What are symmetrical components and why are they used in fault analysis?
Symmetrical components are a technique to resolve unbalanced system quantities like fault currents into balanced sequence components. They simplify the analysis of unsymmetrical faults with multiple reliabilities into isolated single component networks.
How is a short circuit fault different from an open circuit fault?
A short circuit fault is characterized by a low impedance connection between two nodes, allowing excessive current. An open-circuit fault refers to an accidental break or discontinuity in a conductor resulting in no or little current flow.
Why are asymmetrical faults more difficult to analyze than symmetrical ones?
Symmetrical faults have the same magnitude and displacement for all phase fault currents, requiring only positive-sequence analysis. Asymmetrical faults produce zero and negative sequences too, needing 3-sequence networks and multiple solutions, making them more complex.
What is the importance of relay settings based on fault analysis?
Relay settings decide their operating characteristics like pick-up values, time delays, etc. Without coordination studies based on system conditions and fault calculations, relays may not isolate faults quickly or may operate unnecessarily on load currents.
What is fault in power system?
In an electric power system, a fault or fault current is any abnormal electric current. For example, a short circuit is a fault in which a live wire touches a neutral or ground wire.