Research on the Lightning Intruding Overvoltages at AC 500kV Side of the UHVDC Converter Station with VSC-LCC Hybrid Constructure

The LCC-VSC hybrid cascade multi-terminal DC system combines the advantages of LCC and VSC, and the topology of LCC on the rectifier side with LCC and VSC in series on the inverter side has the advantage of large-capacity power transmission. Chuangshu UHVDC substation is the first substation in the world adopting the LCC-VSC hybrid cascade multi-terminal DC technology scheme. In order to ensure the safe and stable operation of the UHVDC converter station with VSC-LCC Hybrid constructure, it is important to study the lightning intruding overvoltages at AC 500kV side. Firstly, the lightning intruding wave overvoltage level on the equipment of the AC side of UHVDC converter station under typical operation mode with LCC structure and VSC structure were given by simulation. Secondly, based on the simulated overvoltages the arresters installation schemes in AC 500kV side of the convert station with VSC-LCC Hybrid system were confirmed. Thirdly, to prove the arresters installation schemes, the mean time between failures of the 500kV system at the AC side of the convert station with VSC-LCC Hybrid system were also calculated. The results obtained in this paper have been used in the design and construction of the project from Baihetan to Jiangsu.