IEEE Power & Energy Magazine - January/February 2016 - 56

these latter include "smart-grid" related technologies, integration of phase-angle measurements into electric grid operations,
additional market products like distributed resources, analysis
methodologies for solar generation forecasting, and management techniques for operating energy storage devices.
with the broad scope of these challenges and the need to
integrate grid operations systems and align them on a common modeling syntax for the electric power grid, ercot
elected to pursue a design based on the iec tc57 ciM.
ercot's approach leverages and extends the ciM. the
result can be seen in Figure 5.
✔ the NMMs repository of master network data is
based on the ciM information model.
✔ input to NMMs from member tsos, generators, and
other sources is standardized on the ciM. Most of this
information comes in the form of incremental updates
of network models.
✔ output of network models from NMMs to ercot
and member business systems is standardized on the
ciM. this establishes consistency of representation

Modeling Authorities' Individual
Grid Models Are Expressed as
CIM EQ Models for a Business
Day and SSH Instances for
Every Reference Point in Time

Quality
Assurance
Gate

Years-Ahead Individual Grid
Models

throughout these business systems, which reduces the
potential for conflicting results and enables straightforward sharing of information among these systems.
the use of the ciM, as both a master data repository and
data exchange standard, provides NMMs a flexible design
that allows for the rapid operational integration of new
devices as necessary to support grid operations. the ciM
not only allows for the extension of its schema (data structure
definitions) but also provides a set of interoperational data
exchange standards that the data adaptors/consumers adhere
to (these allow for the easy migration of data into target
systems). this reduces organizational adoption time, produces a level of modeling consistency and accuracy that the
prevalent industry practices are incapable of, and in general
leads to greater operational awareness of grid conditions and,
therefore, greater reliability of the overall power grid system.

ENTSO-E and CIM for Network Analysis
historically, system operations for all tsos in europe relied primarily on bilateral contracts between adjacent tsos. based on

Solved Base Case
(CGM), Expressed in
CIM TP and SV
Instance for the Target
Time Stamp
What-if Analysis (Contingency Analysis/
Assessment of the Effectiveness of
Remedial Actions)

Year-Ahead Individual
Grid Models

Month-Ahead Individual Grid
Models

Interchange Transaction
Scheduling
(BCC Algorithm)

Network Sensitivity Analysis (Defining Critical
Network Element/Calculating PTDF)

Week-Ahead Individual Grid
Models
Response to a Disturbance in the Time
Domain (Dynamic Stability Analysis)

Pre-Market Closure Day-Ahead
Individual Grid Models

Post-Market Closure Day-Ahead
Individual Grid Models

CGM Methodology
(European Merging Function)

Impact of Planned Outages

Intraday Individual Grid Models
Short-Term Adequacy
Real-Time Snapshot Data

figure 6. The context for the ENTSO-E CGM.
56

ieee power & energy magazine

january/february 2016
Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - January/February 2016
