Research on black-start technology of HVDC power transmission system

A black-start technology of high voltage direct current (HVDC) power transmission system based on pseudo-deicer startup mode is proposed by analyzing HVDC deicer operation mode, which breaks through the technical bottleneck of HVDC power transmission system could not be firstly involve in the grid black-start due to the half-controlled thyristor device and the weak environment of AC grid. In this paper, the conception of pseudo-deicer startup mode is proposed for the first time, and its black-start implementation process is given. In addition, the startup demand of HVDC system inverter station and the AC grid, and the control and protection requirements of AC and DC systems are researched. Finally, examples for ±500kV Long-Zheng HVDC system engineering of China, the feasibility of the black-start technology of HVDC power transmission system based on pseudo-deicer startup mode is demonstrated by simulation. The proposed technology effectively avoid the impact of HVDC transmission power to the AC grid in the black-start beginning, and the transmission power is continuously adjustable, which could realize the synchronization between the transmission power with the recovery process of AC grid and load. It plays a positive role and has important practical significance to speed up the grid rapid recovery after large-scale blackout accidents.