Numerically efficient models of modular multilevel converters for high voltage direct current transmission system and AC-DC super grid
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Meng, Xuekun
issued: 2020-11-05T20:36:02Z
issued: 2020
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: High Voltage Direct Current (HVDC) technology has been widely used in providing interconnection between the remote renewable power plants and the existing power grid infrastructures. The latest development of Modular Multi-level Converter (MMC) in Voltage Source Converter (VSC) family can independently control active and reactive power and provide stability enhancement in weak AC grids. Additionally, harmonic filters are unnecessary in the implementation of MMC as it provides nearly perfect sinusoidal shape waveforms with a sufficient number of levels and switches. In recent years, various projects are developed based on the MMC-HVDC, and it proves its potential in becoming the backbone of the long-distance power transmission in the near future. However, the massive number of power switches in MMC-HVDC also brings notable challenges in digital simulation. Especially for simulating an interconnected system that involves both the MMC-HVDC system and large-scaled AC networks, a large number of switching operations and massive input/output data transfer will introduce a tremendous computational burden. Developing a numerically efficient model for MMC-HVDC interfacing with large-scale AC grids is essential for experimental testing and real-time simulations. This thesis addresses several aspects of the numerically efficient modeling of MMC-HVDC and its integration with a large-scale AC grid. First, a simplified model of MMC is proposed with improved simulation efficiency while preserving accuracy for various transients. The proposed model offers the flexibility in converter operation modes to accommodate the MMC with different submodule topologies and its relevant detailed controls. Next, we extend the concept of the simplified model of MMC into a unified framework to incorporate different levels of simplification into a general circuit structure. The proposed model is validated against state-of-the-art models to demonstrate its significantly improved simulation accuracy.…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/76464
note: Numerically Efficient Models of Modular Multilevel Converters for High Voltage Direct Current Transmission System and AC-DC Super Grid by Xuekun Meng B.A.Sc., The University of British Columbia, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE COLLEGE OF GRADUATE STUDIES (Electrical Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) November 2020 © Xuekun Meng, 2020 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: Numerically Efficient Models of Modular Multilevel Converters for High Voltage Direct Current Transmission System and AC-DC Super Grid submitted by Xuekun Meng in partial fulfillment of the requirements of the degree of Doctor of Philosophy Dr. Liwei Wang, School of Engineering, University of British Columbia Supervisor Dr. Morad Abdelaziz, School of Engineering, University of British Columbia Supervisory Committee Member Dr. Wilson Eberle, School of Engineering, University of British Columbia Supervisory Committee Member Dr. Rudolf Seethaler, School of Engineering, University of British Columbia University Examiner Dr. Venkata Dinavahi, Faculty of Engineering, University of Alberta External Examiner iii Abstract High Voltage Direct Current (HVDC) technology has been widely used in providing interconnection between the remote renewable power plants and the existing power grid infrastructures. The latest development of Modular Multi-level Converter (MMC) in Voltage Source Converter (VSC) family can independently control active and reactive power and provide stability enhancement in weak AC grids. Additionally, harmonic filters are unnecessary in the implementation of MMC as it provides nearly perfect sinusoidal shape waveforms with a sufficient number of levels and switches. In recent years, various projects are developed based on the MMC-HVDC, and it proves its potential in becomin…
has type: Thesis/Dissertation
date issued: 2021-02
is shown at: 10.14288/1.0394911
language: eng
degree discipline: Electrical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/76464