Thomas
Wilkins working with others is working towards characterizing harmonics
and signal distortion on the power system.
Improving power system conditions relates to a
characterization of harmonics and
underlying causes (CHUC) for improvement of the power system waveform
to reduce distortion on polyphase AC and DC power systems. Ideally, we
all would like to improve efficiency, power transfer reliability, and
longevity of equipment or prevent premature aging or damage to said
electrical equipment.
Currently, waveform
distortion causes premature aging of electrical equipment, excessive
heating, current and voltage stresses that cause failure in electrical
components, loss of real power production and consequently loss of
revenue. On polyphase AC power systems and DC power systems, distortion
of the desired signal has consequences. In the past power systems
engineers called this harmonic distortion.
This invention addresses the general nature of signal distortion.
When new
power plants or new components are placed on the power system a harmonic
study is required to discover or predict harmonic issues in the power
system that operators and owners may find unacceptable. Sometimes a
plant developer is required to provide a harmonics study for the
electrical distribution system.
The intent of this study is to confirm that the specified and
supplied equipment will operate properly when installed as specified in
the system and will not adversely impact the operation of other
equipment.
Currently, harmonic studies include all portions of the electrical
distribution system, from the normal and alternate sources of power down
to each load shown on the one-line diagram.
However, some power system elements within the power system are
summarized and not delineated as well as others. The concept of using
harmonics considers operation during normal conditions, alternate
operational configurations, emergency power conditions and any other
operations which could result in harmonic distortion exceeding
proscribed standards.
Harmonic
analysis is usually performed with a simulation which is a series of
harmonic calculations which and discuss the some of the results at the
following locations:
1.
The point of common coupling
2.
Primary side of each unit substation (normal power)
3.
The bus of each switchboard (normal and alternate power)
4.
Each alternate power source (including generators)
5.
The collector system busses within the a distributed generation
system
6.
Various Loads within the power system
The
Harmonic Analyses includes recommendations for mitigating the total
harmonic voltage distortion or total current demand distortion on the
system if the combination of loads exceeds or violates the limits of
various standards. Also, the analysis includes recommendations for
mitigating the impact of the harmonic distortion on plant equipment or
processes if the levels are such that equipment or processes may be
impaired.
However
harmonic analysis is deficient in modern power systems and does not
include switch mode power supplies or other modern piecewise or
nonlinear elements that do not match up with rotating sequence such as
zero, positive, negative, or other sequence referred to linear
transformation in circuits and machines.
Signal
distortion is handled only in the planning phases of a power system that
is to be modified or a new power system. For example, if a new power
plant is to be installed the harmonic study would be performed to assess
its impact on the power system with respect to power quality. This
process uses models of the power system to predict what the harmonic
impact will be and does not assess the actual or measured impact.
CHUC is
a system designed to improve the power system waveform
to reduce distortion on polyphase AC and DC power systems. Ideally, for
the purposes of improved efficiency, power transfer reliability, and
longevity of equipment, prevention of premature aging or damage to
electrical equipment.
We are
currently working with other companies both national and international
for the implementation of CHUC. If you are interested in CHUC or other
technologies please give us a call.
About
Wilkins Alternatives
Copyright 2011, Thomas A. Wilkins All Rights Reserved.
