Substation SCADA Time-Series Anomaly Scrubbing Checklist

Role: Senior Grid Reliability Data Specialist with 15 years of experience in electrical transmission OT and SCADA telemetry analytics.

Context

• Transmission Grid Operator: {{grid_operator_entity}}
• Substation Asset Identifier: {{substation_asset_id}}
• Primary SCADA Protocol: {{scada_protocol}}
• Sensor Noise Tolerance Level: {{noise_filter_tolerance}}
• Telemetry Polling Rate: {{telemetry_sampling_rate}}
• Critical Alarm Threshold: {{critical_alert_threshold}}

Task

Produce a technical sensor data cleaning checklist to eliminate noise, dropouts, and frozen values from high-frequency SCADA historian logs for {{substation_asset_id}} prior to grid contingency modeling.

Method

1. Audit raw log timestamps from {{scada_protocol}} to detect packet drops, latency jitter, and unsynchronized remote terminal unit clocks.
2. Identify stuck or frozen sensor readings across {{telemetry_sampling_rate}} intervals where standard deviation equals zero over sustained operating periods.
3. Apply a deadband filter based on {{noise_filter_tolerance}} to remove high-frequency signal chatter on voltage and current transducers.
4. Isolate genuine physical excursions exceeding {{critical_alert_threshold}} from transient measurement spikes caused by transducer saturation.
5. Handle missing telemetry bursts using forward-fill rules restricted to transient windows or tag records as unobserved.
6. Standardize three-phase telemetry alignment so phase A, B, and C observations share identical time index markers.
7. Generate a clean, flagged time-series dataset ready for ingestion by dynamic line rating and power flow models.

Constraints

• Checklists MUST distinguish clearly between physical grid events and telemetry transmission artifacts.
• The data specialist MUST NOT smooth out genuine tripping events or breaker operations.
• Every verification checkpoint must specify the target telemetry tag type (e.g., MW, MVAR, kV, Bus Frequency).
• Avoid including commercial power market settlement rules.

Output format

1. Timestamp and Protocol Alignment (3-4 markdown checklist items)

2. Transducer Signal Noise & Spike Scrubbing (4-5 markdown checklist items with mathematical limits)

3. Missing Value & Deadband Handling (3 markdown checklist items)

4. Reliability Engineering Gate Checks (3 checklist items with pass/fail criteria)

Self-review

• Did I calibrate the checklist around the specified protocol {{scada_protocol}} and asset {{substation_asset_id}}?
• Are physical fault detections clearly protected from aggressive noise filtering?
• Is the sampling rate properly reflected in the temporal verification steps?