  The decarbonization of many heavy power-consuming industries is dependent on
the integration of renewable energy sources and energy storage systems in
isolated autonomous power systems. The optimal energy management in such
schemes becomes harder due to the increased complexity and stability
requirements, the rapidly varying operating conditions and uncertainty of
renewable sources, the conflicting objectives across different timescales, the
limited amount of reliable power sources and energy storage. The state of
charge management when energy storage is used for multiple services, such as
optimal scheduling and frequency support, is one of the most notorious problems
in this context. To address this issue, an optimal energy management system is
proposed in this paper. It co-optimizes the primary frequency control layer and
the dispatch schedule of conventional generators and energy storage by taking
advantage of an algorithm that provides adaptive active power demand
uncertainty quantification, theoretical guarantees for frequency stability, and
bounds for the reserves for frequency support assigned to the energy storage
system. A convex reformulation is derived enabling the efficient solution of
the involved optimization problem, being a test case of an isolated offshore
oil and gas platform presented for validation.
