Calculation method of protection distance between VDB station of land-based augmentation system and high-voltage transmission line

Abstract

The present invention discloses a method for calculating the protective spacing of a land-based augmentation system VDB station to a high-voltage transmission line. With the airport runway entrance as the origin, a three-dimensional rectangular coordinate system is established, and the signal coverage range of the VDB is set to determine the number of available frequency points in the radio frequency band used by the VDB; the protective spacing of the high-voltage transmission line is calculated by the VDB subsystem to obtain D(i, l) at different working frequencies, and the protective spacing of the VDB station to the high-voltage transmission line. Compared with the prior art, the method calculates the protective spacing of the VDB station to the high-voltage transmission line through relevant data information such as the position of the VDB station, the position of the aircraft, and the position of the high-voltage transmission line, providing a basis and technical means for the electromagnetic environment protection of the VDB station of the land-based navigation system, and providing support for the promotion, application and development of new navigation technologies.

Description

Technical Field

[0001] The present invention relates to the field of aviation, and in particular to a method for calculating the protective spacing between a land-based augmentation system VDB station and a high-voltage transmission line. Background Art

[0002] Since the second industrial revolution, mankind has entered the electrical age. Since then, electricity has become the most widely used energy source and the cornerstone of modern human civilization. With the rapid development of my country's economy, the demand for energy in various provinces, cities and regions has continued to increase, accelerating the vigorous construction of high-voltage transmission lines including ultra-high voltage and ultra-high voltage. However, due to the limitation of the line direction, the electromagnetic radiation generated by high-voltage transmission lines can no longer be ignored. Electromagnetic radiation is generated by corona discharge on the surface of the conductor or line device of the high-voltage transmission line and spark discharge in the line gap. Corona discharge is a discharge phenomenon caused by air ionization due to the high electric field intensity on the surface of the conductor; gap spark discharge is a solitary light discharge and spark discharge phenomenon caused by poor contact or corrosion of the conductor. Corona discharge is the main reason for electromagnetic radiation generated by high-voltage transmission lines.

[0003] With the rapid development of satellite navigation technology and civil aviation, the navigation system is gradually transitioning from the existing land-based navigation system to the satellite-based navigation system. GBAS (Ground Based Augmentation System) is a system planned by the International Civil Aviation Organization (ICAO) based on the global satellite navigation system using differential technology. In 2014, China Electronics Technology Group Corporation developed the first domestic GBAS satellite navigation landing system and carried out installation and airworthiness certification work at Tianjin Binhai International Airport. In 2015, China Civil Aviation introduced the SLS-4000 GBAS equipment of Honeywell of the United States and conducted tests and verification at Shanghai Pudong International Airport.

[0004] GBAS system improves satellite navigation accuracy by differential positioning, and adds a series of integrity monitoring algorithms to improve the system integrity, availability, and continuity indicators, so that aircraft equipped with corresponding airborne equipment within the airspace covered by the airport can obtain precision approach and landing guidance services reaching Category I precision approach (CAT-I) or even higher standards, and one set of equipment can serve multiple runways at the airport, which is also the essential difference from land-based navigation equipment. GBAS works with airborne equipment to provide precision approach guidance for aircraft. It consists of a reference receiving subsystem, a processing subsystem, a very high frequency data broadcast (VDB) subsystem, and a monitoring and maintenance subsystem. The operating frequency band of the VDB subsystem is 108MHz to 117.975MHz.

[0005] At present, the national standard GB6364-2013 "Electromagnetic Environment Requirements for Aeronautical Radio Navigation Stations (Stations)" stipulates the protection distance between airport land-based navigation equipment and high-voltage transmission lines. At present, there are many electromagnetic interference effects on rail transit and high-voltage transmission lines on land-based navigation equipment, but there are few studies and analyses on the protection distance between the VDB subsystem equipment of the GBAS system and high-voltage transmission lines. Zou Jie, in "Analysis of the Interference Protection Distance between VDB and VOR Station of GBAS Navigation System", gives the calculation of the protection distance between VDB and VOR station in the same frequency and different frequency bands according to the analysis method and path loss given in Annex 10 of ICAO; Ye Jiaquan et al. published "Design Method Based on the Effect of Ground Reflection of Maglev Arc on VDB Electromagnetic Compatibility", which is an analysis of the three-dimensional electromagnetic effect of the reflection of the magnetic levitation arc entering the ground on VDB. The GBAS system is an interstellar navigation system as a new navigation technology and is the development trend of future air transportation. Because it is very necessary to take into account and coordinate the contradiction between high-voltage transmission lines and GBAS system while developing cities and aviation. In order to ensure the safety of air transportation and the safe operation of the GBAS system, it is urgent to determine the protection distance between the VDB subsystem and the high-voltage transmission line. At the same time, it can also provide technical support for the design of high-voltage transmission lines and the site selection of the VDB subsystem.

[0006] The definition of protection distance in the national standard GB6364-2013 "Electromagnetic Environment Requirements for Aeronautical Radio Navigation Stations" is: the minimum distance from the radio transmitter and electromagnetic interference radiation source to the antenna of the aeronautical radio station (station) specified to protect the normal operation of the aeronautical radio navigation station (station).

[0007] The protection ratio is defined as the minimum ratio of the signal strength at the receiving point to the interference strength of the same frequency channel to ensure the normal operation of the navigation receiving equipment. Summary of the invention

[0008] The purpose of the present invention is to provide a method for calculating the protection distance between the VDB station of a land-based augmentation system and the high-voltage transmission line. By using relevant data information such as the location of the VDB station, the location of the aircraft and the location of the high-voltage transmission line, combined with all frequency points in the working frequency band of the VDB subsystem, the protection distance between the VDB subsystem equipment and the high-voltage transmission line can be accurately and reliably calculated. Based on this, the site selection of the VDB subsystem or the planning of the high-voltage transmission line can be carried out to avoid electromagnetic interference caused by rail transit and high-voltage transmission lines to land-based navigation equipment.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is: a method for calculating the protection distance between the VDB station of the land-based augmentation system and the high-voltage transmission line,

[0010] With the airport runway entrance as the origin, the extended runway centerline as the x-axis, the vertical direction of the extended runway centerline as the y-axis, and the z-axis directly above the runway entrance, a three-dimensional rectangular coordinate system is established, and the signal coverage range of VDB is set to determine the number of available frequencies in the radio frequency band used by VDB;

[0011] The protection distance of high-voltage transmission lines is calculated through the VDB subsystem. The calculation method is as follows:

[0012] Step 1: Given the initial protection distance value as D0 and the frequency of the VDB station as f l , where l = 0, 1, 2, ..., 398, f l+1 -f l =Δf=25kHz. According to ICAO Annex 10, R=30dB. Combined with the position relationship of the rectangular coordinate system,

[0013] D i =min{L i},

[0014] In the formula, D i is the shortest distance between the VDB station and the high-voltage transmission line, L i is the horizontal distance from the VDB station to the i-th high-voltage transmission line tower, i = 1, 2, 3…, N;

[0015] Step 2, based on the given initial data and in combination with the rectangular coordinate system, calculate the signal-to-noise ratio S between the signal strength generated by the VDB at the aircraft position and the signal strength generated by the high-voltage line;

[0016] Step 3: Determine whether the signal-to-noise ratio S is equal to the protection rate R of VDB.

[0017] If it is equal to R, then record D(i, l) at this time.

[0018] If it is not equal to R, proceed to step 4;

[0019] Step 4: Determine whether (S(i,l)-R)(S(i-1,l)-R) is less than 0.

[0020] If (S(i,l)-R)(S(i-1,l)-R)<0, then let D(i+1,l)=D(i,l)+|D(i,l)-D(i-1,l)| / 2; otherwise, let D(i+1,l)=D(i,l)-|D(i,l)-D(i-1,l)| / 2; then use D(i+1,l) as the given data and return to step 2 to continue the calculation until D(i,l) at different operating frequencies can be obtained. Then we get D=max{D(i,l)}, which is the protection distance of the VDB station to the high-voltage transmission line.

[0021] As a preference, the position coordinates of the VDB subsystem are marked as (x0, y0, z0), and the position coordinates of the aircraft are marked as (x a ,y a ,z a ), the coordinates of any point on the edge of the VDB subsystem signal coverage are marked as (x n ,y n ,z n ), the tower position coordinates of the high-voltage transmission line are marked as (x m ,y m ,z m ).

[0022] Preferably, the method for determining the signal coverage range of VDB is as specified in ICAO Annex 10, which is 140m on both sides of the runway landing point or virtual entry point, with the final approach segment as the reference, and the signal coverage range of VDB is 35°15NM (28km) on the left and right and 10°20NM (37km) on the left and right of the runway landing point or virtual entry point. The minimum radiation field strength at the edge of the signal coverage range is 215μV / m (46.6dBμV / m).

[0023] As a preferred method for determining the number of available frequencies, the VDB subsystem uses a radio frequency band of 108MHz to 117.975MHz, the lowest assignable frequency is 108.025MHz, the highest frequency is 117.950MHz, and the frequency interval (channel interval) is 25kHz, so the VDB subsystem has a total of 398 frequencies available.

[0024] Preferably, in step 2, the method for calculating the signal-to-noise ratio between the signal strength generated by the VDB at the aircraft position and the signal strength generated by the high-voltage line is,

[0025] First, in accordance with ICAO Annex 10, the signal field strength E generated by the VDB at the aircraft location is calculated. VDB信号强度 , the formula is as follows,

[0026]

[0027] In the formula, 46.6 is the minimum signal strength of VDB in ICAO Annex 10, 46.6dBμV / m;

[0028] Secondly, calculate the signal strength of the high-voltage transmission line at the operating frequency of the VDB subsystem at the location of the aircraft: E 高压输电线信号强度 :

[0029]

[0030] Where E0 is the signal strength of the high-voltage transmission line at 0.5MHz and 20m away from the projection of the high-voltage transmission line;

[0031] Then, the shortest distance d between the high-voltage transmission line and the aircraft is calculated according to the rectangular coordinate system. x , we can conclude:

[0032]

[0033] Where, d x X is the straight-line distance from the high-voltage transmission line tower at the location of the field strength of different levels of high-voltage transmission lines measured at a projection distance of 20m from the high-voltage transmission line. i is the distance from the ith high-voltage transmission line tower to the aircraft,

[0034] Then d i =max{h i},

[0035] Therefore, it can be concluded that:

[0036] In the formula, h i is the straight-line distance between the test point and the high-voltage transmission line tower, 66.6 is a constant obtained by subtracting the signal strength of the high-voltage transmission line from the signal strength of the VDB, d i is the straight-line distance from the test point to the i-th high-voltage transmission line tower.

[0037] Compared with the prior art, the advantages of the present invention are:

[0038] (1) This method calculates the protection distance between the VDB station and the high-voltage transmission line through relevant data information such as the location of the VDB station, the location of the aircraft, and the location of the high-voltage transmission line. This provides a basis and technical means for the electromagnetic environment protection of the VDB station of the land-based navigation system, and provides support for the promotion, application and development of new navigation technologies.

[0039] (2) This method comprehensively considers all frequency points in the VDB subsystem operating frequency band. Compared with the protection distance results obtained at a single VDB operating frequency point, they are more accurate and reliable.

[0040] (3) This method provides a technical means for the site selection of VDB subsystems and the planning and design of high-voltage transmission lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is the three-dimensional rectangular coordinate system of the present invention;

[0042] Figure 2 is the standard signal coverage of the GBAS system of the present invention;

[0043] Figure 3 This is a flow chart of the protection distance calculation process of the present invention;

[0044] Figure 4 This is a schematic diagram of the protection spacing calculation method process of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described below. A method for calculating the protective spacing between a land-based augmentation system VDB station and a high-voltage transmission line is as follows. Figure 1 ,

[0046] First, establish a three-dimensional rectangular coordinate system, as shown in the following diagram: Figure 1 As shown in the figure, the airport runway entrance is taken as the origin, the extended line of the runway centerline is the x-axis, the vertical direction of the extended line of the runway centerline is the y-axis, and the z-axis is directly above the runway entrance.

[0047] After the rectangular coordinate system is established, the position coordinates of the VDB subsystem are marked as (x0, y0, z0), and the position coordinates of the aircraft are marked as (x a ,y a ,z a ), the coordinates of any point on the edge of the VDB subsystem signal coverage are marked as (x n ,y n ,z n ), the tower position coordinates of the high-voltage transmission line are marked as (x m ,y m ,z m ), m=1,2,3,...,N, (N≥1).

[0048] According to ICAO Annex 10, the signal coverage range of VDB is 140m on both sides of the runway landing point or virtual entry point, with the final approach segment as the reference, and 35°15NM (28km) and 10°20NM (37km) on both sides of the runway landing point or virtual entry point as the reference. The signal coverage range is shown in the figure below. Figure 2 As shown. The minimum radiation field strength at the edge of the signal coverage is 215μV / m (46.6dBμV / m). The radio frequency band used by VDB is 108MHz~117.975MHz, the lowest frequency that can be assigned is 108.025MHz, the highest frequency is 117.950MHz, and the frequency interval (channel interval) is 25kHz, so the VDB subsystem has a total of 398 frequency points available.

[0049] The calculation process of the protection distance of high-voltage transmission lines by the VDB subsystem is as follows: Figure 3 The specific steps are as follows:

[0050] Step 1: First, the initial protection distance value D0 is given; the frequency of the VDB station is fl ,l=0,1,2,……,398,f l+1 -f l =Δf=25kHz; According to ICAO Annex 10, R=30dB, combined Figure 4 The position relationship in

[0051] D i =min{L i},

[0052] In the formula, D i is the shortest distance between the VDB station and the high-voltage transmission line, L i is the horizontal distance from the VDB station to the i-th high-voltage transmission line tower, i = 1, 2, 3..., N

[0053] Step 2: Based on the given initial data, combine Figure 4 As shown, the signal-to-noise ratio S between the signal strength generated by the VDB at the aircraft position and the signal strength generated by the high-voltage line is calculated.

[0054] (1) First, calculate the signal strength generated by the VDB at the location of the aircraft. According to ICAO Annex 10, the minimum signal strength of the VDB is 215μV / m, that is, 46.6dBμV / m. The signal strength of the VDB at the location of the aircraft is E VDB信号强度 :

[0055]

[0056] In the formula, (2) Calculate the signal strength generated by the high-voltage transmission line at the location of the aircraft. The signal strength of the high-voltage transmission line at the operating frequency of the VDB subsystem at the location of the aircraft is E 高压输电线信号强度 :

[0057]

[0058] Where E0 is the signal strength of the high-voltage transmission line at 0.5MHz and 20m away from the projection of the high-voltage transmission line;

[0059] According to GB15707-2017 "Limits of Radio Interference for High-voltage AC Overhead Transmission Lines" and DL / T5536-2017 "Design Specifications for Protection of DC Overhead Transmission Lines from Impact on Radio Stations", the signal strength of different levels of high-voltage transmission lines at 0.5MHz frequency and 20m away from the projection distance of the high-voltage transmission line is shown in the following table:

[0060]

[0061] d xis the shortest distance between the high-voltage transmission line and the aircraft, combined with Figure 4 It can be concluded that:

[0062]

[0063] Where, d x X is the straight-line distance from the high-voltage transmission line tower at the location of the field strength of different levels of high-voltage transmission lines measured at a projection distance of 20m from the high-voltage transmission line. i is the distance from the ith high-voltage transmission line tower to the aircraft, then d i =max{h i},

[0064] Therefore, it can be concluded that:

[0065] In the formula, h i is the straight-line distance between the test point and the high-voltage transmission line tower, 66.6 is a constant obtained by subtracting the signal strength of the high-voltage transmission line from the signal strength of the VDB, d i is the straight-line distance from the test point to the i-th high-voltage transmission line tower

[0066] Step 3: Determine whether the signal-to-noise ratio at this time is equal to the protection rate R of VDB.

[0067] If it is equal to R, record D(i, l) at this time.

[0068] If not equal, proceed to the next step:

[0069] Step 4, determine whether (S(i,l)-R)(S(i-1,l)-R) is less than 0. If (S(i,l)-R)(S(i-1,l)-R)<0, let D(i+1,l)=D(i,l)+|D(i,l)-D(i-1,l)| / 2, otherwise let D(i+1,l)=D(i,l)-|D(i,l)-D(i-1,l)| / 2; then execute step 2 until D(i,l) at different operating frequencies can be obtained, then D=max{D(i,l)} is obtained, which is the protection distance of the VDB station to the high-voltage transmission line.

[0070] The present invention establishes a new coordinate system, comprehensively analyzes the position data, operating frequency and signal strength data of the VDB station, the position data of the aircraft, and the position and signal strength data of the high-voltage transmission line, and obtains the calculation result of the protection spacing of the high-voltage transmission line by the VDB subsystem, so that the obtained result has high accuracy and reliability. This function can be realized in the form of a software unit, all data information is read in a computer-readable medium, and by inputting the data parameters involved in the present invention, the protection spacing results of the VDB subsystem for high-voltage transmission lines of different levels can be quickly calculated.

[0071] This method can provide a basis for the site selection of tower poles for high-voltage overhead transmission lines, and can also provide technical means for the electromagnetic environment protection of airports, and also provide guarantee for the safe operation of airport aircraft.

[0072] The above is a detailed introduction to the calculation method of the protection distance between the VDB station of the land-based augmentation system and the high-voltage transmission line provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope, and changes and improvements to the present invention will be possible without exceeding the concept and scope specified in the attached claims. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for calculating the protection distance between a land-based augmentation system VDB station and a high-voltage transmission line, characterized in that: In the VDB subsystem, a three-dimensional rectangular coordinate system is established with the airport runway threshold as the origin, the runway centerline extension as the x-axis, the vertical direction of the runway centerline extension as the y-axis, and the z-axis directly above the runway threshold. The signal coverage range of VDB is set, and the number of available frequencies in the radio frequency band used by VDB is determined. The protection distance of high-voltage transmission lines is calculated through the VDB subsystem. The calculation method is as follows: Step 1: Given the initial protection distance value as D0 and the frequency of the VDB station as f l , where l = 0, 1, 2, ..., 398, f l+1 -f l =Δf=25kHz. According to ICAO Annex 10, the protection rate R=30dB. Combined with the position relationship of the rectangular coordinate system, D i =min{L i } In the formula, D i is the shortest distance between the VDB station and the high-voltage transmission line, L i is the horizontal distance from the VDB station to the i-th high-voltage transmission line tower, i = 1, 2, 3…, N; Step 2, based on the given initial data and in combination with the rectangular coordinate system, calculate the signal-to-noise ratio S between the signal strength generated by the VDB at the aircraft position and the signal strength generated by the high-voltage line; Step 3: Determine whether the signal-to-noise ratio S is equal to the protection rate R of VDB. If it is equal to R, then record D(i, l) at this time. If it is not equal to R, proceed to step 4; Step 4: Determine whether (S(i,l)-R)(S(i-1,l)-R) is less than 0. If (S(i,l)-R)(S(i-1,l)-R)<0, then let D(i+1,l)=D(i,l)+|D(i,l)-D(i-1,l)| / 2; otherwise, let D(i+1,l)=D(i,l)-|D(i,l)-D(i-1,l)| / 2; then use D(i+1,l) as the given data and return to step 2 to continue the calculation until D(i,l) at different operating frequencies can be obtained. Then we get D=max{D(i,l)}, which is the protection distance of the VDB station to the high-voltage transmission line.

2. The method for calculating the protective spacing between the land-based augmentation system VDB station and the high-voltage transmission line according to claim 1 is characterized by: The position coordinates of the VDB subsystem are marked as (x0, y0, z0), and the position coordinates of the aircraft are marked as (x a ,y a ,z a ), the coordinates of any point on the edge of the VDB subsystem signal coverage are marked as (x n ,y n ,z n ), the tower position coordinates of the high-voltage transmission line are marked as (x m ,y m ,z m ).

3. The method for calculating the protection distance between the land-based augmentation system VDB station and the high-voltage transmission line according to claim 1 is characterized by: The method for determining the signal coverage range of the VDB is as follows: taking the runway landing point or the virtual entry point as 140m on both sides and the final approach segment as the benchmark, the signal coverage range of the VDB is 35°15NM on the left and right and 10°20NM on the left and right of the runway landing point or the virtual entry point as the benchmark, and the minimum radiation field strength at the edge of the signal coverage range is 215μV / m.

4. The method for calculating the protection distance between the land-based augmentation system VDB station and the high-voltage transmission line according to claim 1 is characterized by: The method for determining the number of available frequencies in the radio frequency band used by the VDB is as follows: the radio frequency band used by the VDB subsystem is 108MHz to 117.975MHz, the lowest assignable frequency is 108.025MHz, the highest frequency is 117.950MHz, and the frequency interval is 25kHz. Therefore, the VDB subsystem has a total of 398 frequencies available.

5. The method for calculating the protective spacing between the land-based augmentation system VDB station and the high-voltage transmission line according to claim 2 is characterized by: In step 2, the signal-to-noise ratio between the signal strength generated by the VDB and the signal strength generated by the high-voltage line at the aircraft location is calculated as: First, according to ICAO Annex 10, the signal strength E generated by the VDB at the aircraft location is calculated. VDB信号强度 , the formula is as follows, In the formula, 46.6 is the minimum signal strength of VDB in ICAO Annex 10, 46.6dBμV / m; Secondly, calculate the signal strength of the high-voltage transmission line at the operating frequency of the VDB subsystem at the location of the aircraft as E 高压输电线信号强度 : Where E0 is the signal strength of the high-voltage transmission line at 0.5MHz and 20m away from the projection of the high-voltage transmission line, d x is the shortest distance between the high voltage transmission line and the aircraft, d i is the straight-line distance from the test point to the i-th high-voltage transmission line tower; Among them, the shortest distance d between the high-voltage transmission line and the aircraft is calculated according to the rectangular coordinate system x , we can conclude: Where, X i is the distance from the ith high-voltage transmission line tower to the aircraft; Therefore, it follows that: In the formula, h i It is the straight-line distance between the test point and the high-voltage transmission line tower.

Images