Abstract: 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.

Abstract: An arrangement for controlling the electric power transmission in a high voltage direct current, HVDC, power transmission system includes at least one HVDC transmission or distribution line for carrying direct current, DC, and the arrangement includes an apparatus connectable to the HVDC transmission or distribution line, the apparatus being arranged to control the direct current of the HVDC transmission or distribution line by introducing a DC voltage in series with the HVDC transmission or distribution line. The arrangement includes a protection device for protecting the apparatus against over-current or overvoltage occurrences. The protection device includes a bypass device connectable to the HVDC transmission or distribution line and connected in parallel with the apparatus. The bypass device is arranged to be in a non-conducting mode and arranged to be set to a conducting mode.

Abstract: 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.

Abstract: A modular voltage source converter (100) comprises a plurality of cells conformal to a basic cell design comprising a first and a second terminal, a capacitor and at least two switches arranged in a half-bridge or full-bridge configuration. In the converter, a first group is formed by a number n of cells (101-k, k=1, n) connected serially at their terminals, and a second group is formed by an equal number n of cells (102-k, k=1, n) connected serially at their terminals. The terminals of the cells (101-k) in said first group are connected, via a resistive or inductive connection element (110-k), to the terminals of corresponding cells (102-k) in said second group.

Abstract: A modular voltage source converter (100) comprises a plurality of cells conformal to a basic cell design comprising a first and a second terminal, a capacitor and at least two switches arranged in a half-bridge or full-bridge configuration. In the converter, a first group is formed by a number n of cells (101-k, k=1, . . . , n) connected serially at their terminals, and a second group is formed by an equal number n of cells (102-k, k=1, . . . , n) connected serially at their terminals. The terminals of the cells (101-k) in said first group are connected, via a resistive or inductive connection element (110-k), to the terminals of corresponding cells(102-k) in said second group.

Abstract: An arrangement for controlling the electric power transmission in a high voltage direct current, HVDC, power transmission system includes at least one HVDC transmission or distribution line for carrying direct current, DC, and the arrangement includes an apparatus connectable to the HVDC transmission or distribution line, the apparatus being arranged to control the direct current of the HVDC transmission or distribution line by introducing a DC voltage in series with the HVDC transmission or distribution line. The arrangement includes a protection device for protecting the apparatus against over-current or overvoltage occurrences. The protection device includes a bypass device connectable to the HVDC transmission or distribution line and connected in parallel with the apparatus. The bypass device is arranged to be in a non-conducting mode and arranged to be set to a conducting mode.