RU2250545C2 - Device for telemetering ice and wind loads on overhead power transmission line conductors - Google Patents

Abstract

FIELD: remote measurements of ice and wind loads on conductors.

SUBSTANCE: set of sine-wave probing signals arrives at conductor being checked by proposed device. Total ice and wind loads set in linear motion rods in warning devices installed at their check points and rejection filters convert these motions into proportional decrease of even frequency signal amplitudes while amplitudes of odd frequencies of each pair do not change in these rejection filters. A decrease in even frequency amplitudes is converted in differential comparison device into signal whose amplitude is proportional to mass of ice deposits in respective spans of line where sensors are installed.

EFFECT: enlarged functional capabilities of device.

1 cl, 3 dwg

Description

The invention relates to the electric power industry and can be used for telemetry of the values of ice-wind loads on an overhead power line wire, used for timely melting of ice-hoar-frost and snow deposits on the line wires.

The level of technology.

A known system for transmitting signals through a power line for detecting icy deposits on wires [1]. In this system, a measuring RF signal of the same frequency is transmitted from the transmitter located at the beginning of the line to the receiver located at the end of the line through the wire of the power line. On a wire in ice-hazardous places (control points) relay-mounted ice sensors are installed. According to the description, if the load of deposits on the wire at the control point does not exceed the weight threshold set in the sensor, then it does not work and has practically no effect on the level of the RF signal at the receiver input. If, at least on one of the sensors, the weight threshold is exceeded, then this sensor is triggered and introduces significant attenuation into the RF signal, which fixes the receiving device, the alarm is triggered and a command is issued for ice melting. Such a system basically has a high probability of false positives or the passage of dangerous ice-wind loads, because this system does not take into account the significant effect on the RF signal level at the input of the receiver of changes in meteorological parameters and changes in the operating modes of the line (loads) and does not take into account the dependence of the sensor threshold on the changing type of deposits, wind direction and speed.

The influence of the instability of the line parameters on the operation of the device [1] is eliminated in the device for remote signaling of ice on the wires of power lines [2], containing a signal unit, a two-frequency transmitter connected via a controlled power line with a two-channel receiver, consisting of two input filters, two amplifiers , comparison block, threshold block, element I. In accordance with the description, in cases when deposits form with maximum permissible thickness on the wires, the ratio e reducing the quantities of signals of two frequency level reaches the threshold level and the device is fixed achieve a certain level of attenuation of said second frequency signal, comparator unit generates a signal, and outputs a switch command to switch Fat melting system.

The disadvantage of this analogue is that, in accordance with the principle of operation, it is triggered by a certain generalized parameter, which depends on the mass, type and distribution of deposits on the line, and does not allow localizing sections of deposits on the line and does not measure intermediate values of the loads of deposits on the wire, while obtaining such information is the main functional purpose of such systems.

One of the devices that determines the location of deposits on the wire of the power line and measures the amount of ice-wind loads caused by these deposits is a device for monitoring the level of ice-wind load on the wires of overhead power lines, selected as a prototype [3]. This device contains a wire equipped with connection systems and end traps, an icy load sensor with a plunger, a four-terminal plunger controlled by the plunger (a band-pass filter in the form of an oscillatory circuit included in the power line wire), two sinusoidal frequency generators, two band-pass filters, two amplitude detectors, differential amplitude meter. The device continuously measures the value of the ice-wind load on the wire at the sensor installation site, recording in the differential amplitude meter a change in the relative level of the amplitudes of two frequencies that are similar in magnitude in the four-terminal resonant circuit connected in series to the wire, which appears when the resonance frequency of the bandpass filter is tuned by the sensor plunger under the action ice-wind load acting on it.

The disadvantage of the prototype is that this device measures the amount of ice-wind load on the line wire only in one place, where the sensor is installed, and basically can not measure the value of ice-wind load in two or more places of one line. This fundamental disadvantage of the prototype is due to the fact that it is impossible to consistently turn on more than one quadripole, because the band-pass filter (resonant circuit) of each input four-terminal network does not let “not its own” pair of frequencies “through itself”. If, in the prototype, the bandwidths of the bandpass filters of the four-terminal circuits are expanded, successively included in the line, this will lead to the influence of the band-pass filters of the four-port circuits on the amplitudes of not “their” frequency pairs and, ultimately, will cause distortion of the measurement results.

The objective of the invention is to create a device that allows you to fundamentally unlimited increase in the number of local sections of simultaneous and continuous measurement of ice-wind loads on the wire of an overhead power transmission line up to each passage of the line.

This goal is achieved by replacing the band-pass filter, connected in series in the line wire, with notch filters connected in parallel with the line and the ground electrode. These replacements also required a corresponding increase in the number of pairs of probe frequencies for polling each sensor of ice-wind load and, accordingly, an increase in the number of elements for generating and processing these frequencies.

Disclosure of the invention.

The subject of the invention is a device for measuring icy-wind loads on an overhead power line wire equipped with linear end traps and connection systems, containing two generators of close-frequency sinusoidal signals, the outputs of which are connected to the first connection system, two band-pass filters of the corresponding frequencies, the inputs of which are connected to the second connection system, an icy-wind load sensor installed in an icy place of the line and mechanically attached Heated on one side to the traverse of the VL support, and on the other hand to the wire, and through its plunger connected to the controlled filter element, two amplitude detectors, the input of each of which is connected to the output of the corresponding band-pass filter, and the output of the band-pass filter is connected to the corresponding the input of the differential comparing device, characterized according to the invention in that 2n-2 generators of close-in-frequency sinusoidal signals, n-1 ice-wind load sensors with plungers, n notch filters are introduced c, 2n-2 bandpass filters, 2n-2 amplitude detectors and n-1 differential-comparison devices, the output of each input generator being connected to the first connection system, and the input of each of 2n-2 bandpass filters connected to the second connection system, each output from 2n-2 bandpass filters connected to the input of the corresponding amplitude detector, the outputs of which are connected in pairs to the inputs of the corresponding differential comparison device from n-1; each of the n-1 sensors of ice-wind load installed in an icy place of the line and mechanically attached on the one hand to the traverse of the overhead line support, and on the other hand to the wire, is connected through its plunger to the controlled element of the corresponding notch filter from n notch filters, a signal the input of each of the n notch filters is connected in parallel to the wire, and its output is connected to the ground electrode.

The specified set of features allows us to solve the problem of the invention - the proposed device simultaneously and continuously measures the value of the ice-wind load on the wire of an overhead power transmission line at each controlled passage of the line.

It should be noted that this set of features is not the sum of technical solutions known from the analogue and prototype, because contains distinctive features from the prototype that are absent in the analogue. Indeed, although the prototype (as in the claimed device) has an overhead power line wire equipped with end linear arresters and connection systems, sinusoidal signal generators, a glaze-wind load sensor with a plunger, band-pass filters, amplitude detectors and a differential-comparing device, it It measures the value of ice-wind load only in one place of the line, where the sensor of ice-wind load with a controlled four-terminal is installed, because the successive incorporation of a four-terminal into the line wire excludes the possibility of including additional four-terminal, without excluding their mutual influence on the measurement results.

Description of the invention.

The implementation of the invention is illustrated by three drawings in figures 1, 2 and 3, which shows a functional diagram of the proposed device (figure 1), the relative position of the amplitude-frequency characteristics of the wire with notch filters and the frequency spectrum of the probing signals (a) relative to the amplitude-frequency characteristics of the strip filters (b) in the absence of ice-wind loads on all controlled sections of the line (figure 2) and the relative position of the amplitude-frequency characteristics of the wire with notch filters and frequency tra probing signals (a) with respect to the amplitude-frequency characteristics of the bandpass filters (b) under the action of wind gust-load only the first controlled portion of the line (3).

A device for measuring ice-wind loads on a wire of an overhead power line (Fig. 1), equipped with end line arresters 1 and connection systems 2, contains 2n generators 3 of sinusoidal signals with output frequencies f ₁ , f ₂ , f ₃ , f ₄ , .. ., f _2n-1 , f _2n , n sensors of ice-wind load with plungers 4, n notch filters 5, 2n band-pass filters 6, tuned respectively to pass frequencies f ₁ , f ₂ , f ₃ , f ₄ , ... , f _2n-1 , f _2n from generators 3, 2n of amplitude detectors 7, forming output voltages U ₁ , U ₂ , U ₃ , U ₄ , ..., U _2n-1 , U _2n , and n differential-comparing devices 8, generating output signals G ₁ , G ₂ , ..., G _n proportional to the corresponding values of ice-wind loads acting on each controlled passage overhead power line.

The device operates as follows.

Frequency generators 3 (Fig. 1) generate a sequence of sinusoidal signals f ₁ , f ₂ , f ₃ , f ₄ , ..., f _2n-1 , f _2n , which through the connection system 2 enter the line wire and propagate through it. At the opposite end of the line, through accession system 2, this sequence of frequencies arrives at 2n band-pass filters 6, each of which is tuned to the corresponding frequency from the sequence f ₁ , f ₂ , f ₃ , f ₄ , ..., f _2n-1 , f _2n . From the output of each band-pass filter 6, the signal is detected by the corresponding amplitude detector 7. From the output of the corresponding amplitude detectors 7, voltages U ₁ , U ₂ , U ₃ , U ₄ , ... ,, ..., U _2n-1 , U _2n are received in pairs to the inputs of the corresponding differential comparing devices 8 and are compared in size. As a result of the comparison, the outputs G ₁ , G ₂ , ..., G _n are formed at the outputs of the differential comparing devices 8, the values of which are proportional to the difference in the amplitudes of the frequency pairs f ₁ and f ₂ , f ₃ and f ₄ , ..., f _{2n- 1} and f _2n .

In the absence of ice-wind load on all controlled spans of the line, the plungers of the sensors of ice-wind load set the notch bands of the corresponding notch filters of the RF ₁ , RF ₂ , ..., RF _n ( _figure 2) symmetrically with respect to frequencies f _cf. 1 = ( f ₁ + f ₂ ) / 2, f _cp.2 = (f ₃ + f ₄ L) / 2, ..., f _cf.n = (f _2n-1 + f _2n ) / 2 of the corresponding pairs of generators, thanks why the frequency pairs f ₁ and f ₂ for the first sensor, f ₃ and f ₄ for the second, etc. with the same attenuation pass the corresponding notch filter RF ₁ , RF ₂ , ..., RF _n and then the rest of the line, the connection system, are highlighted by the corresponding parallel band-pass filters PF ₁ , PF ₂ , PF ₃ , PF ₄ , ..., PF _2n-1 , PF _2n and arrive with equal amplitudes to the amplitude detectors. If the amplitudes of the frequency pairs f ₁ and f _{2 are} equal, for the first sensor, f ₃ and f ₄ for the second, etc. amplitude detectors will generate equal output voltages U ₁ = U ₂ , U ₃ = U ₄ , ..., U _2n-1 = U _2n and, accordingly, differential-comparing devices, will give output voltages G ₁ , G ₂ , ..., G _n equal to zero, which corresponds to zero glaze-wind load on all controlled spans of the line.

When there is an ice-wind load, for example, on the first controlled span of the line, the first sensor rearranges by proportional displacement of the plunger the notch band of the first notch filter PF ₁ closer to the frequency f ₂ , which leads to an increase in the attenuation of the amplitude U _{2 of the} frequency f ₂ in this filter by ΔU ₂ , proportional to the actual value of the ice-wind load on the wire of this span (figure 3). Moreover, with the shift of the notch band of the RF _{1, the} amplitude U _{1 of an} odd frequency f ₁ does not change. Therefore, a decrease in the amplitude U _{2 of the} frequency f ₂ will cause the first differential-comparing device to output a voltage G ₁ proportional to the current value of the ice-wind load on the wire of the first controlled passage. The device works similarly under the action of ice-wind loads on any other controlled span of the power line.

Under the influence of ice-wind loads simultaneously on several controlled spans of the line, the amplitudes of the corresponding even frequencies change independently of each other and are independently converted into a signal at the output of the differential-comparing device, proportional to the ice-wind load on these spans.

Since all climatic influences and changes in the modes of operation of the power line have almost the same effect on the attenuation values of two signals that are close in frequency and their amplitudes are compared differentially (relative to each other), these effects practically do not affect the measurement accuracy and the device only measures the values of glaze -wind loads on a wire of controlled spans of an overhead power line.

The use of differential comparison in the device also eliminates the influence of natural attenuation in the wire of an overhead power transmission line, including that caused by deposits on the entire line, on the measurement of ice-wind loads.

The proposed device allows you to fundamentally unlimited increase in the number of local sections for measuring ice-wind loads on the wire of an overhead power line, which was impossible in the known devices for measuring ice-wind loads on the wire of an overhead power line.

Sources of information

1. Patent for invention No. 2129334, IPC 6 N 04 B 3/54, 1997.

2. Auth. testimonial. USSR No. 748615, IPC N 02 G 7/16, 1980.

3. Auth. testimonial. USSR No. 773808, IPC N 02 G 7/16, 1980.

Claims (1)

A device for measuring icy-wind loads on an overhead power line wire equipped with linear end traps and connection systems, containing two generators of close-frequency sinusoidal signals, the outputs of which are connected to the first connection system, two band-pass filters of the corresponding frequencies, the inputs of which are connected to the second connection system , an icing-wind load sensor installed in an icy-hazardous place and mechanically attached on one side to the traverse about OL VL, and on the other hand, to the wire and through its plunger connected to the controlled filter element, two amplitude detectors, the input of each of which is connected to the output of the corresponding band-pass filter, and the output is connected to the corresponding input of the differential-comparing device, characterized in that 2n-2 generators of close-in-frequency sinusoidal signals, n-1 glaze-wind load sensors with plungers, n notch filters, 2n-2 bandpass filters, 2n-2 amplitude detectors and n-1 differential comparing devices, and the output of each generator from 2n-2 generators is connected to the first connection system, and the input of each of 2n-2 bandpass filters is connected to the second connection system, the output of each of 2n-2 bandpass filters is connected to the input of the corresponding amplitude detector, the outputs of which connected in pairs to the inputs of the corresponding differential comparison device from n-1; each of the n-1 sensors of ice-wind load installed in an ice-hazardous place and mechanically attached on one side to the traverse of the overhead line support, and on the other hand to the wire, is connected through its plunger to a controlled element of the corresponding notch filter from n notch filters, a signal input each of n notch filters is connected in parallel to the wire, and its output is connected to the ground electrode.

Images