03-07-2012, 04:14 PM
distribution system analysis and the future smart grid
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INTRODUCTION
THE Smart Grid means different things to different people.To some it is an emphasis on communications and control,which have not typically been represented in distribution system analysis. To others, the Smart Grid means distributed resources – generation, storage, and demand response. These issues have been addressed by many authors since the early 1990’s and many distribution system analysis tool suppliers have already implemented some capabilities to model distributed resources. However, there remains much work to do.The Distribution System Analysis Subcommittee (DSAS) of the IEEE PES Power Systems Analysis, Computing, and Economics (PSACE) Committee presented a paper at the 2010
IEEE PES General Meeting on this subject.
[1] This paper discusses selected subjects from the DSAS paper in the context of distribution engineering in rural electric utilities. The Distribution Test Feeders Working Group (WG) of the DSAS has already done work on related subjects, for example, to address the concern for having large induction generators (e.g. wind turbine generators) on distribution feeders.
[2]. Part of the motivation for that work was concerns expressed by rural electric utility engineers. The WG is continuing to work in this area and in other areas related to Smart Grid and distribution system analysis tool development. DG is not the only concern.Other perspectives on the Smart Grid contain an emphasis on R. C. Dugan is with EPRI, Knoxville, TN 37932 USA (email:r.dugan[at]ieee.com) R. F. Arritt is with EPRI, Knoxville, TN 37932 USA (email:rarritt[at]epri.com) such things as extensive monitoring, intelligent protection,microgrids, and energy efficiency.What kind of distribution system analysis framework is needed to support the features being proposed for the Smart Grid? Will there be a need for distribution system analysis if everything is monitored thoroughly? What can be done if more
SMART GRID CHARACTERISTICS
Research is just beginning on many issues related to the Smart Grid and its features continue to be defined. Those features likely to have an impact on the direction of distribution system nalysis include:
1. Distributed Resources
a. Generation
b. Renewable Generation (variable resources.)
c. Energy Storage
d. Demand Response
2. Communications and Control
a. AMI deployed throughout the System
b. High-speed Communications to Metering and
Controls
THE STATE OF THE ART
From the late 1960’s to the mid-1980’s distribution system analysis computer programs evolved from simple balanced load voltage drop calculators that automated hand calculations to sophisticated systems with databases and interactive graphics. The system models were still largely based on the simplified radial circuit techniques of the voltage drop calculations. Many power engineers who have been involved largely with transmission system problems and are not
Intimately familiar with the industry are under the mistaken impression that this is still the state-of-the-art in distribution system analysis. There have been many significant advances since that time.
ROLE OF DISTRIBUTION SYSTEM ANALYSIS
What kinds of analyses will distribution engineers want to perform for the future Smart Grid? In some visions of the Smart Grid, the distribution system is saturated with voltage,current, and power monitors with all the data being available on line in a matter of seconds. Some who have this vision foresee a more limited role for distribution planning than today. They suggest that distribution system analysis tools will seldom be needed if engineers can simply sit at their desks and obtain the voltage and power consumption at every customer.Planning becomes more of a straightforward bookkeeping problem. On the other hand, as has happened for many technological advances, there could be a greater need for detailed distribution system analysis to better manage all the technology.Functions such as reconfiguration after an emergency will likely still require significant distribution system analysis capability.