A method for identifying and classifying icing micro-topography of an electric overhead line

Abstract

The application provides a kind of power overhead line icing microtopography identification classification method, comprising the following steps: step one, collect meteorological data of transmission line;Step two, based on large and medium scale background topography, according to the microtopography influence meteorological action characteristics and microtopography landform, comprehensive topographic map contour identification method and three-dimensional network topographic map analysis method, obtain icing prone microtopography first classification;Step three, based on the first classification, icing prone microtopography secondary classification is carried out;Step four, according to the identification elements, "common icing prone microtopography classification and identification table" is proposed;Step five, nine icing prone microtopography auxiliary identification typical maps are formed by induction. It plays an important guiding role in ensuring the economic rationality of transmission line engineering construction and the safety and reliability of operation, and the timely application of icing prone microtopography classification and identification method has achieved good economic and social benefits.

Description

Technical Field

[0001] This invention relates to the field of meteorological geographic information technology, and in particular to a method for identifying and classifying micro-topography of overhead power lines that is prone to icing. Background Technology

[0002] Icing of overhead power lines is a complex interdisciplinary problem with incipient causes. It is a common concern and an urgent issue for countries with severe icing problems worldwide. In the study of icing characteristics of overhead power lines, the research on the influence characteristics of icing-prone micro-meteorological and micro-topographic features, beyond the study of icing weather systems, is a key focus and challenge in line icing surveying, design, and operation and maintenance management. Micro-topography refers to a small, unique local topographic area relative to the larger regional topography. Due to the heterogeneity of the underlying surface, the undulation of micro-topography, the presence of water bodies, and differences in vegetation, it causes small-scale climatic characteristics in the near-surface atmosphere and upper soil layers. This characteristic is generally reflected in individual meteorological values, and sometimes in individual weather phenomena, making certain climatic factors (such as wind speed and humidity) particularly strong at this location, exceeding the average value of general areas. However, changes in these factors do not significantly alter the weather and climate characteristics determined by large-scale processes (advection, fronts). The dynamic and thermal effects of the micro-meteorological and micro-topographical underlying surfaces prone to icing have a significant impact on the spatiotemporal distribution and magnitude of micro-topographic icing. Understanding its icing impact characteristics helps improve the reliability of line icing zone delineation results and assists in the design of overhead power lines to adopt reasonable icing avoidance, prevention, and resistance measures.

[0003] Currently, on the one hand, due to the different purposes of the site layout principles, most basic meteorological stations in China cannot reflect the micro-topographic and micro-meteorological characteristics of areas prone to icing, resulting in an extreme lack of icing observation data. Moreover, their applicability to the survey and design of icing for overhead lines is generally poor. To solve the problem of lack of icing data, conducting specialized meteorological observation and research on icing is one effective way to accumulate data. However, the first problem to be solved in meteorological observation and research on icing is to correctly identify the micro-meteorological and micro-topographic features of areas prone to icing in order to rationally plan the site layout. On the other hand, the current domestic line icing survey and design and line operation and maintenance management lacks "standardized, applicable, and operable micro-meteorological and micro-topographic identification techniques for areas prone to icing". Summary of the Invention

[0004] The technical problem this invention aims to solve is to provide a method for identifying and classifying micro-topography prone to icing on overhead power lines. This method provides scientific guidance for meteorological surveys and design of engineering projects to address icing, rationally determine icing zones and other meteorological conditions, and adopt appropriate icing avoidance, prevention, and resistance measures. It plays a crucial guiding role in ensuring the economic rationality of transmission line construction and the safe and reliable operation of power transmission line projects. The timely application of the classification and identification method for micro-topography prone to icing has yielded significant economic and social benefits.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A method for identifying and classifying micro-topography prone to icing on overhead power lines, characterized by the following steps:

[0007] Step 1: Collect meteorological data for the transmission lines, including air temperature, wind direction and speed, and humidity during the icing period;

[0008] Step 2: Based on the large and medium scale background topography, according to the characteristics of the meteorological effects of micro-topography and micro-topographic features, and by combining the topographic map elevation line identification method and the three-dimensional network topographic map analysis method, the first-level classification of micro-topography prone to icing is obtained.

[0009] Step 3: Based on the primary classification in Step 2, perform secondary classification of icy micro-topography.

[0010] Step 4: Based on the secondary classification of icy micro-topography in Step 3, and according to the identification elements, a "Classification and Identification Table of Common Icing-Prone Micro-Topography" is proposed.

[0011] Step 5: Compile nine typical maps for identifying easily icy micro-topography.

[0012] In step two, the primary classification includes: I-airflow convergence wind duct / wind gap type pass or saddle; II-airflow lifting wind duct / wind gap type watershed or ridge; III-airflow lifting convergence type slope or plateau (hill); IV-water vapor convergence type water area.

[0013] In step three, the secondary classification is based on the primary classification, further subdividing types I and III according to the micro-topographic characteristics of low-altitude and medium-to-high-altitude areas: Type I includes: 1-airflow convergence wind channel / wind gap type saddle; 2-airflow convergence wind channel type pass; Type III includes: 1-airflow lifting convergence type slope; III2-airflow lifting convergence type plateau (hill).

[0014] In step four, the identification elements include the following steps:

[0015] S1. Obtain micro-meteorological characteristics of various types of icing, including icing type, wind characteristics, temperature range, cloud and fog conditions, and water vapor convergence.

[0016] S2. Comprehensive auxiliary identification conditions (factors): Within a typical 2km horizontal range of the pass, the numerical range of the funnel-mouth contraction θ1 or diffusion θ2, the numerical range of the width-to-depth ratio, the numerical range of the terrain slope, the matching of wind direction and terrain, the characteristics of vegetation distribution, the influence range of lakes and rivers, and the degree of influence of cold waves.

[0017] S3. Representative topographic maps and cross-sectional diagrams were created, and representative topographic maps and cross-sectional diagrams were also created for various icy micro-topographic features.

[0018] The numerical range of the flared mouth contraction θ1 and diffusion θ2 is 0.80 to 0.97.

[0019] In step five, the nine typical maps for auxiliary identification of easily icy micro-topography include: a plan view of typical mountain pass micro-topographic factors, a cross-sectional view of typical mountain pass micro-topographic factors, a typical saddle topographic map of airflow convergence wind channel type / wind gap type, a typical mountain pass topographic map A of airflow convergence wind channel type, a typical mountain pass topographic map B of airflow convergence wind channel type, a typical watershed or ridge topographic map of airflow lifting wind channel / wind gap type, a typical slope topographic map of airflow lifting convergence type, a platform (hill) topographic map of airflow lifting convergence type, and a plan view of the water area influence zone of water vapor convergence type.

[0020] In the schematic diagram of the typical mountain pass micro-topographic factors, the contraction degree of the typical mountain pass is θ1=(W1-W2) / W1, the diffusion degree is θ2=(W3-W2) / W3, and the terrain slope is J(‰);

[0021] Wherein, W1 is the horizontal distance between the two ridges (slopes) 2km away on the windward side of the pass; W2 is the width of the pass; W3 is the horizontal distance between the two ridges (slopes) 2km away on the leeward side of the pass.

[0022] In the schematic diagram of the micro-topographic factor profile of the typical mountain pass, the width-to-depth ratio β of the typical mountain pass is (W / D1);

[0023] Where W is the horizontal distance between the two ridges (slopes) at the pass; D1 is the vertical height difference between the top of the lower ridge (slope) on both sides of the pass and the pass.

[0024] The beneficial effects of this invention are:

[0025] 1. By accurately identifying icing-prone micro-topography in the ice zone delineation under design meteorological conditions, the system ensures the safety and reliability of ice zone delineation results for overhead lines, assists in the design of reasonable ice avoidance, prevention, and resistance measures, and helps line operation and maintenance personnel accurately identify icing-prone micro-topography, improving their icing early warning and operation and maintenance capabilities. This system plays a positive guiding role in ensuring the safe and reliable operation of transmission lines and can be widely applied to the survey, design, operation, and maintenance technical management of overhead transmission lines of all levels. It improves the ability of relevant survey and design personnel to accurately identify icing-prone micro-meteorological and micro-topography, and guides and assists line operation and maintenance personnel in accurately identifying icing-prone micro-meteorological and micro-topography, thereby enhancing their icing early warning and operation and maintenance capabilities. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall process of the present invention;

[0027] Figures 2-3 This is a topographic map of the airflow convergence duct type pass according to the present invention;

[0028] Figures 4-5 This is a schematic diagram of the cross-section of an airflow convergence duct type archway;

[0029] Figures 6-7 A schematic diagram of typical mountain pass micro-topographic factors in plan view;

[0030] Figures 8-9 This is a schematic diagram of a typical mountain pass micro-topographical factor profile.

[0031] Figures 10-11 A typical saddle-shaped topographic map showing airflow convergence / wind tunnel / wind outlet types;

[0032] Figures 12-13 A topographic map of a typical mountain pass with converging airflow channels;

[0033] Figure 1 Map B shows a typical mountain pass topography of the airflow convergence channel type.

[0034] Figures 2-3 Topographic map of a typical watershed or ridge type for airflow lifting channels / vents;

[0035] ​ A topographic map of a typical slope with airflow lifting and convergence;

[0036] ​ Topographic map of a convergent plateau (hill) type of airflow lifting;

[0037] ​ This is a schematic diagram of the plan view of the water vapor convergence type water area; Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] like ​ As shown, a method for identifying and classifying micro-topography prone to icing on overhead power lines includes the following steps:

[0040] Step 1: Collect meteorological data for the transmission lines, including air temperature, wind direction and speed, and humidity during the icing period;

[0041] Step 2: Based on the large and medium scale background topography, according to the characteristics of the meteorological effects of micro-topography and micro-topographic features, and by combining the topographic map elevation line identification method and the three-dimensional network topographic map analysis method, the first-level classification of micro-topography prone to icing is obtained.

[0042] Step 3: Based on the primary classification in Step 2, perform secondary classification of icy micro-topography.

[0043] Step 4: Based on the secondary classification of icy micro-topography in Step 3, and according to the identification elements, a "Classification and Identification Table of Common Icing-Prone Micro-Topography" is proposed, as shown in Table 1.

[0044]

[0045]

[0046]

[0047]

[0048] Table 1 shows the classification and identification of common icy micro-topographic features.

[0049] Step 5: Compile nine typical maps for identifying easily icy micro-topography.

[0050] In step two, the primary classification includes: I-airflow convergence wind duct / wind gap type pass or saddle; II-airflow lifting wind duct / wind gap type watershed or ridge; III-airflow lifting convergence type slope or plateau (hill); IV-water vapor convergence type water area.

[0051] In step three, the secondary classification is based on the primary classification, further subdividing types I and III according to the micro-topographic characteristics of low-altitude and medium-to-high-altitude areas: Type I includes: 1-airflow convergence wind channel / wind gap type saddle; 2-airflow convergence wind channel type pass; Type III includes: 1-airflow lifting convergence type slope; III2-airflow lifting convergence type plateau (hill).

[0052] In step four, the identification elements include the following steps:

[0053] S1. Obtain micro-meteorological characteristics of various types of icing, including icing type, wind characteristics, temperature range, cloud and fog conditions, and water vapor convergence.

[0054] S2. Comprehensive auxiliary identification conditions (factors): Within a typical 2km horizontal range of the pass, the numerical range of the funnel-shaped opening contraction or diffusion, the numerical range of the width-to-depth ratio, the numerical range of the terrain slope, the matching of wind direction and terrain, the characteristics of vegetation distribution, the influence range of lakes and rivers, and the degree of influence of cold waves.

[0055] S3, such as ​ As shown, representative topographic maps and cross-sectional schematic diagrams were created. At the same time, representative topographic maps and cross-sectional schematic diagrams of airflow convergence wind tunnel type passes were made for various types of micro-topography that are prone to icing.

[0056] The numerical range of the flared mouth contraction θ1 and diffusion θ2 is 0.80 to 0.97.

[0057] In step five, the nine typical maps for auxiliary identification of easily icy micro-topography include: a plan view of typical mountain pass micro-topographic factors, a cross-sectional view of typical mountain pass micro-topographic factors, a typical saddle topographic map of airflow convergence wind channel type / wind gap type, a typical mountain pass topographic map A of airflow convergence wind channel type, a typical mountain pass topographic map B of airflow convergence wind channel type, a typical watershed or ridge topographic map of airflow lifting wind channel / wind gap type, a typical slope topographic map of airflow lifting convergence type, a platform (hill) topographic map of airflow lifting convergence type, and a plan view of the water area influence zone of water vapor convergence type.

[0058] In the schematic diagram of the typical mountain pass micro-topographic factors, the contraction degree of the typical mountain pass is θ1=(W1-W2) / W1, the diffusion degree is θ2=(W3-W2) / W3, and the terrain slope is J(‰);

[0059] Wherein, W1 is the horizontal distance between the two ridges (slopes) 2km away on the windward side of the pass; W2 is the width of the pass; W3 is the horizontal distance between the two ridges (slopes) 2km away on the leeward side of the pass.

[0060] In the schematic diagram of the micro-topographic factor profile of the typical mountain pass, the width-to-depth ratio β of the typical mountain pass is (W / D1);

[0061] Where W is the horizontal distance between the two ridges (slopes) at the pass; D1 is the vertical height difference between the top of the lower ridge (slope) on both sides of the pass and the pass.

[0062] By accurately identifying icy micro-topography in the ice zone delineation under design meteorological conditions, the system ensures the safety and reliability of ice zone delineation results for overhead lines, assists in the design of reasonable ice avoidance, prevention, and resistance measures, and helps line operation and maintenance personnel accurately identify icy micro-topography, improving their icing early warning and operation and maintenance capabilities. This system plays a positive guiding role in ensuring the safe and reliable operation of transmission lines. It can be widely applied to the survey, design, operation, and maintenance technical management of overhead transmission lines of all levels, improving the accurate identification ability of relevant survey and design personnel of icy micro-meteorological micro-topography, and guiding and assisting line operation and maintenance personnel in accurately identifying icy micro-meteorological micro-topography, thereby enhancing their icing early warning and operation and maintenance capabilities.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for identifying and classifying icing micro-topographies of an electric overhead line, characterized in that: It comprises the following steps: Step one, collecting meteorological data of the power transmission line, the meteorological data including icing period temperature, wind direction and wind speed and humidity; Step two, based on large and medium scale background terrain, according to the micro-terrain influence meteorological action characteristics and micro-terrain landform, the high line identification method and three-dimensional network topographic map analysis method are combined to obtain the easy icing micro-terrain first classification; Step three, in step two, based on the first classification, easy icing micro-terrain second classification is carried out; Step four, in step three, based on the icing micro-terrain second classification, according to the identification elements, the "common easy icing micro-terrain classification and identification table" is proposed; In step four, the identification elements comprise the following steps: S1, obtaining each type of icing micro-meteorological characteristics, the meteorological characteristics including icing type, wind characteristics, temperature range, cloud and fog and water vapor convergence condition; S2, comprehensive auxiliary identification conditions: within 2km range of typical pass, the numerical range of θ1 or θ2 of horn mouth contraction degree and diffusion degree, the numerical range of width-depth ratio, the numerical range of terrain slope, the matching condition of wind direction and terrain, the distribution characteristics of vegetation, the influence range of river and lake water body, the influence degree of cold wave; S3, forming representative topographic map and profile schematic diagram, and corresponding various easy icing micro-terrain representative topographic map and profile schematic diagram are made; Step five, nine easy icing micro-terrain auxiliary identification typical maps are formed by induction.

2. The method of claim 1, wherein the method further comprises: determining a location of the power line; and determining a weather condition at the location of the power line. In step two, the first classification comprises: I-airflow convergence wind channel / wind mouth type pass or saddle; II-airflow lifting wind channel / wind mouth type watershed or ridge; III-airflow lifting convergence type slope or table / land; IV-water vapor convergence type water area influence area.

3. The method of claim 2, wherein the method further comprises: determining a location of the power line; and determining a weather condition at the location of the power line. In step three, the second classification is further divided into: I type includes: 1-airflow convergence wind channel / wind mouth type saddle; 2-airflow convergence wind channel type pass; III type includes: 1-airflow lifting convergence type slope; III2-airflow lifting convergence type table / land, based on the first classification.

4. The method of claim 1, wherein the method further comprises: determining a location of the power line; and determining a weather condition at the location of the power line. The numerical range of θ1 or θ2 of horn mouth contraction degree and diffusion degree is 0.80-0.

97.

5. The method of claim 1, wherein: the step of identifying the micro-terrain of the power line is performed by using a fuzzy logic method. In step five, the nine easy icing micro-terrain auxiliary identification typical maps comprise: typical pass micro-terrain factor plane schematic diagram, typical pass micro-terrain factor profile schematic diagram, airflow convergence wind channel / wind mouth type typical saddle topographic map, airflow convergence wind channel type typical pass topographic map A, airflow convergence wind channel type typical pass topographic map B, airflow lifting wind channel / wind mouth type typical watershed or ridge topographic map, airflow lifting convergence type typical slope topographic map, airflow lifting convergence type table / land topographic map, water vapor convergence type water area influence area plane schematic diagram.

6. A method of identifying and classifying micro-terrain of icing on an electric overhead line according to claim 5, characterized in that: In the typical pass micro-terrain factor plane schematic diagram, the contraction degree θ1 of the typical pass is (W1-W2) / W1, the diffusion degree θ2 is (W3-W2) / W3, and the terrain slope is J (‰); Wherein, W1 is the horizontal distance between two ridges / slopes at 2km in the direction of the windward slope side of the pass; W2 is the width of the pass; W3 is the horizontal distance between two ridges / slopes at 2km in the direction of the leeward slope side of the pass.

7. A method of identifying and classifying micro-terrain of icing on an electric overhead line according to claim 5, characterized in that: In the typical notch micro-terrain factor profile schematic diagram, the width-depth ratio of the typical notch is β=(W / D1). Wherein, W is the horizontal distance between the two sides of the notch; D1 is the vertical height difference between the lower side of the ridge / slope and the notch.

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