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. 

Subject headings

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

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

Keyword

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

Publication and Content Type

ref (subject category)

art (subject category)