A Line Protection Method for Photovoltaic DC Boost Collection System Based on Resonant Current Amplitude Comparison

A DC boosting and line protection technology, applied in photovoltaic power generation, emergency protection circuit devices, electrical components, etc., can solve the problems of low sensitivity to high-impedance faults, large influence of distributed capacitive currents, and limited anti-noise capabilities. Reach the effect of low data storage and transmission requirements

Active Publication Date: 2021-07-09
NORTH CHINA ELECTRIC POWER UNIV (BAODING)
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, the research on the protection of flexible DC lines mainly focuses on time-domain protection and frequency-domain protection. The protection based on time-domain fault information has limited anti-noise ability and low sensitivity to high-impedance faults; although the protection based on frequency-domain information is limited by the transition resistance The impact of noise and noise is small, but it needs to extract multi-band high-frequency quantities, the extraction time is longer, and it is also greatly affected by the distributed capacitance current

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
  • A Line Protection Method for Photovoltaic DC Boost Collection System Based on Resonant Current Amplitude Comparison
  • A Line Protection Method for Photovoltaic DC Boost Collection System Based on Resonant Current Amplitude Comparison
  • A Line Protection Method for Photovoltaic DC Boost Collection System Based on Resonant Current Amplitude Comparison

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0027] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0028] figure 1 Collect system topology diagrams for photovoltaic DC boost, such as figure 1 As shown, after the photovoltaic power generation unit is stepped up by DCT on site, it passes through the collection branch to the collection bus, and then connects to the grid through the sending branch.

[0029] Branch circuit components include converters, current-limiting reactors and DC cables, in which DCT adopts an isolated boost full-bridge conversion structure, and the main topology is composed of BOOST circuits, full-bridge inverters, high-frequency isolation transformers and full-bridge rectifier circuits. Considering the unidirectional transmission power and economic requirements of the photovoltaic power generation unit, the high-voltage side uses a full-bridge uncontrolled device. When the DC line fails, the full-control device of the full-bridge inverter can...

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 line protection method for a photovoltaic DC step-up collection system based on the comparison of resonance current amplitudes. On the basis of analyzing the impedance characteristics of the collection branch and the fault component circuit in the frequency domain, the step characteristics of the voltage between the poles of the DC fault are used. The resonance formed by the boundary element of the branch and the branch circuit is selected to study the specific frequency component higher than the resonance frequency of the branch circuit, and the amplitude characteristics of the specific frequency component of the fault line current are obtained. By comparing the amplitudes of the specific frequency components of the fault current of each branch extracted by the continuous wavelet transform (CWT) algorithm, the fault branch is identified and reliable fault isolation is completed. The invention only needs to extract the specific frequency component of the fault current to complete fault isolation, has low requirements for data storage and transmission, and does not need to consider the error problem caused by communication delay.

Description

technical field [0001] The invention belongs to the technical field of grid connection of new energy power generation, and in particular relates to a line protection method of a photovoltaic DC boost collection system based on comparison of resonant current amplitudes. Background technique [0002] With the development of flexible DC transmission and power electronics technology, photovoltaic DC boost collection and transmission system, as an important form of photovoltaic power generation transmission in the future, has attracted great attention from scholars at home and abroad. Compared with the traditional photovoltaic AC collection system, photovoltaics can reduce line loss through flexible DC boosting, collection and transmission, avoid stability problems caused by parallel connection of multiple inverters, and improve the overall efficiency of the photovoltaic power generation system. Fast and reliable fault isolation technology is the guarantee for the efficient opera...

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): H02H7/26H02J3/38
CPCH02H7/268Y02E10/56
Inventor 贾科施志明毕天姝朱瑞王聪博李俊涛
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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