Probabilistic Stability Assessment.
Will the machines stay in step after a fault, at every operating point?
Rotor-angle and transient stability screening across the scenario library at every candidate connection point: a transient stability index, small-signal damping and critical clearing time.
Why it matters nowAs converters replace synchronous plant, stability decides more connections. A plant can pass on energy and still fail on stability. PSA finds that early, before it turns into a surprise at study stage.
How PSA works.
- 01
TSI screen
A transient-stability index ranks every operating point on first-swing security.
- 02
Damping eigen-screen
Small-signal analysis catches poorly-damped and growing oscillatory modes.
- 03
Critical clearing time
CCT for each POI: how long the system can tolerate the fault before it loses stability.
- 04
EMT hand-off
Binding cases are packaged automatically for detailed PSCAD/EMT study.
Post-fault, the angle either settles or runs away.
Rotor-angle response to the same disturbance under three damping conditions. PSA screens which operating points stay well-damped and which need a closer EMT look.
Figures from an example run on a test network.
Most operating points stay well damped. PSA's job is to catch the few that don't and send only those for detailed EMT study.