A Temperature Detection Method and System for the Outlet Cable of a Transformer Winding

Abstract

The present invention relates to the technical field of cable temperature detection, and specifically relates to a temperature detection method and system for the outgoing cable of a transformer winding, including: obtaining the optical signal of the monitoring point on the outgoing cable of the transformer winding; obtaining the current signal of the outgoing cable of the transformer winding; obtaining the initial corrected optical signal intensity at each moment within the periodic signal segment of the optical signal; obtaining the final deviation value at each moment within each periodic signal segment; obtaining the final influence index of the optical signal intensity of the monitoring point at the current moment affected by the operation of the transformer; obtaining the final corrected optical signal intensity of the monitoring point at the current moment; and obtaining the true temperature value of the monitoring point at the current moment according to the final corrected optical signal intensity. The present invention improves the accuracy of temperature measurement of the outgoing cable of the transformer winding by means of a fluorescence optical fiber temperature sensor during the vibration of the transformer.

Description

Technical Field

[0001] The present invention relates to the technical field of cable temperature detection, and particularly relates to a temperature detection method and system for the outgoing cable of a transformer winding. Background Art

[0002] The outgoing cable of a transformer winding refers to the wire connecting the transformer winding and the external circuit. During the operation of a transformer, a large amount of heat is generated, especially in the outgoing cable of the winding. If the temperature is too high, the insulating material is prone to aging, resulting in insulation breakdown or failure, and triggering safety accidents. Therefore, it is very crucial to detect the temperature of the outgoing cable of the transformer winding.

[0003] When the prior art detects the temperature of the outgoing cable of a transformer winding, the sensor needs to continuously monitor the optical signal reflected or transmitted by the optical fiber, and then obtain the temperature value after corresponding algorithm processing. Since the transformer core generates an alternating magnetic field during operation, the core will exhibit the magnetostrictive effect. The magnetostrictive effect refers to the phenomenon that when a magnetic material changes its magnetization state under the action of an external magnetic field, its size or volume will change slightly. The magnetostrictive effect of the core will cause a certain vibration of the transformer core, and this vibration change will cause an additional stress on the fluorescence optical fiber temperature sensor, resulting in a change in the luminescence characteristics of the fluorescent material in the fluorescence optical fiber, thus leading to inaccurate temperature measurement when using the fluorescence optical fiber temperature sensor to measure the temperature of the outgoing cable of the transformer winding. Summary of the Invention

[0004] To solve the above problems, the present invention provides a temperature detection method and system for the outgoing cable of a transformer winding.

[0005] The temperature detection method and system for the outgoing cable of a transformer winding of the present invention adopt the following technical solutions:

[0006] An embodiment of the present invention provides a temperature detection method for the outgoing cable of a transformer winding, and the method includes the following steps:

[0007] Obtain the optical signal at the monitoring point on the outgoing cable of the transformer winding, where the optical signal includes the optical signal intensities at several moments; obtain the current signal of the outgoing cable of the transformer winding, where the current signal includes the current values at several moments;

[0008] In each optical signal, obtain a number of periodic signal segments; according to each periodic signal segment and the optical signal intensity and current value at the corresponding moment in the previous periodic signal segments, obtain the initial corrected optical signal intensity at each moment within each periodic signal segment; according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each periodic signal segment, and in combination with the current value at the corresponding moment, obtain the final deviation value at each moment within each periodic signal segment, which reflects the influence of the transformer operation on the optical signal intensity.

[0009] According to the final deviation value and the optical signal intensity, obtain the initial influence index at each monitoring point at each moment within each periodic signal segment of the optical signal to which it belongs, which reflects the influence of the transformer operation on the optical signal intensity; according to the difference in the initial influence index at each moment within each periodic signal segment of the optical signals to which the monitoring point and the adjacent monitoring point belong respectively, and the initial influence index, obtain the final influence index of the optical signal intensity of each monitoring point at the current moment affected by the transformer operation.

[0010] According to the final influence index, correct the optical signal intensity of each monitoring point at the current moment to obtain the final corrected optical signal intensity of each monitoring point at the current moment; according to the final corrected optical signal intensity of each monitoring point at the current moment, obtain the true temperature value of each monitoring point at the current moment.

[0011] Further, the specific method for obtaining a number of periodic signal segments in each optical signal is as follows:

[0012] Denote any one of the monitoring points as the monitoring point to be analyzed, and denote the optical signal of the monitoring point to be analyzed as the optical signal to be analyzed; denote the differential signal of the optical signal to be analyzed as the optical differential signal to be analyzed; perform a discrete Fourier transform on the optical differential signal to be analyzed to obtain the frequency spectrum diagram of the optical differential signal to be analyzed, and take the frequency with the largest amplitude in the frequency spectrum diagram as the reference frequency of the optical differential signal to be analyzed, and take the reciprocal of the reference frequency as the reference period of the optical differential signal to be analyzed; starting from the first signal amplitude of the optical differential signal to be analyzed, obtain a signal segment with the same length as the reference period, and denote it as the first signal segment; obtain the extreme value closest to the last signal amplitude in the first signal segment in the optical differential signal to be analyzed, and denote it as the first extreme value, and take the signal segment from the first signal amplitude to the first extreme value in the optical differential signal to be analyzed as the first reference period signal segment of the optical differential signal to be analyzed; starting from the first extreme value of the optical differential signal to be analyzed, obtain a signal segment with the same length as the reference period, and denote it as the second signal segment; obtain the extreme value closest to the last signal amplitude in the second signal segment in the optical differential signal to be analyzed, and denote it as the second extreme value, and take the signal segment from the first extreme value to the second extreme value in the optical differential signal to be analyzed as the second reference period signal segment of the optical differential signal to be analyzed; and so on, to obtain multiple reference period signal segments of the optical differential signal to be analyzed; obtain the division moments of all the reference period signal segments in the optical differential signal to be analyzed, and denote them all as the key division moments; divide the optical signal to be analyzed according to all the key division moments to obtain several periodic signal segments of the optical signal to be analyzed.

[0013] Further, the specific steps for obtaining the initial corrected optical signal intensity at each moment within each periodic signal segment according to the optical signal intensity and current value at the corresponding moment in each periodic signal segment and the previous periodic signal segments are as follows:

[0014] Denote any moment in the optical signal to be analyzed as the moment to be analyzed; denote the periodic signal segment to which the optical signal intensity at the moment to be analyzed belongs as the periodic signal segment to be analyzed; denote the order value of the moment to be analyzed in the periodic signal segment to be analyzed as ;

[0015] ;

[0016] where is the number of the periodic signal segment to be analyzed and the previous periodic signal segments in the optical signal to be analyzed; is the th current value corresponding to the th moment in the current signal within the th periodic signal segment of the optical signal to be analyzed; is the optical signal intensity at the -th moment within the -th cycle signal segment of the optical signal to be analyzed; is to take the absolute value; is the initial corrected optical signal intensity at the -th moment within the cycle signal segment to be analyzed of the optical signal to be analyzed.

[0017] Further, obtaining the final deviation value at each moment within each cycle signal segment, reflecting the influence of the transformer operation on the optical signal intensity, by combining the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each cycle signal segment with the current value at the corresponding moment, includes the following specific steps:

[0018]

[0019] In the formula, is the optical signal intensity at the -th moment within the cycle signal segment to be analyzed of the optical signal to be analyzed; is the initial deviation value of the optical signal intensity at the -th moment within the cycle signal segment to be analyzed of the optical signal to be analyzed, affected by the transformer operation;

[0020] Obtain the final deviation value at each moment within each cycle signal segment, reflecting the influence of the transformer operation on the optical signal intensity, based on the initial deviation value and the current value at the corresponding moment.

[0021] Further, obtaining the final deviation value at each moment within each cycle signal segment, reflecting the influence of the transformer operation on the optical signal intensity, by combining the initial deviation value and the current value at the corresponding moment, includes the following specific steps:

[0022]

[0023] In the formula, is the current value corresponding to the -th moment in the current signal within the cycle signal segment to be analyzed of the optical signal to be analyzed; is the order value corresponding to the -th moment in the optical signal to be analyzed within the cycle signal segment to be analyzed of the optical signal to be analyzed; is the order value corresponding to the -th moment within the -th cycle signal segment of the optical signal to be analyzed in the optical signal to be analyzed; is the order value corresponding to the -th moment within the -th cycle signal segment of the optical signal to be analyzed in the optical signal to be analyzed; is the exponential function with the natural constant as the base; The final deviation value of the optical signal intensity at the th moment within the period signal segment of the optical signal to be analyzed, affected by the operation of the transformer.

[0024] Furthermore, obtaining the initial influence index of each monitoring point at each moment within each period signal segment of the optical signal it belongs to, reflecting the influence of the optical signal intensity by the operation of the transformer, based on the final deviation value and the optical signal intensity, includes the following specific steps:

[0025]

[0026] In the formula, is the initial influence index of the optical signal intensity at the th moment within the period signal segment of the optical signal to be analyzed for the monitoring point to be analyzed, affected by the operation of the transformer.

[0027] Furthermore, obtaining the final influence index of the optical signal intensity at the current moment of each monitoring point, affected by the operation of the transformer, based on the difference in the initial influence indices of each monitoring point and its adjacent monitoring points at each moment within each period signal segment of the optical signals they belong to, and the initial influence index, includes the following specific steps:

[0028]

[0029] In the formula, is the number of period signal segments of the optical signal to be analyzed and the previous period signal segments; is the initial influence index of the optical signal intensity at the th moment within the th period signal segment of the optical signal to be analyzed for the monitoring point to be analyzed, affected by the operation of the transformer; is the th adjacent monitoring point of the monitoring point to be analyzed, and is the initial influence index of the optical signal intensity at the th moment within the th period signal segment of the optical signal it belongs to, affected by the operation of the transformer; is the degree of influence of the optical signal intensity at the th moment within the period signal segment of the optical signal to be analyzed for the monitoring point to be analyzed, affected by the kth adjacent monitoring point;

[0030]

[0031] According to the initial influence index, the degree of influence, and the credibility factor, the final influence index of the optical signal intensity at each monitoring point affected by the transformer operation at the current moment is obtained.

[0032] Furthermore, obtaining the credibility factor of each monitoring point affected by each adjacent monitoring point at each moment within each cycle signal segment of the optical signal to which it belongs according to the difference in the initial influence index of each monitoring point and all adjacent monitoring points at each moment within each cycle signal segment of the optical signal to which they belong includes the following specific steps:

[0033]

[0034] In the formula, is the number of adjacent monitoring points of the monitoring point to be analyzed; is to take the absolute value; is the hyperbolic tangent function; is the credibility factor of the monitoring point to be analyzed affected by the th adjacent monitoring point at the th moment within the cycle signal segment of the optical signal to be analyzed.

[0035] Furthermore, obtaining the final influence index of the optical signal intensity at each monitoring point affected by the transformer operation at the current moment according to the initial influence index, the degree of influence, and the credibility factor includes the following specific steps:

[0036] The optical signal intensity at the current moment is the optical signal intensity at the last moment in the optical signal of the monitoring point;

[0037]

[0038] In the formula, is the number of adjacent monitoring points of the monitoring point to be analyzed; is the initial influence index of the th adjacent monitoring point of the monitoring point to be analyzed on the optical signal intensity affected by the transformer operation at the last moment within the last cycle signal segment of the optical signal; is the degree of influence of the monitoring point to be analyzed on the optical signal intensity at the last moment within the last cycle signal segment of the optical signal affected by the th adjacent monitoring point; is the credibility factor of the monitoring point to be analyzed affected by the th adjacent monitoring point at the last moment within the last cycle signal segment of the optical signal to be analyzed;

[0039] The present invention also provides a temperature detection system for the outgoing cable of a transformer winding, which includes a memory and a processor. The processor executes the computer program stored in the memory to implement the steps of the foregoing method.

[0040] The beneficial effects of the technical solution of the present invention are as follows: According to the present invention, when magnetostrictive effect occurs in the iron core of a transformer, causing the transformer to vibrate, the influence of this vibration on the temperature measurement of the fluorescence optical fiber temperature sensor can be accurately analyzed. By initially correcting the optical signal at the monitoring point on the outgoing cable of the transformer winding, and analyzing the deviation of the optical signal intensity at each moment within each periodic signal segment of the optical signal affected by the operation of the transformer, and the initial influence index affected by the operation of the transformer, the final influence index of the optical signal intensity at the monitoring point on the cable affected by the operation of the transformer at the current moment is determined. And according to the final influence index, the optical signal intensity at the monitoring point at the current moment is corrected to obtain the final corrected optical signal intensity at each monitoring point at the current moment. By the final corrected optical signal intensity, the true temperature value at each monitoring point at the current moment is obtained, which improves the accuracy of temperature measurement of the outgoing cable of the transformer winding by the fluorescence optical fiber temperature sensor when the transformer vibrates. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0042] Figure 1 It is a flowchart of the steps of a temperature detection method for the outgoing cable of a transformer winding provided by an embodiment of the present invention. Detailed Embodiments

[0043] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with the drawings and preferred embodiments, details the specific embodiments, structures, features and their effects of a temperature detection method and system for the outgoing cable of a transformer winding proposed according to the present invention. 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.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs.

[0045] The following specifically describes the specific solutions of a temperature detection method and system for the outgoing cable of a transformer winding in conjunction with the accompanying drawings.

[0046] Please refer to Figure 1 , which shows a flowchart of the steps of a temperature detection method for the outgoing cable of a transformer winding provided by an embodiment of the present invention. The method includes the following steps:

[0047] Step S001: Obtain the optical signal at the monitoring point on the outgoing cable of the transformer winding. The optical signal includes the optical signal intensities at several moments; obtain the current signal of the outgoing cable of the transformer winding. The current signal includes the current values at several moments.

[0048] It should be noted that the working principle of the fluorescence optical fiber temperature sensor: (1) Excitation light source: The fluorescence optical fiber temperature sensor sends light of a certain wavelength into the optical fiber through an excitation light source (usually an LED or a laser). (2) Fluorescence emission: The fluorescence optical fiber material (such as an optical fiber doped with a fluorescent substance) emits fluorescence under the action of the excitation light, and the fluorescence lifetime emitted will change with the change of temperature. (3) Temperature-related fluorescence change: With the change of temperature, the molecular structure of the fluorescent material in the optical fiber will change, resulting in a change in the attenuation rate or wavelength of the fluorescence (such as red shift or blue shift), which can be used to calculate the temperature. (4) Signal acquisition and analysis: Through a spectral analyzer or an optical reading device connected to the optical fiber sensor, the optical signal reflected or transmitted through the optical fiber is monitored in real time, and after corresponding algorithm processing, the temperature value is obtained. The main purpose of this embodiment is to reduce the interference of the transformer operation on the measurement of the optical signal by the fluorescence optical fiber temperature sensor, and then obtain a more accurate temperature of the outgoing cable of the transformer winding based on the optical signal with reduced interference. Before starting the analysis, relevant data is collected first.

[0049] Specifically, obtaining the optical signal at the monitoring point on the outgoing cable of the transformer winding is as follows:

[0050] On the outgoing cable of the transformer winding, a monitoring point is set every preset interval length , , is the length of the outgoing cable of the transformer winding, in meters. A fluorescence optical fiber temperature sensor is installed at each monitoring point, and the optical signal of each monitoring point is obtained through the fluorescence optical fiber temperature sensor. The acquisition frequency of the fluorescence optical fiber temperature sensor is 1 Hz, and the acquisition duration is the most recent 2 hours.

[0051] Furthermore, obtaining the current signal of the outgoing cable of the transformer winding is as follows:

[0052] Obtain the current signal of the outgoing cable of the transformer winding through a current sensor, where the acquisition frequencies and acquisition durations corresponding to the current signal and the optical signal are the same, that is, the acquisition frequency of the current sensor is 1 Hz and the acquisition duration is the most recent 2 hours.

[0053] It should be noted that both the optical signal and the current signal are discrete-time signals.

[0054] So far, obtain the optical signal at the monitoring point on the outgoing cable of the transformer winding; obtain the current signal of the outgoing cable of the transformer winding.

[0055] Step S002: In each optical signal, obtain several periodic signal segments; according to each periodic signal segment and the optical signal intensities and current values at the corresponding moments in the previous periodic signal segments, obtain the initial corrected optical signal intensity at each moment within each periodic signal segment; according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each periodic signal segment, and in combination with the current value at the corresponding moment, obtain the final deviation value at each moment within each periodic signal segment, which reflects the influence of the transformer operation on the optical signal intensity.

[0056] It should be noted that in a transformer, due to the influence of the electromagnetic field generated during the operation of the transformer on the iron core of the transformer, the iron core will exhibit the magnetostrictive effect. The magnetostrictive effect refers to the phenomenon that when a magnetic material undergoes a change in magnetization state under the action of an external magnetic field, its size or volume will change slightly. Since the alternating electric field generated by the transformer is periodic, the expansion and contraction vibration of the iron core also exhibits the same periodic characteristics. This periodic vibration causes the fluorescence in the fluorescence optical fiber temperature sensor to be subjected to additional stress, and the stress is also periodic, and the interference during temperature measurement is also periodically changing. In addition, considering that multi-position measurements are carried out on the outgoing cable of the transformer winding, that is, each position has a corresponding optical signal. Since the degrees of influence of different positions on the outgoing cable by the transformer are different, the actual temperatures of adjacent places are originally close, but the temperatures of the two monitoring points will be different. By combining the optical signals at all monitoring points, analyze the periodic interference of the transformer operation on the fluorescence optical fiber temperature sensors at different positions.

[0057] It should be noted that since the transformer is connected to a sinusoidal AC power supply during operation, the vibration caused by the magnetostrictive effect on the iron core of the transformer also has a certain periodic change, and the fluorescence optical fiber temperature sensor connected to the outgoing cable of the winding will also be interfered with by the same period. Under such interference, the interference during temperature monitoring by the fluorescence optical fiber temperature sensor is also periodically changing, that is, in the monitoring data, the monitored optical signal will exhibit a corresponding periodicity. Therefore, it is necessary to analyze the periodic change of the interference of the monitoring point by the transformer operation.

[0058] Further, it should be noted that in order to avoid the periodic calculation error caused by the change of cable temperature, it is necessary to analyze the change of the optical signal at the monitoring point to judge the interference caused by the transformer, that is, it is necessary to analyze the periodic signal segment of the optical signal.

[0059] Specifically, in each optical signal, several periodic signal segments are obtained as follows:

[0060] Take any monitoring point as the monitoring point to be analyzed, and denote the optical signal of the monitoring point to be analyzed as the optical signal to be analyzed; denote the differential signal of the optical signal to be analyzed as the optical differential signal to be analyzed. It should be noted that the differential signal of the optical signal to be analyzed is obtained by performing a differential operation on the optical signal to be analyzed. The differential operation specifically uses backward difference. Obtaining the differential signal of a discrete-time signal is a conventional method and will not be elaborated in this embodiment; perform a discrete Fourier transform (Discrete Fourier Transform, DFT) on the optical differential signal to be analyzed to obtain the frequency spectrum diagram of the optical differential signal to be analyzed. Take the frequency with the largest amplitude in the frequency spectrum diagram as the reference frequency of the optical differential signal to be analyzed, and take the reciprocal of the reference frequency as the reference period of the optical differential signal to be analyzed; starting from the first signal amplitude of the optical differential signal to be analyzed, obtain a signal segment with the same length as the reference period, denoted as the first signal segment; obtain the extreme value closest to the last signal amplitude in the first signal segment in the optical differential signal to be analyzed, denoted as the first extreme value, and take the signal segment from the first signal amplitude to the first extreme value in the optical differential signal to be analyzed as the first reference period signal segment of the optical differential signal to be analyzed; starting from the first extreme value in the optical differential signal to be analyzed, obtain a signal segment with the same length as the reference period, denoted as the second signal segment; obtain the extreme value closest to the last signal amplitude in the second signal segment in the optical differential signal to be analyzed, denoted as the second extreme value, and take the signal segment from the first extreme value to the second extreme value in the optical differential signal to be analyzed as the second reference period signal segment of the optical differential signal to be analyzed; and so on, to obtain multiple reference period signal segments of the optical differential signal to be analyzed; obtain the division moments of all reference period signal segments in the optical differential signal to be analyzed, all denoted as key division moments; divide the optical signal to be analyzed according to all key division moments to obtain several periodic signal segments of the optical signal to be analyzed.

[0061] It should be noted that since the periods corresponding to different interference stages during the operation of the transformer will have certain differences, the extreme value near the period is selected on the optical differential signal to be analyzed as the end of a period, and this position is used as a new starting point to adjust the next period in the same way to adapt to the change of the period corresponding to the interference stage.

[0062] It should be noted that since the influence of the transformer on the fluorescent optical fiber temperature sensor is mainly caused by the alternating electric field generated by the current in the transformer winding, and the change of the electric field is affected by the change of the current, the period of the interference brought by the transformer to the optical signal monitoring is relatively fast. And within a short period of time, the temperature change of the outgoing cable will not be too large. That is to say, within the recent several cycles, the actual temperature change of a monitoring point is small, or even stable and unchanged. Therefore, the difference between its monitoring value and the actual temperature is the interference situation at the corresponding moment. Based on this, to calculate the deviation value of the optical signal intensity monitored by the transformer on the fluorescent optical fiber temperature sensor at the moment to be analyzed, first analyze the initial corrected optical signal intensity at the moment to be analyzed in the optical signal.

[0063] Specifically, according to the optical signal intensity and current value at the corresponding moment in each cycle signal segment and the previous cycle signal segments, the initial corrected optical signal intensity at each moment within each cycle signal segment is obtained, as follows:

[0064] Denote any moment in the optical signal to be analyzed as the moment to be analyzed; denote the cycle signal segment to which the optical signal intensity at the moment to be analyzed belongs as the cycle signal segment to be analyzed; denote the sequence value of the moment to be analyzed in the cycle signal segment to be analyzed as , that is, the moment to be analyzed is the th moment in the cycle signal segment to be analyzed.

[0065]

[0066] In the formula, is the number of the cycle signal segment to be analyzed and the previous cycle signal segments in the optical signal to be analyzed; is the th cycle signal segment of the optical signal to be analyzed, and the current value corresponding to the th moment in the current signal; is the average value of the current values corresponding to all moments in the th cycle signal segment of the optical signal to be analyzed in the current signal; is the th cycle signal segment of the optical signal to be analyzed, and the optical signal intensity at the th moment; is to take the absolute value; is the initial corrected optical signal intensity at the th moment in the cycle signal segment to be analyzed of the optical signal to be analyzed.

[0067] It should be noted that since the influence of the transformer on the fluorescent fiber temperature sensor is mainly caused by the alternating electric field generated by the current in the transformer winding, and the change of the electric field is affected by the change of the current, the current values at the corresponding moments in the signal segment to be analyzed and the previous signal segments are analyzed to perform weighted averaging on the optical signal intensity, so as to reduce the influence of the transformer operation on the fluorescent fiber temperature sensor. When the smaller the current value corresponding to the th moment in the current signal, it indicates that when the transformer works at the th moment, the generated alternating electric field is weaker, the influence of the fluorescent fiber temperature sensor by the transformer operation is smaller, and the influence on the optical signal intensity during weighting is smaller. Therefore, by

[0068] performing weighted averaging on the optical signal intensity, the initial corrected optical signal intensity at each moment within each period signal segment of each optical signal is obtained.

[0069] Specifically, according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each period signal segment of the optical signal, combined with the current value at the corresponding moment, the final deviation value at each moment within each period signal segment reflecting the influence of the transformer operation on the optical signal intensity is obtained, and the steps included are:

[0070] First, according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each period signal segment of the optical signal, the initial deviation value of the optical signal intensity affected by the transformer operation at each moment within each period signal segment of each optical signal is obtained.

[0071] Secondly, according to the initial deviation value and the current value at the corresponding moment, the final deviation value at each moment within each period signal segment reflecting the influence of the transformer operation on the optical signal intensity is obtained.

[0071] Specifically, according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each period signal segment of the optical signal, the initial deviation value of the optical signal intensity affected by the transformer operation at each moment within each period signal segment of each optical signal is obtained, as follows:

[0072]

[0073] In the formula, is the optical signal intensity at the th moment within the period signal segment to be analyzed of the optical signal to be analyzed; is the initial corrected optical signal intensity at the th moment within the period signal segment to be analyzed of the optical signal to be analyzed; is the initial deviation value of the optical signal intensity affected by the transformer operation at the th moment within the period signal segment to be analyzed of the optical signal to be analyzed.

[0074] It should be noted that the above analyzes the deviation of the optical signal intensity at a certain moment in a single cycle affected by the operation of the transformer. However, it cannot guarantee its universality. It may be a deviation caused by special circumstances. To better analyze the deviation of the optical signal intensity affected by the operation of the transformer, considering multiple historical cycles, the closer to the analysis moment or the closer the current in the cable is to the analysis moment, the more similar its actual temperature is. Therefore, a weighted average is performed on the deviation fluctuations at the same moment in multiple cycles. Accordingly, the initial influence index of the optical signal intensity affected by the operation of the transformer at each moment in each cycle signal segment of the optical signal to which each monitoring point belongs is calculated. First, the final deviation value of the optical signal intensity affected by the operation of the transformer at each moment in each cycle signal segment of each optical signal is analyzed.

[0075] Specifically, according to the initial deviation value and the current value at the corresponding moment, the final deviation value at each moment in each cycle signal segment reflecting the influence of the transformer operation on the optical signal intensity is obtained, as follows:

[0076]

[0077] In the formula, is the number of the cycle signal segment to be analyzed and the previous cycle signal segments in the optical signal to be analyzed; is the current value corresponding to the th moment in the current signal in the cycle signal segment to be analyzed of the optical signal to be analyzed; is the th cycle signal segment of the optical signal to be analyzed, and the current value corresponding to the th moment in the current signal; is the order value corresponding to the th moment in the optical signal to be analyzed in the cycle signal segment to be analyzed of the optical signal to be analyzed; is the th cycle signal segment of the optical signal to be analyzed, and the order value corresponding to the th moment in the optical signal to be analyzed; is the th cycle signal segment of the optical signal to be analyzed, and the initial deviation value of the optical signal intensity affected by the operation of the transformer at the th moment; is to take the absolute value; is the exponential function with the natural constant as the base. In this embodiment, the model is used to present the inverse proportional relationship and normalization processing. is the input of the model; is the order value corresponding to the th moment in the cycle signal segment to be analyzed of the optical signal to be analyzed;

[0078] It should be noted that when is smaller, it indicates that the current value at the th moment in other cycle signal segments before the history of the cycle signal segment to be analyzed is closer to the current value at the th moment in the cycle signal segment to be analyzed. At the same time, the th moment in other cycle signal segments before the history of the cycle signal segment to be analyzed is closer to the th moment in the cycle signal segment to be analyzed. The deviation of the optical signal intensity caused by the operation of the transformer is more likely to be a real deviation rather than an accidental phenomenon. Compared with the historical cycle, the difference is smaller, and it is universal. When weighting, the smaller the correction of the initial deviation value is. Therefore, through weighting and averaging , the final deviation value of the optical signal intensity affected by the operation of the transformer at the th moment in the cycle signal segment of the optical signal to be analyzed is obtained.

[0079] So far, the final deviation value of the optical signal intensity affected by the operation of the transformer at the th moment in the cycle signal segment of the optical signal to be analyzed is obtained.

[0080] Step S003: According to the final deviation value and the optical signal intensity, obtain the initial influence index of each monitoring point at each moment in each cycle signal segment of the optical signal to which it belongs, reflecting the influence of the transformer operation on the optical signal intensity; according to the difference in the initial influence index of each monitoring point and its adjacent monitoring points at each moment in each cycle signal segment of the optical signal to which they belong, and the initial influence index, obtain the final influence index of the optical signal intensity affected by the transformer operation at each monitoring point at the current moment.

[0081] It should be noted that the above analyzes the final deviation value of the optical signal intensity affected by the operation of the transformer at each moment in each cycle signal segment of each optical signal, and then constructs the initial influence index of the optical signal intensity affected by the transformer operation at each monitoring point at each moment in each cycle signal segment of the optical signal to which it belongs.

[0082] Specifically, according to the final deviation value and the optical signal intensity, the initial influence index of each monitoring point at each moment in each cycle signal segment of the optical signal to which it belongs, reflecting the influence of the transformer operation on the optical signal intensity, is obtained as follows:

[0083]

[0084] In the formula, is the final deviation value of the optical signal intensity affected by the operation of the transformer at the th moment in the cycle signal segment of the optical signal to be analyzed;; is the The optical signal intensity at a certain moment; is to take the absolute value; is the initial influence index of the optical signal intensity at the th moment in the signal segment of the analysis period of the optical signal to be analyzed at the monitoring point to be analyzed affected by the transformer operation.

[0085] It should be noted that the greater the final deviation value of the optical signal intensity at the th moment in the signal segment of the analysis period of the optical signal to be analyzed affected by the transformer operation, the greater the influence of the monitoring point to be analyzed at the th moment in the signal segment of the analysis period of the optical signal to be analyzed by the transformer operation, and the greater the initial influence index.

[0086] It should be noted that the above analysis is based on the influence of the transformer on a single monitoring point at a single moment. However, in fact, when detecting the temperature of the outgoing cable through multiple monitoring points, each monitoring point will be affected by other surrounding monitoring points. The closer the fluorescence optical fiber temperature sensor is to the winding end, the greater the influence it receives from the transformer vibration. At the same time, due to the reasons of the optical fiber and other devices connected to it, the vibration of the transformer and the cable will be weakened, and the interference at the subsequent monitoring points farther away will be relatively small; at the same time, because the monitoring points are relatively close, their actual temperatures are almost the same, so their initial influence indexes will also change with the change of adjacent monitoring points. Accordingly, calculate the influence degree of each monitoring point on each adjacent monitoring point at each moment in each cycle signal segment of the optical signal to which it belongs, and first obtain the adjacent monitoring points of the monitoring point.

[0087] Specifically, obtain several adjacent monitoring points of each monitoring point as follows:

[0088] On the outgoing cable of the transformer winding, with the monitoring point to be analyzed as the center, other monitoring points within the range with a neighborhood radius of are used as the adjacent monitoring points of the monitoring point to be analyzed, is a preset first value, which is described as in this embodiment, is the length of the outgoing cable of the transformer winding, in meters.

[0089] Specifically, according to the difference in the initial influence indexes of the monitoring point and the adjacent monitoring points at each moment in each cycle signal segment of the optical signal to which they belong, and the initial influence index, obtain the final influence index of the optical signal intensity of each monitoring point affected by the transformer operation at the current moment, including the steps of:

[0090] First, based on the differences in the initial influence indicators of each moment within each cycle signal segment of the optical signal to which the monitoring point and its adjacent monitoring points belong, the influence degree of each monitoring point by each adjacent monitoring point at each moment within each cycle signal segment of the optical signal to which it belongs is obtained.

[0091] Secondly, based on the differences in the initial influence indicators of each moment within each cycle signal segment of the optical signal to which the monitoring point and all its adjacent monitoring points belong, the credibility factor of the influence of each monitoring point by each adjacent monitoring point at each moment within each cycle signal segment of the optical signal to which it belongs is obtained.

[0092] Finally, based on the initial influence indicator, the influence degree, and the credibility factor, the final influence indicator of the optical signal intensity of each monitoring point affected by the transformer operation at the current moment is obtained.

[0093] Specifically, based on the differences in the initial influence indicators of each moment within each cycle signal segment of the optical signal to which the monitoring point and its adjacent monitoring points belong, the influence degree of each monitoring point by each adjacent monitoring point at each moment within each cycle signal segment of the optical signal to which it belongs is obtained as follows:

[0094]

[0095] In the formula, is the number of the cycle signal segments to be analyzed and the previous cycle signal segments in the optical signal to be analyzed; is the initial influence indicator of the optical signal intensity of the monitoring point to be analyzed affected by the transformer operation at the -th moment within the -th cycle signal segment of the optical signal to be analyzed; is the initial influence indicator of the optical signal intensity of the -th adjacent monitoring point of the monitoring point to be analyzed affected by the transformer operation at the -th moment within the -th cycle signal segment of the optical signal to which it belongs; is the influence degree of the optical signal intensity of the monitoring point to be analyzed at the -th moment within the cycle signal segment to be analyzed of the optical signal to be analyzed affected by the -th adjacent monitoring point.

[0096] It should be noted that ideally, the differences in the initial influence indicators of adjacent monitoring points are small. When the difference in the initial influence indicators of the monitoring point to be analyzed and the adjacent monitoring point at the same moment within the corresponding cycle signal segment is larger, it indicates that the adjacent monitoring point has a greater influence on the monitoring point to be analyzed, that is, the influence degree of the optical signal intensity of the monitoring point to be analyzed at the -th moment within the cycle signal segment to be analyzed of the optical signal to be analyzed affected by the 𝑘-th adjacent monitoring point is greater.

[0097] It should be noted that since not every monitoring point will affect the analyzed monitoring point, and the influence may vary in magnitude, the influence of this monitoring point on the analyzed monitoring point may not be reliable. The more stable the influence, the more reliable it is when estimating the degree of influence. Therefore, based on the stability of this interference in past cycles, the credibility factor of each monitoring point being affected by each adjacent monitoring point at each moment within each cycle signal segment of the optical signal to which it belongs is analyzed.

[0098] Specifically, according to the difference in the initial influence indicators of the monitoring point and all adjacent monitoring points at each moment within each cycle signal segment of their respective optical signals, the credibility factor of each monitoring point being affected by each adjacent monitoring point at each moment within each cycle signal segment of the optical signal to which it belongs is obtained, as follows:

[0099]

[0100] In the formula, is the number of the cycle signal segments of the optical signal to be analyzed and the previous cycle signal segments; is the initial influence index of the optical signal intensity of the monitoring point to be analyzed at the th moment within the th cycle signal segment of the optical signal to be analyzed, affected by the operation of the transformer; is the th adjacent monitoring point of the monitoring point to be analyzed, and the initial influence index of the optical signal intensity at the th moment within the th cycle signal segment of the optical signal to which it belongs, affected by the operation of the transformer; is the number of adjacent monitoring points of the monitoring point to be analyzed; is to take the absolute value; is the hyperbolic tangent function, used for normalization; is the credibility factor of the monitoring point to be analyzed being affected by the th adjacent monitoring point at the th moment within the cycle signal segment of the optical signal to be analyzed.

[0101] It should be noted that when the fluctuation of the difference in the initial influence indicators of the monitoring point and all adjacent monitoring points at each moment within each cycle signal segment of their respective optical signals is smaller, it indicates that this difference in the initial influence indicators is basically stable in the historical cycle signal segments before the cycle signal segment to be analyzed and is frequently occurring. The more reliable it is that the monitoring point to be analyzed is affected by the th adjacent monitoring point at the th moment within the cycle signal segment of the optical signal to be analyzed.

[0102] It should be noted that the above analyzes the influence of the transformer on the analysis monitoring point and the influence of each adjacent monitoring point on the analysis monitoring point. In order to better determine the influence of the transformer operation on the optical signal intensity of the monitoring point at the current moment, consider analyzing the final influence index of the transformer operation on the optical signal intensity of each monitoring point at the current moment by combining the influence of all adjacent monitoring points on the analysis monitoring point with the influence of the transformer on the analysis monitoring point at the current moment.

[0103] Specifically, according to the initial influence index, influence degree, and credibility factor, the final influence index of the optical signal intensity of each monitoring point affected by the transformer operation at the current moment is obtained. The optical signal intensity at the current moment is the optical signal intensity at the last moment in the last cycle signal segment of the optical signal of the monitoring point, as follows:

[0104]

[0105] In the formula, is the number of adjacent monitoring points of the monitoring point to be analyzed; is the th adjacent monitoring point of the monitoring point to be analyzed, and it is the initial influence index of the optical signal intensity at the last moment in the last cycle signal segment of the optical signal affected by the transformer operation; is the influence degree of the optical signal intensity at the last moment in the last cycle signal segment of the optical signal to be analyzed of the monitoring point to be analyzed affected by the 𝑘th adjacent monitoring point; is the credibility factor of the monitoring point to be analyzed affected by the th adjacent monitoring point at the last moment in the last cycle signal segment of the optical signal to be analyzed; is the final influence index of the optical signal intensity of the monitoring point to be analyzed affected by the transformer operation at the last moment in the last cycle signal segment of the optical signal to be analyzed.

[0106] It should be noted that represents the result of adjusting the initial influence index of the optical signal intensity of the monitoring point to be analyzed affected by the transformer operation at the last moment according to the influence degree of the adjacent monitoring points. When the influence degree of the monitoring point to be analyzed by the adjacent monitoring points is greater, the initial influence index of the monitoring point to be analyzed should be reduced to reduce the influence of the adjacent monitoring points, and a weighted average is performed through the credibility factor affected by the adjacent monitoring points. When the credibility factor is greater, it indicates that the influence of the adjacent monitoring points on the monitoring point to be analyzed is more credible and its weight is greater. Finally, the final influence index of the optical signal intensity of the monitoring point to be analyzed affected by the transformer operation at the last moment is obtained.

[0107] Thus, the final influence index of the optical signal intensity of each monitoring point affected by the transformer operation at the current moment is obtained.

[0108] Step S004: Modify the optical signal intensity of each monitoring point at the current moment according to the final influence index to obtain the final modified optical signal intensity of each monitoring point at the current moment; obtain the true temperature value of each monitoring point at the current moment according to the final modified optical signal intensity of the monitoring point at the current moment.

[0109] It should be noted that after obtaining the final influence index of the optical signal intensity of each monitoring point at the current moment affected by the transformer operation, the current optical signal intensity can be modified according to it to obtain the final modified optical signal intensity of each monitoring point at the current moment, and then the true temperature of the monitoring point can be determined according to the final modified optical signal intensity.

[0110] Specifically, modifying the optical signal intensity of each monitoring point at the current moment according to the final influence index to obtain the final modified optical signal intensity of each monitoring point at the current moment is as follows:

[0111]

[0112] In the formula, is the optical signal intensity at the last moment in the optical signal to be analyzed; is the final influence index of the optical signal intensity of the monitoring point to be analyzed at the last moment in the last cycle signal segment of the optical signal to be analyzed affected by the transformer operation; is the final modified optical signal intensity at the last moment in the optical signal to be analyzed of the monitoring point to be analyzed.

[0113] It should be noted that in the working principle of the fluorescence optical fiber temperature sensor, the last step is signal acquisition and analysis: through a spectral analyzer or an optical reading device connected to the optical fiber sensor, the optical signal reflected or transmitted by the optical fiber is monitored in real time, and after corresponding algorithm processing, the temperature value is obtained. The above has obtained the final modified optical signal intensity of each monitoring point at the current moment. Next, the true temperature of the monitoring point at the current moment can be determined according to the final modified optical signal intensity, thus completing the temperature detection of the transformer winding outgoing cable.

[0114] Specifically, obtain the true temperature value of each monitoring point at the current moment according to the final modified optical signal intensity of the monitoring point at the current moment.

[0115] It should be noted that obtaining the true temperature value of each monitoring point at the current moment according to the final modified optical signal intensity of the monitoring point at the current moment is an existing method of the fluorescence optical fiber temperature sensor, which will not be elaborated in this embodiment.

[0116] Through the above steps, a temperature detection method for the transformer winding outgoing cable is completed.

[0117] Another embodiment of the present invention provides a temperature detection system for the outgoing cable of a transformer winding. The system includes a memory and a processor. When the processor executes the computer program stored in the memory, the following operations are performed:

[0118] Obtain the optical signal of the monitoring point on the outgoing cable of the transformer winding, where the optical signal includes the optical signal intensities at several moments; obtain the current signal of the outgoing cable of the transformer winding, where the current signal includes the current values at several moments; in each optical signal, obtain several periodic signal segments; according to each periodic signal segment and the optical signal intensities and current values at the corresponding moments in the previous periodic signal segments, obtain the initial corrected optical signal intensity at each moment within each periodic signal segment; according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each periodic signal segment, and in combination with the current value at the corresponding moment, obtain the final deviation value at each moment within each periodic signal segment, reflecting the influence of the transformer operation on the optical signal intensity; according to the final deviation value and the optical signal intensity, obtain the initial influence index at each moment within each periodic signal segment of each monitoring point in the optical signal to which it belongs, reflecting the influence of the transformer operation on the optical signal intensity; according to the difference in the initial influence indices at each moment within each periodic signal segment of each monitoring point and its adjacent monitoring point in their respective optical signals, and the initial influence index, obtain the final influence index of the optical signal intensity of each monitoring point at the current moment affected by the transformer operation; correct the optical signal intensity of each monitoring point at the current moment according to the final influence index to obtain the final corrected optical signal intensity of each monitoring point at the current moment; obtain the true temperature value of each monitoring point at the current moment according to the final corrected optical signal intensity of each monitoring point at the current moment.

[0119] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A temperature detection method for the outgoing cable of a transformer winding, characterized in that, The method includes the following steps: Obtain the optical signal of the monitoring point on the outgoing cable of the transformer winding, where the optical signal includes the optical signal intensities at several moments; obtain the current signal of the outgoing cable of the transformer winding, where the current signal includes the current values at several moments. In each optical signal, obtain several periodic signal segments; according to each periodic signal segment and the optical signal intensities and current values at corresponding moments in the previous periodic signal segments, obtain the initial corrected optical signal intensity at each moment within each periodic signal segment; according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each periodic signal segment, and in combination with the current value at the corresponding moment, obtain the final deviation value at each moment within each periodic signal segment, which reflects the influence of the transformer operation on the optical signal intensity. According to the final deviation value and the optical signal intensity, obtain the initial influence index at each moment within each periodic signal segment of each monitoring point in the optical signal to which it belongs, which reflects the influence of the transformer operation on the optical signal intensity; according to the difference in the initial influence indices at each moment within each periodic signal segment of each monitoring point and its adjacent monitoring points in the optical signals to which they belong, and the initial influence index, obtain the final influence index of the optical signal intensity of each monitoring point at the current moment under the influence of the transformer operation. Correct the optical signal intensity of the monitoring point at the current moment according to the final influence index to obtain the final corrected optical signal intensity of each monitoring point at the current moment; obtain the true temperature value of each monitoring point at the current moment according to the final corrected optical signal intensity of the monitoring point at the current moment.

2. The temperature detection method for the outgoing cable of a transformer winding according to claim 1, wherein The specific method for obtaining several periodic signal segments in each optical signal is as follows: Denote any one monitoring point as the monitoring point to be analyzed, and denote the optical signal of the monitoring point to be analyzed as the optical signal to be analyzed; denote the differential signal of the optical signal to be analyzed as the optical differential signal to be analyzed; perform a discrete Fourier transform on the optical differential signal to be analyzed to obtain the frequency spectrum diagram of the optical differential signal to be analyzed, take the frequency with the largest amplitude in the frequency spectrum diagram as the reference frequency of the optical differential signal to be analyzed, and take the reciprocal of the reference frequency as the reference period of the optical differential signal to be analyzed; starting from the first signal amplitude in the optical differential signal to be analyzed, obtain a signal segment with the same length as the reference period, and denote it as the first signal segment; obtain the extreme value closest to the last signal amplitude in the first signal segment in the optical differential signal to be analyzed, and denote it as the first extreme value, and take the signal segment from the first signal amplitude to the first extreme value in the optical differential signal to be analyzed as the first reference periodic signal segment of the optical differential signal to be analyzed. Starting from the first extreme value in the optical differential signal to be analyzed, obtain a signal segment with the same length as the reference period, and denote it as the second signal segment; obtain the extreme value closest to the last signal amplitude in the second signal segment in the optical differential signal to be analyzed, and denote it as the second extreme value, and take the signal segment from the first extreme value to the second extreme value in the optical differential signal to be analyzed as the second reference periodic signal segment of the optical differential signal to be analyzed. And so on, to obtain multiple reference periodic signal segments of the optical differential signal to be analyzed. Obtain the division moments of all reference period signal segments in the optical differential signal to be analyzed, and all of them are recorded as key division moments; divide the optical signal to be analyzed according to all the key division moments to obtain several period signal segments of the optical signal to be analyzed.

3. The temperature detection method for the outgoing cable of a transformer winding according to claim 2, characterized in that, The specific steps for obtaining the initial corrected optical signal intensity at each moment within each period signal segment according to the optical signal intensity and current value at the corresponding moment in each period signal segment and the previous period signal segments are as follows: At any moment of the optical signal to be analyzed, it is denoted as the moment to be analyzed; the periodic signal segment to which the optical signal intensity at the moment to be analyzed belongs is denoted as the periodic signal segment to be analyzed; the sequence value of the moment to be analyzed in the periodic signal segment to be analyzed is denoted as ; ； Wherein, is the number of the to-be-analyzed periodic signal segments and the previous periodic signal segments in the to-be-analyzed optical signal; is the th current value corresponding to the th moment in the th periodic signal segment of the to-be-analyzed optical signal in the current signal; is the average value of the current values corresponding to all moments in the th periodic signal segment of the to-be-analyzed optical signal in the current signal; is the optical signal intensity at the th moment in the th periodic signal segment of the to-be-analyzed optical signal; represents taking the absolute value; is the initial corrected optical signal intensity at the th moment in the to-be-analyzed periodic signal segment of the to-be-analyzed optical signal.

4. The temperature detection method for the outgoing cable of a transformer winding according to claim 3, characterized in that, The specific steps for obtaining the final deviation value at each moment within each period signal segment, which reflects the influence of the transformer operation on the optical signal intensity, according to the difference between the optical signal intensity and the initial corrected optical signal intensity at each moment within each period signal segment and combining with the current value at the corresponding moment are as follows: ； Wherein, is the optical signal intensity at the -th moment in the to-be-analyzed periodic signal segment of the to-be-analyzed optical signal; is the initial deviation value of the optical signal intensity at the -th moment in the to-be-analyzed periodic signal segment of the to-be-analyzed optical signal affected by the operation of the transformer; Obtain the final deviation value at each moment within each period signal segment, which reflects the influence of the transformer operation on the optical signal intensity, according to the initial deviation value and the current value at the corresponding moment.

5. The temperature detection method for the outgoing cable of a transformer winding according to claim 4, wherein, The specific steps for obtaining the final deviation value at each moment within each period signal segment, which reflects the influence of the transformer operation on the optical signal intensity, according to the initial deviation value and the current value at the corresponding moment are as follows: ； Wherein, is the current value corresponding to the -th moment in the current signal within the period signal segment of the optical signal to be analyzed; is the sequence value corresponding to the -th moment in the optical signal to be analyzed within the period signal segment of the optical signal to be analyzed; is the sequence value corresponding to the -th moment in the -th period signal segment of the optical signal to be analyzed in the optical signal to be analyzed; is the initial deviation value of the optical signal intensity corresponding to the -th moment in the -th period signal segment of the optical signal to be analyzed affected by the transformer operation; is the exponential function with the natural constant as the base; is the final deviation value of the optical signal intensity corresponding to the -th moment in the period signal segment of the optical signal to be analyzed affected by the transformer operation.

6. The temperature detection method for the outgoing cable of a transformer winding according to claim 5, characterized in that, The specific steps for obtaining the initial influence index at each moment within each period signal segment of the optical signal to which each monitoring point belongs, which reflects the influence of the transformer operation on the optical signal intensity, according to the final deviation value and the optical signal intensity are as follows: ； In the formula, is the initial influence index of the optical signal intensity at the -th moment in the signal segment of the cycle of the optical signal to be analyzed at the monitoring point to be analyzed, affected by the operation of the transformer.

7. The temperature detection method for the outgoing cable of a transformer winding according to claim 2, wherein The specific steps for obtaining the final influence index of the optical signal intensity of each monitoring point at the current moment affected by the transformer operation according to the difference in the initial influence index at each moment within each period signal segment of the optical signals to which the monitoring point and the adjacent monitoring points belong and the initial influence index are as follows: ； Wherein, is the number of the to-be-analyzed periodic signal segments and the previous periodic signal segments in the to-be-analyzed optical signal; is the number of the periodic signal segment; is the initial influence index of the optical signal intensity of the to-be-analyzed monitoring point at the th moment in the th periodic signal segment of the to-be-analyzed optical signal affected by the operation of the transformer; is the initial influence index of the optical signal intensity of the th adjacent monitoring point of the to-be-analyzed monitoring point at the th moment in the th periodic signal segment of the optical signal to which it belongs affected by the operation of the transformer; is the influence degree of the optical signal intensity of the to-be-analyzed monitoring point at the th moment in the to-be-analyzed periodic signal segment of the to-be-analyzed optical signal affected by the th adjacent monitoring point; Obtain the credibility factor of each monitoring point affected by each adjacent monitoring point at each moment within each period signal segment of the optical signal to which it belongs according to the difference in the initial influence index at each moment within each period signal segment of the optical signals to which the monitoring point and all adjacent monitoring points belong; Obtain the final influence index of the optical signal intensity of each monitoring point at the current moment affected by the transformer operation according to the initial influence index, the degree of influence, and the credibility factor.

8. The temperature detection method for the outgoing cable of a transformer winding according to claim 7, characterized in that, The specific steps for obtaining the credibility factor of each monitoring point affected by each adjacent monitoring point at each moment within each period signal segment of the optical signal to which it belongs according to the difference in the initial influence index at each moment within each period signal segment of the optical signals to which the monitoring point and all adjacent monitoring points belong are as follows: ； Wherein, is the number of adjacent monitoring points of the monitoring point to be analyzed and monitored; is to take the absolute value; is the hyperbolic tangent function; is the credibility factor that the monitoring point to be analyzed is affected by the th adjacent monitoring point at the th moment within the period signal segment of the optical signal to be analyzed for the monitoring point to be analyzed.

9. The temperature detection method for the outgoing cable of a transformer winding according to claim 7, wherein, The specific steps for obtaining the final influence index of the optical signal intensity of each monitoring point at the current moment affected by the transformer operation according to the initial influence index, the degree of influence, and the credibility factor are as follows: The optical signal intensity at the current moment is the optical signal intensity at the last moment in the optical signal of the monitoring point; ； Wherein, is the number of adjacent monitoring points of the monitoring point to be analyzed; is the initial influence index of the optical signal intensity at the last moment in the last cycle signal segment of the optical signal on the operation of the transformer for the th adjacent monitoring point of the monitoring point to be analyzed; is the influence degree of the optical signal intensity at the last moment in the last cycle signal segment of the optical signal to be analyzed on the th adjacent monitoring point of the monitoring point to be analyzed; is the credibility factor of the influence of the th adjacent monitoring point on the monitoring point to be analyzed at the last moment in the last cycle signal segment of the optical signal to be analyzed; is the final influence index of the optical signal intensity at the last moment in the last cycle signal segment of the optical signal to be analyzed on the operation of the transformer.

10. A temperature detection system for the outgoing cable of a transformer winding. The system includes a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the computer program is executed by a processor, it implements the steps of the method for detecting the temperature of the outgoing cable of a transformer winding as described in any one of claims 1-9.

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