变压器绕组多倍频振动机理及特性

The vibration signal of transformer windings is closely related to their mechanical conditions. However, the known mechanism of winding vibration can not be adopted to fully support the development and applications of detection methods of the mechanical condition of windings. To deal with the problem, we established a two-wire model of the winding in which the coupling of winding mechanical vibration and surrounding leakage magnetic field is taken into consideration. The Hamilton's principle is used to derive the mathematical equation of the vibration model. The nonlinear vibration phenomenon of the winding caused by the electromechanical coupling is explained, and the winding vibration mechanism is improved. Through theoretical analysis and experimental verification, the conditions of multi-frequency vibration of the winding are determined. The research shows that the vibration of the winding is mainly concentrated at the fundamental frequency of 100 Hz. However, under the effect of electromechanical coupling, parametric resonance will occur when the natural frequency of the winding meets an integer multiple of the current excitation. The research results is of significance for mechanical faults diagnosis, anti-short circuit capability design, and vibro-acoustic reduction of transformer windings.