HVDC technology overview

The chapter first provides an introduction for the technology of both converter technologies and the system aspects, as well as the transmission line technology. It then focuses on the technology of point-to-point connections. Two types of high-voltage direct current (HVDC) technologies, namely, line commutated converters (LCC) and voltage source converters (VSC-HVDC), are described in the chapter. For both technologies, the relevant components in the system are described: the converter, transformers, filters, overhead lines and cables. The aim of the alternate-arm converter (AAC) is to reduce the number of cells, hence the volume and losses of the converter station. Operation of converters produces harmonic current and DC voltage ripples on one terminal which can propagate further into the DC network to other terminal. It is important to consider the transient voltage variation constraint when the size of the DC capacitors is selected.