Magnetically controlled saturable reactor core vibration under practical working conditions

Magnetically controlled saturable reactors (MCSRs) are widely used in high voltage power system, but they make larger vibration and noise than transformers and other types of reactors due to the gapped iron-core structure and magnetic saturation. The main reasons of MCSR vibration are magnetostrictive effect of silicon steel sheet and electromagnetic force between core discs. This paper studies the influence of these two kinds of forces on MCSR vibration, which will be used to help seek new vibration reduction method. Firstly, because MCSRs work in DC bias conditions, multigroup magnetic and magnetostrictive characteristics of silicon steel sheet considering anisotropy under different DC bias excitation conditions are tested. Secondly, based on energy variation principle and virtual work principle, an electro-magneto-mechanical coupled numerical model for MCSRs is established. In order to compare the influence of magnetostrictive effect with electromagnetic force effect on MCSR vibration, vibration accelerations caused by magnetostrictive effect, electromagnetic force and the combination of them are calculated, respectively. From the computation results, it can be seen that the total acceleration is not simple superposition of electromagnetic acceleration with magnetostrictive acceleration. Finally, vibrations of a MCSR under different practical working conditions are tested to prove the validity of the proposed model.