State-of-Charge Balance Control of Distributed Battery Systems with Distinct State-of-Health in DC Microgrids

This paper presents a three-layer hierarchical control scheme that can balance the state-of-charge (SoC) of distributed battery systems (DBS) with distinct state-of-health (SoH) in DC microgrids under the conditions of load variations and cyber attacks. The tertiary control is a consensus control that provides SoC references for the secondary control. The secondary control is an adaptive droop control that provides output voltage deviation reference for the primary control. The primary control is a local proportional-integral (PI) control that tracks the output voltage reference of DBS via the regulation of the grid-connected converter. The effectiveness of the proposed control scheme is validated via a 100 kW photovoltaic (PV)-battery system comprising one new battery and two aged batteries installed on a 380 V DC bus.