Local Case Files

Dropped case files stay in the browser. The current public demo does not upload local .m, .raw, .aux, .epc, .pwb, .dss, .pwd, .csv, .json, or .geojson files.

MATPOWER .m, PSS/E .raw, PowerWorld .aux/.pwb, and PSLF .epc files describe balanced network topology; OpenDSS .dss opens the multiconductor viewer. If a balanced case includes complete coordinates, tellegen draws it directly. Otherwise it creates a local synthetic layout and asks the user to place it on the map. PowerIO classifies dropped JSON by content. A stored generation-2 pio-ir document opens by its value type: a balanced network or DC OPF instance becomes a case, while supported multiconductor networks, instances, and solutions open in the viewer. AC PF and AC OPF instance modules remain unopened until the browser exposes those formulation choices. Transmission exchange JSON opens as a balanced case, and BMOPF or PowerModelsDistribution documents open the multiconductor viewer. The retired bare model-JSON shape is unrecognized; regenerate it from source data as pio-ir. Tellegen does not define a separate saved case format. Other unrecognized JSON falls through to the geographic reader.

After a parsed local case has coordinates, either from the file, a geographic file, or manual placement, tellegen solves the selected formulation in browser WebAssembly. Local case files do not call the tellegen backend solve endpoints.

Manual Placement

For case files with no coordinates, such as a plain case14.m, tellegen computes a deterministic topology layout from buses and in-service branches. The user then clicks the map to center that synthetic layout at the chosen location.

The placed local case can be moved later with the case panel move action. The first version uses explicit click placement rather than drag movement.

After placement, the local case enters the same bus selection and demand slider workflow as the bundled demo cases. The solve card reports the browser solve time and does not show backend iterations.

Geographic Files

Some case files contain network topology but keep map coordinates in separate GIS files. tellegen accepts those files as local geographic files: drop the case file with one or more .csv, .json, or .geojson files, or drop the geographic files after selecting a parsed local case.

All files stay in the browser. The tellegen backend does not receive dropped case files or geographic files.

Parsing is powerio’s GeoLayer tolerant reader, running in WebAssembly: it accepts headerless OpenDSS buscoords CSV, CSV and JSON records with the aliased field names below, and GeoJSON Point/LineString features, and it rejects input carrying no usable coordinates. Applied coordinates land on the network itself (Bus.location, Branch.route), so a saved PowerIO case module or an exported case carries the placement on screen. Loading that module starts a fresh runtime Study at the saved point. Its history records transformations applied to the stored value. The case panel can also download the current layout as a .geo.json layer that PowerIO and Tellegen read back.

Bus Coordinates

The geographic file must identify buses by the same ids used in the case file. CSV and JSON records can use these field names:

Example:

bus_i,Lat,Lon
1,37.77243572,-122.2429162
2,37.77848161,-121.6259513

A geographic file does not need to cover every bus: matched buses place, and the panel reports the matched and unmatched counts. Buses left without coordinates are omitted from the map with a warning; a file that matches nothing is rejected and the case stays placeable. Records can also match by powerio row uid (buses:3) or by case insensitive bus name.

Branch Paths

Branch geometry is optional. Without branch paths, tellegen draws straight segments between placed buses.

CSV and JSON branch records can use:

GeoJSON LineString features are also accepted. The reader matches a route by uid or branch id when present, then by the unordered from/to bus pair. A LineString endpoint can also provide bus coordinates for its f_bus and t_bus properties. Applied routes land in Branch.route and render as polylines instead of straight segments.

Piecewise Costs

A dropped case with MATPOWER model 1 piecewise linear generator costs solves the declared convex curve exactly (formulations). Malformed rows and rows with decreasing segment slopes are rejected before a solve.

Display Files

PowerWorld .pwd files are display overlays. Dropped alone, they show substation symbols at approximate projected positions. Dropped alongside a case file that has no coordinates, the substation points join onto buses through the SubNum field on the bus rows and fill the case’s positions; a .pwd whose numbers match nothing stays a separate overlay entry.