Altering Flux Density Harmonics in the Air-gap of Synchronous Machines by Active Control of the Field Current

• Flux density harmonics in the air-gap of electrical machines create distorted voltage waveforms and can induce vibrations. These problems are difficult to mitigate when the machine is already in operation and therefore a lot of effort is made during the design phase to eliminate them. Still, many in-operation machines experience problems related to harmonics and often the solution is to mechanically reinforce and change modal shapes which is expensive and inconvenient. Using a current controlled switched power supply to excite a synchronous machine and adding specific harmonics to the DC-field current it is shown that it is possible to alter the harmonic content of the flux density in the air-gap, and thus affect  voltage harmonics and the exciting magnetic forces. The method is verified and compared with simulations and experiments on an existing electrical machine. 

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Nyckelord

Air-gap flux density

Finite element

Harmonic waves

Noise reduction

Power electronics

Synchronous machines

Teknisk fysik med inriktning mot elektricitetslära

Engineering Science with specialization in Science of Electricity

Publikations- och innehållstyp

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