Health-Aware Energy Storage System Management Considering State Coupling Characteristics for Navigation in Restricted Waters
Yingbing Luo, Laiqiang Kong, Sidun Fang, Tao Niu, Guanhong Chen, Ailong Fan, Ruijin Liao
Abstract
Uncertain navigation conditions change the propulsion characteristics of all-electric ships, bringing very irregular propulsion power requirements and even causing voltage instability of the system, especially in shallow narrow waters with variable flow fields. Large-scale energy storage systems (ESSs) integration can provide enough operational flexibility, but its real dynamics are difficult to capture in harsh marine applications. To address these issues, a health-aware ESS management considering state coupling characteristics is proposed in this paper. Firstly, a novel electric propulsion power model considering ship dynamics is proposed to quantify irregular power variations for navigation in restricted waters. Then, based on our battery test experiment of six months, considering different swaying and current rate conditions, a state coupling characteristics model of the battery is investigated to quantify its dynamic feasible power range throughout an entire lifecycle. Furthermore, a health-aware ESS power allocation strategy considering battery dynamics is proposed to adaptively regulate power flows. Finally, the proposed method is proven with three case studies, including a lab-scale experimental system. Compared with the conventional methods, the voltage sag and the specific fuel consumption can be reduced by 48.1% and 15.7% at most, respectively, and the battery can always operate within a healthy power range.