Synchronous Motor

A synchronous motor is a type of AC motor where the stator and rotor magnetic fields rotate at the same speed. This means that the rotor turns at a constant speed that is synchronized with the frequency of the AC power supply. The synchronous motor is widely used in industrial applications where constant speed is required.

Working Principle

The synchronous motor consists of a stator and a rotor. The stator has a set of coils that produce a rotating magnetic field when AC voltage is applied. The rotor has a set of permanent magnets or electromagnets that produce a magnetic field. When the stator magnetic field rotates, it induces a magnetic field in the rotor. The rotor magnetic field tries to align with the stator magnetic field and starts to rotate at the same speed.

Advantages

- The synchronous motor operates at a constant speed, which makes it suitable for applications where constant speed is required.
- It has a high power factor, which means that it consumes less reactive power from the power supply.
- It has a high efficiency, which means that it converts more electrical energy into mechanical energy.

Disadvantages

- The synchronous motor is more expensive than other types of motors.
- It requires a separate DC power supply to excite the rotor magnetic field.
- It is not self-starting and requires external means to bring it up to synchronous speed.

Applications

- The synchronous motor is used in industrial applications where constant speed is required, such as synchronous generators, compressors, pumps, and fans.
- It is used in power plants to drive large alternators that produce electricity.
- It is used in electric clocks and timers.

Schcronous Motor