Analysis of Vibration Characteristics of Dry-Type Transformer Iron Core and Windings Based on Multi Physical Field

Abstract

Vibration and noise are problems that cannot be ignored in the normal operation of transformers, the vibration of transformers is coupled by windings and cores, how to distinguish between vibration caused by cores and vibration caused by windings are more critical in transformer vibration fault diagnosis. The vibration of the transformer caused by magnetostriction of the iron core under no load and the vibration of the transformer caused by a short circuit are two typical working conditions. Therefore, in this paper, based on SB20-400VA three-phase three-pillar dry-type transformer, the electric-magnetic-force multi-physical field model of the dry-type transformer is built by COMSOL software, and the vibration characteristics under different working conditions are extracted by simulation under no-load and short-circuit. By analyzing vibration characteristics of the fundamental frequency and harmonic frequency signals, the identification method to distinguish the transformer short-circuit and no-load vibration is found, which lays the foundation for the fault diagnosis of transformer vibration.