Alternating current-to-direct current middle-phase actual air gap calculation method and device and storage medium

Abstract

The invention discloses an alternating current-to-direct current middle-phase actual air gap calculation method and device and a storage medium, and belongs to the technical field of direct current transmission, and the method comprises the following steps: obtaining model parameters; calculating the total length of the insulator string under different voltage grades; after model parameters are imported into a pre-constructed geometric model of the tower head of the power transmission tower, the influences of a grading ring, a split conductor spacing, a conductor vertical small sag and a gap circular margin are considered, and middle-phase air gap calculation is corrected; calculating to obtain the nearest distances from the grading ring to the three sides of the tower window, and calculating to obtain the nearest distances from the center of the split conductor to the three sides of the tower window; taking a smaller value as an actual air gap of the to-be-determined middle phase; the length of a single limb of the V-shaped string is obtained through back calculation; and when the length of the single limb of the V-shaped string is greater than the total length of the insulator string, determining the actual middle-phase air gap to be determined as the final actual middle-phase air gap. According to the method, the actual middle-phase air gap can be accurately calculated, and key theoretical guidance is provided for external insulation cooperation in a power transmission line.

Description

Technical Field

[0001] The present invention relates to a method, device and storage medium for calculating the actual air gap in the middle phase during AC to DC conversion, belonging to the technical field of DC power transmission. Background Art

[0002] With the economic and social development of our country, the way of energy development in the western region and long-distance power transmission to the load-intensive eastern region is gradually becoming an important option for energy balance. Compared with AC, DC has higher transmission efficiency in long-distance power transmission, which can effectively improve the transmission efficiency of energy in the western region. Therefore, it is necessary to convert AC lines to DC operation. However, under DC operation, there are more stringent requirements for the insulation coordination between the middle-phase conductor and the transmission tower. There is an urgent need for a method in the existing technology to accurately calculate the actual air gap in the middle phase, so as to provide key theoretical guidance for the external insulation coordination of transmission lines. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the existing technology and provide a method, device and storage medium for calculating the actual air gap in the middle phase during AC to DC conversion, which can accurately calculate the actual air gap in the middle phase and provide key theoretical guidance for the external insulation coordination of transmission lines.

[0004] To solve the above technical problem, the technical solution adopted by the present invention is as follows:

[0005] In the first aspect, the present invention provides a method for calculating the actual air gap in the middle phase during AC to DC conversion, including the following steps:

[0006] Obtain model parameters, where the model parameters include transmission line tower type parameters, tower head structure parameters, transmission line conductor parameters, length parameters of clamping fittings, and insulator parameters;

[0007] Based on the transmission line tower type parameters, length parameters of clamping fittings, and insulator parameters, calculate the total length of the insulator string at different voltage levels according to insulation coordination;

[0008] After importing the model parameters into a pre-constructed geometric model of the transmission tower head, considering the effects of grading rings, split conductor spacing, vertical sag of the conductor, and clearance circle margin, correct the calculation of the middle-phase air gap to obtain a corrected calculation formula for the middle-phase air gap;

[0009] Based on the corrected calculation formula for the middle-phase air gap, calculate the nearest distances from the grading ring to the three sides of the tower window respectively, and calculate the nearest distances from the center of the split conductor to the three sides of the tower window respectively;

[0010] Take the smaller value of the nearest distances from the grading ring and the center of the split conductor to the three sides of the tower window respectively as the undetermined actual air gap in the middle phase;

[0011] Based on the actual air gap of the undetermined middle phase and combined with the geometric relationship of the geometric model of the transmission tower head, the length of a single limb of the V-string is calculated by back-calculation;

[0012] When the length of a single limb of the V-string is greater than the total length of the insulator string, the actual air gap of the undetermined middle phase is determined as the final actual air gap of the middle phase.

[0013] The tower type parameters of the transmission line include the transmission tower model, the altitude of the operation area of the transmission tower, and the conductor model corresponding to the transmission line tower; the tower head structure parameters include the included angle inside the tower window and the side lengths inside the tower window. The included angle inside the tower window includes the horizontal inclination angles of the main materials on the inner surface of the tower window top, above the K-node, and below the K-node. The side lengths inside the tower window include the upper side length inside the tower window and the side length inside the tower window; the transmission line conductor parameters include the number of splits and the split conductor spacing; the insulator parameters include the insulator model and the thickness of a single insulator.

[0014] The total length of the insulator string is the sum of the insulator string length, the insulator structural height, and the bolt length at the insulator hanging point. Among them, the insulator string length L x is calculated using the pollution withstand voltage formula as follows:

[0015] L x =(A w * | U n | / CF*e 0.1215*m1*(H-1000) / 1000 +L c1 ) / 100 (1),

[0016] where A w is the creepage distance ratio, U n is the voltage level, CF is the creepage coefficient, m1 is the altitude correction coefficient, H is the altitude, and L c1 is the length of the clamping fitting.

[0017] The shortest distances from the grading ring to the three sides of the tower window respectively include the shortest distances from the grading ring to the top of the tower window, the inner surface above the K-node, and the inner surface below the K-node.

[0018] The shortest distances from the center of the bundled conductors to the three sides of the tower window respectively include the shortest distances from the center of the bundled conductors to the top of the tower window, the inner surface above the K-node, and the inner surface below the K-node.

[0019] After importing the model parameters into the pre-constructed geometric model of the transmission tower head, considering the effects of the grading ring, the split conductor spacing, the vertical sag of the conductor, and the clearance circle margin, the calculation of the middle phase air gap is corrected. The corrected calculation formula for the middle phase air gap includes:

[0020] In the geometric model of the transmission tower head, α is the horizontal inclination angle of the main material on the inner surface of the tower window top, is the horizontal inclination angle of the inner main material above the K node within the tower window, is the horizontal inclination angle of the inner main material below the K node, L1 is the upper side length inside the tower window, L g is the side length inside the tower window, is the outer diameter of the insulator grading ring, 、 are the connection distances between the grading ring and the tower connection point and the K node respectively; is the angle between the single limb of the V-string and the connection line between the upper edge of the grading ring and the tower connection point, is the angle between the inner main material above the K node and the connection line between the lower edge of the grading ring and the tower connection point, 、 are the closest distances between the center of the bundled conductors and the inner surface above the K node and the inner surface below the K node respectively, is the distance between the two hanging holes on the V-type series plate; is the distance between the center of the bundled conductors and the connection line of the two hanging holes on the V-type series plate; 、 are the connection distances between the center of the bundled conductors and the connection lines of the grading ring and the tower connection point and the K node respectively; 、 、 are the closest distances between the grading ring and the top of the tower window, the inner surface above the K node, and the inner surface below the K node respectively;

[0021] Among them; (2),

[0022] (3),

[0023] (4),

[0024] (5),

[0025] (6),

[0026] (7),

[0027] (8),

[0028] (9),

[0029] (10),

[0030] (11),

[0031] (12),

[0032] (13),

[0033] (14),

[0034] (15),

[0035] Considering the influence of the spacing of bundled conductors, the following formula is used for correction:

[0036] (16),

[0037] (17),

[0038] Considering the influence of the clearance circle margin on the calculation of the actual air gap, the formula for calculating the actual air gap in the middle phase is corrected again as:

[0039] (18),

[0040] (19),

[0041] (20),

[0042] (21),

[0043] (22),

[0044] Wherein, d y is the clearance circle margin, and d is the spacing of bundled conductors.

[0045] The clearance circle margin includes the electrical margin of the clearance circle and the structural margin of the clearance circle.

[0046] When the length of a single limb of the V-shaped string is not greater than the total length of the insulator string, adjust the length of the clamping fitting, and repeat the following steps again until the length of a single limb of the V-shaped string is greater than the total length of the insulator string:

[0047] After importing the model parameters into the pre-built geometric model of the transmission tower head, considering the influence of the grading ring, the spacing of bundled conductors, the vertical sag of the conductor, and the clearance circle margin, correct the calculation of the middle-phase air gap to obtain the corrected calculation formula for the middle-phase air gap;

[0048] Based on the corrected calculation formula for the middle-phase air gap, calculate the nearest distances from the grading ring to the three sides of the tower window respectively, and calculate the nearest distances from the center of the bundled conductors to the three sides of the tower window respectively;

[0049] Take the smaller value of the nearest distances from the grading ring and the center of the bundled conductors to the three sides of the tower window as the pending actual air gap in the middle phase;

[0050] Based on the actual air gap of the undetermined middle phase and combined with the geometric relationship of the geometric model of the transmission tower head, the length of a single limb of the V-string is calculated by back-calculation.

[0051] In a second aspect, the present invention provides a calculation device for the actual air gap of the middle phase in the conversion from alternating current to direct current, including:

[0052] A model parameter acquisition module for acquiring model parameters, where the model parameters include transmission line tower type parameters, tower head structure parameters, transmission line conductor parameters, the length parameter of the clamping fitting, and insulator parameters;

[0053] An insulator string total length calculation module, based on the transmission line tower type parameters, the length parameter of the clamping fitting, and insulator parameters, calculates the total length of the insulator string under different voltage levels according to insulation coordination;

[0054] A middle phase air gap correction module, after importing the model parameters into the pre-constructed geometric model of the transmission tower head, considering the influences of the grading ring, the spacing between bundled conductors, the vertical sag of the conductor, and the clearance circle margin, corrects the calculation of the middle phase air gap to obtain a corrected calculation formula for the middle phase air gap;

[0055] A calculation module for the nearest distances of the three sides of the tower window, based on the corrected calculation formula for the middle phase air gap, calculates the nearest distances from the grading ring to the three sides of the tower window respectively, and calculates the nearest distances from the center of the bundled conductors to the three sides of the tower window respectively;

[0056] An undetermined middle phase actual air gap selection module for taking the smaller value among the nearest distances from the grading ring and the center of the bundled conductors to the three sides of the tower window respectively as the undetermined middle phase actual air gap;

[0057] A back-calculation module for the length of a single limb of the V-string, based on the undetermined middle phase actual air gap and combined with the geometric relationship of the geometric model of the transmission tower head, back-calculates the length of a single limb of the V-string;

[0058] A confirmation module for the actual air gap of the middle phase, when the length of a single limb of the V-string is greater than the total length of the insulator string, determines the undetermined middle phase actual air gap as the final middle phase actual air gap.

[0059] In a third aspect, the present invention provides a computer-readable storage medium, on which a computer program / instructions are stored. When the computer program / instructions are executed by a processor, the above-mentioned calculation method for the actual air gap of the middle phase in the conversion from alternating current to direct current is implemented.

[0060] Advantages of the present invention: The present invention provides a method, device and storage medium for calculating the actual air gap in the middle phase of AC to DC conversion. Considering the influence of the middle-phase structure of the transmission tower on the line insulation coordination, the actual air gap in the middle phase is calculated. On this basis, the influences of the vertical small sag of the conductor, the spacing between bundled conductors, the grading ring and the clearance circle margin are considered, and a calculation model of the air gap at the tower head of the transmission tower is constructed using geometric relationships, which can accurately calculate the actual air gap in the middle phase and provide key theoretical guidance for the external insulation coordination of transmission lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 is a flowchart of a method for calculating the actual air gap in the middle phase of AC to DC conversion according to the present invention;

[0062] Figure 2 is a model diagram of the tower head of a transmission tower considering a grading ring according to the present invention;

[0063] Figure 3 is a model diagram of the tower head of a transmission tower considering the spacing between bundled conductors according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0064] The present invention will be further described below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be used to limit the protection scope of the present invention.

[0065] Embodiment 1

[0066] As Figure 1 shown, the present invention discloses a method for calculating the actual air gap in the middle phase of AC to DC conversion, including the following steps:

[0067] Step 1: Obtain model parameters, where the model parameters include transmission line tower type parameters, tower head structure parameters, transmission line conductor parameters, length parameters of clamping fittings, and insulator parameters.

[0068] Step 2: Based on the transmission line tower type parameters, length parameters of clamping fittings, and insulator parameters, calculate the total length of the insulator string at different voltage levels according to insulation coordination.

[0069] Step 3: After importing the model parameters into the pre-constructed geometric model of the tower head of the transmission tower, considering the influences of the grading ring, the spacing between bundled conductors, the vertical small sag of the conductor, and the clearance circle margin, correct the calculation of the air gap in the middle phase to obtain a corrected calculation formula for the air gap in the middle phase.

[0070] Step 4: Based on the corrected calculation formula for the air gap in the middle phase, calculate the nearest distances from the grading ring to the three sides of the tower window respectively, and calculate the nearest distances from the center of the bundled conductors to the three sides of the tower window respectively.

[0071] Step 5: Take the smaller value among the shortest distances from the center of the grading ring and the bundled conductors to the three sides of the tower window as the actual air gap of the pending middle phase.

[0072] Step 6: Based on the actual air gap of the pending middle phase and combining with the geometric relationship of the geometric model of the tower head of the transmission tower, inversely calculate the length of a single limb of the V-string.

[0073] Step 7: When the length of a single limb of the V-string is greater than the total length of the insulator string, determine the actual air gap of the pending middle phase as the final actual air gap of the middle phase.

[0074] The present invention takes into account the influence of the middle-phase structure of the transmission tower on the insulation coordination of the line, calculates the actual air gap of the middle phase, and on this basis, considers the influence of the vertical small sag of the conductor, the spacing of the bundled conductors, the grading ring and the clearance circle margin, and constructs a calculation model of the air gap of the tower head of the transmission tower by using geometric relationships, which can accurately calculate the actual air gap of the middle phase and provide key theoretical guidance for the external insulation coordination of the transmission line.

[0075] Embodiment 2

[0076] As Figure 1 shown, the present invention discloses a calculation method for the actual air gap of the middle phase in the conversion from AC to DC, including the following steps:

[0077] Step 1: Obtain model parameters, where the model parameters include transmission line tower type parameters, tower head structure parameters, transmission line conductor parameters, length parameters of the clamping fittings, and insulator parameters. The transmission line tower type parameters include the transmission tower model, the altitude of the operation area of the transmission tower, and the conductor model corresponding to the transmission line tower; the tower head structure parameters include the internal angle of the tower window and the internal side length of the tower window. The internal angle of the tower window includes the horizontal inclination angles of the main materials on the inner surface of the tower window top, the main materials on the inner surface above the K-node, and the main materials on the inner surface below the K-node. The internal side length of the tower window includes the upper internal side length and the side internal side length of the tower window; the transmission line conductor parameters include the number of splits and the spacing of the bundled conductors; the insulator parameters include the insulator model and the thickness of a single insulator.

[0078] The present invention takes a cup-shaped tower of a certain 750 kV AC line segment as an example for analysis. The set standard DC voltage range determined by the conversion from AC to DC is ±500 kV to ±600 kV. The transmission tower model is ZB2311, the altitude H of the operation area of the transmission tower is 1500 m, and the conductor model corresponding to the transmission line tower is steel-core aluminum stranded wire LGJ-400 / 50.

[0079] The tower head structure parameters are as Figure 2 and Figure 3 shown. The horizontal inclination angle α of the main material on the inner surface of the tower window top is 16.59°, and the horizontal inclination angle of the main material on the inner surface above the K-node in the tower window is 86.60°, and the horizontal inclination angle of the main material on the inner surface below the K-node is 47.10°; the upper inner side length L1 of the tower window is 7.356 m, and the side inner side length Lg of the tower window is 8.315 m.

[0080] The equivalent salt deposit density of the selected area for polluted DC is taken as 0.08 mg / cm 2 , and the equivalent ash deposit density is 6 times the equivalent salt deposit density; the number of conductor splits is six, and the split conductor spacing d is 0.4 m; composite insulators are used, and the CF coefficient is 3.8; the length L c1 of the clamping fitting is 48 cm; the altitude correction coefficient m1 is taken as 0.31.

[0081] Step 2: Based on the tower type parameters, clamping fitting length parameters, and insulator parameters of the transmission line, calculate the total length of the insulator string at different voltage levels according to insulation coordination. The total length of the insulator string is the sum of the insulator string length, insulator structural height, and the bolt length at the insulator suspension point. The bolt length at the insulator suspension point is 0.35 m; when a V-shaped string is used for the middle-phase insulator string, according to the equivalent salt deposit density of polluted DC in the selected area, a composite insulator with a flashover voltage per unit length of 87.4 kV can be selected. Through fitting historical data, the creepage distance ratio Aw required for the ±500 kV voltage level can be obtained as 4.82; after considering altitude correction, the insulator string length can be obtained using the pollution withstand voltage method formula:

[0082] L x =(A w *|U n | / CF*e 0.1215*m1*(H-1000) / 1000 +L c1 ) / 100 = 6.94 m.

[0083] Step 3: After importing the model parameters into the pre-built geometric model of the transmission tower head, considering the effects of grading rings, split conductor spacing, vertical small sag of conductors, and clearance circle margin, correct the calculation of the middle-phase air gap to obtain the corrected calculation formula for the middle-phase air gap.

[0084] The transmission tower is a wine glass tower, and the corresponding tower head structure is shown in Appendix Figure 2 、 3 . is the horizontal inclination angle of the main material on the inner surface of the tower window top, is the horizontal inclination angle of the main material on the inner surface above the K node in the tower window, is the horizontal inclination angle of the main material on the inner surface below the K node; L1 is the upper inner side length of the tower window, and the tower window L g is the side inner side length; L c is the single-leg length of the V-shaped string; is the V-string included angle, taken as 105°.

[0085] As shown in Figure 2 . is the outer diameter of the grading ring of the insulator; , are the connection distances between the grading ring and the tower connection point and the K-node respectively; is the angle between the single limb of the V-string and the auxiliary line (the connection line between the upper edge of the grading ring and the tower connection point); is the angle between the main material on the inner side above the K-node and the auxiliary line (the connection line between the lower edge of the grading ring and the tower connection point); , are the closest distances from the center of the bundled conductors (considering the influence of the vertical small sag of the conductors) to the inner side above the K-node and the inner side below the K-node respectively.

[0086] Among them;

[0087] (2),

[0088] (3),

[0089] (4),

[0090] (5),

[0091] (6),

[0092] (7),

[0093] (8),

[0094] (9),

[0095] Such as Figure 3 shown, is the distance between the two hanging holes on the V-type series plate; is the distance between the center of the bundled conductors (considering the influence of the vertical small sag of the conductors) and the connection line of the two hanging holes of the V-type series plate; , are the connection distances from the center of the bundled conductors (considering the influence of the vertical small sag of the conductors) to the grading ring and the tower connection point, and the K-node respectively; , , are the closest distances from the grading ring to the top of the tower window, the inner side above the K-node, and the inner side below the K-node respectively.

[0096] Among them,

[0097] (10),

[0098] (11),

[0099] (12),

[0100] (13),

[0101] (14),

[0102] (15),

[0103] Considering the influence of the split conductor spacing, the following formula is used for correction:

[0104] (16),

[0105] (17),

[0106] In practical engineering applications, the influence of the clearance circle electrical margin and structural margin (clearance circle margin) on the calculation of the actual air gap should also be considered.

[0107] As shown in the appendix Figure 2 、 3 The formula for calculating the actual air gap of the middle phase is:

[0108] (18),

[0109] (19),

[0110] (20),

[0111] (21),

[0112] (22),

[0113] Among them, d y is the clearance circle electrical margin and structural margin; d is the split conductor spacing.

[0114] The vertical small sag L of the conductor c2 is 0.4 m; the split conductor spacing d is 0.4 m; the clearance circle electrical margin and structural margin d y is 0.35 m; the width B2 of the grading ring is 900 mm.

[0115] Step 4: Based on the correction calculation formula for the middle-phase air gap, calculate the shortest distances from the grading ring to the three sides of the tower window respectively, and calculate the shortest distances from the center of the bundled conductors to the three sides of the tower window respectively. Among them, the shortest distances from the grading ring to the three sides of the tower window include the shortest distances from the grading ring to the top of the tower window, the inner surface above the K node, and the inner surface below the K node. The shortest distances from the center of the bundled conductors to the three sides of the tower window include the shortest distances from the center of the bundled conductors to the top of the tower window, the inner surface above the K node, and the inner surface below the K node. Since the center of the bundled conductors is located below the grading ring, the shortest distance from the center of the bundled conductors to the top of the tower window is less than the shortest distance from the bundled conductors to the top of the tower window, so the calculation of the shortest distance from the bundled conductors to the top of the tower window is omitted.

[0116] According to geometric relationship calculation, the distance d from the geometric center of the bundled conductors to the inner side length of the tower window at the ±500 kV voltage level is obtained C1 is 5.81 m, and the distance d from the geometric center of the bundled conductors to the inner lower side length of the tower window C2 is 4.27 m; the distance d from the grading ring to the top of the tower window r1 is 6.43 m, the inner surface above the K node d r2 is 5.97 m, and the shortest distance from the inner surface below the K node is d r3 is 4.79 m.

[0117] Step 5: Take the smaller values of the shortest distances from the grading ring and the center of the bundled conductors to the three sides of the tower window respectively as the undetermined actual air gap of the middle phase.

[0118] By comparing the minimum distances from the bundled conductors to the inner upper side length, the inner side length, and the inner lower side length of the tower window, it can be obtained that at the ±500 kV voltage level, the distance d1 from the bundled conductors to the inner upper side length of the tower window is 6.43 m, the distance d2 from the bundled conductors to the inner side length of the tower window is 5.81 m, and the distance d3 from the bundled conductors to the inner lower side length of the tower window is 4.27 m.

[0119] Step 6: Based on the undetermined actual air gap of the middle phase and combined with the geometric relationship of the geometric model of the tower head of the transmission tower, the single-leg length Lc of the V-string is inversely calculated to be 8.90 m.

[0120] Step 7: When the single-leg length of the V-string is greater than the total length of the insulator string, determine the undetermined actual air gap of the middle phase as the final actual air gap of the middle phase. Compare the single-leg length Lc of the V-string with the total length of the insulator string Lx = 7.36 m. Lc > Lx, indicating that this leg length meets the requirements for insulator placement. Finally, determine that the actual middle-phase gaps are d1 = 6.43 m, d2 = 5.81 m, and d3 = 4.27 m. If the situation of Lc ≤ Lx occurs, then adjust the length of the clamping fitting and repeat Steps 3 to 6 again until Lc > Lx.

[0121] Example 3

[0122] This embodiment discloses a device for calculating the seismic response value of the valve hall structure of an embedded converter station, including:

[0123] A model parameter acquisition module for acquiring model parameters, where the model parameters include transmission line tower type parameters, tower head structure parameters, transmission line conductor parameters, the length parameter of the clamping fitting, and insulator parameters;

[0124] An insulator string total length calculation module, based on the transmission line tower type parameters, the length parameter of the clamping fitting, and insulator parameters, calculates the total length of the insulator string at different voltage levels according to insulation coordination;

[0125] A middle-phase air gap correction module for, after importing the model parameters into a pre-constructed geometric model of the transmission tower head, considering the effects of the grading ring, the spacing between bundled conductors, the vertical sag of the conductor, and the clearance circle margin, correcting the calculation of the middle-phase air gap to obtain a corrected calculation formula for the middle-phase air gap;

[0126] A calculation module for the nearest distances of the three sides of the tower window, which is used to calculate the nearest distances from the grading ring to the three sides of the tower window respectively based on the corrected calculation formula for the middle-phase air gap, and calculate the nearest distances from the center of the bundled conductors to the three sides of the tower window respectively;

[0127] A module for selecting the undetermined actual middle-phase air gap, which is used to take the smaller value of the nearest distances from the grading ring and the center of the bundled conductors to the three sides of the tower window respectively as the undetermined actual middle-phase air gap;

[0128] A module for back-calculating the single-leg length of the V-string, which is used to back-calculate the single-leg length of the V-string based on the undetermined actual middle-phase air gap and in combination with the geometric relationship of the geometric model of the transmission tower head;

[0129] A module for confirming the actual middle-phase air gap, which is used to determine the undetermined actual middle-phase air gap as the final actual middle-phase air gap when the single-leg length of the V-string is greater than the total length of the insulator string.

[0130] Embodiment 4

[0131] This embodiment discloses a computer-readable storage medium, on which a computer program / instructions are stored. When the computer program / instructions are executed by a processor, the above-mentioned method for calculating the actual middle-phase air gap in the conversion from AC to DC is implemented.

[0132] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device generate means for implementing the functions specified in one flow Figure 1 one flow or more flows and / or blocks Figure 1 or means for implementing the functions specified in one block or more blocks.

[0133] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory produce a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or more flows and / or blocks Figure 1 or means for implementing the functions specified in one block or more blocks.

[0134] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or more flows and / or blocks Figure 1 or means for implementing the functions specified in one block or more blocks.

[0135] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A calculation method for the actual air gap in the conversion from AC to DC, characterized in that: The steps include: Obtain model parameters, which include transmission line tower type parameters, tower head structure parameters, transmission line conductor parameters, length parameters of clamping fittings, and insulator parameters; Based on the transmission line tower type parameters, length parameters of clamping fittings, and insulator parameters, calculate the total length of the insulator string at different voltage levels according to insulation coordination; After importing the model parameters into the pre-constructed geometric model of the transmission tower head, considering the effects of grading rings, split conductor spacing, vertical sag of conductors, and clearance circle margin, correct the calculation of the middle-phase air clearance to obtain the corrected calculation formula for the middle-phase air clearance; Based on the corrected calculation formula for the middle-phase air clearance, calculate the nearest distances from the grading ring to the three sides of the tower window respectively, and calculate the nearest distances from the center of the split conductors to the three sides of the tower window respectively; Take the smaller value of the nearest distances from the grading ring and the center of the split conductors to the three sides of the tower window respectively as the pending actual middle-phase air clearance; Based on the pending actual middle-phase air clearance, combined with the geometric relationship of the geometric model of the transmission tower head, inversely calculate the length of a single limb of the V-string; When the length of a single limb of the V-string is greater than the total length of the insulator string, determine the pending actual middle-phase air clearance as the final actual middle-phase air clearance.

2. The method for calculating the actual air gap in the conversion from AC to DC according to claim 1, wherein: The transmission line tower type parameters include the transmission tower model, the altitude of the operation area of the transmission tower, and the conductor model corresponding to the transmission line tower; the tower head structure parameters include the internal angle of the tower window and the internal side length of the tower window. The internal angle of the tower window includes the horizontal inclination angles of the main materials on the inner surface of the tower window top, above the K-node, and below the K-node. The internal side length of the tower window includes the upper internal side length and the side internal side length of the tower window; the transmission line conductor parameters include the number of splits and the split conductor spacing; the insulator parameters include the insulator model and the thickness of a single insulator.

3. The actual air gap calculation method in the conversion from AC to DC according to claim 2, wherein: The total length of the insulator string is the sum of the insulator string length, the insulator structural height, and the bolt length at the insulator hanging point. Among them, the insulator string length is L x It is calculated using the pollution withstand voltage method formula as follows: L x =(A w * | U n | / CF*e 0.1215*m1*(H-1000) / 1000 +L c1 ) / 100 (1), Where A w is the creepage distance per unit voltage, U n is the voltage level, CF is the creepage coefficient, m1 is the altitude correction coefficient, H is the altitude, and L c1 is the length of the clamping fitting.

4. The method for calculating the actual air gap in the conversion from AC to DC according to claim 3, wherein: The nearest distances from the grading ring to the three sides of the tower window respectively include the nearest distances from the grading ring to the top of the tower window, the inner surface above the K-node, and the inner surface below the K-node.

5. A rapid calculation method for the actual air gap in the conversion from alternating current to direct current according to claim 4, characterized in that: The nearest distances from the center of the split conductors to the three sides of the tower window respectively include the nearest distances from the center of the split conductors to the top of the tower window, the inner surface above the K-node, and the inner surface below the K-node.

6. The method for calculating the actual air gap in the conversion from AC to DC according to claim 5, characterized in that: After importing the model parameters into the pre-built geometric model of the transmission tower head, considering the effects of grading rings, split conductor spacing, vertical sag of conductors, and clearance circle margin, the calculation of the middle-phase air clearance is corrected. The corrected calculation formula for the middle-phase air clearance includes: In the geometric model of the transmission tower head, α is the horizontal inclination angle of the main material on the inner surface at the top of the tower window, is the horizontal inclination angle of the main material on the inner surface above the K node in the tower window, is the horizontal inclination angle of the main material on the inner surface below the K node, L1 is the upper side length inside the tower window, L g is the side length inside the tower window, L c is the single-leg length of the V-string, is the V-string angle, is the outer diameter of the insulator grading ring, 、 are the connection distances between the grading ring and the tower connection point, the K node respectively; is the angle between the single leg of the V-string and the connection line between the upper edge of the grading ring and the tower connection point, is the angle between the main material on the inner surface above the K node and the connection line between the lower edge of the grading ring and the tower connection point, 、 are the closest distances from the center of the split conductor to the inner surface above the K node and the inner surface below the K node respectively, is the distance between the two hanging holes on the V-type series plate; is the distance between the center of the split conductor and the connection line of the two hanging holes on the V-type series plate; 、 are the connection distances between the center of the split conductor and the grading ring and the tower connection point, the K node respectively; 、 、 are the closest distances from the grading ring to the top of the tower window, the inner surface above the K node, and the inner surface below the K node respectively; Among them; (2), （3）， （4）， （5）， （6）， （7）， （8）， （9）， （10）， （11）， （12）， （13）， （14）， （15）， Considering the influence of the split conductor spacing, the following formula is used for correction: （16）， （17）， Considering the influence of the clearance circle margin on the calculation of the actual air clearance again, the calculation formula for the actual middle-phase air clearance is corrected again as: （18）， （19）， （20）， （21）， （22）， Among them, d y is the clearance circle margin, and d is the split conductor spacing.

7. The method for calculating the actual air gap in the conversion from AC to DC according to claim 6, wherein: The clearance circle margin includes the electrical margin of the clearance circle and the structural margin of the clearance circle.

8. The method for calculating the actual air gap in the conversion from AC to DC according to claim 1, characterized in that: When the length of a single limb of the V-string is not greater than the total length of the insulator string, adjust the length of the clamping fitting, and repeat the following steps again until the length of a single limb of the V-string is greater than the total length of the insulator string: After importing the model parameters into the pre-constructed geometric model of the transmission tower head, considering the effects of grading rings, split conductor spacing, vertical sag of conductors, and clearance circle margin, correct the calculation of the middle-phase air clearance to obtain the corrected calculation formula for the middle-phase air clearance; Based on the corrected calculation formula for the middle-phase air clearance, calculate the nearest distances from the grading ring to the three sides of the tower window respectively, and calculate the nearest distances from the center of the split conductors to the three sides of the tower window respectively; Take the smaller value of the nearest distances from the grading ring and the center of the split conductors to the three sides of the tower window respectively as the pending actual middle-phase air clearance; Based on the actual air gap of the middle phase to be determined, combined with the geometric relationship of the geometric model of the transmission tower head, the single-leg length of the V-string is calculated by back-calculation.

9. An earthquake response value calculation device for an embedded converter station valve hall structure, characterized in that: Including: A model parameter acquisition module for acquiring model parameters, where the model parameters include transmission line tower type parameters, tower head structure parameters, transmission line conductor parameters, clamping fitting length parameters, and insulator parameters; An insulator string total length calculation module, based on the transmission line tower type parameters, clamping fitting length parameters, and insulator parameters, calculates the total length of the insulator string under different voltage levels according to insulation coordination; A middle phase air gap correction module for importing the model parameters into the pre-constructed transmission tower head geometric model, considering the influence of the grading ring, split conductor spacing, conductor vertical sag, and clearance circle margin, and correcting the calculation of the middle phase air gap to obtain the corrected calculation formula for the middle phase air gap; A calculation module for the nearest distances of the three sides of the tower window, which is used to calculate the nearest distances from the grading ring to the three sides of the tower window respectively based on the corrected calculation formula for the middle phase air gap, and calculate the nearest distances from the center of the split conductor to the three sides of the tower window respectively; A selection module for the actual air gap of the middle phase to be determined, which is used to take the smaller value of the nearest distances from the grading ring and the center of the split conductor to the three sides of the tower window as the actual air gap of the middle phase to be determined; A back-calculation module for the single-leg length of the V-string, which is used to calculate the single-leg length of the V-string by back-calculation based on the actual air gap of the middle phase to be determined and the geometric relationship of the geometric model of the transmission tower head; A confirmation module for the actual air gap of the middle phase, which is used to determine the actual air gap of the middle phase to be determined as the final actual air gap of the middle phase when the single-leg length of the V-string is greater than the total length of the insulator string.

10. A computer-readable storage medium having computer programs / instructions stored thereon, characterized in that: When the computer program / instructions are executed by the processor, the method for calculating the actual air gap of the converted middle phase described in any one of claims 1-8 is implemented.

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