Transformer winding modal parameter identification based on poly-reference least-square complex frequency domain method

摘要

The modal parameter of transformer winding, as direct reflections of mechanical performance, is an important theoretical foundation in the field of transformer manufacturing and detection of winding condition based on vibration. To identify the modal parameters accurately, a modal experiment on a 10 kV transformer winding was conducted in this paper. A PolyMAX method to identify winding natural frequency and damping ratio was proposed using the experiment to identify transformer winding modal parameters. And it uses modal confidence criterion to verify. The first four order modal parameters, including natural frequency, damping ratio were extracted from the vibration signal. The results demonstrate that all the natural frequencies are far from two times of exciting frequency, which indicates that the design is appropriate. The parameters verifies by MAC, which verifies the effectiveness of the proposed method in identifying modal parameters of transformer windings.