METHOD FOR CAPTURING A ROTOR POSITION OF A PERMANENTLY EXCITED SYNCHRONOUS MACHINE, AND PERMANENTLY EXCITED SYNCHHRONOUS MACHINE HAVING MEANS FOR CAPTURING THE ROTOR POSITION THEREOF

摘要

In order to capture a rotor position of a rotor (2) of a permanently excited synchronous machine (1), voltages (27) are applied to stator windings of the synchronous machine (1), wherein higher-frequency additional signals (16) are superimposed on fundamental components (14) of the voltages (27), which are applied for the purpose of operating the synchronous machine (1), at least at low speeds of the synchronous machine (1). As responses to the applied voltages, currents (19-21) flowing through the stator windings are measured. An observer for estimating the rotor position (22) of the permanently excited synchronous machine (1) on the basis of the voltages applied to the stator windings and the currents flowing through the stator windings is defined as an extended Kalman filter (EKF) (12) which comprises a model (13) of the synchronous machine (1). The model (13) of the synchronous machine (1) has a fundamental model component and an additional signal model component. The fundamental components (14) and the additional signals (16) of the applied voltages (27) and the measured currents (19-21) are continuously input to the EKF (12). The EKF (12) is used as the sole observer for the rotor position (22) at all speeds of the synchronous machine (1), with the result that two or more different observers for estimating the rotor position (22) of the permanently excited synchronous machine (1) do not need to be synchronized on the basis of the speed.