Eureka AIR delivers breakthrough ideas for toughest innovation challenges, trusted by R&D personnel around the world.

Extended z transformation-based current forecasting method and device

A technology of current prediction and z-transformation, which is applied in the output power conversion device, the conversion of AC power input to AC power output, electrical components, etc. Solve the effect of switching frequency reduction and avoid inaccurate predicted current

Active Publication Date: 2017-09-26
BEIJING QIANSIYU ELECTRIC +1
View PDF5 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a current prediction method and device based on extended z-transform to solve the influence of too long control delay caused by the reduction of switching frequency in the traditional control method

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
  • Extended z transformation-based current forecasting method and device
  • Extended z transformation-based current forecasting method and device
  • Extended z transformation-based current forecasting method and device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0039] figure 1 The flowchart of the current prediction method based on extended z-transform provided by the present invention, such as figure 1 As shown, the current prediction method based on the extended z-transform of the present embodiment includes:

[0040] Step 101: Perform z-transformation and extended z-transformation on the first current of the four-quadrant converter corresponding to the first moment when the modulation wave is loaded, and obtain the z-transformation result and the extended z-transformation result, wherein the first current is the AC on the grid side The fundamental wave component of the current, and the loading position of the modulated wave corresponds to the peak or valley of the carrier wave, and the z-transformation result is used to characterize the correspondence between the first current and the second current, and the second current corresponds to the second moment of the predicted modulation wave loading For the current of the four-quadra...

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 an extended z transformation-based current forecasting method and device. The method comprises the following steps: performing z transformation and extended z transformation on first current of a four-quadrant converter corresponding to a first moment for modulated wave loading, thus obtaining a z transformation result and an extended z transformation result; building an incidence relation between the z transformation result and the extended z transformation result, and obtaining a differential equation according to the incidence relation, wherein the differential equation is used for indicating an incidence relation among the first current corresponding to the first moment, second current corresponding to a second moment and middle current corresponding to a middle moment; forecasting the second current according to the differential equation, the first current and the middle current, and calculating an amplitude value and a phase, which correspond to the second moment for the modulated wave loading, of a modulated wave according to the second current to control current output from the alternating current side of the four-quadrant converter. According to the extended z transformation-based current forecasting method, the problem of an extremely long control time delay caused by reduction of the switching frequency in a conventional control method is solved, and forecasting of current corresponding to the next modulated wave loading moment is realized.

Description

technical field [0001] The invention relates to electric equipment control technology, in particular to a current prediction method and device based on extended z-transformation. Background technique [0002] The four-quadrant converter is widely used in the AC-DC-AC rectification link of the electric locomotive and EMU traction conversion system, power system Active filtering and harmonic compensation and wind power generation systems. The control method of the four-quadrant converter mainly lies in the control of the alternating current, which is mainly divided into indirect current control and direct current control. Due to the better dynamic performance of direct current control, direct current control is more widely used at present. Usually AC current feedback is introduced in direct current control to participate in the control of AC current. [0003] More and more fields will require to increase the power of the four-quadrant converter. When the power of the four-...

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 Applications(China)
IPC IPC(8): H02M5/293
CPCH02M5/293H02M1/0009H02M5/2932
Inventor 张钢刘志刚牟富强钱江林魏路漆良波吕海臣邱瑞昌杜军路亮陈杰孙星亮
Owner BEIJING QIANSIYU ELECTRIC
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
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