Study of Cyber Attack's Impact on LCC-HVDC System With False Data Injection

Against the crippling assault of power grid, the impact of cyber attack on line-commutated converters based high voltage direct current (LCC-HVDC) system is investigated in this paper when the false data injection (FDI) attacks its control loops. Based on the basic control strategy of LCC-HVDC, the impact on each HVDC control mode is investigated when FDI occurs, including the rectifier side constant DC current control and supplementary damping control, the inverter side constant DC voltage control and constant extinction control. Through the theoretical analysis, it is found that the rectifier side FDI attack would limit the power transmission and increase HVDC's reactive power demand, which will finally lead to instabilities, where the damping ratio could also be decreased if the rectifier supplementary damping control is attacked. Another important fact is that the inverter side attack could have much more severe impact when the false data is injected because the inverter extinction angle may be decreased and causes commutation failures. The above analysis and conclusions are validated by the simulations finally.