Synchrounous motor is three phase motor,but its not self
starting .why?
Answer Posted / piyasa dey
In synchronous machines the stator winding or armature winding is excited by alternating current,therefore a rotating magnetic field is developed in it which is moving at synchronous speed.the field winding is excited by a dc source.a stationary field will be produced.the rotating stator cores will interact with the stationary rotor poles.during the positive half it will rotate in one direction but in the next half cycle the rotating stator cores will change their position and rotor is urged to rotate in opposite direction.due to the rotor inertia,it fails to respond to the change in the direction of electromagnetic torque.that's why it has no starting torque.
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