Recent Advances in High-Voltage Direct-Current Power Transmission and Its Developing Potential

Abstract

To meet the demands of the construction of high-voltage direct-current(HVDC) power transmission in China and closely follow the most frontier technologies used in the manufacture of HVDC power transmission equipments,the up-to-date achievements in the development of HVDC power transmission technology are summarized.In this paper,the features of operational modes of UHVDC power transmission are presented in suammary;the develoment trend of voltage source converter(VSC) technology is described;and it is pointed out that the multi-terminal HVDC power transmission,which integrates the current natural commutation technology with flexible HVDC power transmission technology,will be the development trend of HVDC power transmission in the future.The HVDC power transmission technology utilizing capacitor commutated converters(CCC) and the common ground electrode technology as well as the technologies of converter transformers and converter valves are presented.Three technical lines for the development of optical-fiber current transformer(CT) are summarized,and the prospect of applying the full optical CT based on the principle of fiber optic interferometric sensor in HVDC power transmission is affirmed.The present situation of control and protective system utilized in HVDC power transmission summed up.Based on the operation experience,the technical and managerial dominant positions of adopting regional centralized monitoring and controlling systems(CMCS) in converter substations are expounded.