Patent ID: 8837176

Claim:
A voltage source converter for HVDC power transmission comprising: at least one bridge rectifier having series connected diodes configured to interconnect, in use, a DC network on a DC side of the at least one bridge rectifier and an AC network on a AC side of at least one bridge rectifier; and at least one auxiliary converter comprising a single-phase multilevel converter connected to the DC side of the at least one bridge rectifier, the at least one auxiliary converter configured to modify a DC voltage present on the DC side of the at least one bridge rectifier, wherein the at least one auxiliary converter is controllable to synthesize a predetermined waveform to the DC side of the at least one bridge rectifier resulting in a sine wave, with minimal harmonic distortion, being generated on the AC side of the at least one bridge rectifier, wherein the predetermined waveform is a waveform closely approximating an offset rectified sinusoid waveform on the DC side of the at least one bridge rectifier.