SU1591122A1 - Device for identifying damaged wires of power line with extra wire - Google Patents

Description

The invention is intended for relay protection and system automation of single-circuit AC power lines of high voltage, with an additional wire, connected in parallel to one of its phase conductors. The purpose of the invention -

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increase the transmission capacity of transmission lines with an additional wire in emergency mode when translating it into an incomplete phase mode by detecting and disconnecting only damaged wires. This goal is achieved by the fact that the device ensures the transfer of the power line to work in an incomplete phase mode by detecting and disconnecting only damaged wires during stable two-phase short circuits—. on the line, for which the shear angles between the symmetrical components of the currents of the forward and reverse sequences and the voltages of the forward and reverse sequences are measured and compared in phases and the phases in which the shear angle between the currents of the forward and reverse sequences is less than 90 ° are selected as damaged, and phase shift angles between direct and reverse sequence voltages greater than 90 °, 1 sludge.

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The invention relates to the field of electrical engineering and is intended for the implementation of relay protection and system automation of single-circuit AC power lines of high and low voltages, with an additional wire connected in parallel with one of the phase conductors of the line.

The purpose of the invention is to increase the transmission capacity of the transmission line with an additional wire in post-accident conditions when translating

in the incomplete phase mode by. detecting and disconnecting only the damaged wires.

The drawing shows a block diagram of a device for selecting damaged wires of a transmission line, with an additional wire for interfacial short circuits.

The device contains direct current filters 1 and reverse 2 sequence, connected to current transformers installed on the line,

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1591122

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Voltage filters of direct 3 and inverse 4 sequences connected to voltage transformers of substation buses, blocks 5 (starting organs of phases A, B, C) and b (electoral bodies A »B, C), in which they measure the angles of phase shift between symmetrical components, block 7 of phase-wise summation of signals at logical hell elements I, connected to an additional selector 8. When the line is operating in normal operating mode, there is practically no reverse sequence voltage; , 5 [In single-phase and three-phase short circuits, the device does not work.

It also does not work when the double wires are closed. In the case of a two-phase short circuit, the single 20 wires in blocks 2 and 4 stand out the currents and voltages of the loop sequence appearing on the line.

Direct sequence currents and voltages are present in blocks 1 and 25 3 in both normal and emergency modes.

The currents of the direct and reverse sequence enter the block 5 (starting organ), and the voltages of the same sequential sequences — and block 6 (the electoral organ), compare the angles of the phase shift between the corresponding vectors. The triggering organ triggers in those phases where the compared angles 55 are less than 90 °, and the electoral authority triggers at angles greater than 90 °. The information (signals) from the launching and electoral authorities goes in phases to block 7 of the phase summation of 49 signals. At the output of each of the elements of block 7, a signal is generated to turn off the switches in those phases in which simultaneously appears at the input signal from the electoral and launching bodies 5 and 6.

When a two-phase short circuit occurs between a single and one of the double wires, the starting and electoral authorities 5 and 6 of the damaged phases are triggered and the signals arrive at the logic elements of the block 7 of these phases, the output of which generates signals to turn off their switches, and a single wire turns off directly 'from the signal received at the output of block 7

summing signals of the device, and the dual wire is disconnected through an additional selector 8. Therefore, information (signal) on damage to the dual phase wire, obtained at the output of the block - 7, summing up the device signals, enters the logic element of the additional selector 8, which detects the damaged dual phase wire.

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The use of the device makes it possible to significantly increase the transmission capacity of the transmission line with an additional wire in the post-accident modes due to the transfer of the line to the non-full-phase mode during two-phase short circuits, which leads to an increase in the reliability of the power supply to consumers.

Claims (1)

Claim A device for selecting damaged power transmission lines with an additional wire, containing, by the number of phases, reverse current voltage and voltage filters, designed to be connected to current and voltage protection sensors of the line; reverse sequence voltage filter outputs are connected to the first, second and third selective unit inputs, outputs which is connected to the first, second and third inputs of the unit of the phase summation of signals, the outputs of which are the outputs of the device, the outputs of the current filter The serial sequence is connected to the first, second and third inputs of the starting organ, the outputs of which are connected to the fourth fifth and sixth inputs of the block of phase-by-phase summation of signals, characterized in that, in order to increase the transmission capacity in the post-emergency mode when translating into incomplete phases, operating mode, voltage and current filters of the direct sequence are additionally entered, the inputs of which are connected to the indicated voltage and current protection sensors of the line, and the outputs to the fourth, fifth and sixth th inputs of the electoral organs and trigger respectively. 1591122 -> > >