Time-series analysis¶
Simulate a day or a year of operation — loads following their shapes, PV following the sun, storage charging and discharging — then scrub through the results on the diagram itself.
Switch the toolbar to Time series mode. A transport bar appears under the toolbar, and the snapshot Solve / Auto buttons gray out (individual runs are disabled in this mode; switching back re-enables them).
Running a simulation¶
Assign shapes first — loads need a load shape, PV systems an
irradiance shape, storage a dispatch shape if using follow mode. Elements
without a shape hold their rated values for the whole run.
Then pick the horizon and step in the transport bar and press ▶ Run:
| Horizon | Step | Steps solved |
|---|---|---|
| Daily | 1 h | 24 |
| Daily | 15 min | 96 |
| Yearly | 1 h | 8,760 |
| Yearly | 15 min | 35,040 |
Progress streams live into the Run button (click ✕ to cancel). The engine drives the solution one step at a time and records everything automatically — per-step voltage range at every bus and P/Q/current/loading for every element — so there are no monitor elements to place, and any element can be inspected after the run. Steps that fail to converge are recorded as zeros and counted in the summary rather than aborting the run.
Any edit to the circuit clears the results (like every other result in the app); re-run after changes.
Scrubbing the results¶
When a run completes, the scrubber parks at the system peak hour and the
canvas overlays — voltage badges, loading pies, line colors, power labels,
hover tooltips — show the network at the scrubbed moment. Drag the slider to
move through time, or press the play button to animate through the run
(~10 steps per second). The readout shows the simulation time (13.00 h for
daily runs, Jun 21, h 4092 for yearly).
Tooltips in this mode show each bus's recorded voltage min/max at that step (per-phase magnitudes and angles are not recorded per step) and the element's recorded power and loading.
Yearly runs scrub an envelope
Runs over 2,000 steps are downsampled for display into alternating minimum/maximum buckets (about half a day each for an hourly year). The scrubber then shows those envelope extremes — the bucket's worst case, which is usually what a planning study needs — not the exact network state at a specific hour. A dialog explains this when such a run completes, and an envelope chip stays on the transport bar. Daily runs are never downsampled and scrub exactly, step by step.
The time graph¶
The Graph tab gains a Time sub-mode (selected automatically when a run completes). Plot system totals (total P, losses), per-bus voltage min/max, or per-element P/Q/current/loading over the run — one trace per selected entity (up to 8; the picker defaults to the lowest-voltage buses or most-loaded elements). Yearly plots get month-boundary axis labels; a dashed cursor line tracks the transport-bar scrub position; zoom and pan work as in the snapshot graph.
Above the plot, a summary table reports energy served and losses (MWh and percent), peak demand and when it occurred, the voltage extremes with their bus and hour, and the step count (with any non-converged steps flagged).
Semantics worth knowing¶
- The same shape drives daily and yearly runs (daily shapes repeat across a year). OpenDSS interpolates when the step is finer than the shape interval.
- Storage state of charge carries through the run: it starts at Initial charge and evolves with dispatch and efficiencies, floored at Reserve.
- Snapshot mode is unaffected: it still solves the base case with shapes ignored — see Solving & analysis.