Flicker value calculation method based on improved FFT and inverter

Active Publication Date: 2014-07-16
NINGBO HENGLIDA TECH
View PDF5 Cites 24 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a flicker value calculation method based on improved FFT and an inverter for the above-mentioned existing problems, so as to overcome the problems of large f

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
  • Flicker value calculation method based on improved FFT and inverter
  • Flicker value calculation method based on improved FFT and inverter
  • Flicker value calculation method based on improved FFT and inverter

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0042] Such as figure 1 As shown, this embodiment is based on the improved FFT flicker value calculation method, extracts the voltage flicker signal by calculating the effective value of the voltage, uses the Hanning window function to perform an improved FFT analysis on the voltage flicker signal, and gives the voltage fluctuation and The fitting curve of fluctuating voltage frequency solves the problem of correspondence between voltage fluctuation and fluctuating voltage frequency randomness, and improves the accuracy of flicker value calculation. The specific steps are as follows:

[0043] S1. After the three-phase voltage is conditioned by the signal, the A / D converter completes the slider sampling of the voltage signal of each phase, and obtains the voltage sampling sequence u(i), and the sampling frequency f s =12.8K.

[0044] S2. Calculate the voltage root mean square value with the sampling length H of each half cycle, and obtain a set of voltage root mean square valu...

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 relates to a flicker value calculation method based on improved FFT and an inverter. In order to solve the technical problems, the flicker value calculation method based on the improved FFT and the inverter are provided, and high-precision flicker value calculation is achieved. According to the technical scheme, the method includes the steps that (1), all phases of voltage signals are sampled to obtain a voltage sampled sequence; (2), a voltage root-mean-square value is calculated according to sampling length per semi-circle wave, so that a voltage root-mean-square value sequence is obtained; (3), the average value of the voltage root-mean-square value sequence is calculated, and the average value is subtracted from each voltage root-mean-square value, so that a new voltage root-mean-square value sequence is obtained; the new voltage root-mean-square value sequence is windowed, FFT is performed, and amplitude frequency is corrected through double spectrum line interpolation operation; (5), curve fitting is performed on voltage fluctuation and fluctuation frequency discrete points; (6), please see the formula in the specification, a transient flicker value P is calculated; (7), the steps from one to six are repeated, all transient flicker values P within ten minutes are calculated, and according to the formula in the specification, a short-time flicker value Pst is calculated. The flicker value calculation method and inverter are used for the field of electric power technologies.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to an improved FFT-based flicker value calculation method and an inverter, which are mainly applicable to the electric power technical field. Background technique [0002] With the increase of nonlinear and impact loads in the power grid, voltage fluctuations are becoming more and more serious, which has seriously affected industrial production and social life. Voltage fluctuation is a series of relatively rapid or continuous changes in the root mean square value of voltage. Voltage flicker is an evaluation index to measure the degree of harm caused by voltage fluctuations. It is a harmful result caused by voltage fluctuations and is a sensitive response of the human eye to fluctuations in the illuminance of incandescent lamps. Therefore, real-time monitoring of voltage fluctuations and flicker, that is, accurate measurement of voltage flicker indicators - instantaneous f...

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): G01R19/25G01R23/16H02J3/38
Inventor 周良璋范有周希平张向程郑有波舒元康董良叶帮武沈微强郝涛涂海宁张晓锋侯培明
Owner NINGBO HENGLIDA 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