CN-121978454-A - Corona discharge positioning and temperature measuring method and device based on analog lead

CN121978454ACN 121978454 ACN121978454 ACN 121978454ACN-121978454-A

Abstract

The embodiment of the application discloses a corona discharge positioning and temperature measuring method and device based on an analog wire, wherein the embodiment of the application can control an optical signal receiving and transmitting unit to inject an optical pulse signal into a distributed optical fiber, the optical signal receiving and transmitting unit is used for receiving a backward scattering signal returned by the distributed optical fiber based on the optical pulse signal, the backward scattering signal comprises a Raman scattering sub-signal and a Rayleigh scattering sub-signal, a temperature data sequence distributed along the length of the distributed optical fiber is determined based on the intensity ratio of Stokes light and anti-Stokes light in the Raman scattering sub-signal, and the target position of occurrence of corona discharge on the surface of a metal coating is determined based on the receiving time corresponding to a time domain disturbance characteristic in the Rayleigh scattering sub-signal, the injection time of the optical pulse signal and the propagation speed of light in the distributed optical fiber. Therefore, the embodiment of the application can synchronously realize high-precision positioning of the corona discharge position and accurate measurement of the local temperature rise of the discharge area.

Inventors

CAI FUJIE
DENG XIN
JIANG WEIZE
WU YAHU
CHENG XIANGJIAN

Assignees

四川阿坝金川华电新能源有限公司

Dates

Publication Date: 20260505
Application Date: 20260115

Claims (10)

1. The utility model provides a corona discharge location and temperature measurement method based on analog wire, its characterized in that is applicable to the control unit in the hot state perception system of corona, the control unit is connected with optical signal receiving and transmitting unit communication, optical signal receiving and transmitting unit and distributed optic fibre are coupled optically, the surface of distributed optic fibre is provided with the metal coating, distributed optic fibre with the metal coating constitutes analog wire jointly, the metal coating is connected with high voltage output of high voltage power supply, high voltage power supply's reference terminal ground connection, under the high voltage effect that high voltage power supply applyed, the metal coating surface produces corona discharge, the method includes: Controlling the optical signal receiving and transmitting unit to inject an optical pulse signal into the distributed optical fiber; receiving a back scattering signal returned by the distributed optical fiber based on the optical pulse signal through the optical signal receiving and transmitting unit, wherein the back scattering signal comprises a Raman scattering sub-signal and a Rayleigh scattering sub-signal; determining a temperature data sequence distributed along the length of the distributed optical fiber based on the intensity ratio of Stokes light and anti-Stokes light in the Raman scattering sub-signal, wherein each temperature value in the temperature data sequence corresponds to different positions of the metal coating along the length direction of the metal coating and is used for representing the local temperature rise spatial distribution caused by corona discharge on the metal coating; And determining a target position of occurrence of corona discharge on the surface of the metal coating based on receiving time corresponding to a time domain disturbance characteristic in the Rayleigh scattering sub-signal, injection time of the optical pulse signal and propagation speed of light in the distributed optical fiber, wherein the time domain disturbance characteristic is Rayleigh scattering time domain abnormality generated by local disturbance of the distributed optical fiber when the optical pulse signal propagates to the corona discharge position.
2. The method of claim 1, wherein the raman scattered sub-signals comprise scattered light components generated at different locations along the distributed optical fiber and received at different times; The determining a temperature data sequence distributed along the length of the distributed optical fiber based on an intensity ratio of stokes light to anti-stokes light in the raman scattering sub-signal comprises: Determining a spatial position corresponding to each scattered light component according to a time difference between the injection time of the optical pulse signal and the receiving time of each scattered light component and the propagation speed of light in the distributed optical fiber; and demodulating to obtain temperature values corresponding to each spatial position based on the intensity ratio of Stokes light and anti-Stokes light in scattered light components at each spatial position, and forming a temperature data sequence distributed along the length of the distributed optical fiber.
3. The method as recited in claim 1, further comprising: acquiring a temperature data sequence in a preset time period, wherein the temperature data sequence comprises temperature values corresponding to each space position along the length direction of the distributed optical fiber; Determining a target spatial position corresponding to the target position from among the spatial positions along the length direction of the distributed optical fiber; acquiring continuous temperature data corresponding to the target space position from the temperature data sequence in the preset time period; And analyzing and processing the continuous temperature data corresponding to the target space position to obtain the corona thermal response temperature rise characteristic of the metal coating at the target position.
4. The method of claim 3, wherein analyzing the continuous temperature data corresponding to the target spatial location to obtain a corona thermal response temperature rise characteristic of the metal coating at the target location comprises: Based on continuous temperature data corresponding to the target space position, recognizing a time point when the temperature rise rate exceeds a preset threshold value for the first time as a corona starting time point, and extracting a corresponding temperature rise curve from the continuous temperature data by taking the corona starting time point as a starting point; And carrying out exponential fitting treatment on the temperature rise curve to obtain a temperature rise amplitude and a thermal response time constant which characterize the corona thermal response characteristics of the simulated wire, wherein the temperature rise amplitude is used for characterizing the energy intensity of corona discharge on the surface of the metal coating, and the thermal response time constant is used for characterizing the speed characteristics of the thermal response of the metal coating under the action of the corona discharge.
5. The method of claim 4, wherein said exponentially fitting said temperature rise profile to obtain a temperature rise magnitude and a thermal response time constant characteristic of a simulated wire corona thermal response, comprises: Construction of an exponential fitting model , wherein, As a result of the initial temperature being set, As a point in time at which the corona is initiated, In order to increase the temperature of the liquid, Is a thermal response time constant, and the initial temperature Determining the temperature at the corona initial time point according to the temperature rise curve; taking a plurality of time-temperature data in the temperature rise curve as input, adopting a nonlinear least square method, and adjusting the parameter number through iteration And Minimizing the sum of squares of errors between the output value of the exponential fit model and the measured temperature data; Parameters that will minimize the sum of squares of the errors And The magnitude of the temperature rise and the thermal response time constant, which characterize the wire corona thermal response characteristics, are determined.
6. The method of claim 4, further comprising, after said subjecting said temperature rise profile to an exponential fit to obtain a temperature rise magnitude and a thermal response time constant that characterize the corona thermal response of the simulated wire: acquiring the occurrence time of the time domain disturbance characteristic corresponding to the target position; if the difference between the corona starting time point and the occurrence time of the time domain disturbance characteristic is smaller than a preset time threshold value, confirming that abnormal temperature at the target position is caused by corona discharge, and reserving the corona thermal response temperature rise characteristic for subsequent early warning; otherwise, judging that the abnormal temperature at the target position is caused by a non-corona discharge factor, and discarding the current temperature rise curve and the fitting result.
7. The method of claim 3, further comprising, after said analyzing said continuous temperature data corresponding to said target spatial location to obtain a corona thermal response temperature rise characteristic of said metal coating at said target location: acquiring a mapping relation between a preset early warning level and a preset corona thermal response temperature rise characteristic; Based on the corona thermal response temperature rise characteristic of the metal coating at the target position, determining a corresponding target early warning level from the mapping relation between the preset early warning level and the preset corona thermal response temperature rise characteristic; and sending a corresponding early warning signal to an object associated with the target early warning level.
8. The method of claim 3, further comprising, after said analyzing said continuous temperature data corresponding to said target spatial location to obtain a corona thermal response temperature rise characteristic of said metal coating at said target location: Acquiring environmental parameters of the current environment of the simulation lead; and compensating and correcting the corona thermal response temperature rise characteristic according to the environmental parameter.
9. The method of claim 3, further comprising, after said analyzing said continuous temperature data corresponding to said target spatial location to obtain a corona thermal response temperature rise characteristic of said metal coating at said target location: Acquiring operation state parameters of at least one adjacent analog wire within a preset time period, wherein the at least one adjacent analog wire and the analog wire are in the same physical area, and the operation state parameters comprise at least one of voltage, current and wire surface temperature; estimating the interference degree of the adjacent simulated wire to the local thermal environment at the target position based on the running state parameters of the adjacent simulated wire; And compensating and correcting the corona thermal response temperature rise characteristic according to the interference degree.
10. Corona discharge location and temperature measuring device based on analog wire, its characterized in that is applicable to the control unit in the hot state perception system of corona, the control unit is connected with optical signal transceiver unit communication, optical signal transceiver unit and distributed optic fibre optical coupling, the surface of distributed optic fibre is provided with the metal coating, distributed optic fibre with the metal coating constitutes analog wire jointly, the metal coating is connected with high voltage output of high voltage power supply, high voltage power supply's reference terminal ground connection under the high voltage effect that high voltage power supply applyed, the metal coating surface produces corona discharge, the device includes: The signal injection unit is used for controlling the optical signal receiving and transmitting unit to inject an optical pulse signal into the distributed optical fiber; The signal receiving unit is used for receiving a back scattering signal returned by the distributed optical fiber based on the optical pulse signal through the optical signal receiving and transmitting unit, and the back scattering signal comprises a Raman scattering sub-signal and a Rayleigh scattering sub-signal; The temperature determining unit is used for determining a temperature data sequence distributed along the length of the distributed optical fiber based on the intensity ratio of Stokes light and anti-Stokes light in the Raman scattering sub-signal, and each temperature value in the temperature data sequence corresponds to different positions of the metal coating along the length direction of the metal coating and is used for representing the local temperature rise spatial distribution caused by corona discharge on the metal coating; The position determining unit is used for determining a target position of the occurrence of the corona discharge on the surface of the metal coating based on the receiving time corresponding to the time domain disturbance characteristic in the Rayleigh scattering sub-signal, the injection time of the optical pulse signal and the propagation speed of light in the distributed optical fiber, wherein the time domain disturbance characteristic is Rayleigh scattering time domain abnormality generated by the local disturbance of the distributed optical fiber when the optical pulse signal propagates to the corona discharge position.

Description

Corona discharge positioning and temperature measuring method and device based on analog lead Technical Field The application relates to the technical field of high-voltage engineering, in particular to a corona discharge positioning and temperature measuring method and device based on an analog wire. Background In high-voltage and extra-high voltage transmission systems, corona discharge is likely to occur on the surface of a wire due to electric field concentration. The corona not only causes energy loss, but also generates electromagnetic interference and audible noise, accelerates the aging of insulating materials, and can even cause local overheating after long-term or strong corona discharge so as to induce serious faults such as flashover and the like. Therefore, in experimental research, accurate position location and concomitant local temperature rise measurement of corona discharge events are of great significance in assessing thermal effects and potential hazards. Currently, in a laboratory environment, a wire sample to be measured is usually placed in a high-voltage electric field to excite corona discharge, and an external detection device such as an ultraviolet imager, a radio interferometer or an acoustic sensor is relied on to observe the discharge phenomenon. However, these methods generally have the problems of limited viewing distance, easy interference of strong electromagnetic environment, incapability of directly contacting the surface to be measured, and the like, so that accurate positioning of the corona discharge position is difficult to realize, and local temperature change information of the corona discharge region cannot be accurately obtained. Disclosure of Invention The embodiment of the application provides a corona discharge positioning and temperature measuring method and device based on a simulated wire, which can synchronously realize high-precision positioning of a corona discharge position and accurate measurement of local temperature rise of a discharge area. The embodiment of the application provides a corona discharge positioning and temperature measuring method based on an analog wire, which is applicable to a control unit in a corona thermal state sensing system, wherein the control unit is in communication connection with an optical signal receiving and transmitting unit, the optical signal receiving and transmitting unit is optically coupled with a distributed optical fiber, the outer surface of the distributed optical fiber is provided with a metal coating, the distributed optical fiber and the metal coating jointly form the analog wire, the metal coating is connected with a high-voltage output end of a high-voltage power supply, a reference end of the high-voltage power supply is grounded, and corona discharge is generated on the surface of the metal coating under the action of high voltage applied by the high-voltage power supply, and the method comprises the following steps: Controlling the optical signal receiving and transmitting unit to inject an optical pulse signal into the distributed optical fiber; Receiving a back scattering signal returned by the distributed optical fiber based on the optical pulse signal through the optical signal receiving and transmitting unit, wherein the back scattering signal comprises a Raman scattering sub-signal and a Rayleigh scattering sub-signal; Determining a temperature data sequence distributed along the length of the distributed optical fiber based on the intensity ratio of Stokes light and anti-Stokes light in the Raman scattering sub-signals, wherein each temperature value in the temperature data sequence corresponds to different positions of the metal coating along the length direction of the metal coating respectively and is used for representing the local temperature rise spatial distribution caused by corona discharge on the metal coating; And determining a target position of occurrence of corona discharge on the surface of the metal coating based on receiving time corresponding to time domain disturbance characteristics in the Rayleigh scattering sub-signals, injection time of the optical pulse signals and propagation speed of light in the distributed optical fiber, wherein the time domain disturbance characteristics are Rayleigh scattering time domain abnormality generated by local disturbance of the distributed optical fiber when the optical pulse signals propagate to the corona discharge position. The embodiment of the application also provides a corona discharge positioning and temperature measuring device based on the analog wire, which is suitable for a control unit in a corona thermal state sensing system, the control unit is in communication connection with an optical signal receiving and transmitting unit, the optical signal receiving and transmitting unit is optically coupled with a distributed optical fiber, the outer surface of the distributed optical fiber is provided with a metal coating, the dist