Page 264 - Renewable Energy Devices and System with Simulations in MATLAB and ANSYS

10 Design Considerations for

Wind Turbine Systems

Marcelo Godoy Simões, S.M. Muyeen, and Ahmed Al-Durra

CONTENTS
Abstract ..........................................................................................................................................251
10.1 Introduction ...........................................................................................................................251
10.2 Wind Turbine Components ...................................................................................................252
10.3 Wind Turbine Characteristics ...............................................................................................254
10.4 Wind Energy Generator Systems ..........................................................................................256
10.4.1 Fixed Speed Wind Turbines ......................................................................................257
10.4.2 Variable Speed Wind Turbines ..................................................................................257
10.5 Wind Speed And Generator Performance .............................................................................259
10.6 Wind Turbine Controls .........................................................................................................261
10.6.1 Mechanical Control ..................................................................................................262
10.6.2 Electrical Control ......................................................................................................263
10.7 Summary ...............................................................................................................................264
References ......................................................................................................................................264
Further Reading .............................................................................................................................265

ABSTRACT
In this chapter, the fundamentals of wind energy conversion system including wind turbine com-
ponents, drive train, wind turbine characteristics, and wind generators are explained at the begin-
ning. Then the design considerations of a small wind turbine generator system such as wind speed
probability distribution, component losses, system efficiency, etc., are explained in detail. Different
types of wind turbine generator system topologies including fixed and variable speed systems are
presented. Finally, mechanical, electrical, and overall control schemes of wind energy conversion
system are demonstrated.

10.1 INTRODUCTION
The wind energy conversion has some simple foundations: the kinetic energy of the wind is
converted into mechanical shaft movement with a turbine, then it is converted into electrical energy
with a coupled electrical generator. Therefore, the wind propels the blades of a turbine, rotating a
shaft connected to the generator rotor and in turn producing electricity.
The global installed wind power had a fairly linear increasing capacity from 6 GW in 1996 to
nearly 121 GW in 2008. After that, the growth resembled more an exponential curve, because in
2014 it was estimated at a total worldwide power capacity of 367 GW. There are many potential
applications for small-scale wind users—typically residential, rural, or commercial applications—
either totally isolated or connected to the power grid. When a wind energy system is connected to
the public grid, advanced smart inverters may provide low-voltage support and reactive power com-
pensation if necessary. Small power user (prosumer) motivation is always based on income, in order
to offset their initial investments, by either saving money with their own microgrid or selling power

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