## 3 Evidential Reasoning Algorithm
### Decomposition Model and Transformer Condition Assessment
#### 3.5.1 Baseline Attributes
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \#1 &
\begin{tabular}{c} **Baseline** \\ **Attribute Type** \\ \end{tabular} & **Description** & **Unit** & **Collection Means** & **Weight** \\ \hline
1. & Load & & Type 2 & \(\omega_{11}=0.33\) \\ \hline
2. & Remaining life span & year & Type 2 & \(\omega_{12}=0.33\) \\ \hline
3. & Aging momentum & & Type 2 & \(\omega_{13}=0.33\) \\ \hline
4. & C1 ((HV+MV)\(\cdot\)STN) &
\begin{tabular}{c} Winding capacity in the measured \\ connection (HV + MV)\(\cdot\)STN \\ \end{tabular} & pF & Type 1 & \(\omega_{211}=0.10\) \\ \hline
7. & I1 (HV Phase U) & Magnetizing current for HV Phase U & mA & Type 1 & \(\omega_{221}=0.166\) \\ \hline
13. & R1 (HV: 1U-N) &
\begin{tabular}{c} Winding active resistance between \\ HV: 1U-N \\ \end{tabular} & R/\(\Omega\) & Type 1 & \(\omega_{231}=0.143\) \\ \hline
20. & Asymmetry Lx1 &
\begin{tabular}{c} Dissipative inductance of winding \\ pairs with tap changer position \\ being 1 \\ \end{tabular} & \% & Type 1 & \(\omega_{241}=0.33\) \\ \hline
23. & Hydrogen &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & \(\mu\)L/L (ppm) & Type 1/2 & \(\omega_{311}=0.40\) \\ \hline
24. & Methane &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & \(\mu\)L/L (ppm) & Type 1/2 & \(\omega_{344}=0.05\) \\ \hline
25. & Acetylene &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & \(\mu\)L/L (ppm) & Type 1/2 & \(\omega_{313}=0.40\) \\ \hline
26. & Ethylene &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & \(\mu\)L/L (ppm) & Type 1/2 & \(\omega_{344}=0.05\) \\ \hline
27. & Ethane &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & \(\mu\)L/L (ppm) & Type 1/2 & \(\omega_{315}=0.05\) \\ \hline
28. & Carbon monoxide &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & \(\mu\)L/L (ppm) & Type 1/2 & \(\omega_{316}=0.05\) \\ \hline
29. & Carbon dioxide &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & \(\mu\)L/L (ppm) & Type 1/2 & \(\omega_{317}=0.05\) \\ \hline
30. & Oil moisture &
\begin{tabular}{c} Gases dissolved in transformer \\ oil concentration \\ \end{tabular} & mg/kg & Type 1/2 & \(\omega_{321}=0.20\) \\ \hline
31. &
\begin{tabular}{c} Borderline \\ surface tension \\ \end{tabular} & Borderline surface tension at 20 \({}^{\circ}\)C & mN/m & Type 1 & \(\omega_{322}=0.20\) \\ \hline
32. & Paper moisture & & \% & Type 2 & \(\omega_{323}=0.20\) \\ \hline
35. &
\begin{tabular}{c} Oil temperature in the \\ boiler cover \\ \end{tabular} & & \({}^{\circ}\)C & Type 2 & \(\omega_{324}=0.20\) \\ \hline
36. & Hot-spot oil temperature & & \({}^{\circ}\)C & Type 2 & \(\omega_{325}=0.20\) \\ \hline
37. & R1 ((HV + MV)\(\cdot\)STN) &
\begin{tabular}{c} Insulation resistance of the winding \\ and the core between (HV + MV)\(\cdot\)STN \\ \end{tabular} & G\(\Omega\) (10 min) & Type 1 & \(\omega_{3311}=0.33\) \\ \hline
40. & \
\begin{tabular}{c} \(\tan\) 81 ((HV + MV)\(\cdot\)STN) \\ \end{tabular} &
\begin{tabular}{c} Winding insulation Dielectric loss \\ factor between (HV + MV)\(\cdot\)STN \\ \end{tabular} & \% & Type 1 & \(\omega_{3321}=0.33\) \\ \hline
43. & Oil dielectric strength &
\begin{tabular}{c} Physicochemical tests of \\ transformer oil \\ \end{tabular} & kV & Type 1 & \(\omega_{333}=0.30\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Proposed baseline attributes of a power transformer decomposition model. Based on the quantitative ratings collected, it is necessary to determine qualitative ratings for the above baseline attributes. The qualitative ratings of baseline attributes, together with the weights of the individual baseline attributes form the input for the aggregation process. Ratings of the baseline attributes present the basis for the ratings of the general attributes. Performing aggregation process ratings of the higher-level attributes are determined.