Intelligent Utility Jan-Feb 2013

DISTRIBUTION MANAGEMENT SYSTEMS
Transforming
the electric
utility industry
By Steve Russell
DICTIONARY.COM DEFINES THE INFORMATION
Age as a period “characterized by the gathering and
almost instantaneous transmission of vast amounts of information.”
The development of the distribution management
system (DMS) will enable the electric utility industry to
take advantage of the unprecedented data and technological
advances of the information age resulting in better management
and optimization of distribution grid performance.
Historically, distribution operations have been
characterized by:
? ? The manual operations of devices by field personnel.
? ? Local operation of devices by control panels config-
ured to largely operate independent of one another.
? ? Operational processes based on past practices and a
fixed circuit topology.
? ? Operating parameters based on calculations and
approximations focused on peak loading.
? ? Data spread across multiple databases using various
storage media including computer-based storage as
well as hard copy.
While these approaches have served the electric utility industry
well for over a century, there are inherent limitations
contained in these practices, which DMS enables, that offer
significant benefit to both the customer and utility.
At first glance, the advanced control functions most frequently
discussed in conjunction with DMS would appear
to be its greatest strengths.
The ability to manage and optimize voltage and VAR
flow through volt/VAR control (VVC) and the ability to
automatically locate faults and develop switching solutions
to minimize outage footprints via fault identification and
service restoration (FISR) form the basis for the benefits
made possible by DMS. While both functions generate tremendous
benefit for customers and utilities alike, the real
transformative power of the DMS is contained in the system
model and the continuous, near real-time power flows that
DMS generates.
The heart of a DMS is the data model of the distribution
system. Two types of data are required for the DMS to
accurately represent near real-time conditions for the
system: static and operational.
Static system data is data that describes the distribution
system over an extended time frame. Updates to this data
tend to be long-term in nature and are generally considered
permanent. This data includes information from the GIS for
the distribution connectivity model, system configurations
and land base to represent the distribution lines, as well as
substation internal connectivity to model substation connectivity
and configurations. Additionally, relay settings and
system impedance data are required along with component
and facilities ratings, equipment impedances and ratings,
and device settings from reclosers, capacitors and regulator
control panels. Finally, the DMS could not run near realtime
load flows without customer information regarding
customer count, load data and load schedules.
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