To address the lack of basis for sensor configuration and the incomplete multidimensional feature system in existing acoustic-vibration monitoring

this paper derives parameterized adaptive arrangement criteria for sensor arrays based on vibration propagation wavelength constraints and the three-phase spatial distribution of windings. It establishes a five-dimensional feature diagnosis model with frequency complexity

vibration stationarity

multi-point correlation

energy similarity

and harmonic ratio as dimensions. Alarm thresholds for each dimension are determined with reference to industry standards such as GB/T 6451—2015

DL/T 1540—2016

DL/T 393—2010

statistical results from published literature

and engineering field measurement data

and the differentiated response patterns of each feature under typical fault modes are summarized. Three months of monitoring results for Donghua No. 2 main transformer show that the feature combination at edge measurement points is consistent with a slight loosening pattern of clamping force at the winding end. This judgment is listed as an item pending inspection

and outage verification is planned

providing technical support for condition-based maintenance.