Demag Cranes Subsidiary, Gottwald Port Technology, Together with a Consortium of Partners, is Researching Alternative Drive Systems for Heavy Loads

Gottwald Port Technology GmbH (Gottwald), a subsidiary of Demag Cranes AG, REFU Elektronik GmbH and the Institute for Vehicle Technology (Institut für Kraftfahrzeuge (ika)) at the RWTH Aachen University have formed a consortium to research alternative drive systems for heavy loads. With effect from 1 July 2010, the consortium has received confirmation of funding from the German Federal Ministry of Education and Research (FMER / BMBF) for the consortium project with a view to improving energy efficiency in heavy-load vehicles. The superordinate objective of the project is to research a system solution resulting in energy-efficient heavy-load vehicles.

Consolidating Germany's Position as Technological Leader
The project is an integral part of the funded "Power electronics for energy efficiency enhancement" programme and is being promoted by the BMBF within the context of the German Federal Government's High-Tech Strategy and the EU programme "Information and communication technologies" (ICT 2020) with funding of around 1.17 m euros. The overall volume of the project, which is spread over two years, is around 2.3 m euros. One of the aims of the ICT 2020 programme is to consolidate and expand Germany's technological leadership in the field of ICT.

Improving Efficiency
Industry is keen to move away from diesel-mechanical and diesel-hydraulic drive systems to the less energy-hungry diesel-electric systems to take advantage of their greater efficiency, in particular in heavy-load vehicles. Today, state-of-the-art transport vehicles moving heavy loads outdoors are already generally powered by diesel-electric drive trains. In the main, this system consists of a diesel engine, generator and electric motors for the travel drives which are provided with electricity by a corresponding power electronics unit. This drive system is, itself, able to be optimised, which is why the project encompasses alternative drive technologies, including hybrid drives. In so doing, the project follows the example set by the automotive industry which has been intensively researching and developing alternative drives for some years. At the time of writing, there are a few cars and buses equipped with hybrid drives, including energy storage technologies, available on the market. In connection with alternative drive technologies, various manufacturers have announced their intention of making more intensive use of hybrid drives in the future and have already begun implementing them.

Needs of Cars and Heavy Goods Vehicles (HGVs) Differ Considerably
Since the demands made on drive systems for HGVs differ so fundamentally from those used in cars as regards the vehicle mass, load, speed and acceleration characteristics, duty cycle, overall service life etc. it is hardly possible to transfer technologies successfully from cars to HGVs. The requirements diverge to such an extent that comprehensive research in the field of alternative drives for use in heavy goods vehicles is required.

For this reason, the consortium, under the leadership of Demag Cranes, plans to develop a system solution for energy-efficient drive trains which will be applicable in the future to both heavy goods vehicles and machines handling heavy cargoes. Transfer of the results of the research to other vehicles and applications is definitely encouraged. The diesel-electric drive trains already in use are not optimised enough in terms of energy efficiency to allow them to be used in vehicles where the output demands vary dramatically. Inefficient use of these drives in the transport of heavy loads results in increased vehicle operation costs.

Aim Is for 25 Per Cent Fuel Savings
The objective of the new project, that has just got under way, is to achieve a significant increase in the energy efficiency of the drive trains involving fuel savings of at least 25 per cent. "By achieving the anticipated savings due to alternative drive trains, we will be sustainably reducing the operating costs of heavy goods vehicles on the one hand and, on the other, making a valuable contribution to making our products more environmentally compatible", emphasised Thomas H. Hagen, Member of the Management Board with responsibility for the Industrial Cranes and Port Technology business segments.

Enhancement up to Hybrid Drive
The foundation for the projected system solution will be an optimised diesel-electric drive train which will be systematically examined and then expanded, with the addition of storage media for electrical energy, to make a hybrid drive train. The focus here will be mainly on researching the power and energy flows of main and ancillary consumers on board the vehicle and optimising them with the aid of power-electronic components.

Distribution of Tasks Within the Consortium
The tasks allocated to Demag Cranes include the integration of new drive train components in a vehicle, including the additional electrical storage media for the hybrid drive. The power-electronic components are to be supplied by REFU Elektronik. To boost the energy efficiency of both the hardware and software, the power electronics will be optimised. The potential improvements arising from optimising the drive concept and the new functionalities are to be quantitatively analysed by project partner ika on the basis of simulated calculations. This will produce an optimum choice of components from a holistic point of view and an operational strategy that is in tune with the operative characteristics of the vehicle. Using these findings, a variable system solution for energy-efficient drive trains for HGVs can be systematically examined and evaluated.

Experts in the Field of Diesel-Electric Drive Systems
Demag Cranes has considerable experience in the development and application of diesel-electric drives. Under the Gottwald brand name, the Group manufactures and sells the only Mobile Harbour Cranes worldwide which use this energy-efficient drive technology. Only recently, Gottwald presented the world's first Mobile Harbour Crane with a hybrid electric drive at the TOC Europe 2010 in Valencia, Spain, the world's leading trade fair for port technology. In this system, specially-constructed short-term electrostatic media (high-performance capacitors or ultracaps) store the energy recovered during lowering and braking actions to achieve fuel savings in the two-digit percentage range. This underlines Demag Cranes' claim to be the innovation and technology leader in port technology, which includes its pioneering position in the development of drive systems for the sustainable operation of handling machines.

About Demag Cranes AG
Demag Cranes AG is one of the world’s leading providers of industrial cranes, crane components, harbour cranes and terminal automation technology. Services, in particular maintenance and refurbishment services, are another key element of the Group’s business activities. The Group is divided into the business segments Industrial Cranes, Port Technology and Services and has strong and well-established Demag and Gottwald brands. Demag Cranes sees its core competence in the development and construction of technically sophisticated cranes and hoists as well as automated transport and logistics systems in ports and terminals, the provision of services for these products and the manufacture of high-quality components.

As a global supplier, Demag Cranes manufactures in 16 countries on five continents and operates a worldwide sales and service network that is present in over 60 countries through its subsidiaries, representative offices and a joint venture. In financial year 2008/2009, the Group, with its 5,934 employees, generated revenue of EUR 1,047.6 million. Since the end of June 2006, the Demag Cranes share (WKN: DCAG01) has been listed in the Prime Standard of the German Stock Exchange and is traded on various indices including the MDAX®.

Demag Cranes. We Can Handle It.

About REFU Elektronik GmbH – project partner:
REFU is contributing over forty years of experience in power electronics. The company's key competency and power of innovation lie in the development of such products as drive technology, travel drives, hoists and the provision of the corresponding switch cabinets. REFU also specialises in the field of power-electronics for special-purpose road and rail-mounted vehicles and mining applications.

About RWTH Aachen University, Institute for Vehicle Technology (Institut für Kraftfahrzeuge Aachen (ika)) – project partner:
The Institute for Vehicle Technology (ika) at RWTH Aachen University, under the Directorship of Prof. Lutz Eckstein, deals with all aspects of vehicle research and development. The development of innovative concepts is based on virtual methods closely backed up by real technologies. Special focus is placed on future-orientated methods for designing and constructing innovative systems and components and incorporating them in the system as a whole.

The activities performed by ika range from the initial idea through to the prototype stage and closely interlink research, development and scientific documentation. To this end, ika employs more than 120 full-timers and 140 scientific assistants.