Patent ID: 7495408

Claim:
A method for the no-transmitter speed determination of an asynchronous machine, comprising the steps which follow: a module ( 10 ) for field-oriented regulation calculates the voltages ( 22 ) to be applied to the asynchronous machine ( 11 ) on the basis of a setpoint for the speed ( 20 ), at least two values measured for the conductor current ( 21 ), and a speed ( 28 ) calculated by an observer module ( 12 ), the observer module ( 12 ) has applied thereto the voltage values ( 22 ) obtained from the field-oriented regulation ( 10 ) or the voltage values measured ( 23 ), and calculates a value of the moment-forming current îsq(t) ( 25 ) and an inner moment Mi(t) ( 27 ) of the asynchronous machine from the values applied, a moment module ( 13 ) calculates a load moment Ml(t) ( 26 ) acting upon the asynchronous machine ( 11 ) from the difference of the moment-forming currents from the field-oriented regulation ( 10 ) and the observer module ( 12 ), a speed module ( 14 ) calculates the actual speed ( 28 ) of the asynchronous machine via the load moment ( 26 ) of the moment module ( 13 ) and the inner moment ( 27 ) of the observer module ( 12 ), and further characterized in that the setpoint for the speed ( 20 ) is given by a travel transmitter.