  We propose a novel hierarchical frequency and voltage control design for
multi-area power system integrated with inverter-based resources (IBRs). The
design is based on the idea of prioritizing the use of IBRs over conventional
generator-based control in compensating for sudden and unpredicted changes in
loads and generations, and thereby mitigate any undesired dynamics in the
frequency or the voltage by exploiting their fast actuation time constants. A
new sequential optimization problem, referred to as Area Prioritized Power Flow
(APPF), is formulated to model this prioritization. It is shown that compared
to conventional power flow APPF not only leads to a fairer balance between the
dispatch of active and reactive power from the IBRs and the synchronous
generators, but also limits the impact of any contingency from spreading out
beyond its respective control area, thereby guaranteeing a better collective
dynamic performance of the grid. This improvement, however, comes at the cost
of adding an extra layer of communication needed for executing APPF in a
hierarchical way. Results are validated using simulations of a 9-machine,
6-IBR, 33-bus, 3-area power system model, illustrating how APPF can mitigate a
disturbance faster and more efficiently by prioritizing the use of local
area-resources.
