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In a synchronous motor, Which method is/are used to perform magnetic locking (Starting)?
Induction Motor
Prime Mover or Pony Motor (Auxiliary motor - DC/AC)
Low Supply Frequency
All of these
All of these
In a synchronous motor, all listed methods are utilized to achieve magnetic locking during the starting phase. These methods include using an induction motor principle, employing a prime mover or pony motor, and operating at low supply frequencies.
In a synchronous motor, all listed methods are utilized to achieve magnetic locking during the starting phase. These methods include using an induction motor principle, employing a prime mover or pony motor, and operating at low supply frequencies.
The primary starting mechanism involves producing a rotating magnetic field that can align with the rotor's magnetic field. This is achieved through an induction motor's principle, which temporarily operates the synchronous motor as an induction motor. Alternatively, a pony motor can provide initial torque, while a low supply frequency can assist in synchronizing the rotor with the stator's magnetic field.
Synchronous motors must be started asynchronously before locking in.
Various methods facilitate the initial rotor motion to achieve synchronization.
Allows direct starting of large synchronous motors.
Prevents mechanical stress on the rotor during startup.
Additional equipment may be required, increasing costs.
Complexity in synchronization control may arise.
Hydroelectric plants where synchronization is essential.
Large industrial drives requiring efficient energy conversion.
A standard value for starting under low frequency is typically 50 Hz.
Options A and C are not standalone methods for starting a synchronous motor.
D is correct тАФ all methods listed are valid for achieving magnetic locking in synchronous motors.
Understand the differences in motor starting mechanisms as they may appear in various engineering problems.