A predictive landing failsafe system is adapted to slow or stop a permanent magnet AC motor in response to a selected condition, such as a power outage. In some embodiments, the predictive landing failsafe system may short two or more terminals of the AC motor in response to the selected condition. In some embodiments, one or more resistors may be coupled between the two or more terminals, the resistors lowering the short-circuit current and thus making a more smooth stop for the AC motor. In some embodiments, the AC motor may be used in a drawworks.
PREDICTIVE LANDING FAILSAFE
SYSTEME D'ATTERRISSAGE PREDICTIF A SECURITE INTEGREE
2015-09-17
Patent
Electronic Resource
English
IPC: | B66D Haspeln , CAPSTANS |