Influence Analysis Of AC System Fault On HVDC System In Shenzhen Power Grid

China South Power Grid has been a high voltage, long distance, large capacity power gridwith AC/DC interconnection. With its eight HVDC transmission lines, the capacity ofHVDC has increaseed to72%, and theAC/DC interaction problem is even more serious.Shenzhen power grid is one of the most important load center of China Southern Power Grid.Fault in AC power grid of Shenzhen may cause the commutation failure of Xingan HVDC,even the system instability, resulting in serious economic losses.In order to trengthen and improve the Shenzhen power grid safety and stability controlmeasures, this paper studies the influence of AC system fault on HVDC an system stability inShenzhen Power Grid.This paper is based on the data of the summer of2014, analyzes the impact of various faultconditions in220kV/500kV lines of Shenzhen power grid, on commutation failure, andanalyzes the influence on the stability of the system. Finally, suggestions and measures are putforward to prevent HVDC commutation failure and to improve the system stability.