Modular Multilevel Converter (MMC) has become the most concerned converter topology in the High Voltage Direct Current (HVDC) transmission system, in recent times. The low switching frequency, low converter losses and flexible control made it most attractive topology. It is important to make a research on the loss calculation method of MMC and state formulae for the losses as it is a vital step during the design stage of the MMC based HVDC system.
In this research work, the structure of MMC based HVDC system is discussed. Three sub module topologies’; half bridge, full bridge and clamp double sub module, are discussed. A method based on the average and root mean square (RMS) values of the current passing through the sub module is discussed. The conversion losses in the switching devices of the sub modules are calculated using the method.
A cases study is taken into consideration then with certain parameters. Using these parameters a MATLAB program is developed. With the help of the program the losses and efficiency curves for each switching device by taking each sub module separately are obtained respectively. A comparison of the losses and efficiency of each sub module is also discussed. At the end those factors which effect the losses and efficiency of the sub module are discussed along with the certain aspects for the directions of future work.
Inhaltsverzeichnis (Table of Contents)
- Chapter 1: Introduction
- 1.1 Problem Statement
- 1.2 Aim and Objective
- 1.3 Scope of Work
- 1.4 Organisation of Thesis
- Chapter 2: Literature Review
- 2.1 Introduction
- 2.2 Literature Review
- Chapter 3: Modular Multilevel Converter
- 3.1 Introduction
- 3.2 Modular Multilevel Converter (MMC)
- 3.2.1 Features of Modular Multilevel Converter (MMC)
- 3.2.2 Advantages of Modular Multilevel Converter (MMC)
- 3.2.3 Working of Modular Multilevel Converter (MMC)
- 3.3 Sub Module Topologies
- 3.3.1 Half Bridge Sub Module
- 3.3.2 Full Bridge Sub Module
- 3.3.3 Clamp Double Sub Module
- Chapter 4: Average and RMS Values Calculation
- 4.1 Introduction
- 4.2 Circuit Ananlysis
- 4.3 Conversion Losses
- 4.3.1 Conduction Losses
- 4.3.2 Switching Losses
- 4.4 Half Bridge Sub Module Calculations
- 4.4.1 Average Value of the Current
- 4.4.2 RMS Value of the Current
- 4.5 Full Bridge Sub Module Calculations
- 4.5.1 Average Value of the Current
- 4.5.2 RMS Value of the Current
- 4.6 Clamp Double Sub Module Calculations
- 4.6.1 Average Value of the Current
- 4.6.2 RMS Value of the Current
- Chapter 5: Power Losses Estimation
- 5.1 Introduction
- 5.2 Half Bridge Sub Module
- 5.2.1 Conduction Losses
- 5.2.2 Switching Losses
- 5.3 Full Bridge Sub Module
- 5.3.1 Conduction Losses
- 5.3.2 Switching Losses
Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)
This thesis aims to analyze the efficiency of a Modular Multilevel Converter (MMC) for High Voltage Direct Current (HVDC) systems. It focuses on developing a method for calculating the conversion losses within the MMC, considering different sub-module topologies. The research intends to provide insights into the design and optimization of MMC-based HVDC systems.
- Loss Calculation Methodology for MMCs
- Comparison of Different Sub-Module Topologies (Half-bridge, Full-bridge, Clamp Double)
- Efficiency Analysis of MMC-based HVDC Systems
- Impact of Design Parameters on MMC Efficiency
- Development of a MATLAB program for loss and efficiency calculation
Zusammenfassung der Kapitel (Chapter Summaries)
Chapter 1: Introduction: This chapter introduces the problem of efficient design in MMC-based HVDC systems. It establishes the aim and objectives of the thesis, which is to develop a loss calculation method and analyze the efficiency of different sub-module topologies. The scope of the work is defined, outlining the specific areas of investigation, and the organization of the thesis is detailed, providing a roadmap for the reader.
Chapter 2: Literature Review: This chapter presents a comprehensive review of existing literature on Modular Multilevel Converters (MMCs) and their applications in HVDC transmission systems. It summarizes previous research on loss calculation methods and efficiency analyses, setting the context for the current research and highlighting the gaps in knowledge that this thesis addresses. The review will likely cover various MMC topologies, control strategies, and loss mechanisms. This lays the groundwork for the proposed methodology.
Chapter 3: Modular Multilevel Converter: This chapter delves into the structure and operation of Modular Multilevel Converters (MMCs). It provides a detailed explanation of the MMC topology, highlighting its key features and advantages over other converter types. Different sub-module topologies, such as half-bridge, full-bridge, and clamp double sub-modules, are discussed in detail, comparing their characteristics and suitability for HVDC applications. The chapter likely includes circuit diagrams and operational principles for each topology.
Chapter 4: Average and RMS Values Calculation: This chapter focuses on the calculation of average and root mean square (RMS) values of currents within the different sub-module topologies. A detailed circuit analysis is presented, explaining the methodology used to determine these values. It likely involves deriving mathematical expressions for the average and RMS currents based on the specific switching patterns and operational characteristics of each sub-module. The calculations are crucial for determining conduction and switching losses in the subsequent chapter.
Chapter 5: Power Losses Estimation: This chapter utilizes the average and RMS current values calculated in Chapter 4 to estimate the power losses within each sub-module topology. It separates the losses into conduction and switching losses, providing detailed calculations for each component. The chapter likely presents a comprehensive analysis of the various loss mechanisms within the MMC and explores the impact of different design parameters on overall efficiency. The results are used to compare the relative efficiency of different sub-module topologies.
Schlüsselwörter (Keywords)
Modular Multilevel Converter (MMC), High Voltage Direct Current (HVDC), power losses, efficiency, sub-module topologies, half-bridge, full-bridge, clamp double, conduction losses, switching losses, MATLAB simulation, HVDC transmission.
Frequently Asked Questions: Comprehensive Language Preview of Modular Multilevel Converter Efficiency Analysis
What is the main topic of this thesis?
This thesis analyzes the efficiency of Modular Multilevel Converters (MMCs) in High Voltage Direct Current (HVDC) systems. It focuses on developing a method for calculating conversion losses within the MMC, considering various sub-module topologies (half-bridge, full-bridge, clamp double), and comparing their impact on overall system efficiency.
What are the key objectives of the research?
The key objectives include developing a loss calculation methodology for MMCs, comparing different sub-module topologies, analyzing the efficiency of MMC-based HVDC systems, determining the impact of design parameters on efficiency, and creating a MATLAB program for loss and efficiency calculations.
What are the different sub-module topologies discussed?
The thesis examines three sub-module topologies: half-bridge, full-bridge, and clamp double. Each topology's characteristics and suitability for HVDC applications are compared.
How are power losses estimated?
Power losses are estimated by calculating average and RMS current values for each sub-module topology. These values are then used to determine conduction and switching losses. A detailed circuit analysis is employed for this purpose.
What is the structure of the thesis?
The thesis is structured into five chapters. Chapter 1 provides an introduction, problem statement, objectives, and scope. Chapter 2 reviews relevant literature. Chapter 3 details the structure and operation of MMCs and their sub-module topologies. Chapter 4 calculates average and RMS current values. Chapter 5 estimates power losses and analyzes efficiency.
What software is used for simulations?
The thesis mentions the development of a MATLAB program for loss and efficiency calculations, suggesting the use of MATLAB for simulations.
What are the key findings expected?
The expected findings include a comprehensive loss calculation methodology for MMCs, a comparison of the efficiency of different sub-module topologies, and insights into the impact of design parameters on MMC efficiency in HVDC systems.
What are the key words associated with this research?
Key words include: Modular Multilevel Converter (MMC), High Voltage Direct Current (HVDC), power losses, efficiency, sub-module topologies, half-bridge, full-bridge, clamp double, conduction losses, switching losses, MATLAB simulation, HVDC transmission.
What is the target audience for this research?
The target audience is likely academics and professionals in the field of power electronics, specifically those interested in HVDC transmission and MMC design and optimization.
- Quote paper
- Ehtasham Mustafa (Author), 2014, Analytical Efficiency Evaluation of Modular Multilevel Converter (MMC) for High Voltage Direct Current System (HVDC), Munich, GRIN Verlag, https://www.grin.com/document/316343
