Control development and performance evaluation for battery/flywheel hybrid energy storage solutions to mitigate load fluctuations in all-electric ship propulsion systems. (15th February 2018)

• Record Type: Journal Article
• Authors: Hou, Jun; Sun, Jing; Hofmann, Heath
• Is Part Of: Applied energy. Volume 212(2018)
• Page Start: 919
• Page End: 930
• Publication Date: 2018-02-15
• Subjects: Electric ship propulsion -- Hybrid energy storage -- Multi-objective optimization -- Model predictive control -- Energy management -- Dynamic programming; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2017.12.098
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: A new B/FW HESS is proposed to isolate load fluctuations from the shipboard network. A periodic DP algorithm is developed to reduce the computational cost. A comparative study illustrates the advantages and limitations of B/UC and B/FW HESS. A novel MPC-based approach is developed to facilitate real-time implementation. The proposed MPC is validated in a laboratory-scaled experiment. Abstract: Current trends in both commercial and military ship development have focused on ship electrification. A challenge for electric-ship propulsion systems, however, is large propulsion-load fluctuations. To address this issue, this paper explores a new solution, namely a combined battery and flywheel (B/FW) hybrid energy storage system (HESS) as a buffer to isolate load fluctuations from the shipboard network. Our two main objectives, power-fluctuation compensation and energy saving under various operating constraints, are formulated as a multi-objective optimization problem. Pareto fronts, which illustrate the trade-offs between the main objectives, are obtained by using dynamic programming with the weighted sum method. To quantitatively analyze the performance of B/FW HESS, a comparative study is performed under different sea conditions, where a battery/ultra-capacitor (B/UC) HESS configuration is used as a reference in performance evaluation. Simulation results show the feasibility and effectiveness of B/FW to mitigate the load fluctuations for all-electric ships, especially at high sea states. Furthermore, a model predictive control (MPC) algorithm is developed to facilitate real-time implementation of the proposed solution. A performance comparison between the proposed MPC energy management strategy and the global dynamic programming is performed, and this comparison demonstrates the effectiveness of the proposed MPC strategy.