Page 222 - Renewable Energy Devices and System with Simulations in MATLAB and ANSYS

9 Electric Generators and

their Control for Large

Wind Turbines

Ion G. Boldea, Lucian N. Tutelea, Vandana Rallabandi,
Dan M. Ionel, and Frede Blaabjerg

CONTENTS
Abstract ..........................................................................................................................................209
9.1 Introduction ...........................................................................................................................210
9.2 DFIG .....................................................................................................................................213
9.2.1 Introduction ...............................................................................................................213
9.2.2 DFIG Topology and Circuit Model...........................................................................215
9.2.3 DFIG dq Model and Control .....................................................................................218
9.3 CRIG .....................................................................................................................................221
9.3.1 Introduction ...............................................................................................................221
9.3.2 CRIG Circuit Model and Performance .....................................................................223
9.3.3 CRIG Control ............................................................................................................225
9.4 PMSG ...................................................................................................................................227
9.4.1 Introduction ...............................................................................................................227
9.4.2 Optimal Design of PMSGs .......................................................................................229
9.4.3 Circuit Modeling and Control of PMSG ..................................................................231
9.5 DCE-SG ................................................................................................................................236
9.5.1 Optimal Design of DCE-SG .....................................................................................237
9.5.2 Active Flux–Based Sensorless Vector Control of DCE-SG ......................................242
9.6 Modeling of Electric Generators by Finite Element Analysis (FEA) ...................................246
9.7 Summary ...............................................................................................................................247
References ......................................................................................................................................248

ABSTRACT

The electric generator and its power electronics interface for wind turbines (WTs) have evolved rap-
idly toward higher reliability and reduced cost of energy in the last 40 years. This chapter describes
the up-to-date electric generators existing in the wind power industry, namely, the doubly fed induc-
tion generator, the cage rotor induction generator, and the synchronous generator with DC or per-
manent magnet excitation. The operating principle, performance, optimal design, and the modeling
and control of the machine-side converter for each kind of generator are addressed and evaluated.
In view of the fact that individual power rating of WTs has increased to around 10 MW, generator
design and control technologies required to reach this power rating are discussed.

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