Impact of GPS Spoofing on HVDC Modulation

Abstract

This paper investigates a variety of scenarios in which control signals utilized in high-voltage DC (HVDC) modulation are subjected to oscillatory error due to GPS spoofing of phasor measurement unit (PMU) time synchronization. The result of this spoofing is the presence of forced oscillations in a system through HVDC modulation due to cyclic erroneous measurements. These scenarios are tested in the Kundur two-area system with a supplementary HVDC line which utilizes various supplementary controllers for modulation. The simulation results are examined for system transient behavior as well as for the observable small-signal effects of the GPS spoofed control signals across the system. It is found that the harmonics of the spoofed control signal frequencies can interact with the inter-area modes of the system, resulting in resonant oscillations and the severity of the oscillations is dependent upon the magnitude of the time-error and the damping levels of the system modes.