Abb Technology Ag

Abb Ab

Asea Brown Boveri Ab

Abb Technology Ltd

Abb Schweiz Ag

Björn Thorvaldsson

Bo Bijlenga

Tomas Larsson

Mojtaba Noroozian

Bo Akesson

Mikael Halonen

A compensator for balancing an ac voltage network with a load connected between two phases. The compensator includes a voltage-source converter and a balancing device. The balancing device includes an inductance connected between phases before the load.

Device for balancing a transmission network

A control device for controlling a reactive power compensator connected to an electric power network and arranged to provide reactive power to the electric power network. The control device includes a voltage regulator outputting a control signal to the reactive power compensator for controlling its supply of susceptance to the electric power network. The control device includes a gain-adjusting device arranged to adjust the gain of the voltage regulator relative to the point of operation of the reactive power compensator.

Control device reactive power compensator and method

The invention relates to a poly-phase reactive power compensatorcomprising for each phase a, b, c a reactive power means. The poly-phase reactive power compensatorfurther comprises meansfor transferring susceptance between the phases a, b, c. The invention also provides a control device for controlling the poly-phase reactive power compensator

Poly-phase reactive power compensator

Equipment for exchanging power, in shunt connection, with an electric power network. A reactive impedance element and a voltage source converter provide mutual connection in series. The power network has a nominal voltage of a fundamental frequency and a given phase position. The converter is intended for generating a fundamental-tone voltage within a control range which limits the amplitude of the fundamental-tone voltage. The control range limits the amplitude of the fundamental-tone voltage to a value that is lower than the nominal voltage of the power network and comprises generation of a reactive component of the fundamental-tone voltage with a phase position that either coincides with the phase position for the voltage of the power network, or that deviates by 180&#xb0; electrically form the phase position for the voltage of the power network.

Equipment and method for exchanging power, in shunt connection, with an electric power network, and use of such equipment

A voltage-source converter is connected on its ac-voltage side to a three-phase electric power network via a transformer and on its dc-voltage side to capacitor equipment. The transformer has on its secondary side a first, a second, and a third phase winding, each one with a first and a second winding terminal. Resistor equipment is arranged at the transformer for limiting the current through the converter when connecting the transformer to the power network. The resistor equipment includes a first resistor, connected to the first winding terminal of the second phase winding, and switching equipment is adapted, in an initial position, to block current through the phase windings, in a transition position to form a current path which includes at least the first and the second phase windings and, in series therewith, the first resistor, which current path, when the converter is connected to the transformer, closes through the converter and the capacitor equipment, and, in an operating position, to interconnect all the first winding terminals for forming the common neutral point.

Device for energizing a voltage-source converter

A device for control of a capacitor device for a shunt-connected static compensator unit (COM1, COM2, COM3) for compensation of reactive power in an electric power network (NW). The capacitor device comprises a capacitor and a semiconductor valve, connected in series with said capacitor, with a first semiconductor, corresponding to respectively a first and a second conduction direction for current through the capacitor. The device comprises members (VN, FSD, CU) which, in dependence on a voltage (Uab, Ubc, Uca) sensed at the compensator, alternately generate a firing order for the respective semiconductor. In addition thereto, the device comprises members which, for each of the first and second conduction directions, form a deblocking signal, indicating that the conduction direction associated with the respective firing order does not carry current, and which thus generate a firing order for the second of the first and second conduction directions with an optional delay (T1*f*360.degree.) after the occurrence of said deblocking signal.

Growing community of inventors

Kolbäck, Sweden

Björn Thorvaldsson