Concept for electrically driven work-machine
Fuel cells and hybrid power systems are a hot topic in the car and bus industry. The main motivations are to have zero-emission vehicles and reduce fuel consumption and thus the dependence on oil. Electric drives will also generate other “side benefits” such as less noise, better controllability, a longer lifetime etc.
Wheeled work machines are very comparable to transportation vehicles when it comes to their electrification. The motivation aspects with work machines and transportation vehicles are to some extent the same, as is the main problem – how to carry enough electrical energy on board. However, the variety of work machines of different sizes and for different purposes is huge, and because of this the motivation and requirements for electrification differ greatly from those for road transport.
In the study the task was to find out the motivation, common interests, and solutions for electrification among four work machine manufacturers with very different products. The cooperation and common interest are very welcome because of the small volumes involved. The participating manufacturers may be the biggest ones in their own market but their volumes are tiny when compared to those of transportation vehicles, especially passenger cars. The participating manufacturers were Kalmar Industries (Kone Cargotec), Plustech (Timberjack/John Deere), Patria Vehicles, and Sandvik Tamrock.
In practice the idea was to define a concept for the electrical subsystem of a future work machine based on fuel cell energy. The study concentrates on the electrical subsystems, supposing that enough electric energy is available on board. Thus, in addition to fuel cells, any feasible energy supply, such as a gen-set or a trolley, can also be used.
The study was targeted to the following questions:
- Motivation: Why? Benefits of electrical drives, lifetime, loading, cost of operation, manufacturing costs, environmental aspects, etc.
- Special characteristics of work machines: Typical work cycles (power, torque, speed as function of time) and environmental requirements.
- Benchmarking, commercially-available electrically-powered vehicles and their parameters: work machines, cars, buses, trams (ships, trains)
- Electrical subsystems for electric vehicles: how subsystems can fulfil the special characteristics of work machines
- Evaluations and visions:
- What the bottlenecks in work machine electrification are and how they can be solved
- Possible future standards: energy bus, data connections
- Proposal for concept of electrically-driven work machine
EDrive was carried on years 2002 and 2003