| 摘要 |
A method in connection with a doubly-fed machine, the machine comprising a stator, which is connected to a power network, and a rotor, which is connected through an inverter to the network. The method comprises the steps of determining the rotational speed (nact) of the machine, forming a rotational speed reference (nref) for the machine, measuring network voltage, measuring network current and calculating the active power (Pact) and the reactive power (Qact) of the network. The method also comprises the steps of calculating a machine shaft torque (T), forming a frequency reference (fref), the rotational speed reference (nref) and the shaft torque (T), forming a reactive power reference (Qref), forming an Ir compensation reference (Irref) on the basis of the reactive power reference (Qref) and the reactive power (Qact), and controlling the scalar-controlled inverter on the basis of the frequency reference (fref) and the Ir compensation reference (Irref) formed. |
