Crane hoisting anti-electric shock high-voltage line near electric field source gridding positioning method

Abstract

The invention relates to an anti-electric-shock high-voltage line near electric field source gridding positioning method for crane hoisting, and belongs to the technical field of high-voltage line near electric field source positioning. The method comprises the steps of firstly constructing a high-voltage line near electric field source radio wave propagation model; calculating the receiving signal intensity of the electric field induction device aiming at the near electric field source radiation signal; establishing a differential field intensity model of a high-voltage line near electric field source receiving signal by adopting a gridding multi-site monitoring mode; establishing a high-voltage line near electric field source positioning model; and solving the high-voltage line near electric field source positioning model to obtain high-voltage line near electric field source position coordinates. According to the invention, strong interference resistance, high accuracy and stable positioning result calculation of the near electric field source near the high-voltage line in the hoisting operation are effectively ensured, and reliable safety early warning can be provided for electric shock prevention of the hoisting operation of the crane.

Description

Technical Field

[0001] This invention belongs to the field of high-voltage line near-electric field source positioning technology, specifically relating to a gridded positioning method for high-voltage line near-electric field sources to prevent electric shock during crane hoisting. Background Technology

[0002] Lifting and hoisting operations near energized equipment are high-risk and difficult to manage. Insufficient on-site management capabilities during lifting operations can lead to accidents and large-scale power outages due to inadequate risk control, resulting in serious social impacts. To address the need for real-time monitoring of electric shock prevention during crane lifting operations, high-voltage lines near the lifting site are typically considered as near-field sources. Exploring methods for identifying and determining the direction of near-field sources of high-voltage lines with a certain degree of interference resistance can provide safety warnings for electric shock prevention during crane lifting operations, preventing accidents caused by the boom touching nearby high-voltage lines due to misoperation or blind spots.

[0003] Currently, the industry has developed methods for locating near-electric field sources by deploying broadband photoelectric field sensors with megapixel sampling resolution to synchronously capture waveforms over a wide area. These methods offer advantages such as rapid deployment and low cost. Another approach uses traveling wave fault location to identify live equipment near high-voltage lines. A method combining high-voltage line discharge source location with discharge characteristics observed in withstand voltage tests has been proposed, offering a comprehensive and accurate discharge location method that considers multiple factors. A practical discharge source location example demonstrates the good accuracy of discharge location based on signal strength and oscillation duration. However, this method fails to account for corrections to electric field source propagation losses, resulting in significant location errors that do not meet practical requirements. Furthermore, with the development of proximity sensing technology in recent years, electric field information has been converted into distance information to estimate the distance to live equipment.

[0004] The existing methods for identifying and locating near-electric field sources on high-voltage lines generally suffer from several drawbacks: susceptibility to external environmental interference, low accuracy in location calculations, and a lack of correction for the propagation loss prediction of the equivalent near-electric field source on the high-voltage line, leading to significant location errors that fail to meet practical needs. Therefore, overcoming these shortcomings is a pressing issue in the field of high-voltage line near-electric field source location technology. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a gridded positioning method for high-voltage line near electric field sources to prevent electric shock during crane lifting.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A gridded positioning method for high-voltage power line near electric field sources to prevent electric shock during crane lifting includes the following steps:

[0008] Step 1: Construct a radio wave propagation model for a near-electric field source of a high-voltage line;

[0009] Step 2: Treat the high-voltage line near the lifting operation as a near electric field source. By placing an electric field induction device on the crane, calculate the received signal strength (RSS) of the electric field induction device for the near electric field source radiated signal.

[0010] Step 3: Adopt a gridded multi-site monitoring approach to establish a differential field strength model for the received signals from the electric field source near the high-voltage line;

[0011] Step 4: By introducing the Okumura-Hata prediction model, the fading caused by radio waves propagating from the near electric field source to the monitoring station is predicted, and a near electric field source location model for high-voltage lines is established.

[0012] Step 5: Solve the high-voltage line near electric field source location model to obtain the location coordinates of the high-voltage line near electric field source.

[0013] Furthermore, in step one, the radio wave propagation model of the high-voltage line near the electric field source is as follows:

[0014] L(r) = L0(r) + L1(r) + L2(r) + W(t)

[0015] Where r is the distance from the near-field source to the receiver; L0(r), L1(r), and L2(r) are path fading, shadow fading, and multipath fading, respectively; W(t) is the measurement background noise signal; and L(r) is the signal fading caused during radio wave propagation.

[0016] Furthermore, in step two, the formula for calculating the received signal strength of each electric field sensing device in response to the radiation signal from the near-electric field source is as follows:

[0017] P r =P t -L(r)-W(t)

[0018] Among them, P r P represents the received signal strength of the electric field induction device. t This indicates the intensity of the signal emitted by the near-electric field source.

[0019] Furthermore, the specific method for step three is as follows:

[0020] To facilitate the location and calculation of electric field sources near high-voltage lines, a grid-based multi-site monitoring approach is adopted. Specifically, each monitoring station is an electric field sensing device. Multiple electric field sensing devices are placed on cranes to form multiple monitoring stations for monitoring near electric field sources.

[0021] The differential field strength model for the received signal from the near-electric field source of the high-voltage line is as follows:

[0022] Pr,ij =P r,i -P r,j =L 0.ji (r)+L 1,ji (r)+W ji (r)

[0023] Among them, L 0.ji (r) represents two monitoring stations M i M j The difference in path fading measured; L 1,ji (r) represents two monitoring stations M i M j The difference in shadow fading measured; W ji (r) represents two monitoring stations M i M j The difference in background noise; P r,ij For two different monitoring stations M i M j The difference in received signal strength between them; P r,i For monitoring station M i The received signal field strength; P r,j For monitoring station M j The received signal field strength.

[0024] Furthermore, the specific method for step four is as follows:

[0025] The Okumura-Hata prediction model is as follows:

[0026] L(r) = a + b lg fc lg h t -α(h r )+(mn lg h t )lg r

[0027] Where L represents the signal fading caused during radio wave propagation; f is the operating frequency at which the monitoring station detects and acquires the received signal field strength; h t h is the height of the transmitting antenna. r α(h) represents the height of the receiving antenna; r represents the distance from the near-field source to the monitoring station; α(h) represents the height of the receiving antenna. r ) represents the correction factor; a, b, c, m, and n are the coefficient values ​​obtained from the linear regression fitting;

[0028] Let monitoring station M be set i The received signal field strength is P r,i Radio waves propagate from the near electric field source to the monitoring station M i The resulting fading is L(r) i If the electric field strength P near the electric field source is... t for:

[0029] P t=P r,i +L(r i (6)

[0030] Two different monitoring stations M i M j The difference in field strength received by a near-electric source can be expressed as:

[0031]

[0032] Let a certain monitoring station be taken as the origin of the coordinate system, M0(x0,y0,z0), and this monitoring station is defined as the reference station. Its received field strength is P0. Within this coordinate system, the receiving antenna height of all monitoring stations is the same, which is h. t Let the i-th monitoring station be M. i The coordinates are (x i y i , z i Its received field strength is P i ;

[0033] Therefore, the difference between the received field strength of the near-electric source at the i-th monitoring station and the reference station can be expressed as:

[0034]

[0035] Among them, P i h is the received field strength of the i-th monitoring station; t r is the height of the receiving antenna of the i-th monitoring station; i ri is the distance from the near electric field source to the i-th monitoring station; r0 is the distance from the near electric field source to the reference station;

[0036] This yields the following set of nonlinear equations, which serve as the C-type model for locating the near-electric field source of the high-voltage line. i (x,y,z):

[0037]

[0038] Where N represents the number of monitoring stations.

[0039] Furthermore, the specific method for step five is as follows:

[0040] A genetic algorithm was used to solve the coordinate model for locating the electric field source near the high-voltage line.

[0041] The fitness function for locating the near-electric field source coordinates using the genetic algorithm is:

[0042]

[0043] Among them, F it C represents the fitness value for locating the near-electric field source coordinates. i Model for locating electric field sources near high-voltage lines;

[0044] When solving the problem, the objective is to minimize the fitness value. The specific objective function is:

[0045] K(x,y,z)=argmin(F it )

[0046] Where K(x,y,z) represents the coordinates of the near-field source being solved;

[0047] This allows us to obtain the coordinates of the electric field source near the high-voltage line.

[0048] This invention also provides a gridded positioning system for high-voltage lines near electric field sources to prevent electric shock during crane lifting. It adopts the above-mentioned gridded positioning method for high-voltage lines near electric field sources to prevent electric shock during crane lifting. The positioning system includes an electric field sensing device, which includes a proximity sensing module, a signal amplification module, a signal filtering module, and a parameter calibration module.

[0049] The proximity sensing module is used to acquire radio waves from the electric field source near the high-voltage line used for crane lifting to prevent electric shock.

[0050] The signal amplification module is used to amplify and enhance the detected electric field intensity signal from the electric field source.

[0051] The signal filtering module is used to remove, suppress, and compensate for fading received during signal propagation;

[0052] The parameter calibration module is used to convert electric field strength information into distance information through mathematical calculations.

[0053] Furthermore, the signal filtering module introduces the Okumura-Hata prediction model to predict the fading caused by radio waves propagating from the near electric field source to the monitoring station, and establishes a high-voltage line near electric field source location model.

[0054] Furthermore, the parameter calibration module solves the high-voltage line near-electric field source location model to obtain the location coordinates of the high-voltage line near-electric field source.

[0055] This invention employs a gridded multi-site monitoring method, deploying several monitoring station units according to a unified standard to divide the lifting and hoisting operation area into a grid. Based on the principle that there is a correlation between the electric field strength around high-voltage lines and distance, the electric field strength signal collected by the electric field induction device of the multi-site monitoring station unit represents the distance of that station from the high-voltage line. By differentially processing the electric field received signals collected from each pair of stations, the equivalent electric field source of the high-voltage line is calculated as its specific location. This location is then compared with the safe distance of the high-voltage line to provide a safety warning for preventing electric shock during crane hoisting operations, thus preventing accidents caused by the boom touching nearby high-voltage lines due to misoperation or blind spots during hoisting operations.

[0056] A gridded positioning system for high-voltage line proximity electric field sources to prevent electric shock during crane lifting includes an electric field sensing device, i.e., a monitoring station, consisting of a proximity sensing module, a signal amplification module, a signal filtering module, and a parameter calibration module. For example... Figure 2 As shown. The proximity sensing module acquires the electric field strength signal of the electric field source near the high-voltage line being lifted by the crane for electric shock prevention through a miniature electromagnetic induction element. The signal amplification module amplifies and enhances the detected electric field strength signal. The signal filtering module removes, suppresses, and compensates for noise and fading received during signal propagation. The parameter calibration module converts the electric field strength information into distance information through mathematical calculation.

[0057] This invention proposes a gridded location method for high-voltage power line near-electric field sources to prevent electric shock during crane lifting operations. It employs a gridded multi-site monitoring approach, utilizing differential electric field sensing to locate the equivalent electric field source of the high-voltage power line. Specifically, a differential field strength model is established for the received signal of the near-electric field source of the high-voltage power line to eliminate interference caused by external environment and propagation loss. A linear regression fitting loss prediction model (i.e., the Okumura-Hata prediction model) effectively improves the accuracy and stability of the gridded multi-site measurements. Furthermore, a gridded location solution method for the near-electric field source of the high-voltage power line based on differential field strength is proposed. The optimal solution of the equation system is used to extract the specific location coordinates of the electric field source of the high-voltage power line, effectively ensuring strong anti-interference, high accuracy, and stable location results for near-electric field sources of high-voltage power lines during crane lifting operations. By comparing the location results with a safety threshold, reliable safety warnings can be provided for preventing electric shock during crane lifting operations.

[0058] Compared with the prior art, the beneficial effects of this invention are as follows:

[0059] (1) The present invention adopts a gridded multi-site monitoring method. By using the gridded multi-site differential electric field sensing method, the equivalent electric field source of the high-voltage line is located, which can provide a reliable safety warning for crane hoisting operations to prevent electric shock.

[0060] (2) This invention establishes a differential field strength model for receiving signals from near-electric field sources of high-voltage lines to eliminate interference caused by external environment and propagation loss. By designing a linear regression fitting loss prediction model, the accuracy and stability of gridded multiple access site measurements are effectively improved.

[0061] (3) This invention proposes a gridded positioning solution method for high-voltage line electric field source near the differential field strength. The specific location coordinates of the high-voltage line electric field source are extracted by solving the optimal solution of the equation system. This effectively ensures strong anti-interference, high accuracy and stable positioning results for the electric field source near the high-voltage line during lifting and hoisting operations. The positioning accuracy is improved by more than 30% compared with the existing traditional methods, which can provide safety guarantee for electric shock prevention during lifting and hoisting operations. Attached Figure Description

[0062] Figure 1 This is a flowchart of the gridded positioning method for high-voltage line near electric field sources to prevent electric shock during crane lifting, as described in this invention.

[0063] Figure 2 This is a schematic diagram of the high-voltage line near-electric field source gridding positioning system for preventing electric shock during crane lifting, as per the present invention.

[0064] Figure 3 This is a schematic diagram of the principle of the gridded positioning system for high-voltage line near electric field source to prevent electric shock during crane lifting, as described in this invention. Detailed Implementation

[0065] The present invention will now be described in further detail with reference to the embodiments.

[0066] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the field or according to the product instructions. Materials or equipment whose manufacturers are not specified are all conventional products that can be obtained by purchase.

[0067] Example 1

[0068] like Figure 1 As shown, a gridded positioning method for high-voltage line near electric field sources to prevent electric shock during crane lifting is characterized by the following steps:

[0069] Step 1: Construct a radio wave propagation model for a near-electric field source of a high-voltage line;

[0070] Step 2: Treat the high-voltage line near the lifting operation as a near electric field source. By placing an electric field induction device on the crane, calculate the received signal strength (RSS) of the electric field induction device for the near electric field source radiated signal.

[0071] Step 3: Adopt a gridded multi-site monitoring approach to establish a differential field strength model for the received signals from the electric field source near the high-voltage line;

[0072] Step 4: By introducing the Okumura-Hata prediction model, the fading caused by radio waves propagating from the near electric field source to the monitoring station is predicted, and a near electric field source location model for high-voltage lines is established.

[0073] Step 5: Solve the high-voltage line near electric field source location model to obtain the location coordinates of the high-voltage line near electric field source.

[0074] like Figure 2As shown, the high-voltage line near electric field source grid positioning system for crane lifting anti-electric shock adopts the above-mentioned high-voltage line near electric field source grid positioning method for crane lifting anti-electric shock. The positioning system includes an electric field sensing device, which includes a proximity sensing module, a signal amplification module, a signal filtering module, and a parameter calibration module.

[0075] The proximity sensing module is used to acquire radio waves from the electric field source near the high-voltage line used for crane lifting to prevent electric shock.

[0076] The signal amplification module is used to amplify and enhance the detected electric field intensity signal from the electric field source.

[0077] The signal filtering module is used to remove, suppress, and compensate for fading received during signal propagation;

[0078] The parameter calibration module is used to convert electric field strength information into distance information through mathematical calculations.

[0079] Example 2

[0080] like Figure 1 As shown, a gridded positioning method for high-voltage line near electric field sources to prevent electric shock during crane lifting is characterized by the following steps:

[0081] Step 1: Construct a radio wave propagation model for a near-electric field source of a high-voltage line;

[0082] Step 2: Treat the high-voltage line near the lifting operation as a near electric field source. By placing an electric field induction device on the crane, calculate the received signal strength (RSS) of the electric field induction device for the near electric field source radiated signal.

[0083] Step 3: Adopt a gridded multi-site monitoring approach to establish a differential field strength model for the received signals from the electric field source near the high-voltage line;

[0084] Step 4: By introducing the Okumura-Hata prediction model, the fading caused by radio waves propagating from the near electric field source to the monitoring station is predicted, and a near electric field source location model for high-voltage lines is established.

[0085] Step 5: Solve the high-voltage line near electric field source location model to obtain the location coordinates of the high-voltage line near electric field source.

[0086] In step one, the radio wave propagation model of the high-voltage line near the electric field source is as follows:

[0087] L(r) = L0(r) + L1(r) + L2(r) + W(t)

[0088] Where r is the distance from the near-field source to the receiver; L0(r), L1(r), and L2(r) are path fading, shadow fading, and multipath fading, respectively; W(t) is the measurement background noise signal; and L(r) is the signal fading caused during radio wave propagation.

[0089] In step two, the formula for calculating the received signal strength of each electric field sensing device in response to the radiation signal from the near electric field source is as follows:

[0090] P r =P t -L(r)-W(t)

[0091] Among them, P r P represents the received signal strength of the electric field induction device. t This indicates the intensity of the signal emitted by the near-electric field source.

[0092] The specific method for step three is as follows:

[0093] To facilitate the location and calculation of electric field sources near high-voltage lines, a grid-based multi-site monitoring approach is adopted. Specifically, each monitoring station is an electric field sensing device. Multiple electric field sensing devices are placed on cranes to form multiple monitoring stations for monitoring near electric field sources.

[0094] The differential field strength model for the received signal from the near-electric field source of the high-voltage line is as follows:

[0095] P r,ij =P r,i -P r,j =L 0.ji (r)+L 1,ji (r)+W ji (r)

[0096] Among them, L 0.ji (r) represents two monitoring stations M i M j The difference in path fading measured; L 1,ji (r) represents two monitoring stations M i M j The difference in shadow fading measured; W ji (r) represents two monitoring stations M i M j The difference in background noise; P r,ij For two different monitoring stations M i M j The difference in received signal strength between them; P r,i For monitoring station M i The received signal field strength; P r,j For monitoring station M j The received signal field strength.

[0097] The specific method for step four is as follows:

[0098] The Okumura-Hata prediction model is as follows:

[0099] L(r)=a+b lg f-clg h t -α(h r )+(mn lg h t )lg r

[0100] Where L represents the signal fading caused during radio wave propagation; f is the operating frequency at which the monitoring station detects and acquires the received signal field strength; h t h is the height of the transmitting antenna. r α(h) represents the height of the receiving antenna; r represents the distance from the near-field source to the monitoring station; α(h) represents the height of the receiving antenna. r ) represents the correction factor; a, b, c, m, and n are the coefficient values ​​obtained from the linear regression fitting;

[0101] Let monitoring station M be set i The received signal field strength is P r,i Radio waves propagate from the near electric field source to the monitoring station M i The resulting fading is L(r) i If the electric field strength P near the electric field source is... t for:

[0102] P t =P r,i +L(r i (6)

[0103] Two different monitoring stations M i M j The difference in field strength received by a near-electric source can be expressed as:

[0104]

[0105] Let a certain monitoring station be taken as the origin of the coordinate system, M0(x0,y0,z0), and this monitoring station is defined as the reference station. Its received field strength is P0. Within this coordinate system, the receiving antenna height of all monitoring stations is the same, which is h. t Let the i-th monitoring station be M. i The coordinates are (x i y i , z i Its received field strength is P i ;

[0106] Therefore, the difference between the received field strength of the near-electric source at the i-th monitoring station and the reference station can be expressed as:

[0107]

[0108] Among them, P i h is the received field strength of the i-th monitoring station; t r is the height of the receiving antenna of the i-th monitoring station; i ri is the distance from the near electric field source to the i-th monitoring station; r0 is the distance from the near electric field source to the reference station;

[0109] This yields the following set of nonlinear equations, which serve as the C-type model for locating the near-electric field source of the high-voltage line. i (x,y,z):

[0110]

[0111] Where N represents the number of monitoring stations.

[0112] The specific method for step five is as follows:

[0113] A genetic algorithm was used to solve the coordinate model for locating the electric field source near the high-voltage line.

[0114] The fitness function for locating the near-electric field source coordinates using the genetic algorithm is:

[0115]

[0116] Among them, F it C represents the fitness value for locating the near-electric field source coordinates. i Model for locating electric field sources near high-voltage lines;

[0117] When solving the problem, the objective is to minimize the fitness value. The specific objective function is:

[0118] K(x,y,z)=argmin(F it )

[0119] Where K(x,y,z) represents the coordinates of the near-field source being solved;

[0120] This allows us to obtain the coordinates of the electric field source near the high-voltage line.

[0121] like Figure 2 As shown, the high-voltage line near electric field source grid positioning system for crane lifting anti-electric shock adopts the above-mentioned high-voltage line near electric field source grid positioning method for crane lifting anti-electric shock. The positioning system includes an electric field sensing device, which includes a proximity sensing module, a signal amplification module, a signal filtering module, and a parameter calibration module.

[0122] The proximity sensing module is used to acquire radio waves from the electric field source near the high-voltage line used for crane lifting to prevent electric shock.

[0123] The signal amplification module is used to amplify and enhance the detected electric field intensity signal from the electric field source.

[0124] The signal filtering module is used to remove, suppress, and compensate for fading received during signal propagation;

[0125] The parameter calibration module is used to convert electric field strength information into distance information through mathematical calculations.

[0126] Among them, the signal filtering module predicts the fading caused by radio waves propagating from the near electric field source to the monitoring station by introducing the Okumura-Hata prediction model, and establishes a high-voltage line near electric field source location model.

[0127] The parameter calibration module solves the high-voltage line near electric field source location model and obtains the location coordinates of the high-voltage line near electric field source.

[0128] Example 3

[0129] A gridded method for locating near-electric field sources of high-voltage lines to prevent electric shock during crane lifting is proposed. This method employs a gridded multi-site monitoring approach and uses differential electric field sensing to locate the equivalent electric field source of the high-voltage line. The specific steps are as follows: Figure 1 As shown below:

[0130] Step 1: Construct a radio wave propagation model for a near-electric field source of a high-voltage line;

[0131] Step 2: Treat the high-voltage line near the lifting operation as a near electric field source. By placing an electric field induction device on the crane, calculate the received signal strength (RSS) of the electric field induction device for the near electric field source radiated signal.

[0132] Step 3: Adopt a gridded multi-site monitoring approach to establish a differential field strength model for the received signals from the electric field source near the high-voltage line;

[0133] Step 4: By introducing the Okumura-Hata prediction model, the fading caused by radio waves propagating from the near electric field source to the monitoring station is predicted, and a near electric field source location model for high-voltage lines is established.

[0134] Step 5: Solve the high-voltage line near electric field source location model to obtain the location coordinates of the high-voltage line near electric field source.

[0135] Furthermore, the specific process of establishing the radio wave propagation model of the near-electric field source of the high-voltage line in step one is as follows:

[0136] High-voltage power lines can be considered equivalent to near-field sources (near-field sources are essentially the same as near-field sources; the key point here is that the electromagnetic radiation around a high-voltage power line primarily manifests as a high-voltage electric field, unlike the mixed electric and magnetic fields at the far end). The radiated electromagnetic waves propagate in free space, and the field strength decreases systematically with propagation distance. Therefore, the distance between the near-field source and the receiving device can be calculated using the Received Signal Strength Indicator (RSS) value of the radio signal. This allows for the use of ranging-based positioning algorithms to determine the location of the near-field source. However, in practical applications, radio propagation is closely related to the geographical environment and is highly susceptible to interference, leading to measurement errors in the RSS value and consequently, larger positioning errors.

[0137] Radio signal fading mainly includes path fading, shadow fading, and multipath fading. Therefore, the total fading caused by radio signal propagation can be expressed as:

[0138] L(r)=L0(r)+L1(r)+L2(r,t)+W(t) (1)

[0139] Where r is the distance from the near-field source to the receiver; L0(r), L1(r), and L2(r) are path fading, shadow fading, and multipath fading, respectively; W(t) is the measurement background noise signal; and L(r) is the signal fading caused during radio wave propagation.

[0140] Furthermore, the specific process of analyzing and calculating the received signal strength RSS for the near-electric field source radiated signal in step two is as follows:

[0141] Considering high-voltage power lines near lifting and hoisting operations as near-field electric fields, the electric field strength distribution around them is distance-dependent. Therefore, this characteristic of high-voltage power lines can be utilized to place an electric field induction device, the working principle of which is as follows: Figure 2 As shown: After amplification, filtering, and calibration, the surrounding electric field signal value can be obtained, from which the distance between the device and the high-voltage line can be derived. Converting the collected electric field intensity into distance requires algorithmic processing.

[0142] The received field strength measurement of the radiation signal from the electric field source near the high-voltage line by the electric field induction device is called the Received Signal Strength Indicator (RSS) of the electric field induction device, which is specifically expressed as:

[0143] P r =P t -L(r)-W(t) (2)

[0144] Among them, P r P represents the received signal strength of the electric field induction device. tL(r) represents the intensity of the signal emitted by the near-electric field source, and L(r) represents the signal fading caused by the absence of radio wave propagation.

[0145] Furthermore, the specific process of establishing the differential field strength model of the near-electric field source receiving signal in step three is as follows:

[0146] The design adopts a grid-based multi-site monitoring approach, such as... Figure 3 As shown, each monitoring station is an electric field sensing device. Two different monitoring stations M... i M j The difference in received signal strength between them can be expressed as:

[0147] P r,ij =P r,i -P r,j =L 0.ji (r)+L 1,ji (r)+L 2,ji (r)+W ji (r) (3)

[0148] Among them, L 0.ji (r) represents the difference in path fading measured by the two monitoring stations, which is only related to the difference between monitoring station M and M. i M j It depends on the distance between them; L 1,ji (r) represents the difference in shadow fading measured at the two monitoring stations, which follows a Gaussian distribution; L 2,ji (r) represents the difference in multipath fading measured by the two monitoring stations. Since the dynamic changes in their propagation environments are completely identical, the resulting difference in multipath fading is 0, i.e., L. 2,ji (r) = 0; W ji (r) represents the difference in background noise measured by the two monitoring stations. Therefore, the differential field strength of the signal received by the electric field source near the high-voltage line is:

[0149] P r,ij =P r,i -P r,j =L 0.ji (r)+L 1,ji (r)+W ji (r) (4)

[0150] Furthermore, the specific process of constructing the algorithm for locating electric field sources near high-voltage lines in step four is as follows:

[0151] Since the propagation model characterizes propagation loss, the Okumura-Hata prediction model is used, and linear regression is employed to fit the loss prediction model. The specific introduction of the Okumura-Hata prediction model is as follows:

[0152] L=a+blgf-clgh t -α(hr )+(m-nlgh t )lgr (5)

[0153] Where L represents the signal fading caused during radio wave propagation; f is the operating frequency at which the monitoring station detects and acquires the received signal field strength; h t h is the height of the transmitting antenna. r α(h) represents the height of the receiving antenna; r represents the distance from the near-field source to the monitoring station; α(h) represents the height of the receiving antenna. r ) is a correction factor that is only related to the height h of the transmitting antenna. t Related; a, b, c, m, n are the coefficient values ​​obtained by linear regression fitting. For all monitoring stations, a set of a, b, c, m, n is fitted.

[0154] For grid-based monitoring stations, let monitoring station M be... i The received signal field strength is P r,i The fading caused by radio waves propagating from the near electric field source S to the monitoring station is L(r). i If the electric field strength near the electric field source is:

[0155] P t =P r,i +L(r i (6)

[0156] Therefore, the difference in the received field strength of the near-electric field source between two different monitoring stations can be expressed as:

[0157]

[0158] This is the differential field strength measured by the two monitoring stations for the received field strength of the radiation signal from the electric field source near the high-voltage line. Taking a certain monitoring station as the origin M0(x0,y0,z0), where x0, y0, and z0 are the three-dimensional coordinates of this origin, this monitoring station is defined as the reference station, and its received field strength is P0. The coordinates of the other monitoring stations within this coordinate system are M... i (x i ,y i ,z i Given that the receiving antennas are at the same height and the coordinates of the near electric field source are K(x,y,z), the difference between the received field strength of the near electric field source at a certain monitoring station and the reference station can be expressed as:

[0159]

[0160] Among them, P i h is the received field strength of the i-th monitoring station; t r is the height of the receiving antenna of the i-th monitoring station; i ri is the distance from the near electric field source to the i-th monitoring station; r0 is the distance from the near electric field source to the reference station;

[0161] Furthermore, the following system of nonlinear equations can be obtained:

[0162]

[0163] Where N represents the number of monitoring stations.

[0164] Furthermore, the specific process of solving for the coordinates of the near-electric field source of the high-voltage line in step five is as follows:

[0165] The coordinates of the near-electric source can be obtained by solving the above system of equations. Solving this type of system of equations is transformed into finding the optimal solution. Here, a genetic algorithm is used to find the global optimum by mimicking the mechanisms of selection and inheritance in nature, which has high accuracy and stability. To use the genetic algorithm to solve the problem, the fitness function is constructed as follows:

[0166]

[0167] Among them, F it C represents the fitness value for locating the near-electric field source coordinates. i Model for locating electric field sources near high-voltage lines;

[0168] The C value of each station was obtained by repeatedly measuring the received signal through a grid-based monitoring system. i (i = 1, 2, ..., N). The optimal solution obtained using a genetic algorithm is: K(x, y, z) = argmin(F... it (10)

[0169] Where K(x,y,z) are the coordinates of the near-field source to be solved; the argmin operation is to improve the fitness F of the near-field source location coordinates. it The coordinate values ​​of the near-electric field source that yield the minimum value.

[0170] This is the result of the location calculation of the electric field source position near the high-voltage line.

[0171] Application Examples

[0172] A gridded location method for high-voltage power line near electric field sources to prevent electric shock during crane lifting includes the following steps: An example is shown below:

[0173] Step 1: Construct a radio wave propagation model for a near-electric field source of a high-voltage line;

[0174] L(r)=L0(r)+L1(r)+L2(r,t)+W(t)

[0175] Where r is the distance from the near-field source to the receiver; L0(r), L1(r), and L2(r) are path fading, shadow fading, and multipath fading, respectively; W(t) is the measurement background noise signal; and L(r) is the signal fading during radio wave propagation.

[0176] Therefore, we have: L 0,i (r) = 0.2e 0.06r L 1,i (r) = 0.01r 2 L 2,i (r,t)=0.17tlgr represent the path fading, shadow fading, and multipath fading during the propagation of radio waves from the near-electric field source of the high-voltage line to monitoring station i, respectively.

[0177] L 0,j (r) = 0.3e 0.12r L 1,j (r) = 0.11r 2 L 2,j (r,t)=0.17tlgr represent the path fading, shadow fading, and multipath fading during the propagation of radio waves from the near-electric field source of the high-voltage line to the monitoring station j, respectively.

[0178] Step 2: Treat the high-voltage line near the lifting operation as a near electric field source. By placing an electric field induction device on the crane, calculate the received signal strength (RSS) of the electric field induction device for the near electric field source radiated signal.

[0179] The specific process is as follows:

[0180] P r =P t -L(r)-W(t)

[0181] Among them, P r P represents the received signal strength of the electric field induction device. t Let P represent the intensity of the emitted signal from the near-electric field source, and L(r) represent the signal fading caused by the propagation of the radio wave. t =0.89e 0.95t .

[0182] Step 3: Adopt a gridded multi-site monitoring approach to establish a differential field strength model for the received signals from the electric field source near the high-voltage line;

[0183] In a grid-based monitoring station system, the difference in signal field strength between two different monitoring stations, that is, the differential field strength of the signal received by the electric field source near the high-voltage line, can be expressed as:

[0184] P r,ij =P r,i -P r,j =L 0.ji (r)+L 1,ji (r)+W ji (r) = 0.3e 0.12r -0.2e 0.06r +0.1r 2

[0185] Among them, L 0.ji (r) represents two monitoring stations M i M j The difference in path fading measured; L 1,ji (r) represents two monitoring stations M i M j The difference in shadow fading measured; W ji (r) represents two monitoring stations M i M j The difference in background noise between two different monitoring stations M i M j The difference in received signal strength between them is P r,ij ;P r,i For monitoring station M i The received signal field strength; P r,j For monitoring station M j The received signal field strength.

[0186] Step 4: By introducing the Okumura-Hata prediction model, the fading caused by radio waves propagating from the near electric field source to the monitoring station is predicted, and a near electric field source location model for high-voltage lines is established.

[0187] L=a+b lg fc lg h t -α(h r )+(mn lg h t )lgr

[0188] =0.8+0.67lg 50-0.4lg 6-0.33+(0.21-0.1lg 6)lg 5

[0189] Where L represents the signal fading caused during radio wave propagation; f = 50 Hz is the operating frequency at which the monitoring station detects and acquires the received signal strength; h t =6m is the equivalent transmitting antenna height near the electric field source; h r =6m is the height of the receiving antenna; r=5m is the distance from the near electric field source to the monitoring station; α(h r The correction factor is 0.33, which is only related to the height h of the transmitting antenna. t Related. The coefficients obtained from the linear regression fitting are as follows:

[0190] a=0.8, b=0.67, c=0.4, m=0.21, n=0.1.

[0191] The electric field strength near the source is:

[0192] P t =P r,i +L(r i )

[0193] Taking the deployment of three monitoring stations as an example, the signal field strength P received by monitoring station M1 is... r,1 =600V / m and the fading L(r1) =49 caused during propagation can be obtained by comparing the differences between the transmitted and received signals and statistically analyzing multiple sets of data; similarly, the signal field strength P received by monitoring station M2 r,2 =485V / m and the fading caused during propagation L(r2) = 38; the signal field strength P received by monitoring station M3 r,3 =560V / m and the fading caused during propagation L(r3) = 45. And it has an initial value P0 = 150.

[0194] Therefore, the difference between the received field strength of a near-electric source at a certain monitoring station and the reference station can be expressed as:

[0195]

[0196] Among them, P i h is the received field strength of the i-th monitoring station; t =6 represents the height of the receiving antenna at the i-th monitoring station; r i The distance from the near-field source to the i-th monitoring station

[0197] The difference in the received field strength of the near-electric field source from two different monitoring stations can be expressed as:

[0198] The following system of nonlinear equations (N=3) is obtained:

[0199]

[0200] Among them, P i Pi is the received field strength of the i-th monitoring station; P0 is the received field strength of the reference station.

[0201] Step 5: Solve the high-voltage line near electric field source location model to obtain the location coordinates of the high-voltage line near electric field source.

[0202] According to step five, the fitness function constructed using the genetic algorithm is:

[0203] Among them, F it For near-electric field source location coordinate fitness; C i For step four, monitoring station M i Measurement fits the high-voltage line near-electric field source location model; N=3 is the number of monitoring stations.

[0204] By repeatedly measuring the received signals through gridded monitoring stations, the numerical values ​​of the near-electric field source location models obtained from the measurements fitted by each monitoring station were: C1 = (2.1, 1.8, 3.0); C2 = (1.9, 2.0, 3.1); C3 = (2.2, 2.0, 2.7). The coordinates of the near-electric field source location of the high-voltage line were obtained by solving for the global optimal solution using a genetic algorithm, as follows:

[0205] K(x,y,z)=argmin(F it = (2.1, 1.9, 2.9)

[0206] Here, K(x,y,z) represents the coordinates of the near-field source being solved; F it The fitness of the near-field source location coordinates is defined as the fitness of the near-field source location coordinates; the argmin operation is to make the fitness of the near-field source location coordinates F... it The coordinates of the near-electric field source that yield the minimum value are obtained by numerical solution, i.e., (2.1, 1.9, 2.9).

[0207] Traditional methods based on direct conversion using electric field gradient theory fail to effectively eliminate interference caused by external environment and propagation loss, resulting in weak resistance to environmental interference and low positioning accuracy for electric field sources near high-voltage lines. Under the same conditions, the numerical solution for the near-electric field source coordinates obtained using traditional methods is (4.2, 3.8, 5.2), which differs significantly from the actual coordinates of the near-electric field source near the high-voltage line (2.5, 2.4, 2.8). This indicates that the method proposed in this invention achieves better results in locating near-electric field sources near high-voltage lines.

[0208] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A gridded positioning method for high-voltage lines near electric field sources to prevent electric shock during crane lifting, characterized in that, Includes the following steps: Step 1: Construct a radio wave propagation model for a near-electric field source of a high-voltage line; Step 2: Treat the high-voltage lines near the lifting and hoisting operation as a near-field source, and calculate the received signal strength of the electric field induction device for the near-field source radiated by the electric field induction device by placing an electric field induction device on the crane. Step 3: Adopt a gridded multi-site monitoring approach to establish a differential field strength model for the received signals from the electric field source near the high-voltage line; Step 4: By introducing the Okumura-Hata prediction model, the fading caused by radio waves propagating from the near electric field source to the monitoring station is predicted, and a near electric field source location model for high-voltage lines is established. Step 5: Solve the high-voltage line near electric field source location model to obtain the location coordinates of the high-voltage line near electric field source.

2. The gridded positioning method for high-voltage line near-electric field sources to prevent electric shock during crane lifting, as described in claim 1, is characterized in that... In step one, the radio wave propagation model of the high-voltage line near the electric field source is as follows: L(r) = L0(r) + L1(r) + L2(r) + W(t) Where r is the distance from the near-field source to the receiver; L0(r), L1(r), and L2(r) are path fading, shadow fading, and multipath fading, respectively; W(t) is the measurement background noise signal; and L(r) is the signal fading caused during radio wave propagation.

3. The gridded positioning method for high-voltage line near-electric field sources to prevent electric shock during crane hoisting, as described in claim 2, is characterized in that... In step two, the formula for calculating the received signal strength of each electric field sensing device in response to the radiation signal from the near electric field source is as follows: P r =P t -L(r)-W(t) Among them, P r P represents the received signal strength of the electric field induction device. t This indicates the intensity of the signal emitted by the near-electric field source.

4. The gridded positioning method for high-voltage line near-electric field sources to prevent electric shock during crane lifting, as described in claim 1, is characterized in that... The specific method for step three is as follows: A grid-based multi-site monitoring approach is adopted, specifically: each monitoring station is an electric field sensing device; multiple electric field sensing devices are placed on a crane to form multiple monitoring stations to monitor near electric field sources; The differential field strength model for the received signal from the near-electric field source of the high-voltage line is as follows: P r,ij =P r,i -P r,j =L 0.ji (r)+L 1,ji (r)+W ji (r) Among them, L 0.ji (r) represents two monitoring stations M i M j The difference in path fading measured; L 1,ji (r) represents two monitoring stations M i M j The difference in shadow fading measured; W ji (r) represents two monitoring stations M i M j The difference in background noise; P r,ij For two different monitoring stations M i M j The difference in received signal strength between them; P r,i For monitoring station M i The received signal field strength; P r,j For monitoring station M j The received signal field strength.

5. The gridded positioning method for high-voltage line near-electric field sources to prevent electric shock during crane lifting, as described in claim 1, is characterized in that... The specific method for step four is as follows: The Okumura-Hata prediction model is as follows: L(r)=a+b lg fc lg h t -α(h r )+(mn lg h t )lg r Where L represents the signal fading caused during radio wave propagation; f is the operating frequency at which the monitoring station detects and acquires the received signal field strength; h t h is the height of the transmitting antenna. r α(h) represents the height of the receiving antenna; r represents the distance from the near-field source to the monitoring station; α(h) represents the height of the receiving antenna. r ) represents the correction factor; a, b, c, m, and n are the coefficient values ​​obtained from the linear regression fitting; Let monitoring station M be set i The received signal field strength is P r,i Radio waves propagate from the near electric field source to the monitoring station M i The resulting fading is L(r) i If the electric field strength P near the electric field source is... t for: P t =P r,i +L(r i ) (6) Two different monitoring stations M i M j The difference in field strength received by a near-electric source can be expressed as: Let a certain monitoring station be taken as the origin of the coordinate system, M0(x0,y0,z0), and this monitoring station is defined as the reference station. Its received field strength is P0. Within this coordinate system, the receiving antenna height of all monitoring stations is the same, which is h. t Let the i-th monitoring station be M. i The coordinates are (x i y i , z i Its received field strength is P i ; Therefore, the difference between the received field strength of the near-electric source at the i-th monitoring station and the reference station can be expressed as: Among them, P i h is the received field strength of the i-th monitoring station; t r is the height of the receiving antenna of the i-th monitoring station; i ri is the distance from the near electric field source to the i-th monitoring station; r0 is the distance from the near electric field source to the reference station; This yields the following set of nonlinear equations, which serve as the C-type model for locating the near-electric field source of the high-voltage line. i (x,y,z): Where N represents the number of monitoring stations.

6. The gridded positioning method for high-voltage line near-electric field sources to prevent electric shock during crane lifting, as described in claim 5, is characterized in that... The specific method for step five is as follows: A genetic algorithm was used to solve the coordinate model for locating the electric field source near the high-voltage line. The fitness function for locating the near-electric field source coordinates using the genetic algorithm is: Among them, F it C represents the fitness value for locating the near-electric field source coordinates. i Model for locating electric field sources near high-voltage lines; When solving the problem, the objective is to minimize the fitness value. The specific objective function is: K(x,y,z)=argmin(F it ) Where K(x,y,z) represents the coordinates of the near-field source being solved; This allows us to obtain the coordinates of the electric field source near the high-voltage line.

7. A gridded positioning system for high-voltage lines near electric field sources to prevent electric shock during crane lifting, characterized in that: The high-voltage line near electric field source gridding positioning method for preventing electric shock during crane hoisting, as described in any one of claims 1 to 6, includes an electric field sensing device, which comprises a near-electric field sensing module, a signal amplification module, a signal filtering module, and a parameter calibration module. The proximity sensing module is used to acquire radio waves from the electric field source near the high-voltage line used for crane lifting to prevent electric shock. The signal amplification module is used to amplify and enhance the detected electric field intensity signal from the electric field source. The signal filtering module is used to remove, suppress, and compensate for fading received during signal propagation; The parameter calibration module is used to convert electric field strength information into distance information through mathematical calculations.

8. The high-voltage line near-electric field source gridding positioning system for preventing electric shock during crane hoisting as described in claim 7, characterized in that: The signal filtering module predicts the fading caused by radio waves propagating from a near electric field source to the monitoring station by introducing the Okumura-Hata prediction model, and establishes a near electric field source location model for high-voltage lines.

9. The high-voltage line near-electric field source gridding positioning system for preventing electric shock during crane hoisting as described in claim 7, characterized in that: The parameter calibration module solves the high-voltage line near electric field source location model and obtains the location coordinates of the high-voltage line near electric field source.

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