An optimal control strategy for standalone PV system with Battery-Supercapacitor Hybrid Energy Storage System

• Published in: Journal of power sources Vol. 331; pp. 553 - 565
• Main Authors: Chong, Lee Wai, Wong, Yee Wan, Rajkumar, Rajprasad Kumar, Isa, Dino
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2016
• Subjects: Battery; Control strategy; Fuzzy logic controller; Hybrid Energy Storage System; Particle swarm optimization; Supercapacitor; Supercapacitor; Control strategy; Fuzzy logic controller; Particle swarm optimization; Hybrid Energy Storage System; Battery
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.09.061

This paper proposes an optimal control strategy for a standalone PV system with Battery-Supercapacitor Hybrid Energy Storage System to prolong battery lifespan by reducing the dynamic stress and peak current demand of the battery. Unlike the conventional methods which only use either filtration based controller (FBC) or fuzzy logic controller (FLC), the proposed control strategy comprises of a low-pass filter (LPF) and FLC. Firstly, LPF removes the high dynamic components from the battery demand. FLC minimizes the battery peak current demand while constantly considering the state-of-charge of the supercapacitor. Particle swarm optimization (PSO) algorithm optimizes the membership functions of the FLC to achieve optimal battery peak current reduction. The proposed system is compared to the conventional system with battery-only storage and the systems with conventional control strategies (Rule Based Controller and FBC). The proposed system reduces the battery peak current, battery peak power, maximum absolute value of the rate of change of power and average absolute value of the rate of change of power by 16.05%, 15.19%, 77.01%, and 95.59%, respectively as compared to the conventional system with battery-only storage. Moreover, he proposed system increases the level of supercapacitor utilization up to 687.122% in comparison to the conventional control strategies. •The proposed control strategy comprises low pass filter and fuzzy logic controller.•Membership functions of fuzzy logic controller are optimized by PSO.•The dynamic stress and peak current of the battery are greatly reduced.•The level of utilization of supercapacitor are significantly increased.