Motor winding work.
Winding cooling liquid galvanically separated manifolds.
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.
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