System and method for in-vehicle resolver alignment
AssigneeFord Global Technologies, LLC
InventorsJonathan HAIR, David Crist GABRIEL, Elizabeth Rose BIFANO, Travis SMITH, Arun GANESAN, Brian Khoi-Duy NGUYEN
Life of this patent
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Abstract
An electric drive system for a vehicle includes a speed/position feedback device coupled to an electric machine and configured to provide an index pulse. The system further includes an inverter having a line voltage sensor. The system includes a controller programmed to, responsive to the electric machine rotating at a generally constant speed without commanding the inverter, generate a resolver offset from a time difference between a zero crossing of a line voltage and the index pulse and operate the inverter according to the resolver offset.
Claims20
A vehicle comprising:
- a resolver coupled to an electric machine and configured to provide an index pulse;
- an inverter having a line voltage sensor;
- and
- a controller programmed to, responsive to the electric machine rotating at a constant speed not powered by the inverter, generate an offset for the resolver from a time difference between the index pulse and a zero crossing indicated by the line voltage sensor, and operate the inverter using the offset.
A method comprising:
- operating an engine coupled to an electric machine at a predetermined speed;
- and
- operating, by a controller, the electric machine according to an offset of a resolver coupled to the electric machine derived from a time difference between a zero crossing of a line voltage across phase windings of the electric machine and an index pulse of the resolver.
An electric drive system comprising:
- a resolver coupled to an electric machine and configured to provide an index pulse;
- an inverter having a line voltage sensor;
- and
- a controller programmed to operate the inverter according to a resolver offset that is updated during a drive cycle according to a time difference, between a zero crossing of a line voltage and the index pulse, measured during the drive cycle when the electric machine is unpowered.
Dependencies are inferred from the claim text.