8Krishnayya P C S, Lambeth P J, Maruvada P S, et al. Technical problems associated with developing HVDC converter stations for voltages above 600 kV[J]. IEEE Transactions on Power De- livery,1987,2(1) :174-181.
9CIGRE WG 14.32. HVDC converter stations for voltages above ±600 kV[R]. Paris,France:CIGRE,2002.
10EPRI. Advanced HVDC systems at ±800 kV and above[R]. Palo Alto, USA : Electric Power Research Institute, 2007.