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

A Modular Multilevel Converter DC Harmonic Suppression Method

A modular multi-level, harmonic suppression technology, applied in the direction of converting AC power input to DC power output, electrical components, output power conversion devices, etc., can solve problems such as harmonic hazards in power grids and DC systems, and achieve reduction The effect of harmonic levels

Active Publication Date: 2019-03-12
YUNNAN POWER GRID CO LTD ELECTRIC POWER RES INST
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of this application is to provide a method for suppressing DC harmonics of modular multilevel converters to solve the problem of harmonic harm to the power grid and DC system

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 Modular Multilevel Converter DC Harmonic Suppression Method
  • A Modular Multilevel Converter DC Harmonic Suppression Method
  • A Modular Multilevel Converter DC Harmonic Suppression Method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0040] refer to figure 1 and figure 2 , the embodiment of the present application provides a method for suppressing DC harmonics of a modular multilevel converter, comprising the following steps:

[0041] Obtain the measured value of the circulating current of the three-phase bridge arm;

[0042] Obtaining a DC harmonic current according to the measured value of the circulating current of the three-phase bridge arm;

[0043] Utilizing the characteristics of zero-sequence circulating current on the bridge arm of the MMC DC harmonic current, the three-phase circulating current i acir i bcir i ccir Summing, that is, to get the MMC DC current i dc harmonic components in . And the harmonic components are evenly distributed in the three-phase bridge arms, and the harmonic current flowing into each bridge arm is 1% of the total harmonic current

[0044] determining the frequency of the harmonic current with the highest harmonic value according to the DC harmonic current;

...

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 present application discloses a method for suppressing DC harmonics of a modular multilevel converter, which includes obtaining the measured value of the circulating current of the three-phase bridge arm; obtaining the DC harmonic current according to the measured value of the circulating current; and determining the highest harmonic value according to the DC harmonic current the harmonic current frequency; construct the DC harmonic current into a three-phase symmetrical signal at the harmonic current frequency with the highest harmonic value; transform the three-phase symmetrical signal into a synchronous rotating coordinate system with the highest harmonic current frequency , calculate the DC harmonic compensation electromotive force; transform the DC harmonic compensation electromotive force into the three-phase static coordinate system, and superimpose it on the equivalent electromotive force reference value of the upper and lower bridge arms of each phase, and realize the DC harmonic compensation of the modular multilevel converter inhibition. The embodiment of the present application can not only suppress the harmonics injected into the DC system by the modular multilevel converter, but also compensate the background harmonics in the DC system of the modular multilevel converter. Therefore, it can effectively reduce the Harmonic levels of DC systems with flat converters.

Description

technical field [0001] The present application relates to the technical field of flexible power transmission and distribution of power systems, in particular to a method for suppressing DC harmonics of a modular multilevel converter. Background technique [0002] The Modular Multilevel Converter (MMC) is a new type of voltage source converter, and each bridge arm is formed by cascading sub-modules. Compared with traditional two-level or three-level voltage source converters, MMC avoids the problem that power devices are directly connected in series to form a bridge arm, which is difficult to meet static and dynamic voltage equalization requirements; MMC can easily adjust the number of cascaded sub-modules to To achieve the purpose of increasing voltage and output power; for high-voltage and large-capacity MMC, due to the large number of cascaded sub-modules used, the output voltage step wave is very close to a sine wave, so the output voltage harmonics are very small, and no...

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): H02M7/483
CPCH02M7/483H02M7/4803H02M7/4835
Inventor 段锐敏崔康生文俊郭成彭俊臻李胜男邢超和鹏
Owner YUNNAN POWER GRID CO LTD ELECTRIC POWER RES INST
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