PSCAD Fault Analysis

Simulation of a single-phase line-to-ground fault scenario with overcurrent relay protection (IEEE 50) in PSCAD Free Edition v5. This project replicates a simple protection system and highlights both functionality and limitations faced while using PSCAD Free for educational/proof-of-concept purposes.

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⚙️ Overview

This project models:

• A single-phase power system with a 230 V, 50 Hz AC source
• A line simulated using lumped R, L, and split capacitors (manual Pi-section)
• An overcurrent relay (type 50) with a pickup of 15 A and delay of 0.05 s
• A transistor used as a logic-controlled breaker (due to Free Edition limitations)
• A load (5.3 Ω) connected beyond the fault point
• A fixed line-to-ground fault, hard-connected without switching

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📂 File Structure

pscad-fault-analysis/
├── README.md                  # This file
├── waveforms.csv              # Simulated or placeholder waveform data
├── project/
│   └── project_report.pdf     # Detailed simulation summary & limitations

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⚡ Simulation Summary

• Fault is active from t = 0 s (uncontrollable in Free Edition)
• Relay detects overcurrent (>15 A)
• After a delay of 0.05 s, the relay sends a signal to the transistor
• Transistor opens the circuit, isolating the load

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🔍 PSCAD Free Edition Limitations

This project was built under significant limitations of PSCAD Free v5:

Feature	Status in Free Version
Graph plotting	❌ Not available
Step/Logic blocks	❌ Not available
Logic-controlled breakers	❌ Not available
Fault control timing	❌ Not possible
Waveform export (CSV)	✅ Available
Relay blocks (IEEE 50)	✅ Available

As a workaround:

• The fault is always on (connected directly to ground)
• A Constant block was temporarily used to simulate logic, but ultimately removed
• A Transistor was used in place of a logic-controlled breaker

Despite these constraints, core protection logic is successfully demonstrated.

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📈 Waveforms

See waveforms.csv for exported data:

• Ia_1: Line current
• Relay_output: Relay trip status
• Switch_status: Breaker control status

These can be plotted in Python, Excel, or MATLAB.

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📌 How to Run (Optional)

If re-using the simulation:

1. Open project in PSCAD Free Edition v5
2. Compile (Build)
3. Run (Play button)
4. Export data manually from Output Channels

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📄 License

MIT License — for academic use.

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📌 Author Notes

This simulation was completed under time constraints.