The New Developed Health Index for Power Transformer Condition Assessment

The accurate assessment of power transformer is vital for ensuring reliable and stable operation. Health index (HI) is developed to estimate the health condition. According to the characteristics of transformer, core dynamic parameters that can represent the transformer state are selected to calculate the health index: load, oil chromatography, partial discharge, infrared detection, grounding current of core and vibration. The transformer state is comprehensively evaluated from the perspectives of transformer thermal, electrical, mechanical and load. Then the transformer data is divided into different levels and parts, so multi-parameter statistical analysis is carried on. With the tool of statistical product and service solutions (SPSS), the relationship between the parameters is studied and weight is assigned. Based on contribution analysis, a health evaluation model is put forward. Public factor analysis is an approach to determine the relevance of each variable as well as the influence of diagnostic results on HI. Results obtained by multivariate analysis are also provided to demonstrate the validity and feasibility of assessment model.