Method and system for the determination of wind speeds and incident radiation parameters of overhead power lines

Abstract

The present invention relates to a method and system for the determination of parameters related to the speed of wind that blows near an overhead electrical power line (single or bundle conductors). The parameters include an “effective wind speed” as well as an “effective incident radiation” acting on a power line span. The measurement is made by using the combination of mechanical vibrations and movements / positions in two or three dimensions through sensors in direct link with the power line conductor.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a method and system for the determination of parameters related to the speed of wind that blows near an overhead electrical power line (single or bundle conductors). In particular, such parameters include an effective perpendicular wind speed (hereinafter referred to as the “effective wind speed”), which is the speed that would have a wind blowing perpendicularly to the conductor axis and having the same cooling effect on the conductor as the actual wind. In addition, the combination of solar radiation and albedo on power line conductor is hereinafter referred to as the “effective incident radiation”.BACKGROUND OF THE INVENTION[0002]As explained in U.S. Pat. No. 8,184,015, continuous monitoring of electrical power lines, in particular high-voltage overhead lines, is essential to timely detect anomalous conditions which could lead to a power outage. Measurement of the sag of power lines to determine whether the sag is lower...

AI Technical Summary

Benefits of technology

The present invention provides a power line device and method that overcomes problems in prior art solutions. It uses a power line sensor directly fixed on the conductor with accelerometers in multiple directions. This allows for the measurement of wind speed and incident radiation on the power line using the combination of mechanical vibrations and movements / positions. The sensor must be placed at any position on the line and must be equipped with highly sensitive accelerometers. This technology provides a more accurate and efficient means to measure the environmental factors that affect power line performance.

Problems solved by technology

Indeed, power lines in the field are always subject to movements and vibrations, which may be very small but detectable by their accelerations in both time and frequency domains.

A drawback of all these methods about weather conditions is that none of them is able to generate appropriate weather data which are actually to be used to calculate ampacity, which is a value linked to all critical spans of a power lines.

A critical span is a span for which there is a significant risk of potential clearance violation in any kind of weather situations.

But wind speed measurement is tricky for various reasons.

First, it is not stationary as wind speed can vary significantly within minutes, and there may be wind gusts.

Therefore, a single-spot measurement does not allow computing the global effect of the wind over the whole span.

Similarly, a single-spot measurement of “effective incident radiation” does not allow computing the global effect of the combined effect of sun and albedo over the whole span.

However, this is only a partial solution to the monitoring problem and such systems are solely oriented to evaluate the life time of power line conductor due to the bending fatigue induced by Aeolian vibrations cycles on conductor strands near clamps.

Beside the fact that they only allow a partial monitoring of the power line, all of these methods suffer from drawbacks: optical techniques are sensitive to reductions of the visibility induced by meteorological conditions while the other measurement methods are inaccurate, since sag has to be deduced by algorithms which depend on unavailable and / or uncertain data (e.g. wind speeds, topological data, actual conductor characteristics, .

The drawback of this device is that hot wires anemometer is extremely difficult to manage on a sensor attached to a conductor.

Drawback of such method is that the effect along the span was not taken into account and that such local measurement is not a good indication of what is actually the mean wind speed and global incident radiation along spans of several hundreds of meters with possible variable altitudes and different kind of wind action along the span.

Moreover, there are obvious errors for replica compared to conductor emissivity and absorptivity and global incident radiation mean value along the span.

The drawback of such traditional gauge is that the sensor itself constitutes a perturbation in the local measurement and that low wind speed cannot be measured properly by such gauge.

A drawback of this device is that there is no way to properly determine the “effective wind speed” perpendicular to the conductor if they are less than 3 m / s, which are the basic cases for ampacity determination under critical conditions.

A drawback of this device is that there is no explanation on how to evaluate the wind speed to consider for ampacity determination.

However, there is no mention in the literature to exploit such link in evaluating precisely the acting wind speed on a power line span to compute the ampacity of that line.

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