Pilot protection system and protection method based on virtual transition impedance

A technology of transition impedance and longitudinal protection, applied in emergency protection circuit devices, electrical components, fault locations, etc., can solve problems such as uncertainty and complex compensation methods, and achieve accurate identification.

Active Publication Date: 2016-05-18
NORTH CHINA ELECTRIC POWER UNIV (BAODING) +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Some of the above methods require known line capacitance parameters or compensation capacitor parameters, some compensation methods are more complicated, and some are uncertain to a certain extent

Method used

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  • Pilot protection system and protection method based on virtual transition impedance
  • Pilot protection system and protection method based on virtual transition impedance
  • Pilot protection system and protection method based on virtual transition impedance

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0052] figure 1 It is the structural diagram of the longitudinal protection system based on the virtual transition impedance provided by the present invention, such as figure 1As shown, the virtual transition impedance-based longitudinal protection system provided by the present invention includes a data reading module, a protection calculation module and a protection action module. The connection relationship between them is that the data reading module is connected with the protection calculation module and the protection action module respectively, the protection calculation module is connected with the data reading module and the protection action module respectively, and the protection action module is respectively connected with the data reading module and the protection calculation module. The modules are connected.

[0053] The data reading module is used to collect the sequence voltage at both ends of the line, the sequence current at both ends of the line, the seque...

Embodiment 2

[0148]The correctness and rationality of the above-mentioned system and method are verified through the simulation process as follows. Referring to the parameters of the Beijing-Tianjin-Tangshan 500kV EHV line, a line model with a length of 400km was built in PSCAD / EMTDC. model such as Figure 6 As shown, where the line parameters are: r 1 =0.02083Ω / km, l 1 =0.8948H / km, C 1 =0.0129μF / km; r 0 =0.1148Ω / km, l 0 =2.2886H / km, C 0 =0.00523μF / km.

[0149] M side system: E m =525∠15 0 kV, Z m =7.14+j101.54Ω, zero sequence parameters are the same as positive sequence, N-side system: E n =500∠0 0 kV, Z n =1.428+j20.308Ω, zero sequence parameters are the same as positive sequence. The simulation time is 0.8s, the fault occurs at 0.5s, and the sampling frequency is 6kHz.

[0150] The simulation system sets up 5 fault points in the area, and the distances from the bus M are 0km, 100km, 200km, 300km and 400km respectively. Statistical results show that the maximum single-phas...

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PUM

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Abstract

The invention discloses a pilot protection system and method based on virtual transition impedance in the technical field of power system relay protection. The system comprises a data reading module, a protection computing module and a protection action module. The data reading module is connected with the protection computing module and the protection action module respectively. The protection computing module and the protection action module are connected. The method comprises the steps that sequence voltages at the two ends of a line, sequence currents at the two ends of the line, line sequence impedance and line to-ground sequence capacity are collected, the sequence virtual transition impedance of the line is computed, whether a protection criterion starting condition is met is determined, and under the condition that the protection criterion starting condition is met, whether tripping signals are sent is determined. A criterion is fault total-quantity construction criterion after fault, line fault recognition is accurate, and line capacity does not need to be compensated.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a virtual transition impedance-based longitudinal protection system and a protection method thereof. Background technique [0002] In high-voltage transmission lines, traditional longitudinal protection methods mainly include longitudinal directional protection and current differential protection. Among them, the current differential protection has high sensitivity, has natural phase selection ability, and can adapt to various complex faults and abnormal operation states, and is widely used in power systems. When a high-resistance grounding fault occurs inside, the sensitivity cannot be guaranteed because the load current is included in the measured current. Zero-sequence current differential protection can well reflect asymmetrical faults grounded through transition impedance under normal conditions, but when the line is not in full-ph...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02H7/26G01R31/08
Inventor 马静裴迅马伟闫新王增平
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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