System and method for grouping and pre-charging modular multilevel converter capacitor

A modular multi-level, capacitor charging technology, applied in the direction of AC power input conversion to DC power output, electrical components, output power conversion devices, etc., can solve problems such as large impact currents, achieve simple control, convenient implementation, The effect of reducing power

Inactive Publication Date: 2012-12-19
SHANDONG UNIV
View PDF3 Cites 36 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although in the first and second stages of this method, due to the presence of current limiting resistors, the current impact is not large, but at the beginning of the third stage, because the capacitor voltage is still near the lower critical voltage (all sub-voltages of each bridge arm

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
  • System and method for grouping and pre-charging modular multilevel converter capacitor
  • System and method for grouping and pre-charging modular multilevel converter capacitor
  • System and method for grouping and pre-charging modular multilevel converter capacitor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0041] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0042] Such as figure 1 As shown, two modular multilevel converter topology schematic diagrams are given, which include a first modular multilevel converter 1 and a second modular multilevel converter 2, wherein each phase has upper / lower The next two bridge arms, each bridge arm is composed of N half-bridge sub-modules 3SM and reactor L connected in series; Figure 1a The topology diagram of the half-bridge sub-module 3 is given, which consists of two upper / lower power switches (S1 and S2) with anti-parallel diodes and a capacitor C. S1 and S2 are connected in series with capacitor C in parallel.

[0043] Figure 2a A group schematic diagram of the capacitor pre-charging of the first modular multilevel converter 1MMC1 of the present invention is given, and the upper half bridge sub-module 3 of the upper bridge arm of the first modular multilevel con...

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 system for grouping and pre-charging modular a multilevel converter capacitor. The system comprises at least one modular multilevel converter MMC; an alternating-current side input end of the modular multilevel converter MMC is connected with a series-connected starting current-limiting resistor Rx, a breaker RBK1 (Remote Breaker) and an alternating-current power supply in turn; or the system comprises two modular multilevel converters MMCs which respectively are a first modular multilevel converter MMC1 and a second modular multilevel converter MMC2. A method for grouping and pre-charging the modular multilevel converter capacitor comprises the following steps of: respectively dividing half-bridge sub-modules of two modular multilevel converters MMCs into two groups and four groups, and carrying out grouping and pre-charging. According to the method for grouping and pre-charging the modular multilevel converter capacitor, the pre-charging of a capacitor is shortened, and the power consumption of the current-limiting resistor is reduced; the charging current direction is unnecessary to be detected, and the capacitor voltage closed-loop control is unnecessary as well; and the implementation is simple, and the control is simple.

Description

technical field [0001] The invention relates to a capacitor group precharging system and method, in particular to a modular multilevel converter capacitor group precharging system and method. Background technique [0002] Modular Multilevel Converter (MMC) topology adopts cascaded and modular structure, and can obtain multi-level ladder voltage without direct series connection of power devices, with lower dU / dt and lower Voltage harmonic content has broad application prospects in medium / high voltage large capacity systems (such as flexible direct current transmission). In application, the system usually consists of two three-phase MMC devices, the converter topology is as follows figure 1 As shown in the figure, the upper bridge arm and the lower bridge arm of each phase are formed by cascading N sub-modules (Sub-modular, SM), each sub-module SM is a half-bridge structure, as shown in Figure 2, the sub-module DC side with the same capacitor C in parallel. [0003] When th...

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): H02M1/36
CPCH02M2007/4835H02M1/36H02M7/4835
Inventor 王广柱
Owner SHANDONG 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