Industrial Power System Design in a Utility Environment
BY ROBERT A. DURHAM & MARCUS O. DURHAM
TYPICALLY, LARGE LOADS ASSOCIATED with petroleum distribution systems are located in a relatively confined plant area. Scattered distribution systems do not often have very large capacity. The combination of large industrial requirements coupled with the geographic requirements of a utility system calls for a challenging design. One of the primary duties of electrical engineers in the petroleum industry is the design and construction of power distribution systems. In most other cases, larger systems are located within a defined plant environment [1]. Systems spread
over a large area tend to be smaller in load. The scheme discussed here is unique: a large electrical network is spread over a very large geographic area. This creates an exceptional set of circumstances. At the beginning of the design process, several goals were identified.
■ Downtime must be minimized. Due to the inherent physical characteristics of the process being powered, even short downtime has serious financial consequences.
■ In conjunction with reducing downtime, it was desired that a protection system be designed so that a fault in one area does not affect loads in another area [2].
■ Under normal conditions, a voltage drop of less than 5% at the end of the system is desirable.
This is crucial to assure that full voltage is available on the load side of the transformers [3], [4].
■ Under contingency conditions, it was preferred that the load could be served successfully from either
one of two utility sources.
■ Necessarily, the system would be designed so that the heating of conductors would not cause any
additional sag that would damage the integrity of the load service [5].
The only way to effectively address these issues is to conduct a series of computer model analyses prior to the beginning of construction.
See detail : Industrial Power System Design in a Utility Environment
