SVG negative sequence and zero sequence current compensation method based on improved instantaneous symmetrical component method

A zero-sequence current, instantaneous symmetry technology, applied in the direction of multi-phase network asymmetry reduction, reactive power adjustment/elimination/compensation, multi-phase network elimination/reduction of asymmetry, etc., can solve system hazards and low compensation , serious problems, etc., to avoid inaccuracy and ensure the effect of three-phase symmetry

Active Publication Date: 2017-03-22
NANJING UNIV OF SCI & TECH
View PDF3 Cites 19 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The compensation degree of SVG is not high in normal working state, which makes the utilization rate of SVG lower if SVG only compensates the reactive power in the grid
In the actual power distribution syste

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
  • SVG negative sequence and zero sequence current compensation method based on improved instantaneous symmetrical component method
  • SVG negative sequence and zero sequence current compensation method based on improved instantaneous symmetrical component method
  • SVG negative sequence and zero sequence current compensation method based on improved instantaneous symmetrical component method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0049] figure 1 It is a schematic structural diagram of the three-phase four-wire SVG topology system of the present invention, and the star SVG is connected to the three-phase four-wire distribution network. The star SVG is a three-phase star connection structure, and its topology is composed of a low-voltage three-phase full bridge or a medium-high voltage chain H-bridge. The load current i 1a ,i 1b ,i 1cIncluding active power, reactive power, negative sequence and harmonic current, among which reactive power, negative sequence and harmonic current are injected into the grid, causing power loss of the grid and threatening the stable operation of the system. The star-shaped SVG output current has the same amplitude and opposite direction as the reactive power, negative sequence and harmonic current in the load current, so as to achieve the effect of compensation.

[0050] A kind of SVG negative-sequence zero-sequence current compensation method based on the improved instan...

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 an SVG negative sequence and zero sequence current compensation method based on an improved instantaneous symmetrical component method. An instantaneous value is determined by using the improved symmetrical component method and a trigonometric function decomposition method of the instantaneous value in a phasor time domain; the method comprises the following steps: decomposing the system into a positive, negative and zero three-sequence network to obtain positive, negative and zero three-sequence components without delay, making the SVG to emit reactive current and harmonic current requiring compensation in a power grid by positive sequence current control, and compensating negative sequence and zero sequence components generated by unbalance of three-phase loads by negative sequence and zero sequence current control; and when the volume of the SVG is limited, preferably compensating the negative sequence and zero sequence components to ensure the maximum compensation of the reactive components. By adoption of the SVG negative sequence and zero sequence current compensation method disclosed by the invention, the defects of time delay in the traditional instantaneous symmetrical component method is overcome, the flexibility of the SVG compensation ability is given play, the three-phase symmetry of a common node is preferably ensured, the actual demands of the power distribution system are satisfied, and the psychological expectations of industrial users are also satisfied.

Description

technical field [0001] The invention relates to the technical field of reactive power compensation, in particular to an SVG negative-sequence zero-sequence current compensation method based on an improved instantaneous symmetrical component method. Background technique [0002] With the development of power electronic technology, a large number of nonlinear equipment such as power electronic devices and various new impact loads (such as industrial electric arc furnaces, electric locomotives, rolling mills, etc.) As well as a large number of applications in household appliances, the demand for reactive power has increased significantly, and the harmonic content of the power grid is large. At the same time, problems such as voltage fluctuations, flicker and three-phase imbalance are particularly prominent. Static var generator (SVG) is currently the most advanced reactive power compensation device, which can perform reactive power compensation to the power grid, improve the po...

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): H02J3/18H02J3/26H02J3/01
CPCH02J3/01H02J3/1842H02J3/26Y02E40/10Y02E40/40Y02E40/50
Inventor 吕广强杨鑫顾伟耿严岩郭震
Owner NANJING UNIV OF SCI & TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap