Automatic Reclosing
Automatic reclosing studies evaluate power system dynamic stability and electromechanical stresses when high-voltage transmission lines are automatically re-energized following fault clearance. MEPCO verifies Single-Phase Auto-Reclosing (SPAR) and Three-Phase Auto-Reclosing (TPAR) dead-times, secondary arc extinction, and generator shaft torsional fatigue.
Figure 1: High-voltage transmission lines and substation gantries evaluated for high-speed auto-reclosing schemes.
Technical Scope & Engineering Capabilities
MEPCO Engineering Projects brings specialized domain knowledge, rigorous modeling standards, and practical site experience to every assignment. Our scope covers:
- Single-Phase vs. Three-Phase Reclosing Assessment: Evaluating system stability benefits of Single-Phase Auto-Reclosing (SPAR) for transient single line-to-ground faults.
- Secondary Arc Extinction Time: Calculating capacitive and inductive coupling from energized healthy phases to determine dead-time required for secondary arc de-ionization.
- Generator Shaft Torsional Fatigue: Simulating transient torsional torque stresses across turbine-generator shaft sections when reclosing into an un-cleared permanent fault.
- Out-of-Step / Out-of-Phase Protection: Verifying synchronism check (25) voltage angle and frequency slip tolerances prior to closing.
- Dead-Time & Reclaim Time Optimization: Establishing optimal reclosing sequence timing to maximize grid stability while avoiding equipment overstress.
Software Platforms & Computational Tools
Primary Tools: PSCAD / EMTDC and Siemens PTI PSSE.
Applicable Standards & Grid Codes
Standards: IEEE C37.104 (Guide for Automatic Reclosing of Line Circuit Breakers for AC Transmission Lines), CIGRE Working Group reports.
Methodology & Project Delivery Workflow
Our engineering delivery aligns with MEPCO’s structured 6-stage project execution framework, ensuring quality throughout input verification, design modeling, and client handover:
- Stage 01 — Scope & Criteria Definition: Establish study boundaries, utility tie-in data, single-line diagrams, and client objectives.
- Stage 02 — Data Audit & Modeling Assumptions: Collect, verify, and validate manufacturer datasheets, impedance tolerances, and site operating configurations.
- Stage 03 — Simulation Model Development: Build detailed, validated mathematical digital models in specialized power software.
- Stage 04 — Computational Analysis & Verification: Execute base-case and contingency scenarios, conducting rigorous internal peer reviews.
- Stage 05 — Client Review & Approval: Present study findings, address technical comments, and participate in technical clarification sessions.
- Stage 06 — Final Handover: Deliver formal certified engineering reports, executive summaries, and native simulation model files.
Figure 2: Generator shaft strings evaluated for torsional torque transients during line reclosing under fault conditions.
Completed Project References (From MEPCO Profile)
Selected project assignments delivered by MEPCO demonstrating our technical execution and regional client trust:
| Project Name | Client / Authority | Location | Tools / Mode | Scope Executed |
|---|---|---|---|---|
| High-Voltage Transmission Auto-Reclosing Evaluations | National Transmission Utilities | Egypt & Saudi Arabia | PSCAD / PSSE | High-Speed Auto-Reclosing Sequence Verification, Secondary Arc Extinction, and Shaft Torque Impact Assessment. |
Key Engineering Deliverables & Outputs:
- Automatic Reclosing Engineering Study Report.
- Secondary Arc Current and Recovery Voltage Curves.
- Shaft Torsional Torque Oscillatory Stress Curves.
- Recommended Auto-Reclosing Scheme Settings (Dead-Time, Synchro-Check Angle Window, Lockout Time).
- Native PSCAD and PSSE study cases.
Inquire About This Service
Contact MEPCO’s engineering team for technical proposals, study scope definition, or project consultations:
Email: m.khaled@mepco-tds.com | Phone: +20 11 2696 7082 | HQ: 5 Al-Ibrahimia Street, Cairo, Egypt