Key Features of Short Circuit Analysis in ETAP

1. Fault Type Modeling:

   • Three-Phase Faults: Simulates symmetrical three-phase faults to assess the impact on the system, including fault currents and voltage drops.
   • Line-to-Line Faults: Analyzes line-to-line faults to determine the effects on system stability and protection.
   • Line-to-Ground Faults: Evaluates line-to-ground faults, which are common in power systems, to understand their impact on equipment and protection systems.
   • Double Line-to-Ground Faults: Assesses double line-to-ground faults to ensure that protection devices are properly coordinated and system integrity is maintained.

2. Fault Current Calculation:

   • Fault Analysis: Calculates fault currents for various types of faults using ETAP’s algorithms. This includes determining the magnitude and duration of fault currents at different points in the system.
   • Symmetrical Components: Uses symmetrical components to decompose complex fault conditions into simpler components for more accurate analysis.

3. Protective Device Coordination:

   • Relay Coordination: Simulates the performance of protective relays during fault conditions. ETAP helps in setting relay settings to ensure proper operation and selectivity.
   • Circuit Breaker Analysis: Evaluates the performance of circuit breakers under fault conditions, including their ability to interrupt fault currents and isolate faults.

4. System Impact Assessment:

   • Voltage Drop Analysis: Assesses voltage drops during fault conditions to evaluate their impact on system performance and equipment.
   • Equipment Stress: Analyzes the stress on system components, such as transformers and generators, during fault events to ensure they can withstand fault conditions.

5. Protective Device Settings:

   • Instantaneous Settings: Determines the appropriate instantaneous settings for protective devices to ensure fast clearing of faults.
   • Time-Overcurrent Coordination: Provides analysis of time-overcurrent coordination to ensure that protection devices operate correctly and selectively during fault conditions.

6. Reporting and Documentation:

   • Fault Analysis Reports: Generates detailed reports on fault currents, protective device settings, and system impact. These reports include graphical representations of fault conditions and results.
   • Graphical Output: Provides visual outputs such as fault current plots, voltage drop diagrams, and equipment stress charts.

7. Integration with Other Analyses:

   • Load Flow Integration: Integrates short circuit analysis with load flow studies to provide a comprehensive view of system performance during fault conditions.
   • Transient Analysis: Combines short circuit analysis with transient simulations to assess the dynamic response of the system during faults.