HU181224B - Circuit array for measuring corona-loss of high-voltage cverhead lines - Google Patents

Abstract

The invention is a high voltage power line put on the high voltage of his crown loss for continuous registration of a closed metal cabin suitable. Crown loss calculation methods are known, however, they have little practical significance. THE crown loss is determined primarily by tests or on a short test piece or on the entire power line

Description

to measure your crown loss

The invention is suitable for the continuous recording of the actual crown loss of high voltage power lines in a high voltage closed metal cabin.

Crown loss calculation procedures are known but have little practical significance. The determination of crown loss is primarily based on tests either on a short test piece or on the complete power line.

The principle of compensating for the high capacitance charge current of an idle transmission line has been developed in combination with a differential current transducer method [1]. Known three-ampere measurement [2] and a combination of the wattmeter and Schering bridge method [3] and antenna crown loss measurement [4] are known. A common feature of these methods is that they are sufficiently inaccurate and unsuitable for conducting long-term studies without supervision.

The results obtained by various methods show significant variation and therefore do not apply [1] Die Korona-Messeinrichtung auf Hochspannungspotential, 400 kV-Forschungsgemeinschaft Rheinau, 1958, p. 29-49.

[2] Gábris, F., Gyárfás, J ..: Metóda na meranie strát koronou, Elektrotechnicky Obzor 64, 1975. No. 6. p. 314-344.

[3] Emel'janov, N.P., Kozlov: Koronnüj razrjad na provodah, Nauka i Technika, Minsk, 1971.

[4] Levitov, V. I.: The Corona Peremennogo Toka, Energy, Moscow, 1975.

they are also reliable for power line design.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a circuit arrangement in which the above drawbacks can be overcome. Given that, as voltage levels increase, 5 under particularly adverse meteorological conditions, accurate knowledge of these losses is essential for determining power losses, operating and peak power requirements.

The present invention makes the automatic boom capacitance meter with current comparator developed by Schnell L. for the control of generator insulation [5] suitable for measuring crown loss at the potential of an idle transmission line. The present invention relates to the measurement of power line co15 loss and to the measurement of capacity.

The enclosed metallic cabin placed on the power line voltage includes an automatic bridging capacitance current comparator bridge. The abnormal 20-circuit normal capacitor provides the reference. The current of the wire is supplied through a laboratory-grade current transformer to the automatic boiler capacitance current comparator bridge, which, after the first equalization, continuously registers changes in the capacitor 25 and capacitance, either as a function of voltage or time. The Automatic Hot Capacity Good] Schnell, L .: Messverfahren Taste Controller des Isolierungustandes von Hochspannungsgeneratoren wShrend des Betriebs Bull. ASE. 1973. Issue 2, pp. 84-92.

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The -1181224 meter current comparator bridge is controlled and powered by a current converter with 220 V on the secondary side. Sparks protect against unwanted voltage surges.

The circuit arrangement according to the invention is illustrated in the accompanying 1/1. I will describe in detail:

In the figure, the recorder 6 is connected to an automatic boiler capacity meter with a current comparator bridge. The automatic boiler capacity meter current bridge 2 and the recorder 6 are located in a closed metal cabin 1. Automatic gauge capacitance current comparator 2 bridge bridge with variable speed Nj coil, other bridge with variable speed coil N ₂ and variable resistor R connected in series and parallel with second bridge with variable capacity capacitor C _o measuring bridge contains N zero indicators.

A power transformer 3 is connected to the power line 4, one of whose secondary terminals is metallically connected to the closed metal cabin 1 and the other terminal of which is connected to the automatic bridge capacitor measuring bridge 2. The outputs of the other current transformers 5'5 of the power line 4 are connected to the supply voltage input of the automatic capacitor measuring current comparator 2 and a variable capacitor Q is connected between the secondary outputs. The automatic boiling capacity measuring bridge 2 with current comparator 2 is grounded through a normal capacitor Cn. The capacitance C _{x of the} power line to be measured and the resistance R _x from the derivation are shown in dashed lines. The closed metal cabin 1 is connected to the transformer U potential.

The apparatus according to the invention operates as follows:

Before switching on the power line, the wires connected to the automatic bridging capacitance current comparator bridge 2 must be connected to the enclosed metal cabin 1 to prevent the adverse effects of the power surges.

After switching on the power line 4, the circuit layout according to sheet 1/1 must be restored. In one case, the variable resistor R, the capacitor C _o and the zero indicator N must be balanced.

Thereafter, the measurement is performed automatically and the change in tg and C _x capacity is recorded by the recorder 6.

The crown loss margin shall be calculated by taking into account the angular error of the current transformer 3 and the possible loss of the normal capacitor Cn as follows:

P = U ² _x wc _(x -I- TGO TGO TGO _A + _N) where

P = loss in W of the transmission line due to corona radiation and drainage.

ω = circular frequency

U = test voltage in V _{x x} measured angle of transmission line 4 = angular error of current transformer _N = angle of normal capacitor C _N 15 C _x = measured capacity of line 4 (F)

As can be seen, the circuit arrangement simply enables direct, continuous and accurate measurement of the loss of the power line 4 from corona radiation and drainage (which can be separated if necessary).

The measuring accuracy of the automatic boiler capacity meter with a current comparator bridge shall be within ± 0,1% + Cn of the measuring capacity.

The accuracy of the span measurement shall be within ± 2% of the measuring range.

Claims (2)

Patent claims: 1. Circuit arrangement for measuring crown loss of high-voltage power lines, comprising an automatic beacon capacitance current comparator bridge and a recorder connected thereto 35 units, characterized by a current converter (3) located on the transmission line (4), one of the secondary outputs of the current converter (3) being the automatic bridging capacitance current comparator bridge (2) and the recording unit (6). It is connected to a wall of a closed metal cabin (1) with a potential of 40 power lines (4), the other is connected to one of the bridges of the automatic boom capacity current comparator bridge (2) and that an additional current transformer (5) 45 having its outputs connected to the power input of the auto-capacitor gauge current comparator bridge (2) and a variable-capacitor capacitance (Ca) connected between the secondary outputs, the other bridge of the auto-capacitor gauge current comparator bridge (2) is grounded through. An embodiment of a circuit arrangement according to claim 1, characterized in that one of the electrodes of the normal capacitor (C _N ) is subjected to high voltage, The other 55 are connected to earth potential.