LCC-HVDC vs VSC-HVDC Transmission Systems

HVDC power transmission systems can be classified into 2 categories based on converter technologies that are given below:

1.  Line Commutated Converter (LCC) Based HVDC Transmission Systems

The Line commutated converters (LCC)-based HVDC transmission system is developed based on thyristors. A thyristor is a current-controlled device and therefore it is called a current source converter (CSC) based HVDC transmission system. HVDC converters have one or more six-pulse thyristor bridges. Each bridge consists of six thyristor valves which contain hundreds of individual thyristors. For large systems, the bridges are connected in series in 12-pulse or 24-pulse configurations. The 12-pulse monopole LCC-HVDC is shown in Fig. 1.