Patent ID: 8861231
Filing Date: 2014-10-14
Classification: H02J,H02M,Y02E

Abstract:
1. A voltage source converter for use in high voltage direct current power transmission and reactive power compensation, the voltage source converter comprising three phase elements defining a star connection in which a first end of each phase element is connected to a common junction, each phase element being operably associated in use with a respective phase of a three-phase AC network and including at least one impedance element; at least two converter limbs, each converter limb including first and second DC terminals for connection in use to a DC network and an AC terminal connected in series with a second end of a phase element of the star connection, each converter limb defining first and second limb portions, each limb portion including a chain-link converter connected in series between a respective one of the first and second DC terminals and the respective AC terminal, each chain-link converter including a plurality of chain-link modules connected in series; and a third DC terminal connected between the first and second DC terminals, the third DC terminal being connected to the common junction of the star connection to define an auxiliary connection, wherein in use a current is injected into the auxiliary connection to achieve balance between the voltage levels of the individual chain-link modules of each chain-link converter of each limb portion.