CN-122017816-A - Line sag measurement method, device, medium and product based on traveling wave and temperature frequency wave speed coupling

CN122017816ACN 122017816 ACN122017816 ACN 122017816ACN-122017816-A

Abstract

The invention discloses a line sag measurement method, a device, a medium and a product based on the coupling of traveling wave and temperature frequency wave speed, and relates to the technical field of power transmission lines; and establishing and deriving an sag expression of any point of the overhead conductor, and measuring to obtain the maximum sag of the overhead conductor by combining the coupling coefficient. The invention provides a line sag measurement method, a device, a medium and a product based on the coupling of traveling wave and temperature frequency wave speed, which are used for solving the problem that the sag measurement is inaccurate due to the fact that the coupling influence of temperature and frequency on the traveling wave mode domain wave speed is not considered and the geometrical characteristics of a wire oblique parabola are not fully combined in the existing overhead wire maximum sag calculation method by deriving and locking the maximum sag position through sag expression and combining with a span to finish calculation so as to obtain the maximum sag.

Inventors

PENG XIANGYANG
FAN YAZHOU
ZHOU YUAN
WANG RUI
LI JUNCAI
Gou bin
LI ZHIFENG

Assignees

广东电网有限责任公司电力科学研究院

Dates

Publication Date: 20260512
Application Date: 20260327

Claims (11)

1. The line sag measurement method based on the coupling of the traveling wave and the temperature frequency wave speed is characterized by comprising the following steps of: collecting travelling wave current signals at suspension points at two ends of an overhead conductor; according to the traveling wave current signal, a mode domain wave speed is calculated by combining a temperature frequency wave speed coupling change function, wherein the temperature frequency wave speed coupling change function is established by combining a mode domain electric parameter obtained after the series impedance and the parallel admittance in a power transmission line frequency domain state are converted into a mode domain state; based on the wave speed of the mode field and the time difference that the traveling wave current signal reaches the suspension points at the two ends, performing curve integration by combining the geometrical characteristics of the oblique parabola, and calculating to obtain the oblique parabolic traveling wave coupling coefficient of the lead; And establishing an sag expression of any point on the overhead conductor, deriving, and measuring to obtain the maximum sag of the overhead conductor by combining the spans of the suspension points at the two ends and the oblique-polished travelling wave coupling coefficient of the conductor.
2. The line sag measurement method based on the coupling of a traveling wave and a temperature frequency wave speed according to claim 1, wherein the mode domain wave speed is calculated by combining a temperature frequency wave speed coupling change function according to the traveling wave current signal, specifically: decomposing the travelling wave current signal to obtain a plurality of modal components; Extracting an optimal modal component from the modal components by calculating an envelope entropy; Calculating the energy spectrum of the optimal modal component according to the symmetrical differential energy operator, calibrating the arrival time of the traveling wave and extracting an effective signal segment; And extracting a center frequency from the effective signal section, substituting the center frequency, the ambient temperature of the overhead conductor and the conductor temperature into the temperature frequency wave speed coupling change function, and calculating to obtain the mode domain wave speed.
3. The line sag measurement method based on the coupling of a traveling wave and a temperature frequency wave speed according to claim 2, wherein the traveling wave current signal is decomposed to obtain a plurality of modal components, specifically: Iteratively updating the noise-containing residual error according to preset Gaussian white noise until the residual error signal of the corresponding order shows a single change trend or the extreme point number is smaller than a preset value, and outputting the modal components; And in the first iteration, the noise-containing residual error of the first order is obtained by taking the aggregate mean value of the first-order eigenmode functions as a first-order mode component and calculating according to the travelling wave current signal and the first-order mode component, and the first-order eigenmode function is obtained by superposing the Gaussian white noise in the travelling wave current signal and performing empirical mode decomposition on the generated noise-containing signal.
4. The line sag measurement method based on the coupling of the traveling wave and the temperature frequency wave speed according to claim 2, wherein the optimal modal components are extracted from the modal components by calculating envelope entropy, specifically: And respectively calculating the envelope entropy of the modal components, and defining the modal component corresponding to the maximum envelope entropy as the optimal modal component.
5. The line sag measurement method based on the coupling of the traveling wave and the temperature frequency wave speed according to claim 2, wherein the energy spectrum of the optimal modal component is calculated according to a symmetrical differential energy operator, the arrival time of the traveling wave is calibrated, and an effective signal segment is extracted, specifically: Based on a symmetrical differential energy operator, quantifying the signal energy of the optimal modal component by capturing the signal change intensity of adjacent sampling points in the discrete signal to obtain a plurality of energy values; establishing a mapping relation between the energy values and the corresponding sampling moments, and generating a symmetrical differential energy operator energy spectrum of the optimal modal component; Extracting a first energy mutation peak value from the energy spectrum of the symmetrical differential energy operator, and calibrating a sampling time corresponding to the first energy mutation peak value as a positioning time when the fault traveling wave first reaches a monitoring terminal; and intercepting a traveling wave signal pulse interval corresponding to the positioning moment in the discrete signal sequence of the optimal modal component to obtain the effective signal segment.
6. The line sag measurement method based on the coupling of traveling waves and temperature frequency wave speed according to claim 1, wherein the temperature frequency wave speed coupling change function is established by converting series impedance and parallel admittance in a power transmission line frequency domain state into a mode domain state and combining the mode domain electrical parameters obtained after the conversion, and specifically comprises the following steps: Converting the series impedance and the parallel admittance of the overhead conductor in the frequency domain state of the transmission line into a mode domain state through the Carnobel conversion to obtain the mode domain electrical parameters; Calculating a traveling wave attenuation constant and a phase constant according to the mode domain electrical parameters, and establishing a curve equation of frequency and wave speed based on the traveling wave attenuation constant and the phase constant; substituting the electric parameters of the distribution of the electric transmission line of the overhead conductor into a curve equation of the frequency and the wave speed to obtain the temperature frequency wave speed coupling change function.
7. The method for measuring sag of a line based on coupling of traveling wave and temperature frequency wave velocity according to claim 6, wherein the distributed electrical parameters of the power transmission line include distributed impedance, distributed conductance and distributed inductance.
8. The line sag measurement method based on the coupling of a traveling wave and a temperature frequency wave speed according to claim 1, wherein the curve integration is performed by combining the geometrical characteristics of a diagonal parabola based on the mode domain wave speed and the time difference that the traveling wave current signal reaches the suspension points at the two ends, and the line diagonal-throwing traveling wave coupling coefficient of a wire is calculated, specifically: constructing a coordinate system by taking the lowest point of the overhead conductor as an origin, and establishing a conductor inclined parabolic equation based on the conductor section acting force balance relation by combining the included angles between the connecting lines of the suspension points at the two ends and the horizontal direction; Based on the form of the propagation path of the overhead conductor, carrying out curve integral calculation on the mode domain wave velocity and the time difference of the traveling wave current signal reaching the suspension points at the two ends, parallel-erecting the oblique parabolic equation of the conductor, and establishing an adaptive calculation relation of coordinates of the suspension points at the two ends to obtain an integrated calculation formula; Substituting the span of the suspension points at the two ends, the wave speed of the mode domain and the time difference of the traveling wave current signal reaching the suspension points at the two ends into the comprehensive calculation, and calculating to obtain the oblique-throwing traveling wave coupling coefficient of the lead.
9. The line sag measurement device based on the coupling of the traveling wave and the temperature frequency wave speed is characterized by comprising a signal module, a wave speed module, a coefficient module and a sag module; The signal module is used for collecting travelling wave current signals at hanging points at two ends of the overhead conductor; The wave speed module is used for calculating the mode domain wave speed according to the traveling wave current signal and combining a temperature frequency wave speed coupling change function, wherein the temperature frequency wave speed coupling change function is established by combining the mode domain electric parameters obtained after the series impedance and the parallel admittance in the frequency domain state of the power transmission line are converted into the mode domain state; The coefficient module is used for carrying out curve integration by combining the geometrical characteristics of the oblique parabola based on the mode domain wave velocity and the time difference of the traveling wave current signal reaching the suspension points at the two ends, and calculating to obtain a lead oblique-throwing traveling wave coupling coefficient; and the sag module is used for establishing a sag expression of any point on the overhead conductor, deriving the sag expression, and measuring and obtaining the maximum sag of the overhead conductor by combining the spans of the suspension points at the two ends and the oblique throwing traveling wave coupling coefficient of the conductor.
10. A storage medium, wherein a computer program is stored on the storage medium, and the computer program is called and executed by a computer to implement a line sag measurement method based on coupling of a traveling wave and a temperature frequency wave speed according to any one of claims 1 to 7.
11. A computer program product comprising a computer program or instructions which, when executed by a communication device, implements a line sag measurement method based on the coupling of a travelling wave with a temperature frequency wave velocity as claimed in any one of claims 1 to 8.

Description

Line sag measurement method, device, medium and product based on traveling wave and temperature frequency wave speed coupling Technical Field The invention relates to the technical field of electric power transmission lines, in particular to a line sag measurement method, device, medium and product based on the coupling of traveling waves and temperature frequency wave speed. Background The method is a key core technology for guaranteeing safe and stable operation of the power transmission line, can effectively avoid malignant faults such as line short circuit and broken line caused by discharge or mechanical collision of the overhead conductor with ground facilities and peripheral obstacles due to exceeding of the conductor sag, can provide accurate scientific basis for design optimization of the power transmission line, formulation of operation and maintenance inspection schemes and implementation of dynamic capacity-increasing strategies, and has important significance for reducing potential safety hazards of the power transmission line, reducing operation and maintenance cost and improving stability and reliability of power supply of a power grid. The existing overhead conductor maximum sag calculation method is various in types, mainly comprises manual inspection methods such as an equal length method and an abnormal length method, a mathematical model method for simplifying calculation and guaranteeing accuracy by means of a parabolic model and a catenary model, a sensor parameter detection method for constructing a model by measuring data such as conductor temperature and stress, and a sag prediction method combining a dynamic capacity-increasing model of a power transmission line and an artificial intelligent algorithm. However, the existing calculation method for the maximum sag of the overhead conductor cannot consider the coupling influence of temperature and frequency on the wave speed of the traveling wave mode domain, and the geometric characteristics of the oblique parabola of the conductor are not fully combined, so that the calculation accuracy is limited. Wherein, the manual inspection method cannot realize live real-time detection and has larger error; the mathematical model is not combined with the actual operation condition, the prediction precision is low, the sensor parameter detection method is complex in operation, the electrified installation is at risk and the monitoring cost is high, the intelligent algorithm prediction method lacks mechanism model support, is not attached to the specific condition of a line, and has weak generalization capability. Disclosure of Invention The invention provides a line sag measurement method, device, medium and product based on the coupling of traveling wave and temperature frequency wave speed, which are used for solving the problems that the existing method for calculating the maximum sag of an overhead conductor does not consider the coupling influence of temperature and frequency on the wave speed of a traveling wave mode domain, and the sag measurement is inaccurate due to insufficient combination of geometrical characteristics of a wire oblique parabola. In order to achieve the above purpose, the present application provides a line sag measurement method based on the coupling of a traveling wave and a temperature frequency wave speed, comprising: collecting travelling wave current signals at suspension points at two ends of an overhead conductor; according to the traveling wave current signal, a mode domain wave speed is calculated by combining a temperature frequency wave speed coupling change function, wherein the temperature frequency wave speed coupling change function is established by combining a mode domain electric parameter obtained after the series impedance and the parallel admittance in a power transmission line frequency domain state are converted into a mode domain state; based on the wave speed of the mode field and the time difference that the traveling wave current signal reaches the suspension points at the two ends, performing curve integration by combining the geometrical characteristics of the oblique parabola, and calculating to obtain the oblique parabolic traveling wave coupling coefficient of the lead; And establishing an sag expression of any point on the overhead conductor, deriving, and measuring to obtain the maximum sag of the overhead conductor by combining the spans of the suspension points at the two ends and the oblique-polished travelling wave coupling coefficient of the conductor. The invention firstly collects traveling wave current signals of suspension points at two ends of the overhead conductor, provides accurate original data support for subsequent calculation, and avoids signal source errors. Aiming at the problem that the coupling influence of temperature and frequency on the wave speed of a traveling wave mode domain is ignored, the series impedance and the parallel admittance in the frequency dom