An adaptive two‐level hierarchical controller for universal power sharing and performance enhancement of hybrid energy storage‐supported AC/DC microgrids

Abstract

SummaryThe uncertainties in generation from renewable energy sources and randomness in electric vehicle charging/discharging make the generation and load in the grid more volatile. The large‐scale integration of renewable energy sources and electric vehicles has necessitated the remodeling of conventional control schemes in the microgrid. This article presents an adaptive two‐level hierarchical controller that enriches hybrid AC/DC microgrid performance. The virtual synchronous machine‐based primary controller determines the operating mode of the interlinking converter. In addition, it maintains the system's stability by providing virtual inertia support. The communication‐based secondary controller adaptively chooses the scaling factors based on hybrid AC/DC microgrid operating conditions. The adaptive secondary control loop implemented with the primary controller and hybrid energy storage system reduces the frequency/voltage deviations under extreme load volatility and enhances the transient and steady‐state performance. The novelty of the proposed two‐level hierarchical controller is that the general purpose adaptive scheme improves the power sharing in the microgrid under normal and volatile source and load conditions. The simulations and experimental results confirm the efficacy of the proposed controller. Furthermore, the hierarchical two‐level controller performance is validated using real‐time experiments on a hardware‐in‐the‐loop simulator, OPAL‐RT, and Raspberry Pi microcontroller. The real‐time analysis ascertains that the proposed two‐level hierarchical controller effectively preserves the frequency and voltage profiles and provides accurate power sharing between the subgrids.