Pulse modulated control with field weakening for improved machine efficiency
AssigneeTula eTechnology, Inc.
InventorsPaul Carvell, Adya S. Tripathi
Life of this patent
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Abstract
Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.
Claims38
A method comprising:
- operating an Electrically Excited Synchronous Machine (EESM) in a pulsed mode;
- and
- applying field weakening to the EESM if back electromagnetic force (BEMF) of the EESM is more than a supply voltage used to excite the EESM.
An Electrically Excited Synchronous Machines (EESM) assembly configured to:
- selectively operate in a pulsed mode in which an output of the EESM assembly is pulsed;
- and
- apply field weakening when the EESM assembly is operating in the pulsed mode and a back electromagnetic force (BEMF) of the EESM assembly exceeds a supply voltage used to excite the EESM assembly.
An electric vehicle, comprising:
- an Electrically Excited Synchronous Machine (EESM);
- a controller configured to:
- ascertaining a torque demand;
- ascertaining Noise, Vibration, and Harshness (NVH) associated with operation of the electric vehicle;
- and
- decide to operate the EESM in a continuous mode or a pulsed mode based at least partially on a combination of (a) the ascertained torque demand relative to a threshold and (b) the ascertained NVH of the electric vehicle.
Dependencies are inferred from the claim text.