Research — Generation · Precomputed (draft, unvalidated)

Fast-track screens walk

A generic feeder: a substation, a protective device, a line section with loads, a distributed generator already connected, and a new request. Six interconnection screens act as ordered gates: 15% of peak load, 10% fault-current contribution, 87.5% of the device's interrupting rating, a 20 kW shared-secondary limit, a 240 V service imbalance limit and a 10 MW transient-stability limit. The first one that fails lights up on the feeder and on its gate. Play six short stories, or switch to free play and drag the request along the load bar.

Mode

Story plays a prepared request and its fix. Free play is yours: every control snaps to an exported value.

Story

Free play · set a request, then watch the screens run in order

Request size · new DER (or drag the grip on the load bar)

Line-section peak load

Existing DER on the line section

Service type

Area · transient stability

10 MW screen · new DER

10 MW screen · existing DER

Every control sits on a value the harness was run at; the page looks that cell up and never estimates between two. The three feeder screens come from one grid (three-phase feeder, 4000 A utility-side fault current, device rated 4900 A). The 20 kW, 240 V and 10 MW screens come from their own tables. Arrow widths in free play are a drawing scale only: no amp figure is printed that is not in a cell.

Single-phase service is a different scene: its few-kW units have no cell in the three-phase feeder grid, so those three screens read "not exported" rather than guessing.

Feeder plan · the request walks six ordered screens, the first failure lights up

Geometry: illustrative feederDER fault amps = 0.4 A per kW: demo convention, not an engineering estimateΣ at the device: demo sumDraft, unvalidated harnessutilityexisting DERrequestarrow width ∝ √amps

Walk result

Screen being read · click a gate on the drawing or a row below to read it

Actual

Required

Margin

How the harness read it · its own words, verbatim

    All six screens at this state · the controlling row is the first failing screen

    Walk order is SGIP numbering order. The highlighted row is the composite's first failing screen; when none fails, nothing is highlighted and there is deliberately no overall verdict. Click a row to read that screen.

    Notes the harness attaches to every result · shown even when everything passes

    Every screen · before the request, with the request, after the fix

    Required values are read from the data file. 'Incomplete' means an input is missing and the check did not run, never a pass. 'Not applicable' means the screen's scope precondition is not met (the 20 kW and 240 V screens are not called for three-phase service; that gating is the demo's scene logic and is tagged).

    Precomputed results:every verdict, required value and margin on this page was computed by the real Python harness at export time and is played back from a data file. The page runs no harness logic and holds no standards tables, and it never interpolates between exported values. Not a live API call. Precomputed from the Python harness: ugm-agent-harness (recorded commit a1507b2), a draft with no subject-matter-expert sign-off, called through the new composite run_fast_track_screens, which is itself draft and orders the six screens. Nothing here is an interconnection determination, a Fast Track eligibility decision or an Initial Review approval. The SGIP section numbering (2.2.1.1 to 2.2.1.10) is confirmed only as far as the harness docs record it: a page-image read of a FERC-hosted copy of the pro forma dated August 2018; later FERC orders are not reflected. The pro forma is a template: what binds a real interconnection is the governing tariff or state procedure, and each screen's last note says so. The feeder is a generic illustration (peak load, existing DER, the 4000 A utility-side fault current, the device rating and every position are illustrative), and the pairing "DER fault contribution = 0.4 A per kW" is a demo convention, not an engineering estimate. The 20 kW and 240 V cards are gated out of three-phase scenes by the demo's own scene logic (tagged demo logic), not by a harness result. The 87.5% screen needs the combined fault current, which the exporter summed from utility + existing + proposed DER (tagged demo input). Every verdict, ceiling, margin and note on this page was computed by the real functions at export time and is played back from a data file.Real functions this maps to:check_der_fast_track_15_percent_screen, check_der_fault_current_contribution_10_percent_screen, check_der_short_circuit_interrupting_capacity_87_5_percent_screen, check_der_single_phase_shared_secondary_20kw_screen, check_der_240v_service_imbalance_screen, check_der_transient_stability_10mw_screen, run_fast_track_screens.Not modeled: the rest of Fast Track (size and voltage eligibility, the other 2.2.1 screens, the supplemental review), a jurisdiction override of any percentage (three states codify different ones), study-grade fault-current modelling (the DER amps are a demo pairing), and any real feeder. The drawing is schematic: positions, device and DER symbols are illustrative.See also:Fast-track screens walk, hands-off · Ride-through zones · Cease-to-energize