Patent ID: 6366037
Filing Date: 2002-04-02
Classification: H02K,H02P

Abstract:
Separately excited electric machine with a rotor (2) and a stator (1) and a device for detecting the rotational position of the rotor relative to the stator, wherein the position determination device is provided for determination of the rotational position by evaluation of a signal which can be tapped at the pole winding circuit and is imprinted by pole winding inductivities exhibiting rotational position dependency, wherein the pole winding circuit has phase strands (8-10) that are star-connected and the position determination device is provided for evaluating the potential at the star point (12) relative to ground during motor operation of the machine, wherein the position determination device for determining the rotational position of the rotor (2) during motor operation is configured to employ rotational angle intervals (&Dgr;&PHgr;), in which a periodically repeated pole winding inductivity is contained as a function of the rotational angle of the rotor, wherein the position determination device is configured to extract from the potential at the star point a signal (S) representative of the rotational position of the rotor within the rotational angle interval (&Dgr;&PHgr;), which signal (S) is based on a measuring voltage, overlaid onto an operational voltage and changed according to the respective pole winding intensity, or a voltage value, occurring in response to switching of operational voltage pulses and imprinted by the respective pole winding inductivity.