24-01-2012, 02:43 PM
Power Quality Issues in a Hybrid Power System
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INTRODUCTION
Since ancient times, wind turbine technology has been
used to improve the quality of life for many people. People
have used wind turbines to pump water, mill grain,
and do many other things [1, 2, 3, 4].
In today’s world, wind turbines are used for similar
purposes (i.e., water or oil pumping, battery charging, or
utility generation). One important aspect of wind turbine
applications, especially in an industrial environment, is
that wind turbines generate electricity without creating
pollution. In addition, the generation of electricity using
wind turbines is well suited for isolated places with no
connections to the outside grid
COMPONENTS OF POWER SYSTEM
The system under discussion in this paper consists of
three major subsystems: diesel generator, wind turbine
generator, heavy (industrial) loads. In the power system
network, the balance of active power and reactive power
must be maintained. Thus, the diesel genset must be able
to keep the power balanced when the wind turbine or local
load varies. While important, details of the dynamic
model for electric machines will not be covered here.
Many good textbooks are available on this subject [6, 7].
Diesel Generator
From an electrical system point of view, a diesel generator
can be represented as a prime mover and generator.
Ideally, the prime mover has the capability to supply
any power demand up to rated power at constant frequency,
and the synchronous generator connected to it
must be able to keep the voltage constant at any load
condition.
Induction Machines
Most electric machines used as the prime mover in industry
are induction motors. Two applications of induction
machines in the power system network fall within the
scope of this study. One application is as a generator on
a wind turbine and the other is as a motor driving large
pumps and compressors. By its nature, an induction machine
is an inductive load.
