Sea Technology

JUL 2018

The industry's recognized authority for design, engineering and application of equipment and services in the global ocean community

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Page 41 of 44 July 2018 | ST 41 Patrick Le Fèvre is the chief market- ing and communi- cations officer for Powerbox. He is a degree-qualified engineer with a 25-year track re- cord of success in power electronics. He has pioneered the marketing of new technologies, such as digital power and technical initiatives to reduce energy consumption. Le Fèvre is involved in environmental forums, where he shares his expertise on clean energy. T he public is aware of self-driving cars and other exciting projects in the automotive industry, but far fewer people have heard about un- manned ships and associated proj- ects that will operate large fleets of vessels capable of navigating from port to port without operational crews. Although in its early stages, projects such as the Maritime Un- manned Navigation Through Intelli- gence In Networks (MUNIN) have investigated the feasibility of such technologies. The use of unmanned ships will require extreme reliability from the main generator through to the single point-of-load, and the de- mands placed on power designers will be far beyond anything experi- enced to date. Future generations of power sup- plies for unmanned ships are still under definition. It is important to understand the specificity of the marine segment in terms of environ- mental needs and regulations. Inter- national regulations and standards applying to the marine industry are very complex, requiring an in-depth knowledge of the application and where it will be operated. Power designers must be knowledgeable about marine-specific voltage distri- bution, combining DC and AC net- works, safety regulations and many other aspects, such as operational zones that can vary widely from ship to ship and with the nature of the cargo. Every country with a maritime sector has its own certification au- thority with specific demands for local certification, forcing power designers to keep track of the final application where the power sup- plies will be installed. In general, there is a common group of stan- dards and qualification processes that have similar roots for all coun- tries' certification, though from country to country and maritime subsegments there are also a num- ber of more specific requirements that increase complexity. There is no de facto percentage of common versus specific standards, thus re- quiring power designers to start any new project by reviewing a large number of documents prior to de- signing anything—time consuming but very necessary, hard work. Marine power supply design- ers typically combine the require- ments from all countries active in marine construction and operation to establish a cross-reference table with equivalence and specific ac- tion in the case of major deviations; for example, higher demands on shock and vibration. The toughest requirements per category are then selected and used as reference for designing, verifying and qualifying the final power supply. This is done in close cooperation with the final customer. Combining this design method- ology with an in-depth knowledge of local standards and regulations results in a test protocol that meets international and local require- ments. This test protocol is then applied to all products, simplifying not only the final approval, but also confirming the power supply can be used for replacement or system up- grade purposes in any country. With the increased amount of embedded electronics, the marine industry requires more functionality in a smaller space. Nowadays, ship owners want to equip their vessels with broadband internet connec- tions for both passengers and crew. As a further example, position tracking systems are built-in and require very compact power sup- plies operating in a confined envi- ronment without a fan. Such power supplies have to be designed for optimized conduction cooling. This requires a high degree of integration of the power circuits. The efficiency needs to be as high as possible be- cause a small housing also means that the cooling surface is small- er. The latest resonant circuits and switching control methods achieve efficiency levels up to 95 percent, and power designers are exploring new technologies such as digital control and new-generation galli- um-nitride (GaN) power FET tran- sistors, maintaining high efficiency from very low to high loads. This is an ongoing process that is mandatory for future unmanned ships where maintenance during operation is almost impossible. Re- liability and zero downtime are the rule. Accordingly, power supplies should be able to be connected in parallel for redundancy operation. This requires power designers to in- tegrate more into a smaller package. Existing power solutions for the marine industry have proven their robustness, and power designers are exploring new technologies to improve efficiency and decrease power consumption and dissipa- tion. Unmanned ships will require a level of reliability that will be close to a mythical zero-faults level and the ability for power supplies to be monitored from a central office any- where in the world. For the power designer, it will be an incredible challenge to combine state-of-the- art technologies in switching, ther- mal management, control and intel- ligence. We are close to a new era where power supplies will become self-controlled and able to diagnose early signs of failure to apply cor- rective action. This is no longer a dream; it is soon to be a reality. ST soap box The Challenges of Powering Future-Forward Ships—Patrick Le Fèvre

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