Motor winding work.
Winding cooling liquid galvanically separated manifolds.
MUSK2 Commercialization of a megawatt-class universal high-speed machine Project Objectives
Revolutionize the availability and applicability of megawatt-size high-speed electric motors. Create an electrically robust and highly efficient machine with a wide operation range. Opportunity for customers to purchase a high-speed electric machine without a long product development process. To develop a coupling mechanism that allows the machine to be operated with very small changes in different operating environments and with various applications. Even more environmentally friendly use of high-speed applications.
Project Funding
The MUSK 2 project is funded by Business Finland Research.
Contact Details
Motor directly water cooled end winding makes a neat package.
Accelerating the development of high-speed machines High-speed machines are used in a growing range of applications, including in compressors and turbines. We spoke to Professor Lassi Aarniovuori, Professor Juha Pyrhönen and M.Sc. Juuso Narsakka about the work of the MUSK 2 project in developing a megawatt class universal high-speed machine, which they ultimately aim to bring to the commercial market. There is an extensive industrial market for induction motors, which are used in a wide variety of high-speed applications, including compressors, turbines and large heat pumps. Currently a tailor-made machine is required for each application, then different parts are coupled together in a highly iterative approach. “It takes huge amounts of engineering work to design a whole system,” outlines Lassi Aarniovuori, Associate Professor at LUT University in Finland. As the Principal Investigator of the MUSK 2 project, Professor Aarniovuori is now working to develop a megawatt class universal high-speed machine and to bring it to the commercial market. “In the project we’re working to develop essentially standalone machines, that can be used in various different applications,” he says. MUSK2 project This research centres around the development of a high-speed, modular system which promises to bring significant benefits to the industrial sector, where efficiency and cost-effectiveness are prime
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considerations. In this system, three active magnetic bearings (AMBs) are used instead of the traditional set of two bearings, helping to greatly reduce maintenance costs. “The AMB active materials are like in small electric motors. We use magnetic force to levitate the machine and adjust the position of the shaft relative to the bearings, so there is no contact between
overall, for example by mixing with the gas. By contrast, the high-speed machine that is being developed in the project does not have any roller bearings, while Professor Aarniovuori says it also has some other notable attributes. “The machine is a low-voltage one. We are using a lowvoltage converter, which is significantly lower in cost than its medium-voltage
In the project we’re working to develop essentially a stand-alone
megawatt class universal high-speed machine, that can be used in various different applications. the bearing and the shaft,” explains Professor Aarniovuori. The position of this rotor is measured and controlled on a continuous basis, so there is no need for oil, which Professor Aarniovuori says represents a significant benefit. “Typically, in compressor applications, you would like to have an oil-free system,” he says. The presence of lubricating oil is liable to have a negative impact on the system
competitors,” he outlines. It is much easier to create the insulating layer in the electrical machine, which means that other, more effective materials can be used elsewhere, improving efficiency, while there is no risk of partial discharges of electricity, which can have a detrimental impact on the system. “In low-voltage machines we do not have partial discharges,” stresses Professor Aarniovuori.
EU Research
A further novel aspect of the machine is the direct liquid cooling system, which is a unique way of cooling down an electrical machine. Most heat is typically lost in the windings; in particular the end windings are a problem in high-speed machines. “This is because the wire must go from one side of the machine to the other, in which case it is difficult to cool an electric machine effectively,” says Professor Pyrhönen. Locating the cooling system inside the windings is a highly efficient approach, helping to extend the lifetime of the system and boost performance, while the design of the rotor means it can be used even in demanding conditions. “We have developed a solid rotor which is really durable and is suitable for harsh environments,” outlines Professor Pyrhönen. “For example, it could be used for compressing biogas or even hydrogen.” By utilising those technical advantages, the aim is to commercialise high-speed electric machine in the megawatt power range. Researchers have developed a proof-of-concept (PoC) machine in the lab, which is currently being tested, although Professor Aarniovuori says time is short. “At the same time as we were working on the construction of the machine, we have also had to build testing facilities. This has taken longer than expected,” he explains. The first phase of PoC testing is expected to be complete by the summer. The research
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will be continued at the university as its own projects, but the main focus next will be on commercialization actions.
Project Coordinator, Professor Juha J. Pyrhönen LUT University FI-53851 Lappeenranta Finland T: +358 40 5711 645 E: juha.pyrhonen@lut.fi W: www.lut.fi W: https://research.lut.fi/converis/portal/ detail/Person/176833?page=pers_has_ publ:6&auxfun=&lang=en_GB
Commercialisation There is already a lot of interest in this technology. Yet the ultimate commercial question is how customers feel about the introduction of new technology in part of their system? There is always a hesitancy around adopting new technologies, with companies comparing the benefits of the familiar, the tried and trusted, against the promise and potential of the new. “A company may ask ‘is it worth the risk to buy this new system’? Can we risk our name promoting this?” outlines Narsakka. “However, benefits of the high-speed technology are proven and well-known among customers so, with our new way to offer it for them may change the mindset rapidly”, states Narsakka. Customers need to see how technology works in an industrial environment. A real customer and practical application needs to be found in the first place to enable market penetration. One interesting area in terms of the application of this system is in the heat pump business. Over 30,000 fossil fuel power plants need to be replaced across Europe, representing potentially vast a market. “We have a chance to bring significant benefits in this respect,” says Narsakka.
Lassi Aarniovuori
Juha J. Pyrhönen
Lassi Aarniovuori is an Associate Professor at the Lappeenranta University of Technology (LUT) School of Energy Systems. Juha J. Pyrhönen is Professor of Electrical Machines and Drives at Lappeenranta University of Technology (LUT) in Finland, a position he has held since 1997.
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