  Due to the growing threat of climate change, the worlds governments have been
encouraging the adoption of Electric Vehicles (EVs). As a result, EV numbers
have been growing exponentially which will introduce a large EV charging load
into the power grid. On this basis, we present a scheme to utilize EVs as a
defense mechanism to mitigate Load-Altering (LA) attacks against the grid. The
developed scheme relies on robust control theory and Linear Matrix Inequalities
(LMIs). Our EV-based defense mechanism is formulated as a feedback controller
synthesized using H-2 and H-infinity control techniques to eliminate the impact
of unknown LA attacks. The controller synthesis considers the grid topology and
the uncertainties of the EV connection to the grid. To demonstrate the
effectiveness of the proposed mitigation scheme, it is tested against three
types of LA attacks on the New England 39-bus grid. We test our mitigation
scheme against 800 MW static, switching, and dynamic attacks in the presence of
multiple sources of uncertainty that can affect the EV load during deployment.
The results demonstrate how the grid remains stable under the LA attacks that
would otherwise lead to serious instabilities.
