Simulator 16 User Guide - PowerWorld

PSLF supports up to 8 owners per branch, while Simulator only supports 4. If an EPC file
specifying more than 4 owners is loaded, Simulator will keep track of them with EPC specific
fields.
Transformers
PSLF allows a tertiary bus number of zero (0). Simulator supports this exclusion of the tertiary
bus, but will write it as two 2-winding transformers when exporting to a RAW file.
Multi-Section Lines
In PSLF, intermediate buses are not defined and thus loads, generators, and shunts at these
points are not allowed. When writing out to an EPC file, the multi-section line record is ignored if
intermediate buses have objects.
Area/Zones for Shunt Objects
PSLF allows area and zone designations for specific branches and transformers. Simulator reads
this into EPC specific fields, but does not use them for anything.
Area MW Transactions
PSLF includes tables showing Transactions. The actual scheduled values are informational only.
PSLF does not use these MW Transactions in the power flow solution; instead, it includes a field
with an area specifying the net MW export. When loading an EPC file, Simulator's area field
"Unspecified MW Interchange" is assigned as the "leftover" which isn't included in the
transactions table.
DC Lines
In Simulator, there are distinct container objects for both a two-terminal DC line and a multiterminal
DC line (MTDC). In PSLF, there are only definitions of the DC Buses, AC/DC converter,
and DC line objects. The groupings are then determined by the topology of the DC line links.
PSLF requires that all DC buses throughout the entire model have a unique DC bus number,
which Simulator supports.
Interfaces
PSLF supports the definition of an interface as a group of AC lines (or Multi-Sections lines).
Simulator supports several more types of interface elements, such as Area-To-Area, Zone-To-
Zone, DC Line, Injection group, Generator, Load, or another interface.
Injection Groups
Simulator supports the definition of an injection group which represents a group of generators,
loads, or switched shunts (and can contain other injection groups). This can bus used for
summary calculations, sensitivity-based calculations, or as a source and sink for a transfer. A
user-written EPCL would be required to support this in PSLF.
Substations
In Simulator, each bus can be optionally assigned to a substation. This is useful in oneline
diagram creation and is necessary to support EMS-based full-topology models. PSLF does not
support substations.
Super Areas
In Simulator, Super Area objects can be created and each area can be assigned to one super
area. This is useful in studying groups of areas which are dispatched together (Electricity
Markets). PSLF does not support Super Areas.
Nomograms
In Simulator, Nomogram objects can be created which specify two interfaces and then a twodimensional
limit region. Nomogram limit violation can then be monitored or enforced in
Contingency Analysis, ATC, OPF and SCOPF studies. PSLF does not support Nomograms.
©2011 PowerWorld Corporation
100