US 11,757,388 B2
Method of characterising a synchronous motor
David Moule, Birmingham (GB); Luis Ayala, Radolfzell (DE); and Albert Schwinn, Radolfzel (DE)
Assigned to TRW AUTOMOTIVE GMBH, Alfdorf (DE); and TRW LIMITED, Solihull (GB)
Filed by TRW Limited, Solihull (GB); and TRW Automotive GmbH, Alfdorf (DE)
Filed on Nov. 26, 2019, as Appl. No. 16/695,222.
Claims priority of application No. 1820001 (GB), filed on Dec. 7, 2018.
Prior Publication US 2020/0186069 A1, Jun. 11, 2020
Int. Cl. H02P 21/00 (2016.01); G06F 30/23 (2020.01); G06F 111/10 (2020.01)
CPC H02P 21/0017 (2013.01) [G06F 30/23 (2020.01); H02P 21/0025 (2013.01); G06F 2111/10 (2020.01)] 25 Claims
OG exemplary drawing
 
1. A method comprising the steps of:
Obtaining a plurality of winding flux linkage values or terminal voltages of a motor, each corresponding to a different combination of phase current magnitude and phase advance,
Transforming the plurality of flux-linkage values or terminal voltages of the motor into a rotor dq reference frame to provide one or more dq-axis flux-linkage values or terminal voltages,
Fitting the flux linkage model to the one or more dq-axis flux-linkage values or terminal voltages and their linked phase current magnitude and phase advance using a process of parametric optimization, wherein fitting the flux linkage model to the one or more dq-axis flux-linkage values or terminal voltages and their linked phase current magnitude and phase advance comprises:
using the one or more dq-axis flux-linkage values or terminal voltages to generate at least one map for the d-axis and q-axis flux-linkages, each of the at least one map grouping together flux linkage values or terminal voltages having a common phase advance, and
fitting the flux linkage model to the at least one map using a process of parametric optimisation;
receiving a torque demand signal at an electric power steering system associated with the motor; and
applying, via the motor, a torque to a part of a steering mechanism according to the flux linkage model and the torque demand signal.