Grundfos A/s

Pierre Vadstrup

Niels D Jensen

Heikki Yli-Korpela

Niels Due Jensen

Lars R Enevoldsen

Lasse Llves

Peter Junklas Nybo

Erik Olsen

Per Barth

Nils Bidstrup

The electric motor is equipped with an electronic control, for example in the form of a frequency converter () and comprises at least one Seebeck element () whose one side is connected to the motor () in a heat-conducting manner and whose other side is in heat-conducting connection with a cooling medium. The electrical output power of the Seebeck element () is led to the electronic control () of the motor ().

Electric motor

The method serves for detecting the magnetic flux, the rotor position and/or the rotational speed of the rotor in a single- or multiphase permanent magnet- or -synchronous motor or -generator using the stator voltage equations&#x2003;&#x2003;Equation (1)&#x2003;&#x2003;Equation (2)It is characterized in that with the evaluations one takes into account the energy conditions of the rotor, by which means one may achieve an accuracy which is considerably greater than known methods.

Method for detecting the magnetic flux the rotor position and/or the rotational speed

The method for controlling a voltage/frequency converter controlled single-phase or polyphase electric motor evaluates the phase shifting between the EMF and BEMF by way of the deviation between the zero crossing of the phase current and the voltage produced by the intrinsic induction and readjusts the frequency of the converter accordingly. The measurement of the intrinsic induction is effected in the zero crossing of the current courses of the associated phase, wherein during the measurement the phase is separated from the supply network.

Method for controlling a voltage/frequency converter controlled single-phase or polyphase electric motor

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Tilsit, Denmark

Pierre Vadstrup