Patent ID: 9577568
Date: 2017-02-21
CPC Classifications: H02P

Claim:
1. A method for detecting a wire-break fault during an operation of a brushless D.C. motor having a three-phase stator winding and controlled by pulse width modulation, which comprises the steps of: recording at least one stator winding phase of a stator winding during each pulse width modulation cycle period, a switch-on delay interval for a transition of an electrical phase potentials applied to the stator winding phase from a switch-off potential to a switch-on potential and a switch-off delay interval for a transition of a phase potential from the switch-on potential to the switch-off potential; defining a lower deviation limit for a deviation of recorded switch-off delay intervals from recorded switch-on delay intervals; and deducing the wire-break fault if deviations of the recorded switch-off delay intervals from the recorded switch-on delay intervals fall below the lower deviation limit.