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

Control method for capacitor voltage optimization and equalization of modular multilevel converter submodule

A modular multi-level, capacitor voltage technology, applied in the direction of AC power input conversion to AC power output, AC power input conversion to DC power output, electrical components, etc., can solve problems such as increasing switching loss, and reduce switching frequency. , Low transmission loss, reducing the effect of frequent switching

Inactive Publication Date: 2019-06-07
XIANGTAN UNIV
View PDF1 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The advantage of the traditional balance control method is that it is simple to implement, but the voltage equalization algorithm requires strict sequencing of the capacitor voltage values ​​of the sub-modules at each action moment of the system to control the opening or closing of each module. This frequent switching The action will inevitably increase the switching loss, so it is necessary to carry out corresponding research on the switching frequency of MMC

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
  • Control method for capacitor voltage optimization and equalization of modular multilevel converter submodule
  • Control method for capacitor voltage optimization and equalization of modular multilevel converter submodule
  • Control method for capacitor voltage optimization and equalization of modular multilevel converter submodule

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0023] In order to describe the present invention in more detail, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] The present invention relates to a control method for optimizing and balancing the capacitor voltage of a modular multilevel converter sub-module, and the adopted MMC main circuit topology is as follows: figure 1 shown. The main circuit is composed of network-side MMC and machine-side MMC. Both sides are composed of three-phase six bridge arms. The sub-module of each bridge arm adopts a half-bridge structure. Each phase bridge arm consists of a commutation reactance and N half-bridges. The structure is composed of sub-modules, where each sub-module includes two IGBTs, an energy storage capacitor and a freewheeling diode. By controlling the on and off of the sub-modules, a stable waveform can be output at the output terminal.

[0025] Table 1 shows the working state and...

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 invention is mainly applied to the technical field of power electronics, and aims to provide a control method for capacitor voltage optimization and equalization of a modular multilevel converter submodule. The control method realizes balance control of capacitor voltage of a modular multilevel converter submodule by selecting different optimization algorithms, and mainly comprises thefollowing steps: calculating the number of submodules to be inputted based on a recent level approximation modulation strategy; sorting the submodules on each bridge arm of an MMC system according toa size from large to small; judging the calculated number N of the submodules and the currently inputted submodules n, and selecting different submodule switching modes under different conditions; and finding a submodule with the largest capacitor voltage and a submodule with the smallest capacitor voltage on the current bridge arm, comparing a difference between the submodules, and then selecting different optimization algorithms for switching the submodules. Based on an MMC technology of the present invention, on the premise of controlling the balance of the capacitor voltage of the submodules, the control method can also ensure that the system has a lower switching frequency, and reduces the loss of a power converter in the MMC system.

Description

technical field [0001] The invention relates to the technical field of power electronic converters, in particular to a control method for optimizing and equalizing capacitor voltages of sub-modules of modular multilevel converters. Background technique [0002] At present, the power electronic converter technology has been developed rapidly and has become the core device for power conversion in the power system, especially in the power supply, transmission and configuration of power. Since Professor R. Marquart of the Bundeswehr University in Munich in Germany proposed a modular multilevel converter (MMC) based on a half-bridge structure in 2002, it marked the arrival of conversion devices in the field of power electronics technology transmission. It is a major innovation. Its structure mainly adopts the power semiconductor device with low voltage level - IGBT power tube. Through the parallel connection of IGBT and capacitor to form the sub-module of MMC, it can form a high-...

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): H02M5/458H02M7/487H02M7/539
Inventor 易灵芝刘罗黄晓辉周东访
Owner XIANGTAN UNIV
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