MEEN 225 Lecture Notes - Lecture 23: Synchronous Motor, Induction Motor, Motor Controller
8 Jan 2018
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Document Summary
A synchronous motor has no net starting torque and cannot start by itself. If the rotor field poles are excited by the field current (from dc supply) and the stator terminals is connected to a 3 ac supply, the motor will not start. This brings the machine on the line as a generator. By turning off or disconnecting the prime mover, the machine act as a motor: start as an induction motor by using damper windings the most popular way to start a synchronous motor. 3. a) disconnect the field windings from their dc supply and short them out. 3. b) apply three-phase voltage to the stator of the motor and let the motor accelerate up to near speed. The motor shouldn"t be on load so that their speed can approach synchronous speed as closely as possible. 3. c) connect the dc source to the field circuit.
