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Application of motor capacitors to improve facility power usage in the industrial setting

As deregulation of the electric power system in the United States unfolds, many
customers are experiencing changes in their billing rate structure. Some face the
addition of power factor penalty tariffs, and seek ways to minimize the added burden.
The installation of entrance capacitor banks is the common response, but fails to take
complete advantage of capacitor abilities. Other project designs exist that can harness
these advantages to the full benefit of the customer.
This work will show that distributing shunt capacitors in parallel with induction motors
will elevate power factor and voltage, and also decrease ohmic losses in the wiring and
protection devices that supply the motor. This reduction often produces a better overall
economic solution due to energy savings.
The distribution of capacitors at induction motors reduces the reactive current in the
branch of the distribution system that supplies them. A reduction in the total current
flowing to the motor along the distribution system results in smaller losses throughout
the system. As losses diminish, the total real power drawn through the distribution
system is lessened, and electric bills are reduced. This alternative to entrance capacitor
banks is not as commonly implemented. A misconception that the resistance in facility
distribution systems is relatively low has discouraged distributed motor capacitor
installation for overall facility power factor correction, in favor of entrance capacitor
banks. We will show that the resistance in the distribution system is higher than
typically thought, that motor capacitors can exploit this fact, and can often economically
outperform entrance capacitor banks which are terminated at the point of incoming
utility power.
Motor capacitors are not a new technology. They are commercially available off the
shelf technology, suitable for power factor correction for induction motors. Distributed
capacitors can be utilized for all significantly sized induction motors in a facility. The
elevation in power factor and voltage, reduction in reactive current and real power are
calculated, and trends are observed. The matter is considered from both the standpoint
of engineering and economics to provide an integrated study.

Identiferoai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4315
Date30 October 2006
CreatorsHillhouse, William Jeffrey
ContributorsEnjeti, Prasad
PublisherTexas A&M University
Source SetsTexas A and M University
Languageen_US
Detected LanguageEnglish
TypeBook, Thesis, Electronic Thesis, text
Format3626287 bytes, electronic, application/pdf, born digital

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