Finding the right Energy Management System for dredging vessels
As on-board vessel electrification keeps increasing, Royal IHC is conducting a thorough exploration of fuel cell and battery concepts for dredgers. Jan Boone, an engineer working at Royal IHC, explains why an energy management system (EMS) designed specifically for dredgers is crucial to the transition to electrical power.
Although the fuel cell/battery concept may be a fairly new application in the maritime sector, it is certainly not the most challenging aspect of the design project. Finding the right Energy Management System (EMS) for dredgers is one of the key challenges. For this reason, Royal IHC has been focusing on further development of this type of system for some time, in a number of projects which are part of the R&D mobility sectors (MENENS and Sh2ipdrive) grant scheme. Jan Boone (Engineering) participates in a R&D project of MENENS based on his expertise in the field of EMS
Drive system of the future
“We aim to deliver a proof of concept of our EMS 1.0 by 2025 Q1. This version, which is not yet worked out in detail, is based on direct current as the main power supply in combination with supercapacitators (a kind of miniature battery providing short duration high power output). The electric power comes from a fuel cell/battery combination, following the H2-Hopper design, which we are developing with the Department of Public Works,” explains Jan Boone.
Second control system
“Full electric results in a completely different situation compared to using power from time-honoured diesel generators. After all, energy must now be transported using electricity instead of the diesel's (mechanical) drive shaft. This places additional demands on the Power Management System (PMS), making PMS reliability more important than ever, continues Jan Boone. “The PMS on board of dredgers manages and regulates the power requested at any given moment. The PMS intervenes whenever the electrical grid is at risk of overloading and, for example, might switch off a jet pump. It operates - and reacts - only at specific moments.
"We aim to deliver a proof of concept of our EMS 1.0 by 2025 Q1."
EMS: a must have
The PMS does not look ahead or back. A diesel generator is always on and provides a steady stream of electricity. To optimise the location, where the power comes from, a second control system is required: the EMS. This optimises power and is a must have in vessels using multiple power sources and storage media. Moreover, with the help of energy buffer systems (batteries and supercapacitors), the EMS ensures fuel cells limits long-term. This applies to, for example, peak loads, strong load changes and ensuring minimum load.
Optimal energy flow
Of course, on a fully electric vessel, the PMS works in a similar way, Jan Boone stresses. “In this case, an EMS is necessary to ensure the vessel continues to operate efficiently. It does so by regulating an optimal energy flow between the battery, fuel cell and supercapacitor, so the PMS doesn’t need to intervene. Think of the EMS as the manager, trying to relieve their boss and organising capacity as efficiently as possible.”
Self-learning ability
Jan Boone: “Optimising the energy flow can, for example, be based on fuel consumption. This also increases its ‘range’ - the autonomy of the vessel. Another aspect that needs to be taken into account is the fact that the EMS works on managing elements such as fuel consumption and maintenance needs en route which reduces the total cost of ownership. In effect, the EMS does all the thinking, based on recent history and, where known, the future, and energy consumption data profiles. Thanks to algorithms, our future EMS 2.0 will become self-learning and therefore capable of anticipating even better. However, this is some way off, although Project 1.0 is already well underway.
Hardware-in-the-loop
“We are currently focusing on normal, fault-free operation - happy flows - and providing specifications for the EMS. We are now testing this with hardware-in-the-loop. We’re running a simulation of the vessel's power grid on a real-time target machine, a fast computer built specifically to compute simulations, with the simulation running real-time. We have already run simulations with fuel cells, converters, batteries, supercapacitors, and a load.
"Think of the EMS as the manager, trying to relieve their boss and organising capacity as efficiently as possible."
Simulation
“In the simulation, everything is running satisfactorily. To test whether the EMS programme will work well in practice later, we obviously need a real dredger, with the right specifications. For now, we are only modelling what we need for the electrical system.”
Communicating vessels
”The main challenge for the EMS, according to Jan, is the fact that different systems need to communicate with each other properly. “For example, if the EMS says, ‘Let's make the fuel cell work harder,’ the PMS might say “You can’t do that, because it will overload,” or “The fuel cell shouldn’t be working harder right now.” That's just the PMS, mind you - there are other control systems, too, such as the dredging automation system and the propulsion of a vessel, for example, which need to be coordinated with the EMS.”
More information
Feel free to reach out to Jan Boone . Interested in more of Royal IHC's R&D activities? Check out our website for an overview of all of our dredging innovations.