A half-wavelength transmission line protection method based on transient energy

A technology of transient energy and transmission lines, which is applied in the direction of circuit devices, AC network circuits, emergency protection circuit devices, etc.

Active Publication Date: 2018-12-21
KUNMING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

But this distance protection only applies to phase-to-phase faults

Method used

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  • A half-wavelength transmission line protection method based on transient energy
  • A half-wavelength transmission line protection method based on transient energy
  • A half-wavelength transmission line protection method based on transient energy

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0079] Example 1: Establish as figure 1 The simulation system model of the half-wavelength transmission line is shown, and the model parameters are selected from the UHV 1000kV line parameters, with figure 2 The UHV tower shown is used as a UHV half-wavelength transmission line tower. The line is evenly transposed, the power supply system at both ends, the total length of the line is 3000km, and the simulation step is set to 100kHZ. use image 3 The simulation system shown in the figure analyzes two faults at point F1 in the positive direction and point F2 in the reverse direction at the bus M. The instantaneous power and transient energy curves on the M side are as follows: Figure 4 shown.

[0080] Depend on Figure 4 (a) It can be seen that the change of the positive and negative polarities of the instantaneous power after the fault is not constant due to the traveling wave back and forth between the fault point and the load, which is due to the zero initial state of en...

Embodiment 2

[0086] Example 2: Establish as figure 1 The parameters of the transformer internal fault simulation system model shown are described in detail in Embodiment 1, and will not be repeated here.

[0087] Assuming that a phase-to-ground short-circuit fault occurs on the MN section of the positive direction line on the M side, the short-circuit resistance is 10Ω, and the initial fault angle is 60°. The simulation verification is carried out on different fault locations with an increment of 100km. The state energy value varies with the fault distance as Image 6 shown.

[0088] Depend on Image 6 It can be seen that as the fault distance increases, the absolute value of the transient energy of the fault in the zone will gradually decrease, but the forward and reverse faults can still be reliably identified when the terminal fault occurs.

[0089] Assuming that a phase-A ground fault occurs at 300km in the positive direction on the M side, the initial fault angle is 60°, and the tr...

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PUM

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Abstract

The invention relates to a half-wavelength transmission line protection method based on transient energy, belonging to the technical field of power system relay protection. If a fault is detected, thevoltage and current abrupt change are calculated by transient electrical quantities detected at the first and last terminals, , through the product of transient voltage and the current abrupt changes, the instantaneous power is calculated, and the transient energy is obtained by integrating the instantaneous power. Based on the polarity of the transient energy, the fault criterion is constructedin and outside the region, no matter where the fault point is located on the line, the method can reliably realize the fault identification in and outside the region. In addition, the polarity of transient energy is not affected by the fault angle and the transient resistance changes. Therefore, the transient energy protection method is suitable for half-wavelength transmission lines.

Description

technical field [0001] The invention relates to a half-wavelength transmission line protection method based on transient energy, and belongs to the technical field of electric power system relay protection. Background technique [0002] Half-wavelength AC power transmission refers to the ultra-long-distance AC power transmission technology whose power transmission distance is close to half of the power frequency wavelength. When the power frequency is 50HZ, the power transmission distance is about 3000km. The half-wavelength power transmission technology was proposed by Soviet scholars in the 1940s. Since there was no actual engineering demand at that time, and its key technology had not been broken through, half-wavelength power transmission technology can be used for long-distance, large-scale, large-capacity power transmission problems between energy bases and load centers, but so far there is no half-wavelength power transmission network put into service. As a large-cap...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02H7/26H02J3/00G01R31/08
CPCG01R31/085H02H7/26H02J3/00H02J2203/20Y04S10/52
Inventor 束洪春琚夏阳韩一鸣达惠
Owner KUNMING UNIV OF SCI & TECH
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