Precautionary Analysis of the Design Aspects of a Preventive Autotransformer to Eliminate its Potential Impact on the Results of DGA of Transformer Oil

The article addresses the application of simulation and computer modeling using the Finite Element Method (FEM) to eliminate the potential impact of Preventive Autotransformer design on the results of Dissolved Gas Analysis (DGA) of transformer oil. The paper identifies critical design points of the preventive autotransformer that may contribute to gas emission. It details the potential impact of the construction and insulation system of high-current disc windings with multiple parallel groups. The uniformity of current distribution in the winding sections strongly depends on their placement relative to the core air gaps. The study presents the results of analyses on the impact of Preventive Autotransformer's winding and core air gaps design parameters on the current distribution and resulting temperature increases. The conclusions from the analyses indicate that design errors of Preventive Autotransformer windings can potentially affect DGA results, leading to the risk of incorrect assessment of the technical condition of power transformers. Furthermore, it is confirmed that precautionary analysis of the design aspects of the Preventive Autotransformer to exclude failures is justified and crucial for ensuring the accuracy and reliability of DGA measurements.