MPC Framework for the Energy Management of Hybrid Ships with an Energy Storage System

Spyros Antonopoulos,Miltiadis Kalikatzarakis,Klaas Visser,Vasso Reppa

doi:10.3390/jmse9090993

Abstract

This paper proposes an advanced shipboard energy management strategy (EMS) based on model predictive control (MPC). This EMS aims to reduce mission-scale fuel consumption of ship hybrid power plants, taking into account constraints introduced by the shipboard battery system. Such constraints are present due to the boundaries on the battery capacity and state of charge (SoC) values, aiming to ensure safe seagoing operation and long-lasting battery life. The proposed EMS can be used earlier in the propulsion design process and requires no tuning of parameters for a specific operating profile. The novelties of the study reside in (i) studying the impact of mission-scale effects and integral constraints on optimal fuel consumption and controller robustness, (ii) benchmarking the performance of the proposed MPC framework. A case study carried out on a naval vessel demonstrates near-optimal and robust behaviour of the controller for several loading sequences. The application of the proposed MPC framework can lead to up to 3.5% consumption reduction due to utilisation of long term information, considering specific loading sequences and charge depleting (CD) battery operation.

Highlights

Maritime Organisation (IMO) greenhouse gas (GHG) study in 2020 [1], shipping contributes an average of 2% of total anthropogenic CO2 emissions, while with business as usual (BAU)
The model predictive control (MPC) framework was validated by incorporating the controller in a dynamic Simulink® model of a hybrid power plant of a naval vessel provided by Damen Naval BV
The presence of a shipboard battery pack introduces loading sequence-specific, rather than profile-specific, system behavior. This should be addressed by control policies aiming for optimal fuel consumption and s effective enforcement

Summary

Introduction

Reduction of the environmental impact of ships has been a subject of concern and has been addressed by regional and global regulators. Maritime Organisation (IMO) greenhouse gas (GHG) study in 2020 [1], shipping contributes an average of 2% of total anthropogenic CO2 emissions, while with business as usual (BAU). Projections, the CO2 emissions are expected to increase by 0–50% compared to the 2018 figure. IMO has been actively involved in, amongst other activities, enhancing the energy efficiency of ships, within the MARPOL Annex VI regulatory framework. The. IMO’s efforts aim to reduce GHG emissions to 50% of the 2008 baseline value by 2050. According to all future projections in the study, it is difficult to achieve the CO2 reduction goal solely by means of more efficient conventional propulsion and lower sailing speeds

Methods

Results

Conclusion