A voltage source converter comprising a first converter device comprising: a plurality of director valves (V1, V2, V3, V4, V5, V6), wherein each director valve comprises two anti-parallel thyristors provided in a bridge for switching between two states, the bridge being provided in at least one phase leg (3a-c) connected to a first pair of direct current poles (P1, P2) and comprising a midpoint connected to an alternating current, AC, terminal (TA, TB, TC); and at least one commutation cell (CCA, CCB, CCC) connected to a respective one of the at least one phase leg (3a-c), wherein the commutation cell (CCA, CCB, CCC) is controllable to reverse-bias a thyristor of at least one director valve of a connected phase leg (3a-c) when the thyristor is to stop conducting current; wherein the voltage source converter, further comprises: a three winding transformer; and a second converter device comprising the mentioned features of the first converter device; wherein, for each phase, the AC terminal of the first converter device is connected to a first winding of the three winding transformer, the AC terminal of the second converter device is connected to a second winding of the three winding transformer, and an AC terminal (ACa, ACb, ACc) of the voltage source converter is connected to a third winding of the three winding transformer; each phase leg of the first converter device is connected serially with each phase leg of the second converter device between main direct current poles of the voltage source converter; wherein the third winding comprises, for each phase, a first winding part and a second winding part serially connected between an AC terminal and a counter terminal; and wherein the first winding part is magnetically coupled to the first winding and the second winding part is magnetically coupled to the second winding. a plurality of director valves (V1, V2, V3, V4, V5, V6), wherein each director valve comprises two anti-parallel thyristors provided in a bridge for switching between two states, the bridge being provided in at least one phase leg (3a-c) connected to a first pair of direct current poles (P1, P2) and comprising a midpoint connected to an alternating current, AC, terminal (TA, TB, TC); and at least one commutation cell (CCA, CCB, CCC) connected to a respective one of the at least one phase leg (3a-c), wherein the commutation cell (CCA, CCB, CCC) is controllable to reverse-bias a thyristor of at least one director valve of a connected phase leg (3a-c) when the thyristor is to stop conducting current; wherein the voltage source converter, further comprises: a three winding transformer; and a second converter device comprising the mentioned features of the first converter device; a three winding transformer; and a second converter device comprising the mentioned features of the first converter device; wherein, for each phase, the AC terminal of the first converter device is connected to a first winding of the three winding transformer, the AC terminal of the second converter device is connected to a second winding of the three winding transformer, and an AC terminal (ACa, ACb, ACc) of the voltage source converter is connected to a third winding of the three winding transformer; each phase leg of the first converter device is connected serially with each phase leg of the second converter device between main direct current poles of the voltage source converter; wherein the third winding comprises, for each phase, a first winding part and a second winding part serially connected between an AC terminal and a counter terminal; and wherein the first winding part is magnetically coupled to the first winding and the second winding part is magnetically coupled to the second winding.