Chapter 33, Problem 1RQ

To determine

Identify the two factors that determine the synchronous speed.

Explanation of Solution

Synchronous speed:

The speed at which the magnetic field rotates in a motor is called the synchronous speed. The synchronous speed is given by the formula:

  $s=\frac{120f}{P}$

Here, the synchronous speed in RPM is s, the frequency in Hz is f, and the number of stator poles per phase is P.

The two factors that determine the synchronous speed of the motor are given below:

• The number of stator poles per phase.
• The frequency of the applied voltage.