Preventing Stealthy Attacks on Power Electronics Dominated Grids

Stealthy zero-dynamics attacks are a subset of false data injection attacks (FDIAs) that are especially dangerous, as they are designed to be undetectable by any intrusion detection mechanisms. This paper shows that stealthy attacks can be more destructive on power electronic dominated grids (PEDGs) than traditional power systems, by taking advantage of the low inertia property of PEDGs. The low inertia of these power grids causes the system to be prone to frequency instability when disturbances occur, meaning that an attacker can cause more harm to a system in a shorter amount of time. Another advantage to the attacker is an increased amount of telecommunication devices in PEDGs which provides the attacker with a larger attack surface. It is thus critical that we strive to design PEDGs in such a manner that we minimize their susceptibility to stealthy attacks. We provide a small signal model for a PEDG system, along with the the state space representation of the low-inertia part of the system, and we show that even without the state-space model of the whole system, a stealthy zero-dynamics attack can be constructed and can be successful on a PEDG. Results are also provided to show that strategically choosing model parameters in the design phase of the system can prevent the existence of stealthy zero-dynamics attacks.