Maximum Permissible Slip for Synchronizing Salient-Pole Synchronous Motors

The paper presents a method for determining the maximum permissible slip for synchronization of a salient-pole synchronous motor using machine, load and system parameters. An exact differential equation of motion of the salient-pole rotor during the synchronizing period is derived and then solved by means of a digital computer program using a fourth-order Runge-Kutta method. The synchronizing criterion involves two factors: the displacement angle must decrease, and this angle must not exceed 540 electrical degrees. Curves showing the relationship between load torque and maximum permissible slip with load inertia as a parameter are shown for a given motor. These results are compared with test data on the actual machine.