| 摘要 |
A method and an arrangement for determining the rotation speed of a motor fed by an inverter, the arrangement comprising means (20, 30, 50) for determining the rotation speed of the motor (10) in at least two alternative manners, whereby the means for determining the rotation speed of the motor (10) comprise one of the at least two alternative manners of performance: means (30) for measuring the frequency of the voltage fed to the motor by the inverter (20); and means (30) for estimating the rotation speed of the motor on the basis of the measured frequency. |
