Research on Multi-Energy Integrated Ship Energy Management System Based on Hierarchical Control Collaborative Optimization Strategy

Abstract

The propulsion systems of hybrid electric ship output and load demand have substantial volatility and uncertainty, so a hierarchical collaborative control energy management scheme of the ship propulsion system is proposed in this paper. In a layer of control scheme, the traditional perturbation algorithm is improved. Increasing the oscillation detection mechanism and establishing the dynamic disturbance step length realizes the real-time stability of maximum power point tracking control. In the second-layer control scheme, the power sensitivity factor and voltage and current double closed-loop controller is introduced. By designing a two-layer coordinated control strategy based on the dynamic droop coefficient, the problem of voltage and frequency deviation caused by load switching is solved. In the third-layer control scheme, due to the need of the optimal scheduling function, the multi-objective particle swarm optimization algorithm was improved through three aspects: introducing the mutation factor, improving the speed formula, and re-initializing the strategy. Compared with other algorithms, this algorithm proves its validity in day-ahead optimal scheduling strategy. The superiority of the hierarchical collaborative optimization control schemes proposed was verified, in which power loss was reduced by 39.3%, the overall tracking time was prolonged by 15.4%, and the environmental cost of the diesel generator was reduced by 8.4%. The control strategy solves the problems of the steady-state oscillation stage and deviation from the tracking direction, which can effectively suppress voltage and frequency fluctuations.

Feasibility Assessment of Alternative Clean Power Systems onboard Passenger Short-Distance Ferry

“…In order to reduce vessels' emissions and decarbonize the shipping sector [8,9], different measures could be put in place [10,11], acting at different levels of the vessels. The ship emission reduction measures include optimizing the efficiency of the ship engine by using waste heat recovery [12,13], working on alternative propulsion technologies such as wing sails [14] or electric hybrid propulsion [15], reducing ship resistance via trim optimization [16] or an enhanced vessel design [17], and using voyage optimization measures such as onboard energy management [18] or slow steaming concept [19,20].…”

Special Issue on Smart Control of Ship Propulsion System

“…Ren et al [1] propose a hierarchical collaborative control energy management scheme of the ship propulsion system to cope with the substantial volatility and uncertainty of the output power and load demand of a hybrid electric ship propulsion system. In the first-layer control scheme, tracking control of the maximum power point is realized by adding an oscillation detection mechanism and establishing a dynamic perturbation step.…”