Patent ID: 6396237
Filing Date: 2002-05-28
Classification: H02P

Abstract:
A method of determining rotor position in a switched reluctance machine comprising a rotor, a stator and at least one phase winding, the method comprising:measuring one of main current and flux-linkage in the phase winding during an inactive period in which the phase is not energized; injecting a diagnostic pulse having a predetermined maximum value of current or flux-linkage into the inactive phase winding; measuring total current or flux-linkage in the phase at the end of the pulse; producing a value for the current or flux-linkage due to injection of the diagnostic pulse from the difference between the total current and the main current or flux-linkage; and deriving rotor position from a correlation of the current or flux-linkage with rotor angle for a value of the other of current and flux-linkage.