Double-Line-to-Neutral Short Circuit of an Alternator

Starting with R. H. Park´s formulas for the flux linkages of an ideal synchronous machine, the case of a fault from 2 line terminals of a generator to neutral is treated in a manner similar to that used by Doherty and Nickle for other unsymmetrical faults. Expressions are given for the armature currents in the faulted phases and for the main field current, at any time after the short circuit. An expression for the voltage across the open phase a short time after the fault is also developed.