US 11,888,424 B1
Methods for improving rate of rise of torque in electric machines with stator current biasing
Paul Carvell, San Jose, CA (US); and Philippe Farah, Maisons-Laffitte (FR)
Assigned to Tula eTechnology, Inc., San Jose, CA (US)
Filed by Tula eTechnology, Inc., San Jose, CA (US)
Filed on May 22, 2023, as Appl. No. 18/200,264.
Claims priority of provisional application 63/390,113, filed on Jul. 18, 2022.
Int. Cl. H02P 25/064 (2016.01); H02P 27/08 (2006.01)
CPC H02P 27/085 (2013.01) 17 Claims
OG exemplary drawing
 
1. A method of controlling an electric machine having a separately excitable rotor and stator, the method comprising:
energizing the electric machine comprising:
exciting the rotor with direct current and the stator with a stator biasing current at the same time to generate magnetic flux in the rotor via two separate paths;
terminating the stator biasing current when a desired magnetic flux is generated in the rotor; and
providing a stator flux to the stator such that the electric machine provides torque;
controlling the electric machine to an OFF state by terminating the direct current to the rotor and the stator flux.