Patent ID: 9059651
Filing Date: 2015-06-16
Classification: H02P

Abstract:
1. A device configured to determine the position of a moving rotor in a switched reluctance motor, comprising: a current sensor that samples a signal representative of the current magnitude in a phase winding of said switched reluctance motor while a voltage is applied to said phase winding, a feature detection unit that detects a feature of a second temporal derivative of said signal, and a processing unit that determines the position of the moving rotor taking into account an occurrence of said feature, wherein said occurrence of said feature corresponds to an unaligned or an aligned rotor position, wherein said feature detection unit comprises a zero-crossing detector arranged to detect said feature, said feature being a zero-crossing event of the second temporal derivative of said signal, wherein said determining of the position of the moving rotor comprises determining the sign of a third temporal derivative of said signal when the occurrence of said feature has been detected, wherein a positive sign of the third temporal derivative of said signal corresponds to an aligned rotor position, wherein said aligned rotor position corresponds to a position of minimum reluctance of the motor.