Method for shutting down mine renewable energy source development

Abstract

The invention provides a method for developing renewable energy sources of a closed mine. The method comprises the following steps: calculating a wind-light capacity coefficient of a closed mine unit; evaluating the wind-solar power generation potential of the closed mine unit; closing a wind-solar power generation grid-connected line of the mine unit based on the grid division design; designing a power generation dispatching layer; and constructing a power system model containing a shut-down mine unit to minimize the construction operation cost.

Description

Technical Field

[0001] The present disclosure relates to the fields of new energy development and smart grid technology, and in particular to a method for developing renewable energy in closed mines. Background Art

[0002] my country is currently the world's largest energy consumer and carbon emitter. Under pressure from energy restructuring and carbon emission reduction, my country is urgently developing renewable energy. Furthermore, by 2024, mining operations nationwide will have occupied and damaged approximately 54 million mu (approximately 1.6 million hectares) of land. Therefore, transforming closed mines to utilize renewable energy is a necessary and urgent task. Summary of the Invention

[0003] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present disclosure provides a method for developing renewable energy in a closed mine.

[0004] In order to achieve the above objectives, the technical solutions disclosed in this disclosure are as follows:

[0005] According to an embodiment of the present disclosure, a method for developing renewable energy in closed mines is provided, comprising: calculating the wind and solar capacity coefficient of the closed mine unit; evaluating the wind and solar power generation potential of the closed mine unit; designing the wind and solar power generation grid-connected lines of the closed mine unit based on grid division; designing the power generation scheduling layer; and constructing a power system model including the closed mine unit to minimize construction and operation costs.

[0006] According to an embodiment of the present disclosure, calculating the wind and solar capacity coefficient of a closed mine unit includes calculating the wind power capacity coefficient of the closed mine unit; and calculating the photovoltaic power generation capacity coefficient of the closed mine unit.

[0007] According to an embodiment of the present disclosure, evaluating the wind and solar power generation potential of a closed mine unit includes evaluating the wind power generation potential of the closed mine unit; and evaluating the photovoltaic power generation potential of the closed mine unit.

[0008] According to an embodiment of the present disclosure, the design of a grid-connected wind and solar power generation line for closed mine units based on grid division includes: dividing the wind and solar power generation unit grids based on geographical longitude and latitude information; treating each wind and solar power generation unit grid with a closed mine as a closed mine unit, and connecting it to the nearest substation in the province through a branch line; and connecting the substation to the nearest main node in the same province through a trunk line on the principle of ensuring the shortest total distance for wind and solar power generation grid connection.

[0009] According to an embodiment of the present disclosure, the center point of each county or district is used as the spatial location of the substation, all prefecture-level cities and above in the urban agglomeration are positioned as load centers, and the center point of the load center in space is used as the main node of the power grid.

[0010] According to the disclosed embodiments, designing the generation scheduling layer involves allocating annual power demand to various generator sets on the supply side on an hourly basis, based on a heuristic scheduling sequence. Fixed generator sets are located in the first layer of the generation scheduling layer, while generator sets for closed mine units are located in the second layer.

[0011] According to an embodiment of the present disclosure, when constructing a power system model that includes closed mine units, an objective function is established with the goal of minimizing construction and operating costs. The objective function's constraints include supply and demand balance constraints, wind power and photovoltaic power generation constraints, fixed unit power supply constraints, wind and solar grid connection constraints, inter-provincial transmission line constraints, spare capacity requirements, ramp capacity constraints, and energy storage operation constraints.

[0012] According to an embodiment of the present disclosure, the closed mine renewable energy development method further includes calculating the closed mine unit wind and solar power generation costs and calculating the branch line levelized connection costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0014] Figure 1 Schematic diagram of the working principle of the photovoltaic-pumped storage power station in an abandoned mine.

[0015] Figure 2 This is a flow chart of the method for developing renewable energy in closed mines according to an embodiment of the present disclosure.

[0016] Figure 3 Schematic diagram of the technical process and principle of the closed mine renewable energy development method according to the embodiment of the present disclosure. DETAILED DESCRIPTION

[0017] The present disclosure provides a method for developing renewable energy in closed mines, which uses wind power and photovoltaic power generation as the main renewable energy generation technologies. It innovatively combines the resource endowment conditions and geographical spatial characteristics of closed mines with new energy power system planning, and realizes the spatial site selection and capacity configuration optimization of renewable energy development in closed mines.

[0018] The research and practice of combining closed mines with renewable energy abroad has made relatively mature progress. For example, the Ruhr mining area in Germany has been able to realize continuous power generation of wind power generation projects. At the same time, domestic scholar Zhang Zhenqi believes that the application of photovoltaic power generation technology in abandoned mine tail dams has certain feasibility, and points out from the perspective of economic benefits that photovoltaic power generation systems are an effective choice for the sustainable development of abandoned mining areas. However, there are few domestic scholars who study the site selection of renewable energy development in closed mines. The existing technology is generally based on a single closed mine, combining pumped storage with photovoltaic power generation, and using photovoltaic arrays to transmit solar power generation to nearby pumped storage power stations through confluence. When there are few electrical equipment and the grid load is low, the transformer generates electricity to pump water from the lower reservoir to the upper reservoir, and store this low-valley electricity in the form of water potential energy; when the number of electrical equipment increases and the grid load increases, water is released from the upper reservoir to maintain grid stability. The work flow and principles are as follows: Figure 1 However, the above-mentioned prior art still has the following disadvantages:

[0019] 1. There are few domestic studies on the site selection for renewable energy development in closed mines, and most of them remain at the theoretical stage without specific experimental evidence.

[0020] 2. The current research scale is mainly limited to the level of individual mines, focusing on the feasibility analysis, suitability evaluation and physical utilization potential assessment of specific mines. The research methods adopted are highly context-dependent, resulting in insufficient universality and generalizability of the research results.

[0021] 3. Existing research rarely integrates multiple closed mines on a large scale into the overall planning of the new energy power network from the perspective of the overall energy system. In particular, there are research gaps in key links such as the complementary capacity configuration of multiple power generation layers and the optimization of spatial layout.

[0022] 4. Existing studies rarely consider the accurate temporal and spatial matching of supply capacity and demand response after the development and grid connection of renewable energy from closed mines. None of them include closed mines as an important renewable energy power generation supply side in the planning of future new energy power systems.

[0023] Therefore, the present disclosure provides a method for developing renewable energy in closed mines, which uses wind power and photovoltaic power generation as the main renewable energy power generation technologies, innovatively combines the resource endowment conditions and geographical spatial characteristics of closed mines with new energy power system planning, and realizes the spatial site selection and capacity configuration optimization of renewable energy development in closed mines.

[0024] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0025] In the embodiment of the present disclosure, Figure 2 and Figure 3 As shown, a method for developing renewable energy in a closed mine is provided, comprising the following operations S1-S5:

[0026] S1: Calculate the wind and solar capacity coefficient of the closed mine unit;

[0027] S2: Evaluate the wind and solar power generation potential of closed mine units;

[0028] S3: Based on the grid division design, the wind and solar power generation grid connection lines of the mine unit are closed;

[0029] S4: Design the generation dispatch layer; and

[0030] S5: Construct a power system model that includes closed mine units to minimize construction and operation costs.

[0031] According to an embodiment of the present disclosure, calculating the wind and solar capacity coefficient of a closed mine unit includes calculating the wind power capacity coefficient of the closed mine unit; and calculating the photovoltaic power generation capacity coefficient of the closed mine unit.

[0032] Regarding the calculation of wind power capacity factor: Based on hourly-scale east-west and north-south wind speed simulation data, the wind power capacity factor of the closed mine unit is calculated according to the following formula. First, the wind speed data in the two directions are synthesized using Formula 1.

[0033] (1);

[0034] (2);

[0035] Then, use Equation 2 to convert the real-time wind speed data at the height of the wind turbine hub. and denote the wind speed at the target height and original height respectively, and Represent the target height and original height respectively. is the conversion factor, which varies with different geographical locations. Subsequently, the real-time power of the wind turbine is inferred from the wind speed, as shown in Equation 3.

[0036] (3);

[0037] (4);

[0038] Where, Indicates the real-time power of the fan, Indicates the rated power of the fan. Indicates the real-time wind speed. 、 and They represent the cut-in wind speed, rated wind speed and cut-out wind speed of the wind turbine respectively. Finally, the ratio of the wind turbine's real-time power to its rated power is calculated by formula 4 as the capacity factor of the wind power generation in the closed mine. .

[0039] Regarding the calculation of photovoltaic power generation capacity coefficient: Based on the unit-scale solar radiation data of the closed mine, the photovoltaic power generation capacity coefficient of the closed mine for 8760 hours per year is calculated hour by hour using Formula 5.

[0040] (5);

[0041] Where, and They represent the photovoltaic modules at the calculation time and under standard experimental conditions (the photovoltaic module temperature is 25℃ and the solar radiation is 1000W / m 2 , air quality is 1.5AM) of solar energy conversion efficiency. This paper assumes that the conversion efficiency of photovoltaic modules remains unchanged when the solar radiation changes, that is, and The ratio is always 1. Indicates the power loss during the power generation process of photovoltaic modules. and They represent the calculated shading influence coefficient and temperature influence coefficient respectively.

[0042] According to an embodiment of the present disclosure, evaluating the wind and solar power generation potential of a closed mine unit includes evaluating the wind power generation potential of the closed mine unit; and evaluating the photovoltaic power generation potential of the closed mine unit.

[0043] Regarding wind power potential assessment: First, based on the inherent characteristics of closed mines, a system of indicators for evaluating the suitability of closed mines for wind power development and utilization was constructed. This system assessed the suitability of closed mines nationwide for wind power development and categorized closed mines as either suitable for wind power development or unsuitable. The evaluation indicator system is shown in Table 1.

[0044] Table 1 Evaluation index system for suitability of wind power development in closed mines

[0045]

[0046] Next, for closed mine units suitable for wind power development, their physical potential for wind power development was calculated using Formula 6:

[0047] (6);

[0048] In the formula Indicates the maximum installed capacity potential of wind power generation from closed mine land resources, represents the area of closed mines, Indicates the installed capacity of wind power per unit area.

[0049] Regarding the assessment of photovoltaic power generation potential: Similarly, a suitability evaluation index system for photovoltaic power generation development and utilization in closed mines was established to constrain the suitability of deploying photovoltaic power generation projects in closed mines. The evaluation index system is shown in Table 2.

[0050] Table 2 Suitability evaluation index system for photovoltaic power generation development in closed mines

[0051]

[0052] Assuming that photovoltaic power generation adopts a fixed-angle installation mode, it is necessary to calculate the photovoltaic module installation coefficient of the closed mine unit scale. The photovoltaic installation coefficient refers to the effective photovoltaic panel area coefficient per unit land area. The specific calculation formula is as follows:

[0053] (7);

[0054] Where, Refers to the photovoltaic installation coefficient. Finally, the photovoltaic installed capacity potential is calculated according to Formula 8:

[0055] (9);

[0056] Where, Indicates the maximum installed capacity potential of photovoltaic power generation projects at closed mines; Indicates the power generated per unit area of photovoltaic panels.

[0057] According to an embodiment of the present disclosure, the grid-based design of a closed mine unit wind and solar power generation grid-connected line includes:

[0058] Divide wind and solar power generation unit grids based on geographic latitude and longitude information;

[0059] Identify each wind and solar power unit grid with a closed mine as a closed mine unit and connect it to the nearest substation in the province through a branch line; and

[0060] Under the principle of ensuring the shortest total distance for wind and solar power generation to be connected to the grid, the substation is connected to the nearest main node in the same province through the trunk line.

[0061] According to the embodiment of the present disclosure, the center point of each county or district is used as the spatial location of the substation, all prefecture-level cities and above in the urban agglomeration are positioned as load centers, and the center point of the load center in space is used as the main node of the power grid.

[0062] Specifically, each wind and solar power grid (including both common spatial grids and closed mine grids) is first connected to the nearest substation in its province via branch lines. Subsequently, while minimizing the total distance for wind and solar power grid connection, the substation is connected to the nearest primary node in the same province via trunk lines. (The center of each county or district in China serves as the spatial location of the substation in the model, and all prefecture-level cities and above within the urban agglomeration are positioned as load centers. The load center's spatial center serves as the primary node of the future grid.)

[0063] According to the disclosed embodiment, designing the generation scheduling layer involves allocating annual power demand to various generator sets on the supply side on an hourly timescale based on a heuristic scheduling sequence. Fixed generator sets are located in the first layer of the generation scheduling layer, while generator sets for closed mining units are located in the second layer.

[0064] Specifically, based on a heuristic scheduling sequence, annual electricity demand is rationally allocated to various generators on the supply side on an hourly basis, as shown in Table 3 below. Based on each province's electricity demand and the generation of the first layer of the model's generation scheduling layer, G1 (the fixed generation layer, which prioritizes electricity and is required for operation), the power gap in each province is calculated. The generation of layers G2 through G5 is then used to gradually fill the gap. Renewable energy generation from closed mines is placed in the model's second layer, also known as the variable energy generation layer.

[0065] Table 4 Generation layer scheduling order

[0066]

[0067] According to an embodiment of the present disclosure, when constructing a power system model that includes closed mine units, an objective function is established with the goal of minimizing construction and operating costs. The objective function's constraints include supply and demand balance constraints, wind power and photovoltaic power generation constraints, fixed unit power supply constraints, wind and solar grid connection constraints, inter-provincial transmission line constraints, spare capacity requirements, ramp capacity constraints, and energy storage operation constraints.

[0068] Regarding the objective function construction: The objective function established is to minimize the construction and operation costs of the new energy power system coupled with the development of renewable energy sources for closed mines based on the existing infrastructure and fixed installed capacity. represents a collection of provinces; The provinces involved in the nine clean energy bases are A subset of Represents the set of renewable energy power generation technologies (conventional onshore wind power, conventional photovoltaic power generation, offshore wind power, closed mine photovoltaic power generation, closed mine wind power); Indicates province Renewable energy generation technology The set of grid cells that may be used; Indicates province Zhonghe Substation Connected renewable energy generation technologies The set of grid cells that may be used; Indicates province Renewable energy generation technology a collection of closed mine units that may be utilized; Indicates province Zhongyu Substation Connected renewable energy generation technologies a collection of closed mine units that may be utilized; represents a collection of substations; represents the set of load centers; represents a collection of energy storage technologies (pumped hydro and lithium battery chemical energy storage); represents the collection of power generation layers; Represents a collection of time slices. Indicates the provinces of the nine major clean energy bases New energy technologies Installed capacity planning, in GW; Indicates the power generation layer Unit ramp cost, in yuan / kW; Indicates the power generation layer Unit downhill cost, in yuan / kW; Indicates the power generation layer Unit standby cost, in yuan / kW; Indicates the power generation layer Unit fuel cost, in yuan / kW; Indicates the power generation layer Unit variable operation and maintenance cost, in yuan / kW; Energy storage technology The capital cost is in yuan / kW; Energy storage technology Fixed operation and maintenance costs, in yuan / kW yr; Energy storage technology Variable operation and maintenance costs, in yuan / kWh; Indicates province and Fixed investment in power transmission lines between the two countries, in yuan / kW; Indicates province and Variable investment in power transmission lines between the two countries, in yuan / kW km; Indicates province Power generation layer In time slice The maximum capacity, in GW; Indicates province Renewable energy generation technology Possible use of The maximum installed capacity potential of each grid unit, in GW; Indicates province Renewable Energy Technologies Possible use of The maximum installed capacity potential of each closed mine unit, in GW; Indicates province and The transmission capacity of the existing power transmission lines between them, in GW; Indicates province The maximum installed capacity of pumped hydropower storage in the future, in GW; Indicates province Installed pumped storage capacity, in GW; Indicates province The maximum capacity of coal-fired combined heat and power plants in operation, in GW; Indicates province Power generation layer At the moment The hourly capacity factor is expressed as: Indicates province No. Grid unit renewable energy generation technology At the moment The capacity factor is expressed as; Indicates province No. Renewable energy generation technology for closed mine units At the moment The capacity factor is expressed as; Indicates province No. Grid unit renewable energy generation technology The average annual capacity factor is expressed as; Indicates province No. Renewable energy generation technology for closed mine units The average annual capacity factor is expressed as; Indicates province No. PV module installation factor for each closed mine unit; Renewable energy generation technology The unit installed capacity covers an area of ​​GW / km 2 ; Indicates province No. The area of closed mines, in km 2 ; Indicates province No. Grid Cell Renewable Energy Technologies The levelized cost of the feeder line connected to the substation, in yuan / kWh; Indicates province No. Renewable energy technologies for closed mine units The levelized cost of the feeder line connected to the substation, in yuan / kWh; Indicates province and The distance between inter-provincial transmission lines, in km; Indicates province No. The distance between each grid unit and the substation, in km; Indicates province No. The distance between the closed mine unit and the substation, in km; Indicates province Substation The distance to the load center in km; Indicates province At the moment The electricity demand, in GW; Indicates province At the moment The net electricity demand remaining after deducting the supply required for L1 to operate, in GW; Indicates province No. Grid unit renewable energy generation technology It is expressed as the ratio of installed capacity to maximum potential installed capacity; Indicates province No. Renewable energy generation technology for closed mine units It is expressed as the ratio of installed capacity to maximum potential installed capacity; Indicates province No. Grid unit renewable energy generation technology The levelized cost of electricity, in yuan / kWh; Indicates province No. Renewable energy generation technology for closed mine units The levelized cost of electricity, in yuan / kWh; Energy storage technology The investment recovery coefficient; Indicates province and The investment recovery coefficient of inter-provincial transmission lines; Indicates the investment recovery coefficient of the grid-connected branch line; Indicates the investment recovery coefficient of the grid-connected trunk line; Indicates the power generation layer The maximum climbing rate is expressed as; Indicates the power generation layer The maximum downhill rate is expressed as; Energy storage technology The charging efficiency is expressed as follows; Energy storage technology The discharge efficiency is expressed as; It indicates the lowest transmission efficiency of coal-fired cogeneration if it is put into operation during non-essential operation period; Energy storage technology The self-discharge rate is expressed as; The reserve capacity requirement rate of the power load is expressed; It represents the reserve capacity requirement rate of renewable energy generation technology; Energy storage technology The duration of the time, in hours; Indicates the capital investment cost of the grid-connected line, in yuan / kW km; Indicates the transmission loss rate of the branch lines and trunk lines connecting wind and solar grids, in % / km; Indicates province and Energy loss rate of inter-provincial transmission lines, in % / km; Indicates the power generation layer Energy loss rate after using CCS technology. Indicates province No. Grid cells to develop renewable energy technologies The capacity is expressed as a proportion of the maximum potential; Indicates province No. Closed mines to develop renewable energy technologies The capacity is expressed as a proportion of the maximum potential; Indicates connected provinces Middle Grid unit renewable energy generation technology With substation The capacity of the branch line, in GW; Indicates connected provinces Middle Renewable energy generation technology for closed mine units With substation The capacity of the branch line, in GW; Indicates connected provinces Medium Substation With load center The capacity of the trunk line, in GW; Indicates province and The capacity of inter-provincial transmission lines, in GW; Indicates province China Energy Storage Technology The capacity, in GW; Indicates province Renewable energy generation technology At the moment Power generation (aggregated by grid cells and closed mine cells), in GW; Indicates province China Power Technology (Generation layers L2-L4 and renewable energy generation technology) at the moment The amount of electricity generated that is delivered to other provinces, in GW; Indicates province At the moment Transport to provinces The unit of electricity is GW; Indicates province China Power Technology At the moment Storage to energy storage technology The unit of electricity is GW; Indicates province China Energy Storage Technology At the moment Energy released, in GW; Indicates the deadline ,province Storage in energy storage technology The total energy in GWh; Indicates province China Energy Storage Technology At the moment The spare capacity provided, in GW; Indicates province Middle power generation layer At the moment The spare capacity provided, in GW; Indicates province Middle power generation layer At the moment The load provided, in GW; Indicates province Middle power generation layer At the moment Hourly ramp capacity, in GW; Indicates province Middle power generation layer At the moment Hourly ramp capacity, in GW; Represents a binary variable used to determine the province during the non-essential operation period The coal-fired power generation technology in the L3 layer is Whether it is running; Indicates province Substation in With load center The total annual amount of electricity transmitted, in GWh; Indicates province Medium Substation The levelized cost of the main line connecting to the load center, in yuan / kW; Indicates province Power generation layer At the moment The power generation capacity is in GW. The specific calculation formula of the objective function is as follows:

[0069] (9);

[0070] In the embodiment of the present disclosure, Figure 3As shown, the circuit system model including the closed mine unit is a bottom-up, multi-scale fusion model. With the goal of minimizing the overall construction and operation costs of China's power system, it combines wind and solar energy renewable energy generation technologies at the grid unit and closed mine unit scales with traditional power generation technologies at the provincial and regional scales, such as coal-fired combined heat and power, nuclear power, biomass power generation (BECCS), hydropower, and natural gas power generation (natural gas + CCS), to jointly meet the hourly operation constraints of the power system, including supply and demand balance constraints, spare capacity constraints, and ramping constraints. Based on this, the model optimizes the dispatching and operation of traditional power generation technologies on the supply side, inter-provincial power transmission, and the capacity construction, expansion, dispatching and operation, and spatial layout of new energy generation technologies in spatial grids and closed mine units to obtain the optimal development potential configuration and spatial layout planning of renewable energy in China's closed mines under the goal of carbon neutrality. The constraints may include the following:

[0071] ① Supply and demand balance constraints:

[0072] The electricity demand of each province in each time slice should be equal to the total electricity supply. The specific formula is as follows:

[0073] (10);

[0074] ② Wind power and photovoltaic power generation constraints:

[0075] The power generation utilization of each renewable energy technology at any moment should be less than or equal to the maximum power generation capacity that the installed capacity of the technology can provide at that moment.

[0076] (11);

[0077] The total area occupied by wind power and photovoltaic power generation cannot exceed the total area of the mining area. The specific constraint function is as follows:

[0078] (12);

[0079] The installed capacity of wind and solar power in the nine clean energy bases is constrained, requiring that the installed capacity of wind and solar power in each province involved in the nine clean energy bases must be greater than or equal to the national wind and solar power generation deployment plan for these provinces, as shown in Formula 13:

[0080] (13);

[0081] ③ Fixed unit power supply constraints:

[0082] For fixed units, the amount of electricity they provide in a time slice should be less than or equal to the maximum power transmission capacity of that time slice.

[0083] (14);

[0084] In addition, if coal-fired cogeneration units need to be online to meet power demand during non-essential operation periods, they must meet the following minimum output power restrictions:

[0085] (15);

[0086] (16);

[0087] ④ Constraints on wind and solar grid connection lines:

[0088] The installed capacity of each branch line should be greater than or equal to the maximum power generation of the renewable energy installed in the grid unit or closed mine unit connected to the substation, as shown in the following formula:

[0089] (17);

[0090] (18);

[0091] For the trunk line connecting the substation and the load center during the wind and solar grid connection process, its installed capacity should be greater than or equal to the maximum power transmitted to it by the substation.

[0092] (19);

[0093] ⑤ Constraints on inter-provincial transmission lines:

[0094] At the same time, from the province arrive The sum of the power transmission volume between two provinces and the power transmission volume in the opposite direction should be less than or equal to the installed capacity of the inter-provincial transmission line between the two provinces, and the inter-provincial transmission lines connecting the same province should have the same installed capacity regardless of the transmission direction. The specific constraint function is as follows:

[0095] (20);

[0096] (twenty one);

[0097] For two provinces that already have interprovincial power transmission lines, the capacity of their future interprovincial transmission lines should be greater than or equal to the existing installed capacity:

[0098] (twenty two);

[0099] ⑥ Spare capacity requirements:

[0100] Each province must ensure that the total of all its electricity sources can not only cover the electricity demand, but also meet the capacity margin coefficient. The specific spare capacity constraints are as follows:

[0101] (twenty three);

[0102] The backup capacity provided by fixed units and energy storage units must be greater than or equal to the wind and solar power supply multiplied by a backup coefficient. The reserve capacity constraints of renewable energy units are as follows:

[0103] (twenty four);

[0104] ⑦Climbing capacity constraint:

[0105] In order to extend the service life of the unit and reduce the operating cost of the power system, the output change of the fixed unit in two consecutive time periods is subject to the ramp rate The restrictions are as follows:

[0106] (25);

[0107] (26);

[0108] ⑧ Constraints on energy storage operation:

[0109] It is stipulated that the energy stored by the energy storage system at the start time is the same as the energy stored in the last time slice. The specific constraint function is as follows:

[0110] (27);

[0111] The total energy stored by the energy storage system in a time slice is a function of the energy stored in the energy storage system in the time slice and the charge / discharge schedule in the time slice. In addition, the energy stored in the energy storage system cannot exceed the limits of its capacity and storage duration ( ), the specific restriction function is as follows:

[0112] (28);

[0113] (29);

[0114] For any province and any energy storage technology, the discharge capacity plus the backup capacity minus the charge capacity at each moment should be less than or equal to its specified capacity.

[0115] (30);

[0116] (31);

[0117] (32);

[0118] In addition, at any moment, the sum of the energy storage system's discharge capacity and the backup capacity provided should be less than or equal to the total energy stored in the energy storage system at the previous moment. The specific constraint function is as follows:

[0119] (33);

[0120] Based on the installed capacity of pumped storage hydropower in each province and the future planned installed capacity of pumped storage hydropower, this model sets the upper and lower limits of each province's installed capacity of pumped storage hydropower through Equation 34:

[0121] (34);

[0122] According to an embodiment of the present disclosure, the closed mine renewable energy development method further includes calculating the closed mine unit wind and solar power generation costs and calculating the branch line levelized connection costs.

[0123] In the embodiment of the present disclosure, the power generation cost model is used to determine the levelized cost of wind power and photovoltaic power generation for each spatial grid unit and closed mine unit, with the wind and solar power generation capacity factor of each grid unit and closed mine unit and the capital investment and operation and maintenance cost of the corresponding technology as important parameters. Regarding the calculation of the branch line cost of the closed mine unit: based on the transmission capacity of the branch line connecting the power generation unit and the substation, the levelized connection cost of the branch line is calculated. First, the capital recovery coefficient is used to calculate the levelized cost of wind power and photovoltaic power generation for each spatial grid unit and closed mine unit. Convert the initial investment into annuity, as shown in Formula 35:

[0124] (35);

[0125] Where, is the actual weighted average cost of capital, represents the capital recovery period required for the wind and solar project. Next, the levelized feeder connection cost of each power generation unit is calculated as shown in Equation 36:

[0126] (36);

[0127] Where, represents the capital investment per unit capacity of the transmission line; the average annual capacity factor for wind and photovoltaic power generation per grid unit and mine closure unit; It refers to the loss rate of the transmission line; It refers to the distance between the branch line connecting the power generation unit and the substation, and 8760 refers to the total number of hours in a year.

[0128] The embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that any implementations not depicted or described in the drawings or the main text of the specification are known to those skilled in the art and are not described in detail. Furthermore, the above definitions of the various elements and methods are not limited to the various specific structures, shapes, or methods described in the embodiments, and can be easily modified or replaced by those skilled in the art.

[0129] Furthermore, unless specifically described or required to occur sequentially, the order of the steps is not limited to the order listed above and may be varied or rearranged based on desired design requirements. Furthermore, the above embodiments may be mixed and matched with each other or with other embodiments based on design and reliability considerations. That is, the technical features of different embodiments may be freely combined to form more embodiments.

[0130] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for developing renewable energy from a closed mine, comprising: Calculate wind and solar capacity coefficients for closed mine units; Assessing the wind and solar power generation potential of closed mine units; Based on the grid division design, the mine unit wind and solar power grid connection line is closed; Design the generation dispatch layer; as well as Model the power system including closed mine units to minimize construction and operating costs.

2. The closed mine renewable energy development method according to claim 1, wherein the calculation of the wind and solar capacity coefficient of the closed mine unit comprises: Calculate wind capacity factors for closed mine units; as well as Calculate the photovoltaic capacity factor for closed mine units.

3. The closed mine renewable energy development method according to claim 1, wherein the step of evaluating the wind and solar power generation potential of the closed mine unit comprises: Assessing the wind power potential of closed mine units; as well as Assessing the photovoltaic power generation potential of closed mine units.

4. The closed mine renewable energy development method according to claim 1, wherein the grid-based design of the closed mine unit wind and solar power generation grid-connected lines comprises: Divide wind and solar power generation unit grids based on geographic latitude and longitude information; Identify each wind and solar power unit grid with a closed mine as a closed mine unit and connect it to the nearest substation in the province through a branch line; and Under the principle of ensuring the shortest total distance for wind and solar power generation to be connected to the grid, the substation is connected to the nearest main node in the same province through the trunk line.

5. According to the closed mine renewable energy development method described in claim 4, the center point of each county or district is used as the spatial location of the substation, all prefecture-level cities and above in the urban agglomeration are positioned as load centers, and the center point of the load center in space is used as the main node of the power grid.

6. The method for developing renewable energy in closed mines according to claim 1, wherein the design of the power generation scheduling layer includes rationally allocating the annual power demand to various power generation units on the supply side on an hourly time scale based on a heuristic scheduling sequence.

7. The closed mine renewable energy development method according to claim 6, wherein the fixed units are located at the first level of the power generation scheduling layer, and the generator sets of the closed mine units are located at the second level of the power generation scheduling layer.

8. The closed mine renewable energy development method according to claim 6, wherein when constructing a power system model including the closed mine unit, an objective function is established with the goal of minimizing construction and operation costs.

9. According to the method for developing renewable energy in closed mines as described in claim 8, the constraints of the objective function include supply and demand balance constraints, wind power and photovoltaic power generation constraints, fixed unit power supply constraints, wind and solar grid-connected line constraints, inter-provincial transmission line constraints, spare capacity requirements, ramp capacity constraints, and energy storage operation constraints.

10. The closed mine renewable energy development method according to claim 4, further comprising calculating the wind and solar power generation costs of the closed mine units and calculating the levelized branch line connection costs.

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