Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

A method of longitudinal protection for transmission lines with controllable series compensators using current transients for post-measurement simulation

A series compensation and transmission line technology, applied in the direction of measuring electrical variables, emergency protection circuit devices, instruments, etc., can solve the problems of destroying the uniformity of line impedance and the difficulty of determining the current of series compensation capacitors, etc., to avoid current oscillation and protect the entire length , easy-to-achieve effects

Active Publication Date: 2017-11-10
KUNMING UNIV OF SCI & TECH
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in recent years, it has been found that the installation of the controllable series compensator has changed the line parameters, thereby destroying the uniformity of the line impedance. When the transmission line is short-circuited, the measured impedance of the relay is no longer proportional to the distance between the bus bar and the short-circuit point. , and the series compensation device generally uses a metal oxide arrester (MOV) with nonlinear volt-ampere characteristics. The nonlinearity of the MOV makes it difficult to determine the current flowing through the series compensation capacitor after it is turned on, which brings great harm to traditional power frequency protection. big impact

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method of longitudinal protection for transmission lines with controllable series compensators using current transients for post-measurement simulation
  • A method of longitudinal protection for transmission lines with controllable series compensators using current transients for post-measurement simulation
  • A method of longitudinal protection for transmission lines with controllable series compensators using current transients for post-measurement simulation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Example 1: 500kV line with static synchronous series compensator such as figure 1 shown. The line parameters are as follows: the total length of the line is 150km for the PM section, 150km for the MN section, and 220km for the NQ end. Fault location: Fault F 11A single-phase ground fault occurs at a distance of 30km from the M terminal of the MN section. Ground impedance 0Ω, sampling rate 20kHz.

[0040] (1) Calculate the fault phase current i to the input point of the controllable series compensator according to the Bergeron line model according to step 1 in the manual M,l / 2 i N,l / 2 waveform like Figure 5 shown

[0041] (2) According to step 2 in the manual, the integral value Δ 2ms after the fault is calculated to be 76.0366.

[0042] (3) According to the third criterion in the manual: Δ=76.0366>kg△ set =1.5×10, so it is judged as fault F 11 It is an internal fault (a fault occurs on the protected line).

Embodiment 2

[0043] Example 2: 500kV line with static synchronous series compensator such as figure 1 shown. The line parameters are as follows: the total length of the line is 150km for the PM section, 150km for the MN section, and 220km for the NQ end. Fault location: Fault F 12 A single-phase ground fault occurs at a distance of 90km from the M terminal of the MN section. Ground impedance 0Ω, sampling rate 20kHz.

[0044] (1) Calculate the fault phase current i to the input point of the controllable series compensator according to the Bergeron line model according to step 1 in the manual M,l / 2 i N,l / 2 waveform like Figure 6 shown

[0045] (2) According to step 2 in the manual, the integral value Δ 2ms after the fault is calculated to be 72.4885.

[0046] (3) According to the third criterion in the manual: Δ=72.4885>kg△ set =1.5×10, so it is judged as fault F 12 It is an internal fault (a fault occurs on the protected line).

Embodiment 3

[0047] Example 3: 500kV line with static synchronous series compensator such as figure 1 shown. The line parameters are as follows: the total length of the line is 150km for the PM section, 150km for the MN section, and 220km for the NQ end. Fault location: Fault F 2 A single-phase ground fault occurs at a distance of 40km from the M end of the PM section. Ground impedance 10Ω, sampling rate 20kHz.

[0048] (1) Calculate the fault phase current i to the input point of the controllable series compensator according to the Bergeron line model according to step 1 in the manual M,l / 2 i N,l / 2 waveform like Figure 7 shown

[0049] (2) According to step 2 in the manual, the integral value Δ of 2ms after the fault is calculated to be 4.2134.

[0050] (3) According to the third criterion in the manual: Δ=4.2134set =1.5×10, so it is judged as fault F 2 It is an external fault (the protected line has not failed).

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a longitudinal protection method in which a transmission line with a controllable series compensator is used for post-measurement simulation by using a current transient quantity, and belongs to the technical field of electric power system relay protection. When the transmission line containing the controllable series compensator fails, the voltage and current line modulus values ​​at both ends of the line are respectively calculated according to the Bergeron line parameter model to obtain the line-mode currents on both sides of the input point of the controllable series compensator. Transform to obtain the corresponding fault phase current, sum and integrate the fault phase currents on both sides of the input point in the short window, and judge whether it is an internal fault according to the value of the integral value △. Specific criteria: If △ is less than the set value, it is judged as an out-of-area fault; if △ is greater than the set value, it is judged as an in-area fault. The invention can protect the full length of the line without raising the action time limit. And it is not affected by the fault initial angle, transition resistance and distributed capacitance.

Description

technical field [0001] The invention relates to a longitudinal protection method for a power transmission line with a controllable series compensator for post-measurement simulation by using current transients, and belongs to the technical field of electric power system relay protection. Background technique [0002] The controllable series compensator is a common flexible AC power transmission equipment. Its installation not only increases the transmission capacity of the system, but also increases the stability of the system. However, in recent years, it has been found that the installation of the controllable series compensator has changed the line parameters, thereby destroying the uniformity of the line impedance. When the transmission line is short-circuited, the measured impedance of the relay is no longer proportional to the distance between the bus bar and the short-circuit point. , and the series compensation device generally uses a metal oxide arrester (MOV) with ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H02H7/26G01R31/08G01R31/02
Inventor 束洪春苏玉格白冰
Owner KUNMING UNIV OF SCI & TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com