Operation of thyristor converter links
Design and Operation of Thyristor-Based Converter Stations

The study of the operation of a DC link is based on the analysis of the Graëtz bridge, which is its basic building block. Details are available at [D 3 210] . The preferred configuration for thyristor HVDC converters is a dodecaphase converter, i.e. 12 static switches.

A link comprises at least two converters, one of which operates as a rectifier (transferring active power from the AC network to the DC line) and the other as an inverter (transferring active power in the opposite direction). These two converters are identical, and it's the polarity of the voltage across the converter that determines the direction of power transfer. This polarity...