Page 190 - Renewable Energy Devices and System with Simulations in MATLAB and ANSYS

8 Power Electronics and

Controls for Large Wind

Turbines and Wind Farms

Ke Ma, Udai Shipurkar, Dan M. Ionel, and Frede Blaabjerg

CONTENTS
Abstract ..........................................................................................................................................177
8.1 Introduction ...........................................................................................................................178
8.2 Wind Turbine Systems ..........................................................................................................178
8.3 Specific Issues for Wind Turbine Operation .........................................................................181
8.3.1 Complex Mission Profiles for Wind Turbines ..........................................................181
8.3.2 Strict Codes from Grid Side to Be Connected ..........................................................183
8.3.3 Growing Reliability Requirements ...........................................................................184
8.4 Power Electronics: Devices and Converters .........................................................................185
8.4.1 Power Semiconductor Devices .................................................................................185
8.4.2 Two-Level Converter Topologies ..............................................................................187
8.4.3 Multilevel Converter Topologies ..............................................................................188
8.4.4 Future Converter Topologies.....................................................................................189
8.4.4.1 Cascaded H-Bridge Converter with Medium-Frequency Transformers .....189
8.4.4.2 Modular Multilevel Converter ...................................................................189
8.5 Power Electronic Solutions for Wind Farm ..........................................................................189
8.5.1 Solutions for Wind Power Transmission ..................................................................189
8.5.2 Solutions for Better Grid Support .............................................................................192
8.6 MATLAB Models for Thermal Analysis of Wind Turbines ...............................................193
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8.6.1 Overview of the Models and Relationship................................................................194
8.6.2 Mechanical Model of Turbine and Generator ...........................................................194
8.6.3 Electrical Model of Converter and Control ..............................................................197
8.6.3.1 Generator-Side Converter and Control ......................................................197
8.6.3.2 Grid-Side Converter and Control ...............................................................198
8.6.4 Power Loss and Thermal Modeling ..........................................................................199
8.6.5 Example of the Simulation Results ...........................................................................199
8.7 ANSYS Models for Wind Turbine Systems .......................................................................202
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8.8 Summary ...............................................................................................................................203
References ......................................................................................................................................204

ABSTRACT
Wind power represents a major and growing source of renewable energy for electric power systems.
This chapter provides an overview of state-of-the-art technologies and anticipated developments in
the area of power electronic drives, controls, and electric generators for large multi-megawatt (MW)
wind turbine (WT) systems. The principal components employed in a turbine for energy conversion
from wind to electricity are described, and the main solutions that are commercially available are
briefly reviewed. The specific issues of complex mission profiles, grid codes, and also reliability are

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