Parallel operation of two synchronous machines

The paper derives the equations required in the prediction of the steady-state characteristics of an alternator supplying a synchronous motor, which is of particular interest in electric ship propulsion. These equations are valid for any degree of saliency and any value of synchronous reactance in either machine. Since considerable labour is required in the numerical evaluation of the equations, the power, terminal voltage, armature current and pole angles at pull-out; as functions of the machine synchronous reactances, are given in the form of tables or families of curves. A curve is given showing the variation of the pull-out power with saliency, and another shows the extent to which the pull-out power of a combination of two machines is reduced in comparison with the values which would be obtained if either machine were running on an infinite busbar.