摘要:
An arrangement transmits power between a DC power line and an AC power line carrying a voltage having a number of phases. The arrangement includes a number of transformers, 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 includes a first branch including series connected converter cells and a second branch including series connected switching elements. The primary winding of a transformer is connected to a corresponding AC phase conductor 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.
摘要:
An arrangement transmits power between a DC power line and an AC power line carrying a voltage having a number of phases. The arrangement includes a number of transformers, 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 includes a first branch including series connected converter cells and a second branch including series connected switching elements. The primary winding of a transformer is connected to a corresponding AC phase conductor 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.
摘要:
The present invention relates to an AC/DC converter comprising at least two phase legs connected in series between first and second DC connection terminals of the AC/DC converter, wherein each phase leg comprises: an AC connection having first and second terminals arranged to connect the phase leg to a phase of an AC system; a phase branch comprising at least one converter cell and having first and second branch end terminals; and a capacitor. The capacitor is connected the between the first branch end terminal and the first AC connection terminal, so that the capacitor forms a DC blocking capacitor. The second AC terminal is connected to the second branch end terminal. The series connection of the phase legs between first and second DC connection terminal is such that a first series connection point in a phase leg is located between the first branch end terminal and the capacitor, while a second series connection point is located between the second branch end terminal and the second AC connection. The invention further relates to a method of operating such AC/DC converter.
摘要:
An apparatus for controlling the electric power transmission in a high voltage direct current, HVDC, power transmission system includes at least one HVDC transmission line for carrying direct current, DC. The apparatus includes a first converter for converting alternating current, AC, to direct current and/or direct current to alternating current, and a second converter for converting direct current to alternating current and/or alternating current to direct current, each of the first and second converters having an AC side for output and/or input of alternating current and a DC side for output and/or input of direct current. The first converter is connectable via its DC side to the HVDC transmission line, 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. 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 includes the above-mentioned apparatus.
摘要:
It is presented a converter device arranged to convert power between a first high voltage direct current, HVDC, connection, a second HVDC connection and an AC connection. The converter device comprises: a first power converter comprising a phase leg provided between terminals of the first HVDC connection, the phase leg comprising a positive arm, an inductor, an AC connection and a negative arm. Each one of the positive arm and the negative arm comprises converter cells and one of the converter cells is a first host converter cell. Each converter cell comprises two main switching elements and a storage element, the two switching elements being arranged serially in parallel with the energy storage element. The converter device also comprises a power converter section comprising a first converter cell comprising at least two switching elements connected serially in parallel with the energy storage element of the first host converter cell. The converter device is arranged to control the switching elements of the first switching element string in dependence of the state of the main switching elements of the first host converter cell.
摘要:
It is presented a converter device arranged to convert power between a first high voltage direct current, HVDC, connection, a second HVDC connection and an AC connection. The converter device comprises: a first power converter comprising a phase leg provided between terminals of the first HVDC connection, the phase leg comprising a positive arm, an inductor, an AC connection and a negative arm. Each one of the positive arm and the negative arm comprises converter cells and one of the converter cells is a first host converter cell. Each converter cell comprises two main switching elements and a storage element, the two switching elements being arranged serially in parallel with the energy storage element. The converter device also comprises a power converter section comprising a first converter cell comprising at least two switching elements connected serially in parallel with the energy storage element of the first host converter cell. The converter device is arranged to control the switching elements of the first switching element string in dependence of the state of the main switching elements of the first host converter cell.