Feasibility Analysis of the VSC-HVDC of Development in the Western Part of China

The western part of China has a large number of available new energy resources and mainly relies on two LLC-HVDC(line commutated converter based high voltage direct current,LCC-HVDC) projects to achieve. The western part of China electricity transmission with using LLC-HVDC. But there are drawbacks such as commutation failure and poor ability to absorb new energy. Compared with traditional DC power transmission., VSC-HVDC(voltage source converter based high voltage DC, VSC-HVDC) has the advantages of four-quadrant operation and easy DC power flow reversal. Firstly, this paper introduces the basic principle of VSC-HVDC., including double closed loop control., circulation suppression., submodule operating condition analysis., carrier phase shift control., NLM(nearest-level modulation,NLM) control., etc. Secondly., the advantages of VSC-HVDC are analyzed, and the problems that new energy cannot be absorbed in The western part of China power grid are discussed. Thirdly., the feasibility of MMC-HVDC operation in The western part of China is verified by simulation.