| 摘要 |
At least the direction of the machine flux is calculated in a flux determining device for the field-oriented control of a rotating-field machine. This calculation takes place on the one hand by calculation modelling of the machine dynamics, based on the machine currents (i tau 1, i tau 2) ("current model"), and on the other hand is calculated from the e.m.f., by integration of the machine voltages (U alpha , Uss) ("voltage model"). At low rotation speeds, the integration in the voltage model is inaccurate and the current model provides the direction value required by the controller. At relatively high rotation speeds, the difference between the two direction model values ( psi 1, psi v) is formed and is connected via a regulator (2) to the current model (20), by closing a switch (3), so that the direction of the flux calculated in the current model is slaved to the direction supplied by the voltage model. In consequence, at relatively high rotation speeds, the current model is provided with the dynamics of the voltage model, without discontinuities occurring during the changeover. <IMAGE>
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