Patent ID: 8587234

Claim:
A method for the identification without shaft encoder of electrical equivalent circuit parameters ( 03 , 05 , 15 ) of a three-phase synchronous motor ( 09 ) having a rotor and a stator, the method comprising at least the steps: (a) bringing the rotor ( 11 ) to a standstill position, so that the d flux axial direction of the rotor is aligned opposite the α axial direction of the stator ( 13 ); (b) applying a test signal voltage U 1d in the d flux axial direction of the synchronous motor ( 09 ), whereby the q transverse axial direction remains without current; (c) measuring a signal current I 1d of the d flux axial direction of the synchronous motor ( 09 ); (d) identifying equivalent circuit parameters ( 03 , 05 , 15 ) of the synchronous motor ( 09 ) based on the test signal voltage U 1d and on the signal current I 1d in the d flux axial direction; whereby the supplying of the test signal into the synchronous motor ( 09 ) takes place in such a manner that the rotor ( 09 ) remains torque-free.