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

Method for verifying polarity of zero-sequence current transformer

A zero-sequence current and transformer technology, which is applied in the field of verifying the polarity of zero-sequence current transformers, can solve the problems of time-consuming, manpower and material resources, and low efficiency, and achieve the effect of solving the difficulty of polarity detection

Inactive Publication Date: 2013-05-29
STATE GRID GANSU ELECTRIC POWER CORP DINGXI POWER SUPPLY CO +1
View PDF7 Cites 25 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since in actual engineering, there are as many as a dozen or even dozens of zero-sequence CTs, and the distance between transformers varies from several meters to more than ten meters, only one or a few can be calibrated at a time, so the efficiency of this method is very low , consumes a lot of time, manpower and material resources, and some substations do not allow power outages, and polarity verification cannot be performed at all, because the safety operation regulations of the power system stipulate that all personnel need to keep a certain distance from the live equipment when it is live

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
  • Method for verifying polarity of zero-sequence current transformer
  • Method for verifying polarity of zero-sequence current transformer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0013] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and examples.

[0014] figure 1 The signal acquisition system processing flow chart shown includes the following steps:

[0015] In step 101, read the zero-sequence voltage of the bus and the zero-sequence current sampling values ​​of each line from the analog-to-digital converter A / D, and place them in a designated cache RAM;

[0016] In step 102, the voltage mutation amount is calculated according to the latest sampled value of the zero-sequence voltage collected, and the calculation method is as follows:

[0017] ΔU=U(k)-2U(k-N)+U(k-2N) (1)

[0018] In the formula (1), ΔU represents the sudden change value, U(k) represents the latest sampling value of the zero-sequence voltage, U(k-N) represents the sampling value before one cycle of wave, U(k-2N) represents the sampling value of two weeks before the wave, N represents weekly sampling poin...

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 discloses a method for verifying a polarity of a zero-sequence current transformer. A hardware part comprises a signal acquisition system; a software part comprises a waveform analysis system; and the method comprises the following steps of: capturing an instant single-phase earth fault signal which mainly includes a bus zero-sequence voltage and a zero-sequence current of each line through the signal acquisition system by utilizing the characteristic of frequent instant single-phase earth fault of a distribution network system; and identifying whether a polarity connecting wire of the zero-sequence current transformer of each line is correct through the waveform analysis system based on the maximum zero-sequence amplitude value of a fault line and the characteristic that the phase position is opposite to that of the zero-sequence current of a non-fault line. The method for verifying the polarity of the zero-sequence current transformer solves the polarity verification difficulty of the zero-sequence current transformer in a small-current grounding line selection system efficiently without adding any device or tool, is very time-saving, convenient and fast, and solves a big difficulty in the practical application of small-current products.

Description

technical field [0001] The invention relates to the technical field of equipment manufacturing of a low-voltage distribution network of a power system, in particular to a method for verifying the polarity of a zero-sequence current transformer. Background technique [0002] Most of the 35kV and below low-voltage distribution networks in my country adopt the neutral point non-effective grounding method. The occurrence rate of single-phase ground faults in this type of power grid is very high, accounting for more than 70% of the total failure rate of the power system. After a single-phase ground fault occurs, it must be selected as soon as possible. Faulty lines are eliminated to ensure power operation and equipment safety. [0003] At present, there are many small current grounding line selection devices researched and developed in my country for single-phase ground fault line selection, but the overall line selection accuracy rate is less than 70%, which is difficult to meet ...

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): G01R35/02
Inventor 刘勇智刘海锋曾宇
Owner STATE GRID GANSU ELECTRIC POWER CORP DINGXI POWER SUPPLY CO
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