Patent ID: 8264209
Filing Date: 2012-09-11
Classification: H02P

Abstract:
1. A method of operating a double-fed asynchronous machine with a stator connected to a mains and a rotor connected to an inverter, the method comprising the steps of: detecting a transient change in a mains voltage, obtaining or measuring a rotor parameter and a stator parameter; transforming the obtained or measured rotor parameter and stator parameter from a three-phase system into a two-phase system, producing a stator flux vector and a rotor flux vector; computing from the stator flux vector and the rotor flux vector a flux difference vector; multiplying the flux difference vector by a proportionality factor, producing a voltage value; re-transforming the voltage value into the three-phase system; generating from the re-transformed voltage value an inverter firing pattern which impresses on the rotor a desired value of an electrical parameter which actively reduces a torque occurring during the transient change in the mains voltage.