RECENT ADVANCES IN HIGH-VOLTAGE DIRECT-CURRENT POWER TRANSMISSION SYSTEM

The ever increasing progress of high-voltage high-power fully-controlled semiconductor technology continue to have a significant impact on the development of advance power electronic apparatus used to support optimized operation and efficient management of electrical grids, which in many cas-es are fully or partially deregulated networks. Developments advance both the high voltage direct-current (HVDC) power transmission and the flexibility alternating current transmis-sion system (FACTS) technologies. In this paper, an over-view of the recent advances in the area of voltage source converter (VSC) HVDC technology is provided. Selected key multilevel converter topologies are presented. Control & modeling method are discussed. It is confirmed that the con-tinuous development of power electronics present cost effec-tive opportunities for the utilities to exploit and HVDC re-mains a key technology. In particular, VSC-HVDC can ad-dress not only conventional network issues such as bulk power transmission, asynchronous network interconnection, back-to-back AC system linking and voltage/stability sup-port to mention a few, but also niche markets such as the integration of large scale renewable energy sources with the grid.