
Distribution Network Fault Analysis & Diagnosis
Diagnose distribution network faults using load flow and protective coordination analysis
What You Can Do
You can rapidly diagnose medium-voltage distribution faults by analyzing protective device coordination sequences, load flow impacts, and field crew reports within Claude. The skill helps you distinguish between transient and permanent faults, identify whether issues stem from equipment failure or external factors, and validate remediation strategies before implementing risky switching operations. This accelerates your analytical phase so field resources can be deployed efficiently and switching decisions are made with confidence.
Features
Model fault scenarios and trace current distribution across feeders to understand secondary effects on interconnected equipment
Interpret recloser, fuse, and relay operation logs to identify failed coordination or unexpected device behavior indicating root causes
Synthesize SCADA snapshots, meter data, protection logs, and crew observations into a coherent fault narrative
Distinguish between temporary faults (transient) and permanent equipment failures using recloser reclose attempt patterns and timing analysis
Develop ranked candidate causes (vegetation contact, equipment failure, phase imbalance, etc.) supported by evidence from operational data
Test proposed switching procedures against load flow models to confirm they won't create secondary faults or voltage violations
Conduct systematic reviews to identify preventive measures and coordination adjustments that reduce recurrence probability
Example Output
Example 1: Recloser Miscoordination
Input: Three recloser operations in 8 minutes on feeder 12A, followed by sustained outage. SCADA shows 2.3 kA at first operation, 1.8 kA at second, 0.9 kA at third. Crew reports no visible damage at visible pole-top equipment.
Output:
- Diagnosis: Transient fault (likely vegetation contact) self-clearing during dead time; rapid load pickup during reclose attempts indicates healthy feeder downstream of fault point
- Root Cause: Overgrown tree branch contacting primary conductor at mile 3.2 (matches crew location observations)
- Secondary Finding: Recloser curve miscoordinated with downstream fuse—fuse should have cleared at operation 2
- Action: Schedule vegetation management; adjust recloser timing curve
Example 2: Three-Phase Fault with Load Transfer Impact
Input: Sustained three-phase fault on feeder 7B at 14:23. Load flow shows 4.1 kA symmetrical fault current. Nearby feeder 7A voltage drops 8% during fault. Crew physical inspection reveals failed transformer bushing at substation.
Output:
- Diagnosis: Primary fault: Failed transformer bushing (permanent fault, requires transformer replacement)
- Secondary Impact: Unplanned load transfer to feeder 7A during outage caused overload on downstream switch—recommend temporary load shedding procedure
- Stability Analysis: Switching in backup feeder 8A viable; load flow confirms acceptable voltage profile
- Coordination Note: Main station breaker operation correct; recloser on feeder 7B prevented cascading failure to parallel feeders
- Recommendation: Restore via feeder 8A temporary feed while transformer is replaced
What's Included
- SKILL.md: Complete fault analysis framework and decision logic
- Fault Analysis Template: Structured worksheet for organizing SCADA data, protection logs, field observations, and hypothesis testing
- Load Flow Checklist: Quick-reference checklist for modeling distribution faults and validating remediation switching sequences
- Protective Device Coordination Matrix: Reference table mapping recloser/fuse curves to fault current ranges for rapid interpretation of operation sequences
- Post-Restoration Analysis Workbook: Systematic review process to identify root causes, preventive measures, and coordination improvements
Who It's For
- Distribution system engineers responding to sustained feeder outages
- Utility control center operators analyzing protective device operation sequences during faults
- Distribution operations managers conducting post-incident reviews to prevent recurrence
- Utility planners assessing protective device coordination schemes for adequacy
- Field service coordinators planning switching procedures for fault restoration
Best For
- Diagnosing single-phase and three-phase faults on 4-35 kV distribution feeders
- Analyzing protective device miscoordination and unexpected relay/recloser behavior
- Validating switching procedures before field crews execute high-risk maneuvers
- Distinguishing transient faults from permanent equipment failures using operational data
- Conducting post-restoration root cause analysis to inform preventive maintenance and coordination upgrades







