Optimal Scheduling of Mobile Energy Storage Capable of Variable Speed Energy Transmission

As a flexible type of energy transmission carrier, mobile energy storages usually are studied with a fixed driving speed, resulting in unsatisfactory system operation results. To address the problem, an optimal scheduling strategy of mobile energy storage capable of variable-speed energy transmission is proposed. Firstly, by analyzing the hydrogen-carrier vessel (HCV)’s variable speed-spatiotemporal characteristic mapping mechanism and the ability to supply hydrogen and electricity, an interisland energy variable-speed transmission model is developed. On this basis, an island energy microgrid (EMG) operation model compatible with variable-speed transmission energy is established, in order to reconcile HCV with hydrogen balance, power flow and frequency response. Additionally, considering the impact of uncertainties on the energy output, energy demand, frequency stability, and especially energy transmission sequencing, a stochastic dispatching strategy of the island energy microgrid groups (EMGG) is designed. This model is first linearized as a mixed-integer linear program (MILP) problem, and then is solved quickly by a two-layer algorithm, where the upper layer finely manages the possible optimal EMG power reserve that ensures the frequency security, and the lower layer optimally coordinates the inter-island variable-speed energy transmission and island EMG operation. Finally, case studies on Island groups in the South China Sea verify the effectiveness of the proposed strategy.