Accurate fault point positioning method and system for electric tracing band based on pulse reflection method

Abstract

The present application relates to the technical field of line fault location, and particularly relates to an electric heat tracing band fault point accurate positioning method and system based on a pulse reflection method.The present application obtains a state difference degree according to the difference between the high temperature performance of each suspected temperature rising point and the temperature value of each actual temperature rising point, and the distance of the corresponding positions of the two temperature rising points on the electric heat tracing band, and selects a matching temperature rising point from the actual temperature rising points;obtains a temperature rising delay reasonable degree according to the consistency between the difference between the distance of each suspected temperature rising point and the expected distance of the matching temperature rising point and the numerical difference between the two suspected temperature rising points;and determines a rough fault point according to the state difference degree and the temperature rising delay reasonable degree, and performs accurate positioning.The present application accurately screens out the rough fault point caused by the shielding layer fault by comprehensively considering the high temperature, delay consistency, space, and temperature state coincidence degree of the high temperature change point, and reduces the probability of misjudging the normal temperature change point as a fault.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of line fault location, in particular to a method and system for accurately locating fault points of an electric heat tracing band based on a pulse reflection method. BACKGROUND

[0002] An electric heat tracing band is a device that converts electrical energy into heat energy to provide heating and insulation for pipelines and equipment, and its core structure includes a heating body, an insulation layer, a shielding layer, and an outer sheath. The braided shielding layer of the electric heat tracing band not only provides electromagnetic shielding and anti-interference capability, but also bears the safety functions of grounding protection and leakage circuit conduction. The breakage of the shielding layer will cause the grounding protection of the heat tracing band to fail, increase the risk of electric shock and leakage, and weaken the electromagnetic shielding effectiveness, which may cause signal interference or misoperation. Therefore, detecting the integrity of the shielding layer is a necessary link to ensure the safe operation of the electric heat tracing system and to achieve accurate fault location.

[0003] Currently, the pulse reflection method is the mainstream technology for locating shielding layer breakage faults. This method injects a pulse signal into the electric heat tracing band. When the signal encounters an impedance mutation point caused by the breakage of the shielding layer during transmission along the line, a reflected echo will be generated. By measuring the time difference between the pulse emission and the echo return, and combining the signal propagation speed, the distance of the fault point can be calculated. However, the temperature distribution along the line is uneven during the operation of the electric heat tracing band. Temperature changes can significantly affect the electrical parameters of the insulation material, such as the dielectric constant and the resistance of the conductor, causing the characteristic impedance of the line to change with temperature. The impedance change caused by temperature also produces a reflected pulse, which is mixed with the fault reflected pulse at the shielding layer breakage point, seriously interfering with the identification of the true fault point, thereby causing inaccurate fault location of the electric heat tracing band and reducing reliability. SUMMARY

[0004] To solve the technical problem that the pulse reflection method cannot distinguish between the reflected impedance change caused by temperature fluctuations and the fault reflection caused by shielding layer breakage, resulting in inaccurate fault location of the electric heat tracing band, the purpose of the present application is to provide a method and system for accurately locating fault points of an electric heat tracing band based on a pulse reflection method. The technical solution adopted is as follows:

[0005] In the first aspect, an embodiment of the present application provides a method for accurately locating fault points of an electric heat tracing band based on a pulse reflection method, which comprises:

[0006] Transmitting a pulse to the electric heat tracing band, obtaining a pulse reflection sequence and temperature values distributed along the length of the electric heat tracing band to form a temperature distribution sequence; selecting a suspected temperature rise point in the pulse reflection sequence and an actual temperature rise point in the temperature distribution sequence;

[0007] According to the numerical difference between each suspected temperature rising point and its previous adjacent element, and the numerical difference between the previous and the next adjacent elements of each suspected temperature rising point, the high temperature performance degree of each suspected temperature rising point is obtained;

[0008] According to the difference between the high temperature performance degree of each suspected temperature rising point and the temperature value of each actual temperature rising point, and the distance between the corresponding positions of the two temperature rising points on the electric heat tracing band, the state difference degree of each suspected temperature rising point and each actual temperature rising point is obtained, and the matching temperature rising point of each suspected temperature rising point is selected from the actual temperature rising points;

[0009] According to the consistency between the difference between the distance of each suspected temperature rising point and the expected distance of its matching temperature rising point and the numerical difference between the corresponding two suspected temperature rising points, the temperature rising delay rationality of each suspected temperature rising point is obtained; according to the state difference degree and the temperature rising delay rationality, the rough fault point in the suspected temperature rising points is selected;

[0010] According to the temperature value corresponding relationship of the matching temperature rising point of the rough fault point, the rough fault point is accurately positioned.

[0011] Further, the high temperature performance degree of each suspected temperature rising point is obtained, including:

[0012] The slope of each element in the pulse reflection sequence and the minimum value element is obtained;

[0013] For each suspected temperature rising point, the element between the suspected temperature rising point and its adjacent previous minimum value element is recorded as an analysis element; the numerical difference between the suspected temperature rising point and each analysis element is adjusted by using the slope of each analysis element of the suspected temperature rising point to obtain the effective temperature rising of the corresponding analysis element; the mean value of the effective temperature rising of all analysis elements of the suspected temperature rising point is normalized to obtain the reflection amplitude rising degree;

[0014] The numerical mean value of the elements between the suspected temperature rising point and its adjacent previous minimum value element and next minimum value element is calculated, and is recorded as left temperature reference value and right temperature reference value in turn; it is judged whether the left temperature reference value is less than or equal to the right temperature reference value, if yes, the reflection attenuation degree of the suspected temperature rising point is set to zero, if not, the difference between the left temperature reference value and the right temperature reference value of the suspected temperature rising point is taken as the reflection attenuation degree;

[0015] According to the reflection amplitude rising degree and the reflection attenuation degree, the high temperature performance degree of the suspected temperature rising point is obtained.

[0016] Further, the state difference degree of each suspected temperature rising point and each actual temperature rising point is obtained, including:

[0017] The suspected temperature rising point and the actual temperature rising point are denoted as an analysis temperature rising point, and a distance between a corresponding position of the analysis temperature rising point on the electric heat tracing belt and a position of the pulse is obtained and denoted as an analysis distance;

[0018] The numerical value of each element in the temperature distribution sequence is normalized, and the processing result is taken as an actual high temperature;

[0019] The absolute value of the difference between the high temperature performance of each suspected temperature rising point and the actual high temperature of each actual temperature rising point and the absolute value of the difference between each suspected temperature rising point and each actual temperature rising point are calculated, and the product of the two absolute values is normalized to obtain the state difference degree of each suspected temperature rising point and each actual temperature rising point.

[0020] Further, the temperature rising delay rationality of each suspected temperature rising point is obtained, comprising:

[0021] An optional suspected temperature rising point is denoted as a target point, and an optional suspected temperature rising point is denoted as an example point from the remaining suspected temperature rising points; the distance between the matching temperature rising point of the target point and its adjacent previous actual temperature rising point is taken as the numerator, the distance between the matching temperature rising point of the example point and its adjacent previous actual temperature rising point is taken as the denominator to obtain a ratio, and the product of the ratio and the distance between the example point and the adjacent previous suspected temperature rising point is taken as an expected delay distance.

[0022] It is judged whether the distance between the target point and its adjacent previous suspected temperature rising point is greater than the expected delay distance, if yes, the delay comparison index between the target point and the example point is a first preset value, if not, the delay comparison index between the target point and the example point is a second preset value;

[0023] It is judged whether the temperature value of the matching temperature rising point of the target point is greater than the temperature value of the matching temperature rising point of the example point, if yes, the temperature comparison index between the target point and the example point is a first preset value, if not, the temperature comparison index between the target point and the example point is a second preset value;

[0024] The absolute value of the difference between the delay comparison index and the temperature comparison index between the target point and the example point is calculated, and the difference between the constant 1 and the absolute value is taken as the temperature rising delay consistency between the target point and the example point; the temperature rising delay consistencies between the target point and all the remaining suspected temperature rising points are averaged to obtain the temperature rising delay rationality of the target point.

[0025] Further, the suspected temperature rising point is selected, comprising:

[0026] The temperature rising delay rationality of each suspected temperature rising point is negatively correlated, and the product of the mapping result and the state difference degree is normalized to obtain the fault degree of each suspected temperature rising point.

[0027] The suspected temperature rising point with the fault degree greater than the preset fault threshold is recorded as a rough fault point.

[0028] Further, the accurate positioning of the rough fault point comprises:

[0029] The temperature values of all actual temperature rising points between each suspected temperature rising point and the matched temperature rising point of the adjacent previous suspected temperature rising point are averaged as the ambient temperature of each suspected temperature rising point.

[0030] The absolute values of the differences between each rough fault point and the ambient temperatures of the remaining suspected temperature rising points except all rough fault points are calculated, and the suspected temperature rising point corresponding to the minimum absolute value of the difference is recorded as the reference position point of the rough fault point.

[0031] The calculation formula of the distance from the final position of each rough fault point to the emission position of the pulse is as follows:

[0032] In the formula, U is the distance from the final position of each rough fault point to the emission position of the pulse. is the distance between the matched temperature rising point of the adjacent previous suspected temperature rising point of each rough fault point and the emission position of the pulse; and W is the distance between each rough fault point and the adjacent previous suspected temperature rising point. is the distance between the reference position point of each rough fault point and the adjacent previous suspected temperature rising point. is the distance between the matched temperature rising point of the reference position point of each rough fault point and the matched temperature rising point of the adjacent previous suspected temperature rising point of the reference position point.

[0033] Further, the selection of the matched temperature rising point of each suspected temperature rising point from the actual temperature rising points comprises:

[0034] Based on the state difference degree, the DTW algorithm is used to match the suspected temperature rising points in the pulse reflection sequence with the actual temperature rising points in the temperature distribution sequence, and the actual temperature rising point matched with each suspected temperature rising point is recorded as the matched temperature rising point thereof.

[0035] Further, the acquisition method of the effective rising temperature comprises:

[0036] The absolute values of the slopes of each analysis element of the suspected temperature rising point are negatively correlated and normalized, the numerical difference values of the suspected temperature rising point and each analysis element thereof are weighted processed by using the processing result, and the effective rising temperature of each analysis element of the suspected temperature rising point is obtained.

[0037] Further, the selection of the suspected temperature rising point in the pulse reflection sequence and the actual temperature rising point in the temperature distribution sequence comprises:

[0038] The pulse reflection sequence and the temperature distribution sequence are recorded as an analysis sequence, curve fitting is performed on the elements in the analysis sequence, and the element at the position of the maximum point on the obtained fitting curve is recorded as a maximum element;

[0039] The maximum elements in the pulse reflection sequence and the temperature distribution sequence are recorded as suspected temperature rising points and actual temperature rising points, respectively.

[0040] In a second aspect, another embodiment of the present application provides a pulse reflection method-based electric heat tracing band fault point accurate positioning system, which comprises:

[0041] A data acquisition module is configured to emit pulses to the electric heat tracing band, acquire a pulse reflection sequence and temperature values distributed along the length of the electric heat tracing band to form a temperature distribution sequence, and select suspected temperature rising points in the pulse reflection sequence and actual temperature rising points in the temperature distribution sequence.

[0042] A high temperature performance analysis module is configured to acquire a high temperature performance degree of each suspected temperature rising point according to the numerical difference between each suspected temperature rising point and its previous adjacent element and the numerical difference between each suspected temperature rising point and its adjacent element.

[0043] A temperature rising point matching module is configured to acquire a state difference degree of each suspected temperature rising point and each actual temperature rising point according to the difference between the high temperature performance degree of each suspected temperature rising point and the temperature value of each actual temperature rising point and the distance between the corresponding positions of the two temperature rising points on the electric heat tracing band, and select a matching temperature rising point for each suspected temperature rising point from the actual temperature rising points.

[0044] A fault point preliminary determination module is configured to acquire a temperature rising delay rationality degree of each suspected temperature rising point according to the consistency between the difference between the distance of each suspected temperature rising point from the remaining suspected temperature rising points and the expected distance of the matching temperature rising point and the numerical difference between the corresponding two suspected temperature rising points, and select a rough fault point from the suspected temperature rising points according to the state difference degree and the temperature rising delay rationality degree.

[0045] A fault point accurate positioning module is configured to accurately position the rough fault point according to the temperature value corresponding relationship of the matching temperature rising point of the rough fault point.

[0046] In the embodiment of the present application, in order to distinguish the shielding layer fault point on the electric heat tracing band from the reflection pulse caused by temperature change, the present scheme obtains high temperature performance degree by comprehensively considering the high amplitude characteristics and high temperature attenuation characteristics of the pulse reflection caused by temperature change, and then obtains state difference degree by analyzing the difference degree of the suspected temperature rising point and the actual temperature rising point in temperature and spatial characteristics, so as to determine the matching temperature rising point of each suspected temperature rising point; considering that the propagation speed of the pulse through the high temperature area decreases, the reflection will produce time delay, and the temperature rising delay reasonable degree checks whether the spatial position offset of the suspected temperature rising point conforms to the delay phenomenon expected by the temperature of the matching temperature rising point, and by comprehensively considering the state difference degree and the temperature rising delay reasonable degree, the rough fault point caused by the shielding layer disconnection can be accurately screened out, and the probability of misjudging the normal temperature change point as a fault is significantly reduced; by the temperature value corresponding relationship of the matching temperature rising point, the equivalent propagation speed of the local area where the fault point is located is indirectly determined, the rough fault point is accurately mapped to the real physical space of the electric heat tracing band, the positioning error caused by the propagation speed fluctuation due to temperature change is effectively corrected, and finally the accurate defect position is output, so that the positioning accuracy is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, and the advantages thereof, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0048] Figure 1 A step flow chart of an electric heat tracing band fault point accurate positioning method based on pulse reflection method provided by an embodiment of the present application;

[0049] Figure 2 A high temperature performance degree obtaining method flow chart provided by an embodiment of the present application;

[0050] Figure 3 A system structure diagram of an electric heat tracing band fault point accurate positioning system based on pulse reflection method provided by an embodiment of the present application;

[0051] Figure 4 A computer device schematic diagram of an electric heat tracing band fault point accurate positioning device based on pulse reflection method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined inventive purpose, the specific implementation, structure, features and effects of the method and system for accurately locating fault points of an electric heat tracing band based on the pulse reflection method according to the present application are described in detail as follows in combination with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0054] The specific scheme of the method and system for accurately locating fault points of an electric heat tracing band based on the pulse reflection method according to the present application is described in detail below in combination with the drawings.

[0055] Embodiment 1:

[0056] The present application proposes a method for accurately locating fault points of an electric heat tracing band based on the pulse reflection method, please refer to Figure 1 which shows a step flowchart of the method for accurately locating fault points of an electric heat tracing band based on the pulse reflection method according to one embodiment of the present application. The method comprises:

[0057] Step S1: transmitting a pulse to the electric heat tracing band, acquiring a pulse reflection sequence and temperature values distributed along the length of the electric heat tracing band to form a temperature distribution sequence; selecting a suspected temperature rise point in the pulse reflection sequence and an actual temperature rise point in the temperature distribution sequence.

[0058] The optical fiber temperature sensor integrated in the electric heat tracing band is connected to the host of the distributed optical fiber temperature sensing system (DTS), the host of the DTS transmits a laser pulse to the optical fiber temperature sensor, collects the backscattered light signal, and the system calculates the temperature value of each sampling point along the entire optical fiber. The position of each optical fiber temperature sensor is a sampling point. Starting from the power supply end, i.e. the transmission position of the pulse, the temperature values of all sampling points in the length direction of the electric heat tracing band are sequentially arranged to obtain a temperature distribution sequence. The value of the i-th element in the temperature distribution sequence represents the temperature at the i-th sampling interval meter from the power supply end. The output end of the pulse reflectometer is connected to the power supply end of the electric heat tracing band through a special fixture, the pulse reflectometer transmits a pulse to the electric heat tracing band, and simultaneously continuously collects the signals reflected from the electric heat tracing band along the line to form a pulse generation sequence. The value of each element in the sequence represents the signal intensity transmitted back at the corresponding reflection time.

[0059] ​In one implementation form of the embodiment of the application, the spatial sampling interval L is set to 0.1 meters, i.e., the distance between two adjacent sampling points is set to 0.1 meters; and the sampling frequency of the reflected signal is set to 500 megahertz.

[0060] When the local temperature of a certain position on the self-limiting temperature electric tracing band rises close to the transition zone of the positive temperature coefficient thermistor, the resistivity of the conductive polymer core body sharply rises, so that the equivalent impedance at the position is obviously greater than that of the surrounding area, resulting in a stronger positive reflection peak of the pulse at the position, and the higher the temperature, the greater the impedance difference, and the stronger the reflection amplitude. In addition, when the shielding layer of the electric tracing band is disconnected, the outer conductor shielding loop is damaged, the signal transmission path is discontinuous, and the electromagnetic field distribution suddenly changes, which also produces a reflection wave with a large amplitude at the disconnection position of the shielding layer. Therefore, the suspected temperature rising points in the pulse reflection sequence are strong reflections caused by the disconnection of the shielding layer and the temperature change. The temperature distribution sequence can accurately detect the temperature of each position on the electric tracing band, and an actual temperature increase also forms a maximum value, and the actual temperature rising point is caused by the temperature change. It should be noted that the number of suspected temperature rising points is greater than the number of actual temperature rising points.

[0061] Step S2: obtaining a high-temperature performance degree of each suspected temperature rising point according to the numerical difference between each suspected temperature rising point and its previous adjacent element, and the numerical difference between the previous and subsequent adjacent elements of each suspected temperature rising point.

[0062] The pulse reflection caused by the temperature change has a high amplitude characteristic, and the high-temperature performance of the suspected temperature rising point is presented through the change of the reflection amplitude of the suspected temperature rising point and the upstream position; under high temperature, signal attenuation is intensified, and thermal influence can cause the reflection amplitude reference downstream of the suspected temperature rising point to appear a more significant decrease compared with the upstream, and the numerical difference between the previous and subsequent adjacent elements of the suspected temperature rising point presents an attenuation characteristic. By comprehensively analyzing the high-temperature performance degree of the suspected temperature rising point and the temperature value of each actual temperature rising point, and the distance of the corresponding two temperature rising points on the corresponding position of the electric tracing band, the state difference degree of each suspected temperature rising point and each actual temperature rising point is obtained, and the matching temperature rising point of each suspected temperature rising point is selected from the actual temperature rising points.

[0063] Step S3: obtaining a state difference degree of each suspected temperature rising point and each actual temperature rising point according to the difference between the high-temperature performance degree of each suspected temperature rising point and the temperature value of each actual temperature rising point, and the distance of the corresponding two temperature rising points on the corresponding position of the electric tracing band, and selecting a matching temperature rising point of each suspected temperature rising point from the actual temperature rising points.

[0064] The accurate positioning of the disconnection defect of the shielding layer is limited by the propagation speed characteristic of the electromagnetic wave in the medium, which depends on the dielectric constant and magnetic permeability of the medium, and the dielectric constant of the insulating material of the electric tracing band has a temperature correlation. When the electric tracing band is working, the temperature field along the line is non-uniformly distributed, resulting in a difference in the actual propagation speed of the pulse signal in different sections. Therefore, the accurate fault position cannot be directly calculated only according to the corresponding reflection time of the suspected temperature rising point in the pulse reflection sequence.

[0065] To solve this problem, the actual temperature distribution obtained by the distributed optical fiber temperature measurement system is introduced, and the actual temperature rise point can accurately present its accurate position on the electric heat tracing band. By analyzing the difference degree of the suspected temperature rise point and the actual temperature rise point in temperature and spatial characteristics, the state difference degree is obtained, and the matching relationship between the two is established, so as to determine the matching temperature rise point of each suspected temperature rise point. Finally, based on the matching relationship, the accurate inference of the fault point position is realized.

[0066] Step S4: According to the distance between each suspected temperature rise point and the rest of the suspected temperature rise points, the delay degree of the expected distance of the matching temperature rise point, and the consistency between the numerical difference of the corresponding two suspected temperature rise points, the temperature rise delay rationality of each suspected temperature rise point is obtained; According to the state difference degree and the temperature rise delay rationality, the suspected temperature rise point is selected as the rough fault point.

[0067] When the pulse passes through the high temperature area, the transient impedance distribution of the electric heat tracing band is no longer uniform. The temperature rise will cause the dielectric constant to rise and the propagation speed to drop, and the reflection peak will move slightly to the right, that is, the time delay increases, so the high temperature position point meets the physical logic that "temperature rise will cause delay to increase". The difference between each suspected temperature rise point and the rest of the suspected temperature rise points and the expected distance of the matching temperature rise point presents the delay degree, and the numerical difference between each suspected temperature rise point and the rest of the suspected temperature rise points presents the temperature characteristics. Analyzing the consistency of the two, the temperature rise delay rationality is obtained, so as to evaluate whether the suspected temperature rise point in the self-limiting temperature electric heat tracing band is caused by temperature rise or barrier point failure.

[0068] Next, the suspected temperature rise points caused by the disconnection of the shielding layer and temperature change are distinguished. The state difference degree and the temperature rise delay rationality analyze the possibility that the suspected temperature rise point is caused by the shielding layer failure from the consistency of the state characteristics of space and temperature, delay phenomenon and high temperature phenomenon, and obtain the rough fault point.

[0069] Step S5: According to the temperature value corresponding relationship of the matching temperature rise point of the rough fault point, the rough fault point is accurately positioned.

[0070] Because the propagation speed of the pulse on the electric heat tracing band is affected by the temperature, the temperature rise will cause the signal propagation speed to decrease, so that the position calculation of the rough fault point is not accurate. Assuming that the signal propagation speed is the same at the same temperature. The temperature value corresponding relationship of the matching temperature rise point of the rough fault point represents the propagation speed of the rough fault point, and based on the temperature value corresponding relationship of the matching temperature rise point of the rough fault point, the rough fault point is accurately positioned.

[0071] In the embodiment of the present application, the method for obtaining the suspected temperature rising point and the actual temperature rising point comprises: recording the pulse reflection sequence and the temperature distribution sequence as an analysis sequence, performing curve fitting on the elements in the analysis sequence, and recording the position element of the maximum point on the obtained fitting curve as a maximum value element; and recording the maximum value element in the pulse reflection sequence and the temperature distribution sequence as the suspected temperature rising point and the actual temperature rising point, respectively.

[0072] It should be noted that the strong reflection usually occurs at the position where the characteristic impedance of the electric heat tracing band changes significantly, and the strong reflection is divided into two cases: the impedance change strong reflection caused by temperature fluctuation and the fault strong reflection caused by the breakage of the shielding layer. The strong reflection can cause the value of the element in the pulse reflection sequence to increase, thereby forming a maximum value. The temperature distribution sequence can accurately present the temperature at each position of the electric heat tracing band, and the actual temperature increase can also form a maximum value. The method for obtaining the fitting curve is as follows: constructing a two-dimensional space by taking the subscript of the element in the sequence as the horizontal axis and the value of the element as the vertical axis, mapping the elements in the analysis sequence to the two-dimensional space, obtaining the corresponding scatter points, and performing curve fitting on the scatter points by using the least square method to obtain the fitting curve.

[0073] Preferably, in some possible implementation manners of the embodiment of the present application, the method for obtaining the high-temperature performance degree can refer to Figure 2 which shows a flowchart of a method for obtaining a high-temperature performance degree provided by an embodiment of the present application, and the method comprises the following steps.

[0074] Step S210: obtaining the minimum value element in the pulse reflection sequence and the slope of each element; for each suspected temperature rising point, recording the element between the suspected temperature rising point and the adjacent previous minimum value element as an analysis element; adjusting the value difference between the suspected temperature rising point and each analysis element of the suspected temperature rising point by using the slope of each analysis element of the suspected temperature rising point, to obtain the effective temperature rise of the corresponding analysis element; and performing normalization processing on the mean value of the effective temperature rise of all analysis elements of the suspected temperature rising point, to obtain the reflection amplitude rising degree.

[0075] In the embodiment of the present application, the method for obtaining the effective temperature rise is: the absolute value of the slope of each analysis element of the suspected temperature rise point is negatively correlated and normalized, the difference between the suspected temperature rise point and each analysis element is weighted using the processing result, and the effective temperature rise of each analysis element of the suspected temperature rise point is obtained. It should be noted that the adjacent element before the suspected temperature rise point refers to the analysis element. When the absolute value of the slope of the analysis element is closer to 0, the change of the reflection amplitude in the corresponding interval of the analysis element is slow, and the comparison between the suspected temperature rise point and the analysis element can better reflect the rising degree of the reflection amplitude of the suspected temperature rise point; otherwise, the amplitude in the corresponding interval of the analysis element has changed rapidly, and the suspected temperature rise point may only be a continuation of the change, and the comparison of the numerical change between the suspected temperature rise point and the analysis element will introduce noise, resulting in inaccurate evaluation of the reflection amplitude rise. Therefore, the absolute value of the slope of the analysis element is negatively correlated with the effective temperature rise. If the reflection amplitude rise degree, the higher temperature performance of the suspected temperature rise point is more obvious.

[0076] In the embodiment, the to-be-processed data is taken as the index of the exponential function with a natural constant as the base, the to-be-processed data is negatively correlated and normalized, and other methods can also be used to achieve the negative correlation and normalization, which is not limited herein.

[0077] It should be noted that each element in the pulse reflection sequence has a corresponding reflection time, and the ratio of the numerical difference between each element and its adjacent previous element to the difference of the corresponding reflection time is taken as the slope of each element. The method for obtaining the minimum value element and the maximum value element is similar, and the maximum value point on the fitting curve in the method for obtaining the maximum value element is replaced by the minimum value point, and other contents remain unchanged.

[0078] Step S220: Calculate the numerical average of the elements between the suspected temperature rise point and its adjacent previous minimum value element and the numerical average of the elements between the suspected temperature rise point and its adjacent next minimum value element, and sequentially record them as the left temperature reference value and the right temperature reference value; determine whether the left temperature reference value is less than or equal to the right temperature reference value, if yes, set the reflection attenuation degree of the suspected temperature rise point to zero, and if not, take the difference between the left temperature reference value and the right temperature reference value of the suspected temperature rise point as the reflection attenuation degree.

[0079] It should be noted that the elements between the suspected temperature rise point and its adjacent previous minimum value element and the elements between the suspected temperature rise point and its adjacent next minimum value element represent the previous and next adjacent elements of the suspected temperature rise point, respectively. At high temperature, the signal attenuation is intensified, and the thermal influence may cause the reflection amplitude reference downstream of the suspected temperature rise point to appear more significant decline compared with the upstream. Therefore, the greater the reflection attenuation degree, the more serious the signal attenuation after the suspected temperature rise point, and the higher the temperature of the position corresponding to the suspected temperature rise point.

[0080] Step S230: Obtain the high temperature performance degree of the suspected temperature rise point according to the reflection amplitude rise degree and the reflection attenuation degree.

[0081] The greater the reflection amplitude rising degree and the reflection attenuation degree, the higher the temperature of the position corresponding to the suspected temperature rising point, and the greater the high temperature performance degree. Therefore, the reflection amplitude rising degree and the reflection attenuation degree are positively correlated with the high temperature performance degree. In the embodiment of the present application, the product of the reflection amplitude rising degree and the reflection attenuation degree of the suspected temperature rising point is normalized to obtain the high temperature performance degree.

[0082] In the embodiment of the present application, the normalization processing is performed using the maximum-minimum normalization, and normalization methods such as function transformation and Sigmoid function can also be selected, which are not limited herein.

[0083] Preferably, in some possible implementation manners of the embodiment of the present application, the state difference degree is obtained by: recording the suspected temperature rising point and the actual temperature rising point as an analysis temperature rising point, obtaining the distance between the position corresponding to the analysis temperature rising point on the electric heat tracing band and the emission position of the pulse, recorded as an analysis distance; performing normalization processing on the numerical value of each element in the temperature distribution sequence, and taking the processing result as an actual high temperature; calculating the absolute value of the difference between the high temperature performance degree of each suspected temperature rising point and the actual high temperature of each actual temperature rising point, and the absolute value of the difference between the analysis distance of each suspected temperature rising point and each actual temperature rising point, and performing normalization processing on the product of the two absolute values to obtain the state difference degree of each suspected temperature rising point and each actual temperature rising point.

[0084] It should be noted that the numerical value of the element in the temperature distribution sequence, i.e. the temperature value, is normalized by the maximum-minimum normalization in the embodiment, and the obtained actual high temperature directly represents the actual thermal state of the suspected high temperature point; the high temperature performance degree indirectly represents the actual thermal state of the suspected high temperature point through electrical characteristics. The difference between the high temperature performance degree of the suspected temperature rising point and the actual high temperature of the actual temperature rising point, and the difference between the analysis distance of the suspected temperature rising point and the actual temperature rising point, analyze the state difference between the suspected temperature rising point and the actual temperature rising point from two aspects of temperature characteristics and spatial characteristics, to obtain the state difference degree. The smaller the state difference degree, the closer the temperature and position of the suspected temperature rising point and the actual temperature rising point, and the greater the possibility that the two points represent the temperature change at the same position on the electric heat tracing band.

[0085] It should be noted that the analysis distance of the i th temperature rising point in the temperature distribution sequence is equal to The reflection echo is affected by temperature and causes the change of propagation speed. The position of the suspected temperature rising point on the electric heat tracing band determined by the reflection echo may have errors, but the distance between the suspected temperature rising points caused by the temperature change is very short and can be ignored. Therefore, the analysis distance of the suspected temperature rising point is equal to the corresponding reflection time of the suspected temperature rising point and meters per second. In the embodiment of the present application, the Sigmoid function is used for normalization, and other normalization methods such as function transformation, maximum-minimum normalization, etc. can also be selected, which are not limited herein.

[0086] Preferably, in some possible implementation manners of the embodiment of the present application, the method for obtaining the matching temperature rising point of the suspected temperature rising point comprises: based on the state difference degree, matching the suspected temperature rising point in the pulse reflection sequence with the actual temperature rising point in the temperature distribution sequence by using the DTW algorithm, and recording the actual temperature rising point matched with each suspected temperature rising point as the matching temperature rising point of the suspected temperature rising point. The dynamic time warping (DTW) algorithm is a technology known to those skilled in the art, and will not be described here. It should be noted that the state difference degree is equivalent to the distance between two objects in the DTW algorithm. Because the number of suspected temperature rising points is more than the number of actual temperature rising points, multiple suspected temperature rising points can correspond to the same actual temperature rising point.

[0087] In other embodiments of the present application, the first actual temperature rising point in the temperature distribution sequence is taken as the matching temperature rising point of the first suspected temperature rising point in the pulse reflection sequence; the second suspected temperature rising point is recorded as the initial analysis point, and it is determined whether the state difference degree between the first actual temperature rising point and the matching temperature rising point thereof is less than a preset difference threshold. If not, the state difference degrees between the initial analysis point and the matching temperature rising point of the adjacent previous suspected temperature rising point of the initial analysis point and the actual temperature rising point after the initial analysis point are calculated, and the actual temperature rising point corresponding to the smallest state difference degree is recorded as the matching temperature rising point of the initial analysis point. If yes, the state difference degrees between the initial analysis point and the actual temperature rising point after the matching temperature rising point of the adjacent previous suspected temperature rising point of the initial analysis point are calculated, and the actual temperature rising point corresponding to the smallest state difference degree is recorded as the matching temperature rising point of the initial analysis point; the adjacent next suspected temperature rising point of the initial analysis point is recorded as the updated analysis point, the matching temperature rising point of the updated analysis point is determined, all suspected temperature rising points are traversed, and the matching temperature rising point of each suspected temperature rising point is determined.

[0088] It should be noted that if the state difference between the first suspected temperature rising point and its matching temperature rising point is greater than or equal to the preset difference threshold, it indicates that the first suspected temperature rising point is likely not caused by the local temperature change on the electric heat tracing band, i.e., it is likely caused by the shielding layer failure, and therefore, when analyzing the matching temperature rising point of the first suspected temperature rising point, the first actual temperature rising point also needs to be considered. Conversely, it indicates that the first suspected temperature rising point is likely caused by the shielding layer failure, and the first suspected temperature rising point and its matching temperature rising point are likely caused by the local temperature change on the electric heat tracing band, and the matching is successful, and therefore, when analyzing the matching temperature rising point of the first suspected temperature rising point, the actual temperature rising point after the first actual temperature rising point needs to be considered. Since the fault positioning is performed immediately after the electric heat tracing band fails, the fault position is usually less than the temperature change position, and the mean value of the state difference between all the actual temperature rising points in the temperature distribution sequence and the suspected temperature rising points with the same subscript in the pulse reflection sequence is used as the preset difference threshold.

[0089] Preferably, in some possible implementation manners of the embodiments of the present application, the method for obtaining the temperature rising delay rationality degree comprises: taking an optional suspected temperature rising point as a target point, and taking an optional suspected temperature rising point other than the target point as an example point; taking the distance between the matching temperature rising point of the target point and its adjacent previous actual temperature rising point as the numerator, and taking the distance between the matching temperature rising point of the example point and its adjacent previous actual temperature rising point as the denominator to obtain a ratio value, and taking the product of the ratio value and the distance between the example point and its adjacent previous suspected temperature rising point as an expected delay distance; judging whether the distance between the target point and its adjacent previous suspected temperature rising point is greater than the expected delay distance, and if yes, the delay comparison index between the target point and the example point is a first preset value, and if not, the delay comparison index between the target point and the example point is a second preset value; judging whether the temperature value of the matching temperature rising point of the target point is greater than the temperature value of the matching temperature rising point of the example point, and if yes, the temperature comparison index between the target point and the example point is the first preset value, and if not, the temperature comparison index between the target point and the example point is the second preset value; calculating the absolute value of the difference between the delay comparison index and the temperature comparison index between the target point and the example point, and taking the difference between the constant 1 and the absolute value as the temperature rising delay consistency degree between the target point and the example point; and averaging the temperature rising delay consistency degrees between the target point and all the other suspected temperature rising points to obtain the temperature rising delay rationality degree of the target point.

[0090] It should be noted that the ratio is used to eliminate the interference of the reference distance difference between the target point and the example point, and the expected delay distance represents the expected delay adjustment distance of the example point after the influence of the reference distance is eliminated, so that the delay comparison is more focused on the relative change caused by temperature. If the distance between the target point and its adjacent previous suspected temperature rise point is greater than the expected delay distance, it means that the actual distance of the target point is greater than the adjusted distance of the example point, indicating that the delay phenomenon of the target point is more serious than that of the example point, and the temperature of the target point at the corresponding position of the electric heating tape is higher than that of the example point at the corresponding position in theory because the temperature rise will intensify signal attenuation and decrease in propagation speed. The temperature comparison index is used to verify whether the delay comparison index is reasonable. If the delay comparison index and the temperature comparison index between the target point and the example point are the same, it indicates that the delay behavior is consistent with the temperature behavior, that is, the higher the temperature of the suspected temperature rise point, the more serious the delay. The temperature rise delay consistency degree obtained by averaging the comparison results of the target point and the remaining suspected temperature rise points is the temperature rise delay rationality, which can reduce random errors. The greater the temperature rise delay rationality, the more likely the suspected temperature rise point is caused by high temperature and the less likely the suspected temperature rise point is caused by the shielding layer failure.

[0091] In the embodiment, the first preset value and the second preset value are used to convert the delay signal and the temperature information into binary indexes for analyzing the consistency of the delay and the temperature. The first preset value and the second preset value can be set to constants 1 and 0 in sequence, or can be set to other unequal values. The implementer can set them according to the specific situation.

[0092] It should be noted that the temperature rise delay consistency degrees between the target point and the remaining suspected temperature rise points and the example point are obtained in the same way, and the temperature rise delay rationalities of the suspected temperature rise point and the target point are obtained in the same way.

[0093] Preferably, in some possible implementation manners of the embodiment, the acquisition method of the rough fault point comprises: performing negative correlation mapping on the temperature rise delay rationality of each suspected temperature rise point, performing normalization processing on the product of the mapping result and the state difference degree, and obtaining the fault degree of each suspected temperature rise point; and recording the suspected temperature rise point with a fault degree greater than a preset fault threshold as the rough fault point.

[0094] It should be noted that the suspected temperature rising point generated due to the shielding layer failure does not appear temperature change at the corresponding position, and does not appear delay phenomenon generated due to the temperature being too high, so the temperature rising delay rationality of the suspected temperature rising point generated due to the shielding layer failure is smaller; meanwhile, the matching temperature rising point of the suspected temperature rising point is generated due to the actual temperature being too high, and the difference between the temperature and the position of the suspected temperature rising point and the matching temperature rising point is more significant than the difference between the temperature and the position of the suspected temperature rising point generated due to the actual temperature being too high and the matching temperature rising point, so the state difference degree of the suspected temperature rising point generated due to the shielding layer failure is greater. If the temperature rising delay rationality is greater and the state difference degree is smaller, the possibility that the suspected temperature rising point is generated due to the shielding layer failure is greater, and the failure degree is greater. The suspected temperature rising point with the failure degree greater than the preset failure threshold is generated due to the shielding layer failure. The maximum and minimum normalization method is used for normalization processing in the embodiment of the application.

[0095] In one implementation manner of the embodiment of the application, the preset failure threshold is set to 0.8, and the implementer can set it according to the specific situation.

[0096] Preferably, in some possible implementation manners of the embodiment of the application, the acquisition method of the final position of the rough failure point comprises: averaging the amplitudes of all actual temperature rising points between each suspected temperature rising point and the matching temperature rising point of the adjacent previous suspected temperature rising point of the suspected temperature rising point as the environmental temperature amplitude of each suspected temperature rising point; calculating the difference absolute values between each rough failure point and the environmental temperature amplitudes of the remaining suspected temperature rising points except all rough failure points, and selecting the suspected temperature rising point corresponding to the minimum difference absolute value as the reference position point of the rough failure point; and the calculation formula of the final position of the rough failure point is as follows:

[0097]

[0098] In the formula, U is the distance from the final position of each rough failure point to the emission position of the pulse; is the distance between the matching temperature rising point of the adjacent previous suspected temperature rising point of each rough failure point and the emission position of the pulse; W is the distance between each rough failure point and the adjacent previous suspected temperature rising point of the rough failure point; is the distance between the reference position point of each rough failure point and the adjacent previous suspected temperature rising point of the rough failure point; is the distance between the matching temperature rising point of the reference position point of each rough failure point and the matching temperature rising point of the adjacent previous suspected temperature rising point of the reference position point.

[0099] It should be noted that the embodiment assumes that the signal propagation speed is the same at the same temperature. The ambient temperature represents the overall temperature of the local area of the suspected temperature rise point, which is used to estimate the propagation speed of the pulse at the position corresponding to the suspected temperature rise point. The pulse has a similar propagation speed at the position corresponding to the suspected temperature rise point and its reference position point. The reference position point is caused by the actual temperature change, which matches the temperature rise point and has accurate position information, which can be used to calibrate the position of the rough defect point. and The time delay caused by the temperature leads to inaccuracy, but The direct measurement of the optical fiber temperature is accurate, and the formula is corrected by proportional change: assuming that the distance proportion in the pulse reflection sequence is similar under similar ambient temperature should be consistent with the accurate distance proportion , wherein is the distance between the rough defect point and the adjacent previous suspected temperature rise point. The accurate position of the adjacent previous suspected temperature rise point of the rough defect point is provided to the distance of the final position of the rough defect point.

[0100] It should be noted that the adjacent previous suspected temperature rise point of each suspected temperature rise point in the embodiment cannot be the rough defect point.

[0101] So far, the present application is completed.

[0102] Embodiment 2:

[0103] The present application provides an electric heat tracing band fault point accurate positioning system based on pulse reflection method, please refer to Figure 3 , which shows a system structure diagram of an electric heat tracing band fault point accurate positioning system based on pulse reflection method provided by an embodiment of the present application. The system comprises:

[0104] The data acquisition module 610 is used for transmitting a pulse to the electric heat tracing band, acquiring a pulse reflection sequence and a temperature value distributed along the length of the electric heat tracing band to form a temperature distribution sequence; selecting a suspected temperature rise point in the pulse reflection sequence and an actual temperature rise point in the temperature distribution sequence;

[0105] The high temperature performance analysis module 620 is used for acquiring the high temperature performance degree of each suspected temperature rise point according to the numerical difference between each suspected temperature rise point and its previous adjacent element, and the numerical difference between the previous and subsequent adjacent elements of each suspected temperature rise point;

[0106] The temperature rise point matching module 630 is used for acquiring the state difference degree of each suspected temperature rise point and each actual temperature rise point according to the difference between the high temperature performance degree of each suspected temperature rise point and the temperature value of each actual temperature rise point, and the distance of the corresponding positions of the two temperature rise points on the electric heat tracing band, and selecting the matching temperature rise point of each suspected temperature rise point from the actual temperature rise point;

[0107] The fault point preliminary determination module 640 is configured to obtain a temperature rise delay rationality of each suspected temperature rise point according to a consistency between a difference between a distance of each suspected temperature rise point from the remaining suspected temperature rise points and an expected distance of the matching temperature rise point of each suspected temperature rise point and a numerical difference between the corresponding two suspected temperature rise points; and select a rough fault point from the suspected temperature rise points according to the state difference degree and the temperature rise delay rationality.

[0108] The fault point precise positioning module 650 is configured to precisely position the rough fault point according to a temperature value corresponding relationship of the matching temperature rise point of the rough fault point.

[0109] It should be noted that the device provided in the above embodiment is only used as an example for the division of the above functional modules, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the computer device is divided into different functional modules to complete all or part of the functions described above. In addition, the electric tracing band fault point precise positioning system and the electric tracing band fault point precise positioning method provided in the above embodiment belong to the same concept, and the specific implementation process is described in the method embodiment, which will not be described here.

[0110] Embodiment 3:

[0111] Figure 4 A computer device schematic diagram of an electric tracing band fault point precise positioning device provided in an embodiment of the present application. As shown in the example, Figure 4 the computer device includes a memory 701, a processor 702, and a computer program 703 stored in the memory 701 and running on the processor 702, wherein when the processor 702 executes the computer program 703, the computer device can execute any of the above-described electric tracing band fault point precise positioning methods based on the pulse reflection method.

[0112] In addition, the present application also protects a device, which can include a memory and a processor, wherein the memory stores executable program code, and the processor is configured to call and execute the executable program code to execute the electric tracing band fault point precise positioning method based on the pulse reflection method provided in the present application.

[0113] The present embodiment can divide the device into functional modules according to the above method examples, for example, each functional module can be corresponding, or two or more functions can be integrated in one processing module, and the integrated module can be realized in the form of hardware. It should be noted that the division of modules in the present embodiment is illustrative, and is only a logical function division, and another division method can be used in actual implementation.

[0114] It should be understood that the device provided by the embodiment is used to execute the above-mentioned one kind of pulse reflection method-based electric heat tracing band fault point accurate positioning method, and thus the same effect as the above-mentioned implementation method can be achieved.

[0115] In the case of using the integrated unit, the device can include a processing module and a storage module. When the device is applied to the equipment, the processing module can be used to control and manage the actions of the equipment. The storage module can be used to support the equipment to execute mutual program codes and the like.

[0116] The processing module can be a processor or a controller, which can realize or execute various exemplary logical blocks, modules and circuits contained in the disclosure of the present application. The processor can also be a combination of computing functions, such as one or more microprocessor combinations, a combination of digital signal processing (DSP) and microprocessor, and the like. The storage module can be a memory.

[0117] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0118] Each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other. Each embodiment focuses on the difference from other embodiments.

[0119] The above-mentioned is only the preferred embodiment of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement and the like made within the principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for accurately locating the fault point of an electric tracing band based on the pulse reflection method, characterized in that, The method comprises: Pulse is emitted to the electric heat tracing pipe, a pulse reflection sequence and a temperature value distributed along the length of the electric heat tracing pipe are acquired to form a temperature distribution sequence, and a suspected temperature rise point in the pulse reflection sequence and an actual temperature rise point in the temperature distribution sequence are selected; A high temperature performance degree of each suspected temperature rise point is acquired according to the numerical difference between each suspected temperature rise point and its previous adjacent element and the numerical difference between the previous and subsequent adjacent elements of each suspected temperature rise point; A state difference degree of each suspected temperature rise point and each actual temperature rise point is acquired according to the difference between the high temperature performance degree of each suspected temperature rise point and the temperature value of each actual temperature rise point and the distance of the corresponding positions of the two temperature rise points on the electric heat tracing pipe, and a matching temperature rise point of each suspected temperature rise point is selected from the actual temperature rise points; A temperature rise delay rationality degree of each suspected temperature rise point is acquired according to the consistency between the difference between the distance of each suspected temperature rise point and the expected distance of the matching temperature rise point and the numerical difference between the two suspected temperature rise points, and a rough fault point is selected from the suspected temperature rise points according to the state difference degree and the temperature rise delay rationality degree; The rough fault point is accurately positioned according to the temperature value corresponding relationship of the matching temperature rise point of the rough fault point; The state difference degree of each suspected temperature rise point and each actual temperature rise point comprises: the suspected temperature rise point and the actual temperature rise point are recorded as analysis temperature rise points, the distance between the corresponding positions of the analysis temperature rise points on the electric heat tracing pipe and the emission position of the pulse is recorded as analysis distance; the numerical value of each element in the temperature distribution sequence is normalized, and the processing result is taken as an actual high temperature; the absolute value of the difference between the high temperature performance degree of each suspected temperature rise point and the actual high temperature of each actual temperature rise point and the absolute value of the difference between the analysis distance of each suspected temperature rise point and each actual temperature rise point are calculated, and the product of the two absolute values is normalized to obtain the state difference degree of each suspected temperature rise point and each actual temperature rise point. The temperature rise delay rationality of each suspected temperature rise point is obtained, including: taking an optional suspected temperature rise point as a target point, and taking an optional suspected temperature rise point from the remaining suspected temperature rise points as an example point; taking the distance between the matching temperature rise point of the target point and the adjacent previous actual temperature rise point thereof as a numerator, and taking the distance between the matching temperature rise point of the example point and the adjacent previous actual temperature rise point thereof as a denominator to obtain a ratio value; taking the product of the ratio value and the distance between the example point and the adjacent previous suspected temperature rise point as an expected delay distance; judging whether the distance between the target point and the adjacent previous suspected temperature rise point thereof is greater than the expected delay distance, if yes, the delay comparison index between the target point and the example point is a first preset value, if not, the delay comparison index between the target point and the example point is a second preset value; judging whether the temperature value of the matching temperature rise point of the target point is greater than the temperature value of the matching temperature rise point of the example point, if yes, the temperature comparison index between the target point and the example point is the first preset value, if not, the temperature comparison index between the target point and the example point is the second preset value; calculating the absolute value of the difference between the delay comparison index and the temperature comparison index between the target point and the example point, and taking the difference between the constant 1 and the absolute value of the difference as the temperature rise delay consistency between the target point and the example point; averaging the temperature rise delay consistencies between the target point and all the remaining suspected temperature rise points to obtain the temperature rise delay rationality of the target point.

2. The method according to claim 1, characterized in that, The high temperature performance degree of each suspected temperature rise point is obtained, including: Obtaining the slope of each element and the minimum value element in the pulse reflection sequence; For each suspected temperature rise point, the element between the suspected temperature rise point and the adjacent previous minimum value element is recorded as an analysis element; the numerical difference between the suspected temperature rise point and each analysis element thereof is adjusted by using the slope of each analysis element of the suspected temperature rise point to obtain the effective temperature rise of the corresponding analysis element; the mean value of the effective temperature rise of all the analysis elements of the suspected temperature rise point is normalized to obtain the reflection amplitude rise degree; The numerical mean values of the elements between the suspected temperature rise point and the adjacent previous minimum value element and the adjacent next minimum value element thereof are calculated and recorded as left temperature reference value and right temperature reference value in sequence; judging whether the left temperature reference value is less than or equal to the right temperature reference value, if yes, the reflection attenuation degree of the suspected temperature rise point is set to zero, if not, the difference between the left temperature reference value and the right temperature reference value of the suspected temperature rise point is taken as the reflection attenuation degree; The high temperature performance degree of the suspected temperature rise point is obtained according to the reflection amplitude rise degree and the reflection attenuation degree.

3. The method according to claim 1, characterized in that, The suspected temperature rise point is selected, including: The temperature rise delay rationality of each suspected temperature rise point is negatively correlated, and the product of the mapping result and the state difference degree is normalized to obtain the fault degree of each suspected temperature rise point; The suspected temperature rise point with a fault degree greater than a preset fault threshold is recorded as a rough fault point.

4. The method according to claim 1, characterized in that, The rough fault point is accurately positioned, including: The temperature values of all the actual temperature rise points between each suspected temperature rise point and the matching temperature rise point of the adjacent previous suspected temperature rise point thereof are averaged to obtain the environmental temperature of each suspected temperature rise point; Calculate the absolute value of the difference between each rough fault point and the ambient temperature of the remaining suspected temperature rise point except all rough fault points, and select the suspected temperature rise point corresponding to the minimum absolute value as the reference position point of the rough fault point; The calculation formula of the distance between the final position of each rough fault point and the emission position of the pulse is as follows: ; where U is the distance from the final position of each coarse fault point to the position of the pulse's emission; is the distance between the matching temperature point of the adjacent previous suspected temperature point of each coarse fault point and the position of the pulse's emission; W is the distance between each coarse fault point and its adjacent previous suspected temperature point; is the distance between the reference position point of each coarse fault point and its adjacent previous suspected temperature point; is the distance between the matching temperature point of the reference position point of each coarse fault point and the matching temperature point of the adjacent previous suspected temperature point of the reference position point.

5. The method for pinpointing the fault point of the electric tracing band based on the pulse reflection method according to claim 1, characterized in that, Selecting the matching temperature rise point of each suspected temperature rise point from the actual temperature rise point includes: Based on the state difference degree, the DTW algorithm is used to match the suspected temperature rise point in the pulse reflection sequence with the actual temperature rise point in the temperature distribution sequence, and the actual temperature rise point matched with each suspected temperature rise point is recorded as the matching temperature rise point thereof.

6. The method for pinpointing the fault point of the electric tracing band based on the pulse reflection method according to claim 2, characterized in that, The effective temperature rise acquisition method includes: The absolute value of the slope of each analysis element of the suspected temperature rise point is negatively correlated and normalized, and the processing result is used for weighted processing of the numerical difference between the suspected temperature rise point and each analysis element thereof, to obtain the effective temperature rise of each analysis element of the suspected temperature rise point.

7. The method of claim 1, wherein, Selecting the suspected temperature rise point in the pulse reflection sequence and the actual temperature rise point in the temperature distribution sequence includes: The pulse reflection sequence and the temperature distribution sequence are recorded as analysis sequences, and the elements in the analysis sequences are curve fitted, and the element at the position of the maximum value point on the obtained fitting curve is recorded as the maximum value element; The maximum value elements in the pulse reflection sequence and the temperature distribution sequence are recorded as suspected temperature rise points and actual temperature rise points, respectively.

8. A system for precise location of a fault point of an electric tracing band based on the pulse reflection method, characterized in that The system includes: The data acquisition module is used for emitting pulses to the electric heat tracing band, acquiring the pulse reflection sequence and the temperature value distributed along the length of the electric heat tracing band to form the temperature distribution sequence; selecting the suspected temperature rise point in the pulse reflection sequence and the actual temperature rise point in the temperature distribution sequence; The high temperature performance analysis module is used for acquiring the high temperature performance degree of each suspected temperature rise point according to the numerical difference between each suspected temperature rise point and its previous adjacent element, and the numerical difference between the previous and subsequent adjacent elements of each suspected temperature rise point; The temperature rise point matching module is used for acquiring the state difference degree between each suspected temperature rise point and each actual temperature rise point according to the difference between the high temperature performance degree of each suspected temperature rise point and the temperature value of each actual temperature rise point, and the distance between the corresponding positions of the two temperature rise points on the electric heat tracing band, and selecting the matching temperature rise point of each suspected temperature rise point from the actual temperature rise point; The fault point preliminary determination module is used for acquiring the temperature rise delay rationality of each suspected temperature rise point according to the consistency between the difference between the distance of each suspected temperature rise point and the remaining suspected temperature rise points and the expected distance of the matching temperature rise point thereof, and the numerical difference between the corresponding two suspected temperature rise points; and selecting the rough fault point from the suspected temperature rise points according to the state difference degree and the temperature rise delay rationality. The fault point precise positioning module is used for precisely positioning the rough fault point according to the temperature value corresponding relationship of the matching temperature rise point of the rough fault point. The state difference degree of each suspected temperature rising point and each actual temperature rising point is obtained, including: recording the suspected temperature rising point and the actual temperature rising point as an analysis temperature rising point, obtaining the distance between the corresponding position of the analysis temperature rising point on the electric heat tracing band and the emission position of the pulse, recorded as an analysis distance; performing normalization processing on the numerical value of each element in the temperature distribution sequence, and taking the processing result as an actual high temperature; calculating the difference absolute value of the high temperature performance degree of each suspected temperature rising point and the actual high temperature of each actual temperature rising point, and the difference absolute value of the analysis distance of each suspected temperature rising point and each actual temperature rising point, and performing normalization processing on the product of the two difference absolute values to obtain the state difference degree of each suspected temperature rising point and each actual temperature rising point. The temperature rising delay reasonable degree of each suspected temperature rising point is obtained, including: optionally recording one suspected temperature rising point as a target point, and recording one suspected temperature rising point from the remaining suspected temperature rising points as an example point; taking the distance between the matching temperature rising point of the target point and its adjacent previous actual temperature rising point as the numerator, and the distance between the matching temperature rising point of the example point and its adjacent previous actual temperature rising point as the denominator to obtain a ratio, and taking the product of the ratio and the distance between the example point and the adjacent previous suspected temperature rising point as an expected delay distance; judging whether the distance between the target point and its adjacent previous suspected temperature rising point is greater than the expected delay distance, if yes, the delay comparison index between the target point and the example point is a first preset value, if not, the delay comparison index between the target point and the example point is a second preset value; judging whether the temperature value of the matching temperature rising point of the target point is greater than the temperature value of the matching temperature rising point of the example point, if yes, the temperature comparison index between the target point and the example point is a first preset value, if not, the temperature comparison index between the target point and the example point is a second preset value; calculating the difference absolute value of the delay comparison index and the temperature comparison index between the target point and the example point, and taking the difference between the constant 1 and the difference absolute value as the temperature rising delay consistency degree between the target point and the example point; averaging the temperature rising delay consistency degrees between the target point and all the remaining suspected temperature rising points to obtain the temperature rising delay reasonable degree of the target point.

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