| 摘要 |
An indirect position estimator for a switched reluctance motor applies short duration, low level sensing pulses to two unenergized phases of the motor. A change in phase current during a sampling period, resulting from the application of the sensing pulse, is sensed and processed to produce an indication of a pair of estimated angles for each of the unenergized phases. A pair of angles for one such unenergized phase is shifted by a value equal to the phase displacement between the two unenergized phases and the shifted angles are then compared to the angles of the second phase to determine which angles match. The matching angle is produced as a signal indicative of the estimated instantaneous rotor position. If any stator phase changes state during the sampling period, or if the two initially unenergized phases do not remain unenergized throughout the sampling period, a signal corresponding to an extrapolated rotor position is produced instead of the signal indicative of estimated instantaneous rotor position. Extrapolation preferably includes a least squares recursive estimation, with exponential forgetting, of speed. |
