US 11,901,853 B1
Technology for sensorless detection of reverse rotation and speed estimation for electric machines
Alexander George Parlos, Austin, TX (US); and Gang Li, Austin, TX (US)
Filed by Veros Systems, Inc., Austin, TX (US)
Filed on Jun. 11, 2018, as Appl. No. 16/005,571.
Claims priority of provisional application 62/484,816, filed on Apr. 12, 2017.
Int. Cl. H02P 23/12 (2006.01); H02P 6/17 (2016.01); H02P 6/28 (2016.01); H02P 6/26 (2016.01)
CPC H02P 6/17 (2016.02) [H02P 6/26 (2016.02); H02P 6/28 (2016.02)] 20 Claims
OG exemplary drawing
 
1. A computer system implemented method for determining rotation of a de-energized electric machine without accessing the machine, wherein the machine in the energized state rotates in a reference direction, the method comprising:
detecting by the computer system, for a recorded waveform of multi-phase electrical power indicia for supply conductors of the machine measured remotely from the machine, that a first time segment of the recorded waveform corresponds to an electrically energized state of the machine and that a second time segment of the recorded waveform corresponds to an electrically de-energized state of the machine, wherein since the second time segment of the recorded waveform is for the de-energized state, the second time segment is for times when the recorded waveform arises from power induced on the supply conductors for the machine by rotation of the machine; and
determining by the computer system that the machine in the de-energized state has rotated in a direction reverse to the reference direction, wherein the determining that the machine in the de-energized state has rotated in a direction reverse to the reference direction includes the computer system comparing the first and second time segments of the recorded waveform.