Simulator 16 User Guide - PowerWorld

Transient Stability Transient Limit Monitors
The Transient Limit Monitors page is found on the Transient Stability Analysis dialog.
When running a transient stability simulation, the actual numerical results and plotting is useful, but
sometimes what you really want to know is if and when any particular Operating Standards were
violated. For example, tn the Western United States there are particular standards for voltage dips and
frequency deviations referred to as WECC Category B and WECC Category C standards. You can think
of this similarly to how Limit Monitoring works in traditional power flow based contingency analysis. In
traditional contingency analysis we do not report the voltage at every bus and the flow on every line
during each contingency. Instead we only report violations of limits, which greatly reduces the amount
of output data created by the tool.
In order to provide the ability to flag violations of these standards, PowerWorld has created an object
called a Transient Limit Monitor which provides a great deal of flexibility for allowing the simulation to
automatically monitor for these types of standards without requiring us to store the entire trace of
each monitored quantity. When creating a transient stability monitor, you choose a field for a
particular type of object and then build a description of what is considered a limit violation.
Defining Transient Limit Monitors
To define Transient Limit Monitors, look on the Transient Stability dialog under Transient Limit
Monitors and choose the Transient Limit Monitors option. When choosing this a case information
display listing the transient limit monitors will be shown. For more information see Transient Stability
: Defining Transient Limit Monitors.
Viewing Transient Limit Monitor Violations
While running a transient stability simulation, violations of the transient limit monitors defined will be
recorded and listed under the Transient Limit Monitors\Monitor Violations table on the Transient
Stability Analysis Dialog. Monitor Violations will be designated by which transient contingency caused
them so that when running multiple transient contingencies you will be able to see which
contingency caused the violation. It may be feasible for you to abandon storing all the transient
stability numerical results and instead only store the violations of the limit monitors. If violations are
found you can then revisit the run and store appropriate results. For more information on monitor
violations seeTransient Stability : Transient Limit Monitors Violations.
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