| 摘要 |
<p>In order to detect the rotor resistance in the case of a rotating-field machine, the magnitude of the flux or the e.m.f. is calculated on the one hand in a detector circuit 14 from the current and voltage and on the other hand in a computing-model circuit 18 from the current, rotor position and a parameter value for the rotor resistance. If the component of the stator current parallel to the field is suddenly changed, the two magnitudes having a different time relationship are changed to a new value. During this transient process, the difference between the magnitudes is supplied to a regulator 33 by means of whose output signal the parameter value RL for the rotor resistance is changed. In the steady state, the two magnitudes are identical if the rotor resistance parameter RL which is used is equal to the actual rotor resistance. This balancing can be carried out, in particular, even at rest or when the machine is idling, and thus provides the correct rotor resistance which is required, for example, in order to determine the flux angle during field-oriented operation of the rotating-field machine. <IMAGE></p> |
