Patent ID: 6737837
Filing Date: 2004-05-18
Classification: G05F

Abstract:
A device for control of power flow in a three-phase ac transmission line, comprising for each of its phases a transformer with a primary winding and a secondary winding, the secondary winding being intended for serial connection into the respective phase of the transmission line, and the primary winding of the transformer being intended to be supplied with a voltage that is dependent on a controllable part of the voltage between the other two phases of the transmission line, wherein the device comprises, for each of the phases of the transmission line, a series circuit with a first and a second terminal and a connection point, the series circuit comprising a first reactive impedance element with a fixed reactance connected between the first terminal and the connection point, and a second reactive impedance element with a variable reactance connected between the connection point and the second terminal, wherein one of said terminals is coupled to the respective phase in the transmission line and the other of the terminals is coupled to a terminal at each of the other two series circuits, such that, for all the phases, either the first or the second terminal is coupled to the transmission line, and the primary winding is coupled between the connection points at the other two series circuits.