How does a Synchronous Motor get started from no load to full load?

Starting a synchronous motor from no load to full load normally requires many phases to ensure smooth and efficient operation.

Initial Excitation

To create a magnetic field in the rotor, the synchronous motor must be stimulated before operation. This is accomplished through connecting the rotor windings to a DC source, which generates a magnetic field that interacts with the stator’s revolving magnetic field during operation.


This stage involves synchronizing the motor’s rotational speed with the frequency of the provided AC power, resulting in efficient functioning at the specified speed.

Starting Sequence

Connect the motor to the power supply using a starter device, like as a soft starter (or) variable frequency drive (VFD). These devices regulate the voltage & frequency applied to a motor during start-up, allowing for smooth acceleration.


The motor’s rotor progressively accelerates from standstill to synchronous speed. During this stage, the motor may draw a higher current as it overcome inertia & frictional forces to achieve its operating speed.

Load Connection

As the motor attains synchronous speed, the load is gradually linked to the shaft. This is often accomplished through the use of a clutch (or) coupling mechanism, which allows for controlled interaction of the load and the motor.


During startup, adjust voltage, frequency, and excitation for smooth acceleration & stable operation. To improve efficiency and performance, the control system can make these modifications manually or automatically.


After reaching full load, adjust the motor to maintain synchronous speed under varied load situations. This entails fine-tuning excitation or modifying power factor to improve efficiency and performance across the motor’s working range.

Overall, starting a synchronous motor from no load to full load necessitates precise regulation of voltage, frequency, & excitation to ensure smooth acceleration and steady operation while minimizing stress on the motor and linked equipment.