Single-phase short-circuit torque

The analysis of synchronous machines previously published by Doherty and Nickle is expanded in this article to include the calculation of torque due to single-phase short-circuit. The torque is expressed as the sum of odd and even harmonic series which are simply related to those previously derived for the armature current. The effect of amortisseur windings also is taken into account. As an illustration of the application of the equations, the short circuit torque is calculated for a 100,000 kva generator.