Page 6 - COMSOL_News_2016
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FIGURE 3. Simulation results showing the       FIGURE 4. Left: COMSOL® software results showing levels of magnetic ux in the steel. Right:
magnetic ux density (left) and Lorentz forces  Results showing the resonance of the core. Deformations are exaggerated for visibility.
(right) in the transformer coil windings.

magnetic ux generated in the

transformer core and windings (see

Figure 3, left), Lorentz forces in

the windings (see Figure 3, right),

mechanical displacements caused by

the magnetostrictive strains, and the

resulting pressure levels of acoustic

waves propagating through the tank.

They work closely with the Business

Unit ABB Transformers, often relying           FIGURE 5. Results of the acoustic analysis showing the sound pressure eld around the core (left)
on the experience and expertise of             and around the transformer (right).

Dr. Christoph Ploetner, a recognized

professional in the eld of power

transformers, to ensure that they satisfy

business needs and requirements.               (see Figure 4). “Resonances are easily    Including parametric studies that

One simulation models the noise                excited by the magnetostrictive strains   illustrated the complex relationships

emanating from the core due to                 and cause high vibration ampli cation     between design parameters (such as

magnetostriction. The team began               at these frequencies.”                    tank thickness and material properties)

with an electromagnetic model to               They were then able to predict the        and the resulting transformer hum

predict the magnetic elds induced by           sound waves moving through the oil        made it possible to adjust the geometry

the alternating current, and then the          and calculate the resulting vibrations of and setup of the core, windings, and

magnetostrictive strains in the steel.         the tank, implying sound radiation into tank to minimize the noise.

   Their geometry setup included the           the surrounding environment               ð SPREADING
steel core, windings, and an outer             (see Figure 5).                           SIMULATION CAPABILITIES
domain representing the tank. “We
                                                  They also simulated the displacements
                                               of the coil windings that cause load noise THROUGHOUT ABB
obtained the displacement from the

magnetostrictive strains, then calculated      and determined the surface pressure       The CRC team continues to use the
the resonance for different frequencies        on the tank walls due to the resulting    COMSOL software to not only improve
using a modal analysis,” said Kavasoglu        sound eld (see Figure 6).                 their understanding and their models,

                                                                                         but to extend their knowledge to the

“We've also been using the COMSOL Server™ license                                        rest of ABB’s designers and to the
                                                                                         business unit. Using the Application
to distribute our app to other o ces for testing, which                                  Builder in COMSOL Multiphysics, they
makes it easy to share it. This worldwide license is                                     have begun creating apps from their
great; with a global organization, we expect users in                                    multiphysics models, which can be
                                                                                         easily customized to suit the needs

our other locations around the world to bene t from                                      of each department.
                                                                                            These simulation applications simplify
”these apps.
                                                                                         testing and veri cation for the designers

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