Synchronous Motor | Electrical Machines
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
Engineering Electrical Machines - II : UNIT II : Synchronous Motor : Anna University Two Marks Questions & Answers
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
They are not self starting and requires an additional facility to make it self starting.
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
This characteristics is similar to a normal capacitor which always takes leading power factor current.
Synchronous Motor
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
There may be swinging of machine due to variations in load or due to any other reason.
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
When motor is loaded, the rotor pole axis falls back with respect to stator.
Synchronous Motor
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
The gross mechanical power developed per phase will be equal to the difference between pin per phase and the per phase copper losses of the winding.
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
The motor armature current has two components Id and Iq.
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
Thus when Ra is negligible, θ = 90o for maximum power developed. The corresponding torque is called pull out torque.
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
Net input to the synchronous motor is the three phase input to the stator.
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
So once Ebpb is calculated, load angle δ can be determined by using sine rule.
Synchronous Motor
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
Excitation can be increased by increasing the field current passing through the field winding of synchronous motor.
Subject and UNIT: Electrical Machines II: UNIT II: Synchronous Motor Engineering Electrical Machines - II
At start, consider normal behaviour of the synchronous motor, where excitation is adjusted to get Eb = V i.e. induced e.m.f. is equal to applied voltage. Such an excitation is called Normal Excitation of the motor.