Low-Frequency Performance of a Wound-Rotor Induction Motor for Mine Hoist Drives

This paper describes the application to a mine hoist of a wound-rotor induction motor with low-frequency dynamic braking. The advantages of this type of drive over other mine hoist drives are discussed. Induction motor performance on low-frequency is compared with operation on normal frequency. Methods of predicting low-frequency performance are developed, calculated performance is compared with test results, and precautions to be taken in the design of a wound-rotor motor for this application are described.