General loop current control method for modular multi-level converter considering low frequency oscillation

A modular multi-level, multi-level converter technology, applied in the output power conversion device, the conversion of AC power input to DC power output, electrical components and other directions, can solve the current distortion of the bridge arm, increase the commutation device wear, system failure, etc.

Active Publication Date: 2013-12-25
HUNAN UNIV
View PDF4 Cites 24 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the operation of the converter, because the actual working conditions are much more complicated than the ideal conditions, the bridge arm current is distorted, and its components also contain double frequency and its multiple sub-harmonic cur

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
  • General loop current control method for modular multi-level converter considering low frequency oscillation
  • General loop current control method for modular multi-level converter considering low frequency oscillation
  • General loop current control method for modular multi-level converter considering low frequency oscillation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0046] The bridge arm circulation of the modular multilevel converter is divided into two parts: the double frequency circulation and the low frequency oscillation circulation. The general circulation control method can suppress the two circulation currents at the same time. General circulation control method.

[0047] 1. For low-frequency oscillating circulation, its causes and oscillation frequency are analyzed as follows:

[0048] image 3 For the single-phase structure diagram of the modular multilevel converter, the KVL equation and the KCL equation are respectively established, and it can be obtained

[0049] - U d 2 + u xp + i xp R + L di xp dt + u xo ...

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 general loop current control method for a modular multi-level converter considering low frequency oscillation. The general loop current control method is mainly used for restraining a low frequency oscillation loop current and a second harmonic generation loop current in a bridge arm loop current of the modular multi-level converter. The relation between a bridge arm voltage and the bridge arm loop current is analyzed to obtain the oscillation frequency of the low frequency oscillation loop current of the converter so as to provide beneficial evidence for the design of a control system; the cut-off frequency of a low pass filter is set according to the calculated value of the oscillation frequency; the bridge arm loop current passes through the low pass filter to obtain a direct current component, and then the direct current component is subtracted by the bridge arm loop current to obtain an alternating component of the bridge arm loop current; the alternating component contains a harmonic component of the low frequency oscillation loop current and a harmonic component of the second harmonic generation loop current; the alternating component passes through a regulator to obtain a control reference voltage of the bridge arm loop current, and the control reference voltage is added to a modulating signal. By means of the general loop current control method, a low frequency oscillation component and a second harmonic generation component in the bridge arm loop current are simultaneously restrained, the loop current control system is simplified, split-phase control over the loop currents is realized, loss of the converter is lowered, and the dynamic stability of the system is enhanced.

Description

technical field [0001] The invention relates to a control method in the field of light direct current transmission (VSC-HVDC), in particular to a general circulation control method for a modular multilevel converter considering low-frequency oscillation. Background technique [0002] The superior performance of direct current transmission in long-distance power transmission makes it have extremely promising application prospects in long-distance transmission of renewable energy such as wind power and offshore power generation. The modular multilevel converter is based on the medium voltage of light direct current transmission Novel topology of source converter (VSC-HVDC). Modular multilevel converters have been widely researched and applied in the fields of light DC transmission and medium and high voltage reactive power compensation due to their advantages of high power factor, low distortion rate, small device withstand voltage, and good fault tolerance redundancy. Altern...

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): H02M7/483H02M7/5387
Inventor 罗安徐千鸣周发云熊桥坡何志兴刘爱文谢龙裕田园
Owner HUNAN UNIV
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