ERCOT Grid Contingency Analysis

Inspect an ERCOT case for study year, season, dispatch, topology, and revision metadata.

Open and solve an ERCOT base case in PSS®E 35 using an appropriate steady-state solution method.

Diagnose common causes of a base case that does not solve or does not match its saved solved state.

Create a case-provenance record that documents data sources, software version, and study assumptions.

Interpret PSS®E bus, branch, transformer, generator, load, area, zone, and owner records used in contingency analysis.

Trace the electrical connection between a candidate point of interconnection and the surrounding transmission network.

Interpret area interchange schedules, tie-line flows, and swing-bus behavior in an ERCOT case.

Define source and sink subsystems for a transfer between areas or regions.

Choose a balancing method for an incremental generation or load transfer.

Account for incremental system losses when measuring a transfer.

Use distribution factors to identify facilities that are sensitive to a proposed transfer.

Locate the current ERCOT documents governing steady-state planning events and performance criteria.

Translate applicable ERCOT event categories into explicit PSS®E outage definitions.

Translate applicable thermal criteria into normal and emergency rating checks.

Translate applicable voltage criteria into pre-contingency and post-contingency checks.

Determine which operator actions or system adjustments are permissible for each studied event.

Define rules for separating pre-existing problems from project-caused or project-worsened violations.

Construct a study matrix covering facility type, operating mode, case, transfer direction, and contingency class.

Explain the distinct roles of `.sub`, `.mon`, `.con`, and `.dfx` files in PSS®E contingency analysis.

Write a subsystem definition that selects the intended source, sink, and study regions.

Choose a monitored network scope that captures credible local and inter-area impacts without monitoring the entire model unnecessarily.

Write a monitor file containing the required branch, transformer, interface, and bus-voltage checks.

Write single-element contingencies for transmission lines, transformers, generators, and shunts.

Represent credible multi-element and common-mode outages without accidentally creating unrelated N-2 combinations.

Compile a distribution-factor file and resolve subsystem, monitor, and contingency compilation errors.

Audit subsystem, monitor, and contingency coverage for missing, duplicate, or out-of-service equipment.

Configure an AC contingency-analysis run with documented solution options and rating selections.

Run a baseline ACCC study in PSS®E and preserve its inputs, progress log, and output files.

Extract branch-loading and bus-voltage violations from ACCC results.

Identify the monitored element, contingency, rating, loading, and voltage associated with each violation.

Classify contingency outcomes as solved, islanded, diverged, or otherwise invalid.

Diagnose false violations caused by ratings, statuses, duplicate circuits, metering ends, or model defects.

Validate a severe ACCC result by reproducing the outage in an interactive AC power-flow case.

Calculate the remaining thermal or voltage margin for a limiting contingency.

Define a machine-readable run manifest containing cases, scenarios, transfers, contingencies, thresholds, and output locations.

Specify the required PSS®E automation sequence from case loading through result export.

Define stable identifiers that prevent buses, circuits, transformers, scenarios, and contingencies from being confused.

Specify logging and exception handling for non-convergence, islanding, missing equipment, and malformed input files.

Define acceptance tests that compare an automated run with a manually verified PSS®E run.

Review LLM-generated PSS®E automation for hidden assumptions, unsafe defaults, and incomplete error handling.

Document PSS®E 34 and 35 environment differences that affect script execution and reproducibility.

Represent a proposed generator at a candidate point of interconnection for steady-state screening.

Set generator voltage-control, reactive-limit, and power-factor assumptions for a screening scenario.

Represent incremental load withdrawal at a candidate bus or group of buses.

Represent BESS charging and discharging as separate steady-state operating modes.

Execute a stepwise transfer search to bracket the first unacceptable steady-state result.

Use a bisection search to refine the maximum passing transfer within a stated MW tolerance.

Identify the contingency and monitored facility that set the reported hosting-capacity limit.

Test how the hosting-capacity result changes under an alternative balancing or dispatch assumption.

Distinguish simultaneous N-2 analysis from sequential N-1-1 analysis and ordinary N-1 screening.

Select credible outage pairs using topology, common-mode exposure, prior N-1 severity, and applicable criteria.

Estimate the computational growth caused by expanding an N-1 list into outage pairs.

Create a controlled set of multi-element contingencies for selected simultaneous N-2 events.

Model the sequence and permitted intermediate adjustments for a selected N-1-1 event.

Separate credible limiting results from outages that merely island load or generation by construction.

Report N-2 and N-1-1 results separately from the core N-1 hosting-capacity estimate.

Select future-year, seasonal, and load-level cases relevant to a proposed ERCOT investment.

Define dispatch sensitivities for nearby conventional generation, renewables, and storage.

Define topology and planned-outage sensitivities that could materially alter transfer capability.

Run a consistent hosting-capacity study matrix across multiple cases and sensitivities.

Calculate a capacity range from scenario-specific limiting results rather than reporting only one MW value.

Identify assumptions that dominate the uncertainty in a candidate point-of-interconnection result.

Assign a confidence classification to a screening result based on case coverage, model quality, and result stability.

Compare candidate locations using capacity, constraint severity, uncertainty, and data-quality indicators.

Use flow changes and network topology to explain why a particular facility limits a proposed injection or withdrawal.

Screen whether redispatch or renewable curtailment relieves a limiting contingency.

Screen whether a line or transformer rating change materially increases the passing transfer.

Screen whether a conceptual transmission reinforcement materially increases the passing transfer.

Screen whether voltage-control or reactive-support changes relieve a voltage-limited result.

Quantify the incremental MW benefit of a candidate mitigation by rerunning the same study matrix.

Classify a potential network upgrade as avoidable, scenario-dependent, or consistently indicated by the screening evidence.

Define GIS join keys that connect PSS®E equipment records to authoritative spatial assets.

Design separate tables for study runs, scenarios, contingencies, monitored assets, violations, and hosting-capacity summaries.

Define fields for base values, post-contingency values, limits, margins, transfer levels, and result status.

Represent buses, lines, transformers, candidate points, and constraint relationships with appropriate GIS geometries.

Export normalized contingency results to validated CSV and Excel files.

Export candidate sites and constrained network assets to valid GeoJSON.

Specify GIS layers, filters, labels, and symbology for capacity, severity, scenario, and confidence.

Validate row counts, identifiers, units, coordinates, null handling, and referential integrity before GIS handoff.

Write a study specification for one generation, load, or BESS candidate using explicit cases, criteria, and assumptions.

Build the subsystem, monitor, and contingency inputs for the selected candidate study.

Produce a manually verified baseline result against which automation can be tested.

Prepare an implementation brief for generating the required PSS®E automation with an external coding assistant.

Determine N-1 hosting capacity for both applicable transfer directions across the selected scenarios.

Perform a selective N-2 or N-1-1 sensitivity on the candidate's most consequential constraints.

Assemble an auditable results package containing assumptions, quality checks, capacity ranges, limiting constraints, and GIS-ready exports.

State the investment conclusions that the screening supports and the additional studies required before commitment.