hydropower output during the specified time period; yes Thermal power output during the period; yes Gas-fired power generation using natural gas storage during the specified time period; In order to achieve the power system's source-load supply and demand balance and maintain the power system's operational safety, it is also necessary to meet the power balance of the power system, as shown in equation (14): （14）； In the formula: This refers to the electricity generated by the wind power station and fed into the grid. This refers to the electricity generated by the photovoltaic power station and fed into the grid. This refers to the electricity generated by the hydropower station and fed into the grid. This refers to the electricity generated by thermal power plants connected to the grid. It refers to gas-fired power plants that use natural gas for energy storage and power generation; It is the load-side demand of the power system; according to formula (14), the power system maintains the supply and demand balance between the source and the load, avoids the danger caused by the imbalance between supply and demand, and ensures the stable operation of the power system.

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