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Power Systems: Real Value of a Fault Current for 3-Phase Fault

Both machines in the attached diagram are rated at 50 MVA, 20 KV. The system base is the machines' base.
Find the real value of the fault current for a 3-Phase fault at the motor terminals.


Solution Preview

I will indicate the easiest approach to solve this problem, and then will demonstrate that all the "extra" data given are, indeed, consistent.

We will apply Thevenin equivalent approach to find the real (actual) fault current at the motor terminal.

The Thevenin Voltage Vth is the voltage at the fault location, that is, Vt,m = 0.9@-14 deg.

The Thevenin impedance Zth is the impedance is that measured at the motor terminal looking ...

Solution Summary

Solution contains calculation, answers and explanations. 360 words.