Magnetostriction in transformer

When the magnetization is taken away, it goes back to its original condition. A transformer is magnetically excited by an . The variation of materials' magnetization due to the applied magnetic field changes the magnetostrictive strain until reaching its saturation value, λ. This paper also discusses the winding . The basic cause of transformer noise is magnetostriction : the expansion and contraction of the iron core (laminations) due to the magnetic effect of alternation current flowing through the transformer coils.

Magnetostriction may be partially controlled by the transformer design, .

Abstract: An important source of transformer noise is magnetostrictive vibration of the magnetic core.

Harmonic analysis of magnetostriction is necessary to quantify its influence on acoustic noise but it implied here that the most . Abstract- An important source of transformer noise is magnetostrictive vibration of the magnetic core. As AC current flows through the core of the transformer , Hysterisis effect takes place and hence there is continues magnetisation and demagnetisation of the core which leads to continuos alteration in the physical dimensions of the core. The dominant source of vibration is magnetostriction of the transformer steel. See for instance C-Core Noise: Causes and Cures from core manufacturer Arnold Magnetics. The indicate very high variations of ε. The aim of the present study was to investigate the corresponding dependencies for the second key characteristic, i. MS), as the most significant source of no-load . This effect is the reason of humming sound that we hear in transformer.

Next, we can go through some of the effects used in magnetostriction. The magnetic magnetostriction forces in the lap-joint regions, constituting another significant source of permeability, can be controlled by rearranging the step- lapped joint structure. Then, the computed local flux distributions were compared with experimental data. Single-phase pad-mounted distribution transformers with a . Hz since the iron material associated with the transformer core responds mechanically to the magnetic field which is impressed upon it.

The effect is called magnetostriction , and it is . Abstract: This study investigates extremely low noise level for three-phase three- limb transformer core, which the magnetostriction variation effect of external stress on three-phase power transformer core, with capacity of 450kVA, which induced different noise and vibration variation, is performed. Magnetic Forces on Transformer Core Noise and Vibration. Cardiff School of Engineering, Cardiff University.