  Small-Signal Stability (SSS) is crucial for the control of power grids.
However, False Data Injection (FDI) attacks against SSS can impact the grid
stability, hence, the security of SSS needs to be studied. This paper proposes
a formal method of synthesizing FDI attack vectors (i.e., a set of measurements
to be altered) that can destabilize power systems. We formulate an FDI attack
as an optimization problem using AC power flow, SSS model, and stability
constraints. The attacker capability is modeled as the accessibility to a
limited set of measurements. The solution of the proposed FDI attack model
provides a destabilizing attack vector if exists. We implement the proposed
mechanism and evaluate its performance by conducting several case studies using
the WSCC 3-machine 9-bus system. The case study results showed that the
possibility of random FDIs (i.e., with no knowledge of the power system) in
launching a destabilizing attack is too low to be successful. However, an
intelligent attacker can leverage the grid knowledge to make the system
unstable, even with limited access to the measurements.
