Minimizing energy storage utilization in a stand-alone dc microgrid using photovoltaic flexible power control

• Main Authors: Yan, Hein Wai, Narang, Aditi, Tafti, Hossein Dehghani, Farivar, Glen G., Ceballos, Salvador, Pou, Josep
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Electrical and electronic engineering; Engineering::Electrical and electronic engineering::Power electronics; DC Microgrid; Photovoltaic Power System; Energy Storage System
• Online Access: https://hdl.handle.net/10356/150189
• Institution: Nanyang Technological University

DC microgrids (dcMGs) are gaining popularity for photovoltaic (PV) applications as the demand for PV generation continues to grow exponentially. A hybrid control strategy for a PV and battery energy storage system (BESS) in a stand-alone dcMG is proposed in this paper. In contrast to the conventional control strategies that regulate the dc-link voltage only with the BESS, the proposed control strategy exploits both the PV system and the BESS to regulate the dc-link voltage. The PV acts as the primary dc voltage regulator allowing for the battery to remain standby as a secondary dc voltage regulating resource. As a result, the proposed control strategy minimizes the utilization of the BESS in order to prolong its lifetime while maintaining the state-of-charge (SoC) of the battery within a desired range. To achieve that, the flexible power point tracking (FPPT) concept is applied to the PV system to enhance the dynamic performance of the dcMG by adaptively adjusting the PV output power according to the load profile. The performance of the proposed control strategy is verified with experimental results. Furthermore, the effectiveness of the proposed control strategy on prolonging the lifetime of a lithium-ion battery and a lead-acid battery is investigated via a simulation case study with one-day load and irradiance curve profiles.