High speed electrical machines
Thanks to the recent advances in the field of power
electronics, the interest of industry and academia towards high speed
electrical machines has increased in the last years also due to the
their potential advantages in terms of increased power density and
elimination of gear-boxes. Possible applications of such technology can
range from aerospace field to the generation of electrical energy from
renewable sources, and cogeneration. The maximum operating frequency of
the electrical machines is limited by losses in magnetic materials. New
ferromagnetic materials capable of extreme working conditions (high
temperatures, high mechanical stress and vibration) will be considered
for the design of novel electrical machines. High performances and low
power losses have to be guaranteed also at high frequencies and in
presence of harmonics. Such requirements are a major limit for the use
of traditional materials. The above mentioned technologies will be also
applied in the field of wind power generation and cogeneration.
Non-conventional electrical generators, having radial or axial flux and
ring structures with high pole number, will be considered. Direct drive
generation systems will also allow to reduce the overall dimension and
increase efficiency of the devices. Finally, the design stage cannot be
considered separate from the development of the electric machine
control system to ensure optimum utilization of the entire energy
conversion system. In particular, sensorless control strategies
(without position and speed sensors) are very interesting to increase
system reliability and reduce its complexity.