Quantifying Cyber Attacks on Industrial MMC-HVDC Control System Using Structured Pseudospectrum

This letter assesses the impact of cyber-attacks on the control system of the modular multilevel converter (MMC)-based high-voltage dc (MMC-HVdc) transmission technology. Specifically, the small-signal model of the MMC-HVdc is characterized by a closed-loop matrix and the distance to the small-signal instability is then quantified by structured pseudospectrum. Furthermore, a vertical search method is proposed to quantify the boundary of the structured pseudospectrum. The proposed quantification model with the vertical search method can be extended to the control of other power electronics-based systems. Case studies on a two-terminal MMC-HVdc system verify the effectiveness of the qualification method.