Transient stability with ANDES in Electrisim

Transient stability in Electrisim is an ANDES time-domain simulation: it shows whether synchronous machines stay in step after a bus fault or a line trip, and how bus voltage recovers. Open Simulate → Transient Stability (ANDES) on a diagram that already has at least one synchronous generator with dynamics. PSS/E .dyr files, including CMLD and PERC1 records, are not imported.

What the study does

Electrisim sends the diagram to the backend, builds an ANDES system, runs a power flow for the operating point, then integrates with TDS.run() out to the end time you set (default 10 s). You can apply a three-phase fault on a bus (fault_tf / fault_tc, default 1.0 s / 1.1 s) and optionally trip a line.

• Generator speed and rotor angle versus time
• Bus voltage and an approximate system frequency from mean speed
• Machine models GENROU or GENCLS, with EXDC2 or SEXS excitation and a TGOV1 governor
• Empty Dynamics-tab fields filled with textbook defaults, listed in the result

The same dynamic network, without a fault, is what eigenvalue analysis linearises. Use that when you want damping and mode frequency at the current dispatch, and time-domain when you want the swing after a specific event.

What it does not do

• No PSS/E .raw or .dyr import. Build the diagram in Electrisim, or start from an IEEE benchmark template.
• Not the full ANDES model catalogue. Static generators, three-winding transformers, and DC lines are skipped or warned.
• Not EMT. This is RMS electromechanical simulation, not sub-cycle electromagnetic transients.
• An external grid by itself is not enough. You need at least one synchronous generator; mark one as slack, or pair generators with an external grid.

Parameter tables and the mapping steps are in the transient stability documentation. If you are comparing this with a transmission dynamics package, see the PSS/E alternative page. Cloud studies start at $10 per month.

Run the study in the browser: app.electrisim.com. A demo two-machine case can be imported from transient_stability_two_machine_demo.py (File → Import).