Abstract:
An apparatus (302) for controlling the electric power transmission in a high voltage direct current, HVDC, power transmission system comprising at least one HVDC transmission line (102, 104, 106, 108, 110, 112, 114) for carrying direct current, wherein the apparatus (302) comprises a DC-to-DC converter (304) and a second converter (306) for converting alternating current to direct current and/or direct current to alternating current, the DC-to-DC converter having two DC sides for output and/or input of direct current, the second converter having an AC side (308) for output and/or input of alternating current and a DC side (310) for output and/or input of direct current. The DC-to-DC converter is connectable to the HVDC transmission line (102), and the second converter is connected via its DC side to the DC-to-DC converter. The second converter is connectable via its AC side to an AC source (314), and the apparatus is adapted to control the direct current of the HVDC transmission line by introducing a DC voltage in series with the HVDC transmission line. A HVDC power transmission system comprising the above-mentioned apparatus (302).
Abstract:
A DC-DC converter (200) for load flow control in a high voltage direct current (HVDC) grid is provided. The converter comprises four transistor-diode pairs (T1/D1–T4/D4) and an inductor (L), arranged to constitute a combination of two buck and two boost converters. The DC-DC converter may be used to introduce a series direct voltage ( U 0 ) into a transmission line of an HVDC grid for the purpose of controlling the load flow in the grid. The converter is operable in all four quadrants and is capable of introducing a direct voltage of either polarity in series with the transmission line, resulting in power extraction from the line or power infeed into the line, respectively, for both directions of current ( I 132 ) through the line. Further, an HVDC grid terminal and a method of load flow control in an HVDC grid are provided.
Abstract:
An apparatus (302; 602; 902) for controlling the electric power transmission in a high voltage direct current, power transmission system comprising at least one HVDC transmission line (102, 104, 106, 108, 110, 112, 114) for carrying direct current. The apparatus (302) comprises a first converter (304) a second converter (306) each of the first and second converters having an AC side (308, 310) for output and/or input of alternating current and a DC side (312, 314) for output and/or input of direct current, and an electric power transformer (318) connected between the first and second converters. The first converter is connectable via its DC side to the HVDC transmission line (102), each of the first and second converters is connected via its AC side to the electric power transformer, and the second converter is connectable via its DC side to a DC source (316). The apparatus is adapted to control the direct current of the HVDC transmission line by introducing a DC voltage in series with the HVDC transmission line (102).
Abstract:
It is presented a high voltage DC/DC converter for converting between a first DC connection and a second DC connection. The high voltage DC/DC converter comprises: a first set of DC terminals; a second set of DC terminals); a multiphase transformer device comprising a plurality of primary windings and a corresponding plurality of secondary windings; a first converter arranged to convert DC to AC, comprising a plurality of phase legs serially connected between the first set of DC terminals, wherein each phase leg is connected to an AC connection of a respective primary winding; and a second converter arranged to convert AC from the secondary windings to DC on the second set of DC terminals.
Abstract:
The invention concerns an arrangement (23) for transmitting power between a DC power line (12) and an AC power line (22A, 22B, 22C) carrying a voltage having a number of phases. The arrangement comprises a number of transformers (20A, 20B, 20C), one for each phase and a number of power transfer modules, one for each phase, connected in series between the DC power line and ground, where each module comprises a first branch including series connected converter cells (CA1, CA2, CB1, CB2, CC1, CC2 ) and a second branch comprising series connected switching elements (SW1A, SW2A, SW1B, SW2B, SW3A, SW3B). The primary winding of a transformer (20A, 20B, 20C) is connected to a corresponding AC phase conductor (22A, 22B, 22C) of the AC power line and the secondary winding is connected between a midpoint of the first branch and a midpoint of the second branch of a corresponding power transfer module.
Abstract:
An apparatus (302; 602) for controlling the electric power transmission in a high voltage direct current, power transmission system comprising a plurality of HVDC transmission lines (102, 104, 106, 108, 110, 112, 114) for carrying direct current, wherein the apparatus (302) comprises a first converter (304) and a second converter (306). Each of the first and second converters having an AC side (308, 310) for output and/or input of alternating current and a DC side (312, 314) for output and/or input of direct current. The AC side of the first converter is connected to the AC side of the second converter, the first converter is connectable via its DC side to a first HVDC transmission line (102) and the second converter is connectable via its DC side to a second HVDC transmission line (108). The apparatus is adapted to control the direct current of the first HVDC transmission line (102) by introducing a DC voltage in series with the first HVDC transmission line (102).
Abstract:
An apparatus (302; 602; 802; 902) for controlling the electric power transmission in a high voltage direct current, HVDC, power transmission system comprising at least one HVDC transmission line (102, 104, 106, 108, 110, 112, 114) for carrying direct current. The apparatus comprises a first converter (304; 604) and a second converter (306; 606) each of the first and second converters having an AC side (308, 310) for output and/or input of alternating current and a DC side (312, 314) for output and/or input of direct current. The first converter is connectable via its DC side to the HVDC transmission line (102), the AC side of the second converter is connected to the AC side of the first converter, and the second converter is connectable via its DC side to a DC source (316). The apparatus is adapted to control the direct current of the HVDC transmission line by introducing a DC voltage in series with the HVDC transmission line (102).
Abstract:
It is presented a high voltage DC/DC converter for converting between a first DC connection and a second DC connection. The high voltage DC/DC converter comprises: a first set of DC terminals; a second set of DC terminals); a multiphase transformer device comprising a plurality of primary windings and a corresponding plurality of secondary windings; a first converter arranged to convert DC to AC, comprising a plurality of phase legs serially connected between the first set of DC terminals, wherein each phase leg is connected to an AC connection of a respective primary winding; and a second converter arranged to convert AC from the secondary windings to DC on the second set of DC terminals.
Abstract:
An apparatus (302; 602; 802; 902) for controlling the electric power transmission in a high voltage direct current, HVDC, power transmission system comprising at least one HVDC transmission line (102, 104, 106, 108, 110, 112, 114) for carrying direct current. The apparatus comprises a first converter (304; 604) and a second converter (306; 606) each of the first and second converters having an AC side (308, 310) for output and/or input of alternating current and a DC side (312, 314) for output and/or input of direct current. The first converter is connectable via its DC side to the HVDC transmission line (102), the AC side of the second converter is connected to the AC side of the first converter, and the second converter is connectable via its DC side to a DC source (316). The apparatus is adapted to control the direct current of the HVDC transmission line by introducing a DC voltage in series with the HVDC transmission line (102).
Abstract:
The invention concerns an arrangement (23) for transmitting power between a DC power line (12) and an AC power line (22A, 22B, 22C) carrying a voltage having a number of phases. The arrangement comprises a number of transformers (20A, 20B, 20C), one for each phase and a number of power transfer modules, one for each phase, connected in series between the DC power line and ground, where each module comprises a first branch including series connected converter cells (CA1, CA2, CB1, CB2, CC1, CC2 ) and a second branch comprising series connected switching elements (SW1A, SW2A, SW1B, SW2B, SW3A, SW3B). The primary winding of a transformer (20A, 20B, 20C) is connected to a corresponding AC phase conductor (22A, 22B, 22C) of the AC power line and the secondary winding is connected between a midpoint of the first branch and a midpoint of the second branch of a corresponding power transfer module.