Method for state identification and magnetization of an inverter-fed (inverter-supplied) asynchronous machine which preferably has no position transmitter or rotation speed transmitter, having an unknown magnetization state, and a circuit arrangement or carrying out this method

Abstract

Abstract An asynchronous machined with an unknown magnetization state is magnetized. In this case, the present electrical operating state of the asynchronous machine 5 is initially confirmed by real- time evaluation of the current profiles in the phases with the inverter "short-circuited". The rotation direction is determined by a second such measurement. A stator current space vector is repeatedly applied in the rotor flux space vector direction, as a result of which the flux continuously increases, provided the rotation speed is not too low. At low rotation speeds and at rest, the flux determination is highly inaccurate, and the flux fluctuates on average about the value zero, which results in one criterion for determining low rotation speeds. In order to build up the flux, the current space vector is now evaluated on the bases of a voltage space vector pulse in order to determine the rotation speed, with the time profile of the stator current component which is parallel to the voltage space vector being noticeably dependent on the rotation speed as the rotation speed rises. The stator current component which is at right angles to the voltage space vector has a clear functional relationship to the rotation speed and the rotation direction. Once the rotation speed has been determined, a stator current space vector which rotates at this rotation speed is applied, by which means a flux spacer vector rotating at the same rotation speed is formed in the direction of the stator space vector. <IMAGE>

Inventors

• 👤 Manfred Dipl Ing Dr Schroedl
• 👤 Robert Dipl Ing Remta

Bibliographic Details