This article introduces a unified Hamiltonian formulation for controlling grid-connected direct current microgrid via interconnection and damping assignment–passivity-based control. The direct current microgrid includes hydro–solar–wind hybrid renewable energy systems and battery/supercapacitor hybrid energy storage system. Hybrid renewable energy systems are integrated as a disturbed direct current source, while hybrid energy storage system is integrated via semi-active topology, where the battery is connected to the direct current bus through a bidirectional dc-to-dc converter. The proposed Hamiltonian approach allows us to design a control strategy for the bidirectional dc-to-dc converter and the grid-connected three-phase inverter to (1) reject power disturbances in the direct current bus via the supercapacitor and ensure smooth current in the battery as well as in the grid and (2) assign the system to a desired equilibrium after sharp changes. In the studied article, the stability of the system under the interconnection and damping assignment–passivity-based control controller is investigated. The interconnection and damping assignment–passivity-based control controller is compared with two conventional proportional–integral–based controllers through simulations under the MATLAB/Simulink environment. The main contributions in this article are the unified hybrid modelling for dc-to-dc power converter and grid-connected inverter using port-Hamiltonian approach, external disturbance rejection in the multi-source power system using interconnection and damping assignment–passivity-based control, and the assurance of global asymptotic stability of the closed-loop system.
An Active Hybrid Energy Storage System Utilising a Fuzzy Logic Rule-Based Control Strategy
