Arrangement and method for force compensation in electricalmachines

摘要

An electrical machine (1) comprises a rotor (20), a stator (10), a rotor power supply (50), at least one sensor (70) and a rotor magnetization control arrangement (60). The rotor has rotor windings (22) for controlling magnetization of rotor magnetic poles (24). The sensor is arranged to measure a parameter associated with a relative force between the stator and the rotor. The rotor magnetization control arrangement is communicationally connected to the sensor for receiving a signal representing the measured parameter. The rotor magnetic poles are divided into at least two groups (23). The rotor magnetization control arrangement is arranged for controlling the magnetization of the groups individually by providing a respective individually controllable rotor current. The rotor magnetization control arrangement is arranged to individually control the rotor currents in dependence of the signal representing the measured parameter. A method for controlling such an electrical machine is also disclosed.