The main objective of the monitored
elements input analysis function is to provide a very fast and
simple set of functions to study the impact of transactions on
specified monitored branches, interfaces, and flowgates. PSS™MUST
provides two different approaches and groups of functions for
monitored element analysis covering the most frequently asked
question related to monitored elements response to various transaction
related events.
The monitored element impact
analysis function allows the user to evaluate the impact of
one user selected study transfer on various monitored parameters.
This type of analysis allows the user to evaluate flow changes
due to scheduling additional transactions, report PTDF and OTDF
factors for all monitored elements, identify monitored elements
that can be impacted by the selected study transfer, and study
OTDF factors variation for different contingencies.
The monitored element sensitivity
analysis function allows the user to evaluate the sensitivity
of one or several monitored elements to various transactions.
There are three sensitivity analysis functions. The study transfer
participating points sensitivity report allows the user to
evaluate the response of the selected monitored elements to all
the participating points in importing or exporting subsystems.
The transaction sensitivity report evaluates the impact
of user defined transactions sets. The subsystem sensitivity
report contains sensitivity factors for all specified subsystems.
Monitored element sensitivity analysis provides a very efficient
way to identify transactions which have the largest impact on
the few selected or overloaded flowgates. This type of analysis
provides the network sensitivity factors which will form the basis
for Transmission Loading Relief (TLR).
OTDF sensitivity report allowing the user to study the variation
of OTDF factors for the same monitored element under all contingencies
Branch and interface impact reports
are ordered by either:
Bus numbers for branches or input order for interfaces.
Monitored elements loading; to be exact, reports are ordered
by the loading level at the maximum specified study transfer
level.
Absolute impact value.
A user has the option to eliminate
reporting monitored elements loaded below the user-specified threshold
or with the impact below user-specified impact threshold. All
impact reports have a columnar structure. An experienced MS Excel
user can easily customize this report.
Subsystem
sensitivity report contains sensitivity factors for all
specified subsystems, which allows the user to evaluate the
relative impact of the various subsystems on the selected monitored
element. Subsystem sensitivity factors can be reported with
respect to transfer to the user defined reference subsystem
or with respect to the system swing bus.
All three reports have a similar format and the same custom functions
accessible via the right mouse click menu. All these reports are
parsed in Excel spreadsheet format so a user can apply all standard
MS Excel functions to these reports.
This group of functions provides
reports on the incremental flow distribution caused by a user-specified
study transfer. The functions also provide reports on initial
and final interface flows before and after scheduling of a specified
study transaction, a report on total systems balances, and a flow
report for tie branches between selected areas, zones, and subsystems.
There are three levels of impact
analysis:
The Total Participation
Factor (TPF) report, which summarizes the impact on areas,
zones, or subsystems due to wheeling caused by the specified
study transfer.
The Ties report, which
contains a detailed report on all tie branches between selected
areas, zones, and subsystems.
The main objective of the impact
analysis function is to evaluate interface flows between areas
and zones, however, only areas are considered in the GAPP report.
There are three alternative methods for specifying impacted systems:
by areas, by zones, or by subsystems as defined
in the subsystem definition files.
Analysis by areas/zones is
the most widely used. However, analysis by subsystems (e.g., based
on subsystem definitions provided in the subsystem file) is much
more versatile and allows analysis for virtually any user-defined
bus or set of buses. Therefore, the system description can range
from global definitions such as regional systems (VACAR, MAPP,
SPP, etc.) to detailed definitions such as portions of a utility.
The impact of bus-to-bus transactions can also be analyzed.
One unusual feature of the impact
analysis is that it allows evaluation of interface flows between
different types of subsystems (e.g., between areas and
zones and even between overlapping systems). IPF for overlapping
systems shows the percentage of flow that leaves the FROM system
and arrives at the TO system.
By specifying a study transfer from
one subsystem within a control area to another subsystem within
the same control area, the effect of internal shifts in dispatch
on the surrounding systems (loop flows) can be determined.
By default, the area/zone impact analysis functions compute TPF/IPF/PTDF
factors for the base case, but the user has the option to compute
the same factors for any of the specified contingencies. The user
may select a contingency by specifying the contingency number.
A contingency ID number is reported with contingency labels on
all FCITC reports and within contingency analysis reporting functions.
The bubble
diagrams provide a convenient visual display of flow distribution
analysis results for transmission areas and zones. Every bubble
is associated with an area/zone and provides user-selected information
about this area/zone, while bubble connections provide information
on interface flows between selected areas/zones. All data displayed
graphically via a bubble diagram are also available through the
table reports using impact analysis functions.
Eleven different types of data can
be reported inside of a bubble with three being displayed simultaneously:
TPF report showing the impact of a study transfer on
areas/zones using the NetArAr TPF definition. TPF values are
shown in percent.
Initial Balance showing MW flows between areas/zones
in the current load flow case. This report provides an efficient
way to review area/zone balances in the load flow case.
Final Balance report after scheduling study transfer
at specified transfer level.
Balance Change report due to scheduling study transfer.
Number of Buses report shows the number of busses in
the area/zone.
Number of Branches and Ties report shows the number
of internal branches and ties in an area/zone.
Total Load report showing the total load within an
area/zone.
Total Generation showing the total generation within
an area/zone.
Maximum Total Generation showing the maximum possible
generation (excluding offline generation) within an area/zone.
Maximum Generation Including Offline showing the maximum
possible generation (including offline generation) within an
area/zone.
Total Losses showing the total loss within an area/zone.
There are also four types of reports
available for connections between areas/zones:
IPF shows the impact of a study transfer on area/zone interchanges
using the IPF net interface flow definition.
Initial Flow shows the MW flows between areas/zones in the
current load flow case. This report provides an efficient way
to review area/zone balances in the load flow case.
Final Flow shows the after scheduling study transfer at the
specified transfer level.
Flow Changes shows the changes in flow after scheduling transfers.
The third and fourth report types can be efficiently combined
with the transaction scheduling system as both initial and final
flows reported via bubble diagrams reflect scheduled transactions
added to the original case.
Planned enhancements in future PSS™MUST
releases for the bubble diagram function will include the following:
Currently, the bubble diagram provides reports for the base
case only. Future PSS™MUST releases will allow reports
for any specified contingency.
