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

Transformer longitudinal error protecting element with maximum zero sequence ratio brake

A zero-sequence current, ratio braking technology, applied in electrical components, emergency protection circuit devices, etc., to avoid inconsistencies in errors

Inactive Publication Date: 2008-02-06
ZHEJIANG UNIV
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Visible, by Y 0 The unbalanced current caused by side zero-sequence fault current is ignored in the traditional ratio differential 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
  • Transformer longitudinal error protecting element with maximum zero sequence ratio brake
  • Transformer longitudinal error protecting element with maximum zero sequence ratio brake
  • Transformer longitudinal error protecting element with maximum zero sequence ratio brake

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] A transformer longitudinal differential protection element with maximum zero-sequence current ratio braking can be realized through the circuit block diagram in Figure 3. The element is composed of the maximum value circuit 01, the multiplier A 1 , B 1 、C 1 , 02, adder A 3 , B 3 、C 3 and comparator A 4 , B 4 、C 4 constitute. Where n=3 is the number of transformer neutral point grounding sides (or branch numbers), and the ratio brake coefficient K in the existing ratio differential protection Z 0.5, zero sequence braking coefficient K 0 is 0.3. When the differential current is greater than the braking current including zero-sequence current, the comparator outputs the ratio differential action signal of the corresponding phase. Applying this scheme can completely avoid the Y with the only power supply when the errors of the three-phase current transformers are inconsistent. 0 The misoperation of the transformer differential protection caused by the ground fau...

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

This invention discloses a longitudinal deviation protection element for a transformer with the largest side zero-sequence rate brake, which carries out weight and sum of three phase brake currents representing the through current in the differential protection of the present transformers with the maximum value in the zero sequence current of the earth side of each neutral point to get brake currents of three phases containing the zero sequence current to be used to get rate brake elements of related phases with the three phase differential currents, when the differential current is greater than the brake current containing the zero sequence current, a rate differential action signal of a related phase is output.

Description

technical field [0001] The invention relates to a power system relay protection element, in particular to a transformer differential protection element with maximum zero-sequence current ratio braking Background technique [0002] The current longitudinal differential protection of power transformers consists of components such as differential quick-break, ratio differential, excitation inrush current detection, and over-excitation detection. According to DL / T 684-1999 "Large Generator Transformer Relay Protection Setting Calculation Guidelines", the block diagram of transformer longitudinal differential protection is shown in Figure 1, and the principle wiring example of longitudinal differential protection is shown in Figure 2. Usually using a current transformer for Y 0 Y / Δ transformation is performed on the three-phase current on the side to eliminate the influence of zero-sequence current. Obviously, after the transformation, each current does not contain the zero-seq...

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): H02H7/045
Inventor 徐习东
Owner ZHEJIANG UNIV
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