A sub-module pressure equalization control method in the process of switching on and off of a converter station and its valve group

A technology of voltage equalization control and valve group, which is applied in the direction of converting AC power input to DC power output, output power conversion devices, electrical components, etc., and can solve overvoltage/undervoltage of half-bridge sub-modules and clamping twin sub-modules, etc. Problems such as uneven voltage and cost increase achieve the effect of solving current impact, reducing equipment cost, and strengthening technical economy

Active Publication Date: 2019-08-06
XUJI GRP +4
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0016] The purpose of the present invention is to provide a sub-module pressure equalization control method in the process of switching on and off the valve group of the converter station and its valve group, which is used to solve the overvoltage / undervoltage of the half-bridge sub-module and the clamping twin sub-module in the process of switching on and off the MMC valve group The problem of equal voltage unevenness, and the problem of increasing the cost by increasing the proportion of the full bridge sub-module

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 sub-module pressure equalization control method in the process of switching on and off of a converter station and its valve group
  • A sub-module pressure equalization control method in the process of switching on and off of a converter station and its valve group
  • A sub-module pressure equalization control method in the process of switching on and off of a converter station and its valve group

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0037] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0038] For such as figure 1 The single-stage system of the double-ended high-voltage flexible DC system shown is analyzed as diagram 2-1 , Figure 2-2 It can be seen from the simulated waveform diagrams of sending and receiving ends during the operation of the valve group when the proportion of the MMC full-bridge sub-module under conventional control is 50% and the content in the background technology. , the upper and lower arm currents of phase A of the MMC high valve group at the sending end are And it is always negative; the upper and lower bridge arm currents of phase A of the MMC high valve group at the receiving end are And it is always positive, that is to say, the root cause is that there is no positive and negative alternation in t...

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 sub-module pressure equalization control method for a converter station and its valve group switching on and off. During the valve group switching on / off process, the control increases the command value of the reactive current of the valve group, so that the valve group works Under the working condition that the amplitude of the AC current on the valve side is greater than two-thirds of the DC bus current amplitude, positive and negative alternating bridge arm currents are created to realize the voltage equalization control of the sub-modules. The control method avoids voltage overvoltage or undervoltage of the half-bridge sub-module and / or clamping twin sub-module caused by the continuous positive or negative current of the bridge arm, thereby solving the problem of current impact caused by uneven voltage of the factor module. The invention only improves the control strategy, does not need to increase the number of full-bridge sub-modules, effectively reduces the equipment cost, and has strong technical economy. Moreover, the control method has less impact on the AC system and has strong practicability.

Description

technical field [0001] The invention belongs to the technical field of flexible direct current transmission, and in particular relates to a method for controlling voltage equalization of sub-modules during switching on and off of a converter station and a valve group thereof. Background technique [0002] With the rapid development of modern power grids and the upgrading of power electronics technology, flexible DC transmission systems based on Modular Multilevel Converter (MMC) technology have made great progress. MMC has many advantages such as independent control of active and reactive power, no commutation failure, and power supply for passive islands. At the same time, the MMC system also has low switching frequency, low switching loss, no need for AC filter banks, and strong scalability. And other advantages, which makes MMC gradually realize the engineering application, and can be used in the occasion of high DC voltage and high power transmission. [0003] At presen...

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
CPCH02M7/483H02M7/4835
Inventor 宣佳卓杨美娟吴金龙王先为马焕姚为正陆翌童凯陈骞
Owner XUJI GRP
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