Snapshots

A Snapshot represents a point or range in time that Cruncher uses to transform a Seed Case into a case ready for analysis. Each Snapshot applies the study’s configured inputs (e.g., outages, weather, forecasts, voltage schedules, OPF) relative to a common Target Time chosen when the Study runs.

Time Model

Snapshots are defined relative to a Study run’s Target Time:

• Offset — The time difference from the Target Time. Offsets must be unique within a study’s Snapshot set (e.g., +01:00, +02:00).
• Duration — The time window around the Snapshot time that determines which time-varying data points are considered. By default this is 0:00 (instantaneous, “at the time”). A positive duration looks after the time, and a negative duration looks before the time (e.g., -01:00 means the hour preceding the Snapshot time).

Examples

• Offset = +03:00, Duration = 0:00: Apply only data active exactly at Target Time + 3 hours.
• Offset = +12:00, Duration = -01:00: Apply data active during the hour leading up to Target Time + 12 hours (i.e., an “hour ending” convention).

Snapshot Configuration

Each Snapshot includes the following key settings:

• Seed Case — Select which Seed Case to use as the base. In scheduled runs, Seed Case mapping can also be determined dynamically by day/time.
• Offset — Required; must be unique in the set.
• Duration — Optional; default is 0:00. Positive looks after the time; negative looks before.
• Skip Analysis — Exclude this Snapshot when the Analysis phase runs.
• Skip Voltage Conditioning — Exclude this Snapshot from Voltage Conditioning even if enabled for the Study.

Duration Aggregation

When Duration is non-zero, multiple data points may fall inside the window. Cruncher aggregates those values using the study’s duration settings:

• Aggregation methods: Average, Median, Maximum, Minimum, First, Last.
• Per-type control: Independent aggregation choices can be set for Loads and Generators, with a Default for other object types.

Managing Snapshots

From the Snapshots tab you can:

• Add New — Create a single Snapshot.
• Add Multiple — Create a series with patterned offsets.
• Edit Last Selected — Modify the highlighted Snapshot.
• Select All / Delete All Selected — Bulk operations.
• Apply Preset Snapshot List — Replace the current set with a preset:
  • Future Hour Ahead: three offsets +01:00–+03:00, duration 0:00.
  • Next Day Study: 24 offsets +01:00–+24:00, each duration -01:00 (hour ending).
  • Week Ahead Study: two blocks, +06:00–+10:00 and +15:00–+19:00, duration 0:00.