  Power systems are moving towards hybrid AC/DC grids with the integration of
HVDC links, renewable resources and energy storage modules. New models of
frequency control have to consider the complex interactions between these
components. Meanwhile, more attention should be paid to cyber security concerns
as these control strategies highly depend on data communications which may be
exposed to cyber attacks. In this regard, this article aims to analyze the
false data injection (FDI) attacks on the AC/DC interconnected system with
virtual inertia and develop advanced diagnosis tools to reveal their
occurrence. We build an optimization-based framework for the purpose of
vulnerability and attack impact analysis. Considering the attack impact on the
system frequency stability, it is shown that the hybrid grid with parallel
AC/DC links and emulated inertia is more vulnerable to the FDI attacks,
compared with the one without virtual inertia and the normal AC system. We then
propose a detection approach to detect and isolate each FDI intrusion with a
sufficient fast response, and even recover the attack value. In addition to
theoretical results, the effectiveness of the proposed methods is validated
through simulations on the two-area AC/DC interconnected system with virtual
inertia emulation capabilities.
