Unlock instant, AI-driven research and patent intelligence for your innovation.

Distance protection fault impedance computing method and system based on high frequency temporary state quantity

A technology of distance protection and fault impedance, applied in the field of electric power, can solve problems such as affecting the performance of distance protection, measuring impedance can not truly reflect the fault location, etc., achieving good engineering practical value, rich harmonic components, and improving the effect of operating time.

Active Publication Date: 2019-08-02
STATE GRID ZHEJIANG ELECTRIC POWER CO LTD HANGZHOU POWER SUPPLY CO +1
View PDF3 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the existence of transition resistance when a single phase is grounded makes the measured impedance unable to truly reflect the fault location, which seriously affects the action performance of the distance protection

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
  • Distance protection fault impedance computing method and system based on high frequency temporary state quantity
  • Distance protection fault impedance computing method and system based on high frequency temporary state quantity
  • Distance protection fault impedance computing method and system based on high frequency temporary state quantity

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0053] The embodiment of this application proposes a calculation method for distance protection fault impedance based on high-frequency transient quantities, such as figure 1 shown, including:

[0054] Step 1: Collect cable data, the cable data includes the current at the distance protection installation, the high-frequency harmonics in the voltage, and the line unit resistance and inductance in the cable data;

[0055] Step 2: According to the current and high-frequency harmonics in the voltage of the distance protection installation in the cable data, calculate the distance percentage from the fault point to the protection installation;

[0056] Step 3: Based on the obtained distance percentage, combined with the line unit resistance and inductance in the cable data, calculate the true fault impedance of the distance protection.

[0057] Specifically, with figure 2 Taking the dual power supply system shown as an example, the working principle of the distance protection fa...

Embodiment 2

[0094] The distance protection fault impedance calculation system 2 based on the high-frequency transient quantity provided by the present invention, such as Figure 7 As shown, the system includes a data reading module 21, a distance percentage calculation module 22 and a fault impedance calculation module 23;

[0095] The data read-in module 21 is respectively connected to the fault distance percentage calculation module 22 and the fault impedance calculation module 23;

[0096] The distance percentage calculation module 22 is connected with the fault impedance calculation module 23;

[0097] The data read-in module 21 is used to obtain the line length, line unit inductance, line unit resistance, phase current and voltage at the protection installation, and send the collected data to the distance percentage calculation module;

[0098] The distance percentage calculation module 22 is used to extract the high-frequency harmonics in the current and voltage of the protection i...

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 distance protection fault impedance computing method and system based on high frequency temporary state quantity. The method comprises the following steps: collecting cable data, wherein the cable data comprises high frequency harmonic waves in current and voltage at the position of distance protection installation and circuit unit resistance and inductance in cable data;according to the high frequency harmonic wave in current and voltage at the position of distance protection installation in cable data, calculating the distance percentage from a fault point to the position of protection installation; and based on the obtained distance percentage, in combination with the circuit unit resistance and inductance in cable data, calculating distance protection real fault impedance. The distance protection fault impedance is not influenced by transition resistance and fault position by extracting high frequency harmonic wave components in voltage and current after faults, and the calculation errors are superior to those in traditional schemes respectively; the more the harmonic wave components, the calculation result gets closer to the actual value; the length of a sampling window required by the high frequency harmonic waves is extracted, the action time of distance protection is promoted, and the method has good engineering practical value.

Description

technical field [0001] The invention belongs to the field of electric power, and in particular relates to a distance protection fault impedance calculation method and system based on high-frequency transient quantities. Background technique [0002] According to the requirements of the national standard, the line protection device in the high-voltage and above power system must be equipped with staged distance protection and fast distance protection functions as an effective supplement to differential protection (pilot protection). However, the existence of transition resistance when single-phase grounding makes the measured impedance unable to truly reflect the fault location, which seriously affects the action performance of the distance protection. Contents of the invention [0003] In order to solve the shortcomings and deficiencies in the prior art, the present invention proposes a distance protection fault impedance calculation method and system based on high-frequen...

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
IPC IPC(8): G01R27/02G01R27/16G01R31/08
CPCG01R27/16G01R27/02G01R31/088
Inventor 马伟黄晓波罗少杰尤敏吴靖侯伟宏陈嘉宁丁冬林森章玮明陈聪王明昶金公羽张魁
Owner STATE GRID ZHEJIANG ELECTRIC POWER CO LTD HANGZHOU POWER SUPPLY CO