PERC Studio 1.2.1

PERC Studio 1.2.1 is a patch release with a clearer voltage chart in the live preview.

Download

• PERC-Studio-1.2.1-win64.zip: the portable desktop app for Windows 10/11 (64-bit). Extract it to a folder
  you keep and run Create Desktop Shortcut.cmd once. No installation, administrator rights or Python needed.
  If you have 1.2.0, extract 1.2.1 to its own folder and delete the old one; settings and black-box runs carry over.
• SHA256SUMS.txt: checksums for the download.

This release is not code-signed, so Windows SmartScreen asks for confirmation on first run: click More info,
then Run anyway. Neither PSS/E nor the PERC1/PERC2 model DLLs are included.

The automation CLI (perc-studio <command>) and the test suite come with a source install; see the README.

User-facing

• Voltage card: timer bars. On the live preview's Voltage at the load bus card, and in the saved report, which
  shares it, each voltage trip or cease point is now a short red bar at its level. The bar starts with the event and
  is as long as its delay. It replaces the dashed line that used to cross the whole plot.
  • The point that tripped or ceased the load is solid, the points the event reaches are half strength, and the rest
    are faint.
  • Hover a bar for its CONs, its delay and what it did in this event.
  • The legend reads "Trip thresholds". The green dashed reconnect line is unchanged.
• PERC1 DLL and PERC2 DLL: every trip stage on the voltage card. All 4 stages per direction (VDPA-VDPA3,
  VDUA-VDUA3) are drawn, each as long as its delay plus CMTDELAY. Before, only stage 1 (VDPA, VDUA) was.
  The PERC2 DLL also shows VLBLK/VUBLK when momentary cessation is on. Repeated stages appear once (presets
  pad the tables).
• Qt for Python (PySide6) 6.12. The only visible change is slightly less left padding on the text in numeric fields.

Developer

• preview.page.voltage_cease_points() lists the drawn points for PERC2, the PERC1 DLL and the PERC2 DLL, matched to
  the simulator's trip_events.
• Tooling updates: ruff 0.17.2, actions/checkout 7, astral-sh/setup-uv 7.

Full changelog: v1.2.0...v1.2.1

PERC Studio 1.2.0

PERC Studio 1.2.0 is the first open-source release.

Download

• PERC-Studio-1.2.0-win64.zip: the portable desktop app for Windows 10/11 (64-bit). Extract it to a folder
  you keep and run Create Desktop Shortcut.cmd once. No installation, administrator rights or Python needed.
• SHA256SUMS.txt: checksums for the download.

This release is not code-signed, so Windows SmartScreen asks for confirmation on first run: click More info,
then Run anyway. Neither PSS/E nor the PERC1/PERC2 model DLLs are included.

The automation CLI (perc-studio <command>) and the test suite come with a source install; see the README.

Open-source release

• PERC Studio is now open source under the MIT License, at https://github.com/TimThacker/perc-studio. Questions and
  bug reports go to GitHub Issues; the About page, the documentation and the ZIP's README point there.
• One command, perc-studio, replaces both perc1-param-app (the desktop app) and perc1-dev (the CLI):
  perc-studio opens the app, perc-studio <command> runs the automation CLI and perc-studio help lists the
  commands. The distribution is renamed perc-studio too.
• The app-wide environment variables are renamed PERC_STUDIO_*: PERC_STUDIO_PSSE_VERSION, _PSSE_DIR,
  _PSSE_PYTHON, _PSSE_PSPY, _PSSE_DLLS (the PSS/E selection) and PERC_STUDIO_SIGN_ARGS, PERC_STUDIO_SIGNTOOL
  (code signing).
• The settings folders are now %LOCALAPPDATA%\perc-studio and %APPDATA%\perc-studio. An existing
  perc1-param-app folder is moved there on first start, so settings and black-box runs carry over.
• Removed the development-only Questionnaire and the legacy two-input screening derivation (trip magnitude x reconnect
  time). The PERC1 DLL's default parameters are now a literal set (PERC1_DEFAULT_CONS), identical to the values the
  derivation produced; Screening and Post-Commissioning are unchanged.
• The PSS/E validation libraries, the rigs that ran them and their tooling are not part of the public repository. Their
  results are summarized in the model pages, and the figures are kept as frozen PSS/E results.
• One app for everyone: the installer and portable ZIP now include Black-Box Validation, user-defined model blocks
  and the black-box guide. The production/development edition split (and PERC1_EDITION) is gone. The
  automation CLI and the test suite are part of the project and install from source.
• Dropped the unused requests dependency.
• New: GitHub Actions CI (tests and lint on Windows), a code of conduct, CITATION.cff and Dependabot version updates.

User-facing

• PERC Studio. The app is now named PERC Studio: window title, app bar, About page, installer, portable ZIP and the .dyr header comment.
  Titles no longer say PERC1 or CLOD (the Cooling motors step, the review table rows, the model-version caption); each report names the models it
  actually used.

• HTML report restyled to match the app. The report uses the app's fonts, colours and cards, and draws each block with the same three
  charts as the live preview (event, power and state strip, comparison with the standard) under a TRIPS / RIDES THROUGH strip, in place of the
  old 2x2 chart. The title is "Screening Report" or "Data Center Load Model Report", with the models listed under it.

• Documentation figures redrawn. The PERC1 standard and PERC1 DLL validation figures on the model pages (cease cycle, Tdelay
  NaN, Vrecon stranding, post-fault spike, exponents and droop, Vcease knife edge, Tdelay window, multi-stage undervoltage) use the
  same style as the PERC2 ones: a conclusion title, a how-to-read line, one panel per quantity and the legend beside the panels. The
  data and the claims are unchanged.

• Documentation: the PERC1 standard Tdelay hazard is described as intermittent. A dip that ends while Tdelay is running
  always drops the model's load fraction to almost zero; the network then returns not-a-number, a wrong load or a normal result at
  random (not-a-number in 71 of 470 repeated PSS/E runs). The model pages and the behavior page now say so, with the measurements.

• Documentation: a "Load models" group. A model overview comparing the PERC1 DLL, PERC1 standard,
  PERC2 standard and PERC2 DLL v2.3 (capabilities, PSS/E versions, dependencies, hazards and validation
  coverage), and one page per model with its PSS/E validation results and plots.

• PERC2 standard model (PSS/E 36.7 PERCxx2U). A third model version for IT, VFD and
  Screening blocks: momentary and 4-point long cease for low and high voltage with their own
  reconnect settings, a low/high-frequency cease that never reconnects, droop, voltage exponents
  and current limits with a total-current limit. Presets fill it from their full multi-stage
  tables; the editor warns about every value PSS/E 36.7.1 would change or mishandle (including
  its third long-cease point using the first point's time). .dyr export and import, the live
  preview and the HTML report support it. Documented in the model reference and the model
  behavior page.

• PERC2 DLL v2.3 (ISO-NE PERC2_v3x_v2p3.dll). A fourth model version: the PERC1 DLL with a
  reactive-power lead-lag and momentary cessation's own reconnect band and ramps (179 values).
  Presets carry over from the PERC1 DLL with the voltage reconnect ramps adjusted for the load
  factor (v2.3 stretches them; the PERC1 DLL does not) and the reconnect voltage capped at
  0.95 pu. .dyr export and import tell its PERCBL records from the PERC1 DLL's by their value
  count. The editor warns about what PSS/E showed the DLL does: the PSS/E 36 build stopping PSS/E
  after a high-voltage momentary cessation and returning not-a-number for any TA/TB, the
  ignored 50 Hz flag, unchecked out-of-range values, and momentary cessation being taken over by
  a trip stage. Documented in the model reference and the model behavior page.

• Redesigned window. A new app bar with the workflow tabs and a version pill, a lighter
  theme with IBM Plex fonts (bundled, SIL OFL), and the same layout on Screening and each
  Post-Commissioning block: a model bar on top, the load and parameters on the left, the test
  event and charts on the right.

• Model bar. PERC1 model version, PSS/E record format (Screening), ride-through preset with
  an Internal / Published standard badge and Preset docs, and Import .dyr….

• Edits are tracked. Parameters are shown as rows with a one-line summary each; click a row
  to edit it. Edited rows are shaded and bold and counted ("2 edited"), Reset is available
  only when something changed, and Revert this row undoes one row. Changing preset, file or
  model with edits asks first. ZIP exponent and Current limits are separate rows.

• Live preview. A verdict strip (TRIPS / RIDES THROUGH, load tripped, reconnects, ramp) above
  three charts: the voltage (or frequency) at the bus, power output with an Online / Ceased /
  Reconnecting strip and the fraction that ceased, and a full-width Voltage vs. standard card
  that says where the event falls on the preset's envelope.

• Post-Commissioning. Steps along the top with each block's MW and the load split; each
  block has its own model strip (blocks can use different PERC1 versions); Facility response
  to this event shows every block's response to the same event; Review & export lists each
  block's model, source and edits.

• Import .dyr. Each block (Screening, IT, VFD) has an Import .dyr… button that loads a PERC1
  record from an existing .dyr file so you can inspect it in the live chart before any simulation.
  The block switches to the file's model (DLL or standard), every CON appears in the editor, and the
  chart shows the model without a preset envelope. A file with several records asks which to load.
  Values outside the editor's usual range are kept, not clamped, and flagged. The file's name
  replaces the preset field; Reset to file restores the file's values (the block stays on the
  file), and Use a preset instead or choosing a preset replaces the imported record. CLOD records
  are recognized but cannot be inspected.