Calculates short-circuit currents; symmetrical components handle unbalanced faults.
Faults: three-phase (symmetrical), line-to-ground, line-to-line, double line-to-ground. Fault current I_f=V/Z_th in pu. Studies size breakers and set relays. Most faults are single line-to-ground.
A 100 MVA, 10% reactance source gives 1000 MVA fault level.
Fault analysis tells you how much current flows during a short circuit, which sets the rating of breakers and the design of protection.
Calculates short-circuit currents; symmetrical components handle unbalanced faults.
Fault analysis tells you how much current flows during a short circuit, which sets the rating of breakers and the design of protection.
The maximum short-circuit current a bus can deliver, which determines the breaking capacity needed for equipment on that bus.
Single line to ground faults are not balanced, so the simple single-phase model fails, and symmetrical components are used.
Typical applications include setting the breaking capacity of a breaker in a factory switchboard, checking the fault level at a bus to avoid overstressing equipment and designing the protection for a generator against a short circuit.
Study "Load flow analysis" first (topic 71 of 106 in Electrical Engineering). It covers the groundwork this topic builds on.
Fault MVA. DC offset. Arcing faults are lower current.
A 100 MVA, 10% reactance source gives 1000 MVA fault level.
The next topic is "Symmetrical components", which builds directly on this one.
It is classed as Intermediate in Electrical Engineering (topic 72 of 106). It is an intermediate topic. Work through the beginner topics in Electrical Engineering first.
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