Dynamic Snapshot Analysis

Dynamic Snapshot Analysis is an experimental feature in Cruncher that helps users to prioritize which Snapshots should undergo full Contingency Analysis when computational resources are limited. By ranking and clustering Snapshot cases according to preconfigured or user-defined criteria, Dynamic Snapshot Analysis aims to identify those most likely to reveal system issues and groups similar Snapshots so that representative cases can be analyzed instead of the full set. Trial and error may be necessary to develop user-defined criteria that accurately identifies cases of particular interest.

Purpose

Running full Contingency Analysis on every Snapshot can be computationally expensive. Dynamic Snapshot Analysis provides a decision-support layer, allowing users to focus processing effort where it matters most. This reduces study time while still capturing meaningful risk coverage.

Methods

• TOPSIS Ranking — Technique for Order Preference by Similarity to Ideal Solution. Produces a numerical index ranking Snapshots relative to ideal and worst-case conditions.
• OPTICS Clustering — Ordering Points to Identify the Clustering Structure. Groups Snapshots by similarity so representative cases can be chosen for deeper analysis.

Criteria

Dynamic Snapshot Analysis evaluates Snapshots based on three preset criteria and any user-specified custom criteria:

• High Voltage Risk — Evaluates likelihood of bus voltages exceeding defined upper limits.
• Low Voltage Risk — Evaluates likelihood of bus voltages falling below defined lower limits.
• Branch Limit Risk — Evaluates likelihood of monitored branches nearing or exceeding their contingency limits.
• User-Specified Model Filters — Apply filters to flag Snapshots with case characteristics of interest.
• User-Defined Criteria — Defined by object type, field, and optional filter, allowing flexible customization of ranking and grouping.

Outputs

Results from Dynamic Snapshot Analysis are included in both the Snapshot Report and the Analysis Report:

• Snapshot Report — Displays criteria values, TOPSIS rankings, and OPTICS groupings for each Snapshot.
• Analysis Report — Adds Contingency Analysis results to the above, enabling users to validate and refine the criteria’s predictive accuracy.