What does slip frequency refer to in motor operation?

Slip frequency in motor operation specifically refers to the difference between the actual speed of the rotor and the synchronous speed of the motor. In an induction motor, the synchronous speed is the speed at which the magnetic field rotates, determined by the supply frequency and the number of poles in the motor. However, the rotor always runs at a speed slightly lower than this synchronous speed to produce torque. The difference between these two speeds is what is termed the slip frequency, and it is crucial because it helps to establish the rotor’s torque production.

Understanding slip is important for diagnosing motor performance issues and the efficiency of the motor. For instance, if the slip is too high, it can indicate potential problems like excessive load or even mechanical issues in the motor. Thus, slip frequency directly plays a vital role in the analysis and operation of electric motors.