Evaluation of the Energy System of an IWW vessel with electric propulsion
Dipl.-Ing. Keno Leites, Vasken Ketchedjian, Zeppelin Power Systems GmbH, Hamburg
Motivation
Increasingly strict regulations, such as the extended application of the EU Emissions Trading System (ETS) to all shipping involving EU ports, the FuelEU Maritime Regulation (FEUM) and the Alternative Fuel Infrastructure Regulation (AFIR) require the reduction of greenhouse gas emissions from the maritime industry. Alternative ways for on-board power generation and propulsion are, therefore, gaining increased attention from the maritime industry. This development goes hand in hand with the trend to electrify systems, be it propulsion or hotel load, and thus hybridise on-board energy systems. Hybridised diesel-electric systems enable a stepwise transition from the fossil fuel driven maritime energy system, towards a system fuelled by renewable energy carriers, without harmful emissions. Data analysis and system modelling are two effective tools to evaluate and optimise the performance of current systems. Furthermore, detailed studies of the load profile of a vessel can be used in conjunction with system models to prepare suitable configurations and operational strategies for such hybrid systems.
Methodology
The methodology begins with a system-level analysis of measurement data from the vessel or a comparable one to establish the requirements for an optimized operational strategy. Further a model of the hybrid energy system (HES) is developed and subsequently evolved to a simulation framework. The model is used to determine an appropriate sizing relationship between the energy converters and the ESS. Finally, the control algorithm is refined to reflect the characteristics and operational limitations of the components and perform a goal-driven optimization of the system behaviour.
System Analysis
This paper describes the concept of the Zeppelin system analysis for a diesel-electric energy system, which use a high voltage DC-Link. Existing systems are analysed to evaluate energy flows at both sides of the diesel-electric or the hybrid energy system to identify efficiency improvements. The analysis of the measured data enables the assessment of the system performance within different operating modes of the vessel, such as navigation in hybrid or electrical mode and berthing mode with or without shore connection. This analysis contributes to the simulation of operating strategies and the design of new use‑case‑specific configurations to reduce the energy consumption. The concept is based on employing a goal-based optimization of the energy consumption of the vessel. Using Zeppelin+, relevant data can be captured and monitored from the relevant machinery components of the vessel, which comprise of diesel generator sets, power electronics, motors and other consumers. Existing systems are analysed to evaluate energy flows in a diesel-electric or hybrid energy system and to identify efficiency improvements.
Vessel Analysis
This paper presents a ship system analysis with resulting proposals for the operational strategy and possible refit of an ESS.
During the study, the relevant available data were identified, recorded on typical journeys and analysed for values out of the desired ranges. These phases are filtered with operational necessities (such as safety requirements), so that the unnecessary inefficient phases remain.
Based on the results, recommendations for a more efficient operation of the vessel are derived. Additionally, a modification proposal to the generator setup by introducing an ESS is developed.
Some of the core results will be presented.
