Patent ID: 8422260

Claim:
An arrangement connected to a direct voltage network for transmitting high voltage direct current, said arrangement being provided for converting direct voltage into alternating voltage and conversely, said arrangement comprising: a multi-cell Voltage Source Converter having: at least one phase leg connected to opposite poles of a direct voltage side of the converter and comprising a series connection of switching cells, each switching cell having at least one energy storing capacitor as well as two terminals respectively connected to two immediately adjacent switching cells in said series connection of switching cells, a mid point of said series connection of switching cells dividing said series connection of switching cells into two halves of said series connection of switching cells and forming a phase output being configured to be connected to an alternating voltage side of the converter, and for each half of said series connection of switching cells, an inductance device in the form of a phase reactor arranged to connect a corresponding one of the two halves of said series connection of switching cells to said mid point, and a transformer, for each of the at least one phase leg, configured to connect said phase output to an alternating voltage phase line associated with said phase leg, the transformer including two primary windings and a secondary winding, wherein said phase reactors of the at least one phase leg are built in in said transformer by using the two primary windings of the transformer, each of the two primary windings connects a corresponding one of the two halves of said series connection of switching cells to the mid point, each of the two primary windings of the transformer is arranged to interact with the secondary winding of the transformer that is connected to said alternating voltage phase line, and said two primary windings are so located with respect to each other such that a dc component of a current flowing from one of said poles to the other of said poles through said mid point flows in substantially opposite directions through the two primary windings.