What does the term "synchronous speed" refer to in motor control?

The term "synchronous speed" refers to the speed of the rotating magnetic field produced by the stator winding in an AC motor. This speed is determined by the frequency of the electrical supply and the number of poles in the motor. It is a critical concept in motor control as it represents the ideal speed at which the motor's magnetic field rotates, allowing for efficient functioning with minimal losses. When the motor operates at this speed, it achieves maximum efficiency and torque with corresponding frequency.

While the physical speed of the motor shaft is also important, it typically operates at a speed that is less than the synchronous speed due to factors such as load and slip. Maximum theoretical performance speed is a broader concept and doesn't directly describe the condition when the magnetic field rotates in sync with the motor's rotor. Adjusted speed based on load involves real-world variations in speed as the motor works under different conditions, further indicating that synchronous speed is purely a theoretical and ideal condition, not affected by external loads.