A power converter for converting power between a first high voltage direct current, DC, connection, a second high voltage DC connection and a high voltage alternating current, AC, connection, the power converter comprising: a first phase arrangement comprising a first converter arm, a second converter arm, a third converter arm, a fourth converter arm, a fifth converter arm and a sixth converter arm; wherein the first, second third and fourth converter arms are serially connected in the mentioned order between two terminals (11, 12) of the first high voltage DC connection, and each one of the first, second, third, and fourth converter arms comprises a plurality of converter cells (7a-c), where a cell is a combination of semiconductor switches and energy storing elements; the fifth converter arm is arranged between a first terminal of the second high voltage DC connection and a first connection point, being a point between the first converter arm and the second converter arm; the sixth converter arm is arranged between a second terminal of the second high voltage DC connection and a second connection point, being a point between the third converter arm and the fourth converter arm; and the high voltage AC connection is connected between the second converter arm and the third converter arm, wherein each one of the fifth and sixth converter arms (4a-b) are arranged to detect an AC component of the first connection point and second connection point, respectively, and operate according to the detected AC component to remove any AC component at the respective connection points when transferring power to the second high voltage DC connection or to add a suitable AC component when the power transfer occurs from the second high voltage DC connection. a first phase arrangement comprising a first converter arm, a second converter arm, a third converter arm, a fourth converter arm, a fifth converter arm and a sixth converter arm; wherein the first, second third and fourth converter arms are serially connected in the mentioned order between two terminals (11, 12) of the first high voltage DC connection, and each one of the first, second, third, and fourth converter arms comprises a plurality of converter cells (7a-c), where a cell is a combination of semiconductor switches and energy storing elements; the fifth converter arm is arranged between a first terminal of the second high voltage DC connection and a first connection point, being a point between the first converter arm and the second converter arm; the sixth converter arm is arranged between a second terminal of the second high voltage DC connection and a second connection point, being a point between the third converter arm and the fourth converter arm; and the high voltage AC connection is connected between the second converter arm and the third converter arm, wherein each one of the fifth and sixth converter arms (4a-b) are arranged to detect an AC component of the first connection point and second connection point, respectively, and operate according to the detected AC component to remove any AC component at the respective connection points when transferring power to the second high voltage DC connection or to add a suitable AC component when the power transfer occurs from the second high voltage DC connection.