A method for screening reservoir area sites that can be used for the construction of pumped-storage power stations on a large scale

Abstract

The present invention discloses a method for screening reservoir area sites that can be used for the construction of pumped storage power stations on a large scale, including: obtaining candidate area geographical data to identify a set of reservoir basin areas, and when there is no water system involved, traversing the geometric center points of the bottom surfaces of each reservoir area to calculate the elevation differences and screening to obtain an upper and lower reservoir set; when there is a water system involved, traversing all water systems, rasterizing each water system, respectively calculating the distances and elevation differences between the pixel points of each water system buffer zone and the geometric center points of the bottom surfaces of the elements in the reservoir basin area set, screening and marking the available pixel points to obtain an available set of all water systems. The present invention can screen out combinations of depressions and water systems that can be used for pumped storage construction in natural depressions and water systems on a large scale. By constructing a KD-Tree using river pixel points, the search for the pixel points closest to the river can be accelerated, thereby increasing the efficiency of upper and lower reservoir pairing.

Description

Technical Field

[0001] The present invention relates to the field of water conservancy and hydropower, and in particular to a site selection method for a power station. Background Art

[0002] Pumped-storage hydropower stations, also known as storage hydropower stations, utilize excess electricity generated during low-load periods to pump water to an upper reservoir and release it to a lower reservoir for power generation during peak load periods. They can convert excess electricity generated during periods of low grid load into high-value electricity during peak periods. They are also suitable for frequency and phase modulation, stabilizing the power system's frequency and voltage, providing emergency backup, and improving the efficiency of thermal and nuclear power plants within the system. Pumped-storage hydropower stations are the most reliable, economical, long-life, large-capacity, and technologically mature energy storage devices in the power system, making them a crucial component of renewable energy development. The construction of supporting pumped-storage hydropower stations can reduce nuclear power unit operating and maintenance costs and extend unit life. They can also effectively mitigate the impact of wind farm integration on the grid, improve the coordination between wind farms and the grid, and enhance the safety and stability of grid operations.

[0003] my country has a vast and complex terrain with many naturally formed depressions and basins that are more suitable for the construction of pumped storage power stations. Other depressions and basins formed in the mountains that can form reservoirs through artificial water injection will gradually become the main resources for the construction of pumped storage power stations.

[0004] Chinese patent CN113487246A "A method and system for site selection of a pumped storage power station based on artificial intelligence" is only applicable to the site selection of a pumped storage power station in an existing water system. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in view of the problem that the current site selection method can only select sites from existing water systems, a method for screening the construction sites of pumped storage power stations on a large scale is provided.

[0006] The technical solution of the present invention is: a method for selecting a reservoir site that can be used for the construction of a pumped storage power station on a large scale, comprising: obtaining geographic data of a candidate area to identify and obtain a reservoir basin area set; when no water system is involved, traversing the geometric center point of the bottom surface of each reservoir basin, calculating the elevation difference and distance between the upper and lower reservoirs to obtain an upper and lower reservoir set; when a water system is involved, traversing all water systems, rasterizing each water system and its buffer zone, respectively calculating the elevation difference and distance between each water system buffer zone pixel and the nearest water system pixel, screening and marking available pixels, and obtaining an available screening set of all water systems.

[0007] Obtain the candidate area's ground DEM, high-resolution terrain surface images, and land classification data, establish a geographic information database with the acquired data, obtain the current selected area's terrain data scale based on the geographic information database, and divide the terrain data into large-scale data and small-scale data.

[0008] Terrain recognition and depression recognition are performed on large-scale data to obtain a reservoir basin area set, while depression recognition is performed on small-scale data to obtain a reservoir basin area set.

[0009] The ground DEM is excavated and filled to generate a depression model, and then the depression area model is extracted.

[0010] By setting two search radii, large and small, we can obtain two terrain classification results, namely valley or flat land, and take the intersection of the two.

[0011] The screening conditions are: h1≤H≤h2 and s1≤S≤s2 (h1 is the minimum elevation difference between the upper and lower warehouses, h2 is the maximum elevation difference between the upper and lower warehouses, H is the calculated elevation difference between the upper and lower warehouses; s1 is the minimum distance between the upper and lower warehouses, s2 is the maximum distance between the upper and lower warehouses, and S is the calculated distance between the upper and lower warehouses).

[0012] The screening of upper and lower reservoirs without water system participation at large scale or small scale includes: first, vectorizing the reservoir area of ​​the reservoir basin area set; calculating the reservoir basin volume as the reservoir capacity, and excluding the area with a reservoir capacity less than V (V is the input reservoir capacity); extracting the geometric center point of the bottom surface of the reservoir basin model; sampling the elevation of the reservoir basin center point and sorting it in order from large to small; traversing each reservoir basin center point and the reservoir basin center point with an elevation less than its own and making a judgment, the conditions are: h1≤H≤h2 and s1≤S≤s2 (h1 is the minimum elevation difference between the upper and lower reservoirs, h2 is the maximum elevation difference between the upper and lower reservoirs, H is the calculated elevation difference between the upper and lower reservoirs; s1 is the minimum distance between the upper and lower reservoirs, s2 is the maximum distance between the upper and lower reservoirs, and S is the calculated distance between the upper and lower reservoirs); the pairing result obtained by traversal and screening is the upper and lower reservoir set that meets the conditions.

[0013] The screening steps for the available water system set include: First, obtain the water system feature set N from the geographic information database, initialize the variable i = 0, and perform traversal and matching when i < N. The processing process is as follows: Obtain the information of the i-th water system feature; rasterize the water system, obtain the elevation value of the raster pixel, and construct a KD-Tree using all the pixels of the water system; buffer the water system, rasterize the water system buffer, and obtain the elevation value of the raster pixel; access each water system buffer pixel of the rasterized water system buffer; calculate respectively: the elevation difference and distance between this pixel and the nearest water system pixel; make a judgment and screening with the conditions h1 ≤ H ≤ h2 and s1 ≤ S ≤ s2 (h1 is the minimum elevation difference between the upper and lower reservoirs, h2 is the maximum elevation difference between the upper and lower reservoirs, H is the calculated elevation difference between the upper and lower reservoirs; s1 is the minimum distance between the upper and lower reservoirs, s2 is the maximum distance between the upper and lower reservoirs, S is the calculated distance between the upper and lower reservoirs) and mark this pixel as available; increment the water system variable i = i + 1 to achieve analysis of each water system and obtain the entire available water system screening set.

[0014] After obtaining the terrain data of the selected area, judge its scale. The terrain data with a scale greater than or equal to 1:10,000 is classified as large-scale data, and the terrain data with a scale less than 1:10,000 is classified as small-scale data. For large-scale data, first perform depression identification to obtain the reservoir basin area set, then judge whether there is water system participation. When there is no water system participation, perform upper and lower reservoir screening. When there is water system participation, perform screening of the available water system set, and analyze from the entire water system screening set to obtain the reservoir area set that meets the screening conditions.

[0015] For small-scale data: First, judge whether there is water system participation. When there is no water system participation, first perform depression identification to obtain the reservoir basin area set, and then perform upper and lower reservoir screening; when there is water system participation, perform screening of the available water system set.

[0016] The beneficial effects of the present invention are: The present invention can screen out the combinations of depressions and water systems that can be used for pumped storage power station construction in natural depressions and water systems on a large scale. Using river pixels to construct a KD-Tree can accelerate the search for the pixel closest to the river, thereby increasing the efficiency of upper and lower reservoir pairing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flat area surrounded by high places on the ground.

[0018] Figure 2 Terrain classification results at large-scale scales.

[0019] Figure 3 Terrain classification results at small-scale scales.

[0020] Figure 4 It is a flowchart. <​​​In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific implementation disclosed below. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the technical field of the present invention.

[0022] The present invention screens locations suitable for building a pumped storage power station through ground DEM and related parameters.

[0023] Step 1: Obtain the candidate area's ground DEM, terrain surface high-resolution imagery, and land classification data.

[0024] Step 2 uses the data obtained in step 1 to establish a geographic information database, and obtains the scale of the terrain data of the current selected area based on the geographic information database. The present invention considers terrain data with a scale greater than 1:10,000 as large scale and scale less than 1:10,000 as small scale. Based on this rule, the terrain data of the two scale categories are analyzed separately.

[0025] Step 3: At a large scale, to obtain the terrain characteristics of a flat area surrounded by high ground, the r.geomorphon tool library of GRASSGIS is used to perform parametric analysis and calculation to perform terrain identification, and a terrain area that may be suitable for the reservoir basin site selection is obtained. Figure 1 The same area may be classified into different types of terrain at different scales. For example, if we observe the area between two mountains at a relatively large scale, we may find that it is a valley. If we observe the area at a smaller scale, we may find some small flat lands and flat lands at the foot of the mountain. Figure 2 、 Figure 3 . Therefore, the present invention adopts two methods to extract the reservoir area, namely terrain recognition and depression recognition. Terrain recognition is to set two search radii, large and small, so that we can obtain terrain classification results at large and small scales. Through the parameters we set, the terrain characteristics of the target area (flat area surrounded by surface heights) are summarized as flat land at a small scale and valleys at a large scale. Therefore, by taking the common area of ​​the valleys and flat lands of the two terrain classification results, we can roughly obtain the terrain recognition results that meet our expected terrain characteristics.

[0026] Step 4 Depression Identification: First, perform filling and excavation analysis on the ground DEM, and then extract the depression area model. This analysis task is completed through the GRASS GIS and GDAL software toolkits: call the r.fill.dir toolkit to generate a depression-free DEM, call the r.mapcalc toolkit to extract the depression area, and call the gdal_polygonize.py toolkit to vectorize the depression area.

[0027] Step 5 Take the union of the terrain identification results and the depression identification results to obtain the set of basin areas suitable for building a reservoir area within the region.

[0028] Step 6 Determine whether there is a water system involved in the candidate area at a large scale.

[0029] Step 7 Matching of reservoir areas without water system participation at a large scale

[0030] 7.1 First, vectorize the set of basin areas obtained in Step 5;

[0031] 7.2 Calculate and analyze to obtain the basin volume as the reservoir capacity, and剔除regions with a reservoir capacity less than V (V is the input reservoir capacity volume);

[0032] 7.3 Extract the geometric center point of the bottom surface of the basin model: Call the QGIS toolkit to extract the geometric center of the regional bottom surface;

[0033] 7.4 Perform elevation sampling on the geometric center points of the basin bottom surface and sort them in descending order;

[0034] 7.5 Traverse each geometric center point of the basin bottom surface and the geometric center points of the basins with elevations lower than its own and make a judgment. The conditions are: h1 ≤ H ≤ h2 and s1 ≤ S ≤ s2 (h1 is the minimum elevation difference between the upper and lower reservoirs, h2 is the maximum elevation difference between the upper and lower reservoirs, H is the calculated elevation difference between the upper and lower reservoirs; s1 is the minimum distance between the upper and lower reservoirs, s2 is the maximum distance between the upper and lower reservoirs, S is the calculated distance between the upper and lower reservoirs);

[0035] 7.6 The paired results obtained through traversal and screening are the set of conforming upper and lower reservoirs.

[0036] Step 8 Matching of reservoir areas with water system participation:

[0037] 8.1 First, obtain the water system feature set N from the geographic information database, initialize the variable i = 0, and perform traversal and matching when i < N. The internal processing is as follows:

[0038] 8.1.1 Obtain the information of the i-th water system feature;

[0039] 8.1.2 Rasterize the water system, obtain the elevation values of the raster pixels, and construct a KD-Tree using all the pixels of this water system;

[0040] 8.1.3 Establish a buffer zone for the water system, rasterize the buffer zone, and obtain the elevation value of the raster pixel;

[0041] 8.1.4 Access each water system buffer pixel of the rasterized water system buffer;

[0042] 8.1.5 Calculate respectively: the distance and elevation difference between the pixel and the nearest water pixel;

[0043] 8.1.6 Filter and mark the pixel as available based on the conditions h1≤H≤h2 and s1≤S≤s2 (h1 is the minimum elevation difference between the upper and lower reservoirs, h2 is the maximum elevation difference between the upper and lower reservoirs, H is the calculated elevation difference between the upper and lower reservoirs; s1 is the minimum distance between the upper and lower reservoirs, s2 is the maximum distance between the upper and lower reservoirs, and S is the calculated distance between the upper and lower reservoirs). Elevation difference and distance refer to calculating the elevation difference and distance between each pixel point in each water system buffer and each pixel point in the nearest water system.

[0044] 8.1.7 Water system variable i=i+1, realizes water system-by-water system analysis and obtains the available screening set of all water systems.

[0045] 8.2 If the scale of the topographic map is large: the reservoir basin set that meets the screening conditions can be analyzed from the entire water system screening set, that is, the reservoir basin set that meets the conditions h1≤H≤h2 and s1≤S≤s2 (h1 is the minimum elevation difference between the upper and lower reservoirs, h2 is the maximum elevation difference between the upper and lower reservoirs, H is the calculated elevation difference between the upper and lower reservoirs; s1 is the minimum distance between the upper and lower reservoirs, s2 is the maximum distance between the upper and lower reservoirs, and S is the calculated distance between the upper and lower reservoirs).

[0046] Step 9: If the terrain data scale is small, the steps are as follows:

[0047] 9.1 Determine whether there is a water system involved. If there is no water system involved, execute steps 5 and 7.

[0048] 9.2 If there is a water system involved, perform step 8.1.

[0049] The above-described embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for screening reservoir site selection for pumped-storage power station construction over a large area, characterized in that it includes: Obtain the basin area set by identifying the geographical data of the candidate area. Identify the basin area set by terrain identification and depression identification of large-scale data, and identify the basin area set by depression identification of small-scale data; Terrain identification includes: obtaining two terrain classification results of valleys or flatlands by setting two search radii of different sizes, and taking the intersection of the two; Depression identification refers to filling and excavating the ground DEM to generate a depression model, and then extracting the depression area model; Taking the union of the terrain identification result and the depression identification result can obtain the basin area set suitable for building a reservoir area within the area; For large-scale data, first identify the basin area set by depression identification, and then judge whether there is a water system involved. When there is no water system involved, conduct upper and lower reservoir screening. When there is no water system involved, traverse the geometric center points of the bottom surfaces of each basin, calculate their elevation differences and distances, and screen to obtain the upper and lower reservoir sets; When there is a water system involved, conduct screening of the available water system set, and analyze from the entire water system screening set to obtain the reservoir area set that meets the screening conditions; When there is a water system involved, traverse all water systems, rasterize each water system and its buffer area, calculate the elevation differences and distances between the pixels of each water system buffer area and the nearest water system pixel respectively, screen and mark the available pixels to obtain the entire available water system screening set; For small-scale data: First judge whether there is a water system involved. When there is no water system involved, first identify the basin area set by depression identification, and then conduct upper and lower reservoir screening; When there is a water system involved, conduct screening of the available water system set. When there is a water system involved, traverse all water systems, rasterize each water system and its buffer area, calculate the elevation differences and distances between the pixels of each water system buffer area and the nearest water system pixel respectively, screen and mark the available pixels to obtain the entire available water system screening set.

2. The method for screening reservoir site selection for pumped-storage power station construction over a large area according to claim 1, characterized in that The obtaining of the geographical data of the candidate area includes: obtaining the ground DEM, high-resolution terrain surface images, and land use data of the candidate area, establishing a geographical information database with the obtained data, obtaining the scale of the terrain data of the current selected area according to this geographical information database, and dividing the terrain data into large-scale data and small-scale data.

3. The method for screening reservoir site selection for pumped-storage power station construction over a large area according to claim 1 or 2, characterized in that The screening of the upper and lower reservoirs without water system participation at large scale or small scale includes: First, vectorize the basin area set; calculate the basin volume as the reservoir capacity, and eliminate the areas with reservoir capacity less than V, where V is the input reservoir capacity volume; extract the geometric center point of the bottom surface of the basin model; sample the elevation of the basin center point and sort it in descending order; traverse each basin center point and the basin center points with elevation less than itself and make a judgment. The screening conditions are: h1≤H≤h2 and s1≤S≤s2, where h1 is the minimum elevation difference between the upper and lower reservoirs, h2 is the maximum elevation difference between the upper and lower reservoirs, H is the calculated elevation difference between the upper and lower reservoirs; s1 is the minimum distance between the upper and lower reservoirs, s2 is the maximum distance between the upper and lower reservoirs, and S is the calculated distance between the upper and lower reservoirs; traverse the paired results obtained by screening, which is the set of upper and lower reservoirs that meet the conditions.

4. The method for selecting a reservoir area site for a pumped-storage power station construction by large-scale screening according to claim 3, characterized in that the screening steps of the available water system set include: First, obtain the water system element set N from the geographic information database, initialize the variable i = 0, and perform traversal and matching when i < N. The processing process is as follows: Obtain the information of the i-th water system element; rasterize the water system, obtain the elevation value of the raster pixel, and construct a KD-Tree using all the pixels of the water system; establish a buffer for the water system, rasterize the water system buffer, and obtain the elevation value of the raster pixel; access each water system buffer pixel of the rasterized water system buffer; calculate respectively: the elevation difference and distance between this pixel and the nearest water system pixel; make a judgment and screening with the conditions of h1≤H≤h2 and s1≤S≤s2 and mark this pixel as available; increment the water system variable i = i + 1 to achieve analysis of each water system and obtain the entire available water system screening set.

5. The method for selecting a reservoir area site for a pumped-storage power station construction by large-scale screening according to claim 3, characterized in that: after obtaining the terrain data of the selected area, judge its scale. The terrain data with a scale greater than or equal to 1:10000 is classified as large-scale data, and the terrain data with a scale less than 1:10000 is classified as small-scale data.

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