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US 9,849,806 B1Granted
Current based six step control
AssigneeFord Global Technologies, LLC
InventorsWei Xu, Fazal Urrahman Syed
Life of this patent
Estimating the term…
Abstract
A vehicle powertrain includes a DC-DC converter and a controller. The DC-DC converter is coupled between a traction battery and an inverter for an electric machine. The controller is configured to, in response to a rotational speed of the electric machine dropping below a back EMF threshold speed, transition to a current control based six step inverter mode and operate the DC-DC converter to output a voltage less than an open circuit voltage of the traction battery.
Claims20
A vehicle powertrain comprising:
- a DC-DC converter coupled between a traction battery and an inverter for an electric machine;
- and
- a controller configured to, in response to a rotational speed of the electric machine dropping below a back EMF threshold speed, transition to a current control based six step inverter mode and operate the DC-DC converter to output a voltage less than an open circuit voltage of the traction battery.
A method of operating a vehicle powertrain, the method comprising:
- receiving a torque request;
- and
- in response to a rotational speed of an electric machine dropping below a back electromotive force threshold speed,
- transitioning to a current control based six step inverter mode that is executed according to winding current direct and quadrature components of the electric machine, and the torque request, and
- operating a DC-DC converter to output a bus voltage to the electric machine less than an open circuit voltage of a traction battery.
2 more elements
A vehicle comprising:
- a DC-DC converter coupled between a traction battery and an inverter for an electric machine;
- and
- a controller configured to, in response to vehicle speed dropping below a threshold speed while a torque request is below a torque threshold, execute a six step control mode for the inverter according to winding current direct and quadrature components associated with the electric machine to drive the electric machine without back electromotive force feedback.
Dependencies are inferred from the claim text.