Menetelmä ja laite sähkökäyttöjärjestelmän energiatehokkuuden maksimoimiseksi

The present disclosure discloses a method and an apparatus implementing the method for maximising energy efficiency of an electric drive system comprising an electric motor and a load. In the method, the torque characteristics of the system can be selected from two types of behaviour: linear and quadratic behaviour of a torque of the motor in respect to a rotational speed of the motor. The method gathers a plurality of data points and with which behaviour the data points correlate best. The torque characteristics to be used are determined on the basis of the correlation, and the motor is controlled on the basis of the determined torque characteristics.