Definition

1. Noun:
   • A type of electric motor: A synchronous motor is an electric motor in which the rotational speed of the shaft is synchronized with the frequency of the alternating current (AC) power supply. This means the motor runs at a constant speed, known as the synchronous speed, regardless of the load, as long as the load does not exceed the motor's capacity.

Usage

• Noun:
  • A synchronous motor is often used where constant speed is critical, such as in clocks, timers, and tape drives.
  • The factory replaced the induction motor with a synchronous motor to maintain precise rotational speed for the conveyor belt.
  • The operation of a synchronous motor requires AC power at a specific frequency.

Advanced Usage

• "To operate as a synchronous motor": To function in the mode where speed is locked to the supply frequency.
  • When properly excited, the machine can operate as a synchronous motor.
• "Synchronous motor drive": A system or controller designed to power and control a synchronous motor.
  • The new design incorporates a high-efficiency synchronous motor drive.

Variants and Related Words

• Synchronous machine (n): A broader term for any electrical machine (motor or generator) that operates at synchronous speed.
  • A synchronous machine can function as either a motor or a generator.
• Synchronous speed (n): The constant speed at which the magnetic field rotates in a synchronous motor, determined by the power supply frequency and the number of motor poles.
  • The synchronous speed for this 4-pole motor on a 60 Hz supply is 1800 RPM.

Synonyms

• Constant-speed motor: A motor that maintains a fixed speed under varying loads (this is a descriptive synonym, with "synchronous motor" being a specific technical type).

Related Phrases

• To run synchronously: To operate in sync with the frequency of the power supply.
  • The rotor must run synchronously with the stator's rotating magnetic field.
• To pull into step: The process by which a synchronous motor accelerates from rest to reach its synchronous speed.
  • The motor's damper windings help it pull into step with the supply frequency.

Related Concepts

• Power factor correction: A common application for synchronous motors, where they are used to improve the power factor of an electrical system.
  • The plant installed a synchronous motor primarily for power factor correction.
• Field excitation: The direct current supplied to the rotor windings of a synchronous motor to create its magnetic field.
  • Adjusting the field excitation controls the motor's power factor.

Noun

1. electric motor in which the speed of rotation is proportional to the frequency of the A.C. power