Page 173 - Power Quality in Electrical Systems

Chapter
11

Power Quality Events

Previous chapters have described power-quality deficiencies
such as line-voltage sags, voltage interruption, and the effects
of harmonic currents, as well as the remedies for these
conditions. In this chapter, we will describe the sensitivities
and reactions of equipment subjected to these deficiencies.
Equipment affected by power-quality deficiencies and described
in this chapter include the following:
■ Personal computers
■ Controllers
■ AC and DC contactors

(Electric motor drive equipment is covered in Chapter 12.)

Introduction

The purpose for analyzing the electrical system and the response of
critical equipment to power-quality deficiencies is to minimize the mis-
operation of each piece of equipment and the system in which it is
located. The following two comprehensive methods of analysis can be
used.

Method 1
C. P. Gupta et al. described a theoretical method incorporating the fol-
lowing steps [11.1]:

1. Prepare a network model of the electrical system, including the pro-
tective equipment and the connection of the critical load equipment.

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