# Life Cycle Cost Estimation and Analysis of Transformers Based on Failure Rate
## 4 Discussion  
Generally speaking, the initial procurement cost of transformer equipment with high voltage level, large rated capacity, and large size and weight is often relatively high. However, in the evaluation of the life cycle cost, we need to consider multiple factors, including procurement cost, operating cost, maintenance cost, and waste disposal cost. Therefore, we first compared the full life cost of five transformers and observed the trend in changes in full life cost under different voltage levels. Figure 5 more clearly shows the cost differences of transformers with different voltage levels. The following figure reflects the predicted value of the life cycle cost of transformers, which can be used to determine the fluctuation range and average value of the corresponding equipment's life cycle cost. The fluctuation of the life cycle cost of transformers indicates that these costs may vary under different practical applications and operating conditions. This volatility may be caused by factors such as specific requirements of the power grid, changes in power load, and differences in maintenance and repair costs. The average value reflects the comprehensive analysis results of a large number of data points and can be used as a reference indicator for evaluating the cost-effectiveness of transformers. The voltage level is crucial for transformers, as it directly affects the efficiency of energy transmission, the stability of the power grid, and the compatibility of equipment, as well as the safety and maintenance costs of the system. Choosing and configuring the voltage level of transformers appropriately is crucial for achieving efficient, reliable, and safe power systems. In order to compare the impact of voltage level on the life cycle cost of transformers more clearly, we predicted the cost of five typical voltage levels of transformers and drew data distribution and fluctuation diagrams. This comparative analysis is elucidated in Figures 6-10. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Operating Year** & **C1 (USD k)** & **C2 + C3 + C4 (USD k)** & **C5 (USD k)** & **Predicted C2 + C3 + C4 (USD k)** & **LCC (USD k)** \\ \hline
2016 & 34.13 & 1.01 & \(-\)2.45 & & \\
2017 & 34.13 & 1.53 & \(-\)2.45 & & \\
2018 & 34.13 & 2.42 & \(-\)2.45 & & \\
2019 & 34.13 & 3.50 & \(-\)2.45 & & \\
2020 & 34.13 & 0.28 & \(-\)2.45 & & \\
2021 & 34.13 & 0.13 & \(-\)2.45 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The specific cost prediction results. Figure 5: Comparison chart of life cycle cost of transformers with different voltage levels. Figure 8: Schematic diagram of life cycle cost prediction for 220 kV transformers. Figure 6: Schematic diagram of life cycle cost prediction for 35 kV transformers. Figure 7: Schematic diagram of life cycle cost prediction for 110 kV transformers. Figure 9: Schematic diagram of life cycle cost prediction for 330 kV transformers. Analyzing the life cycle cost prediction schematic for transformers across various voltage levels, the average life cycle cost of 330 kV transformers--serving as a benchmark for evaluating cost-effectiveness--is notably lower than that of 220 kV transformers and marginally less than that of 110 kV transformers. These prediction outcomes highlight that the initial cost alone does not exclusively determine the life cycle cost of equipment. A comprehensive evaluation, considering various factors, becomes imperative in the equipment selection process. Shown in Table 3 is the data organization of the predicted full life cycle cost for transformers of different voltage levels. After organizing the equipment data provided by a northern power company from 2016 to 2021, we found that different manufacturers have a significant impact on the cost of transformers. Differences in materials, manufacturing processes, production batches, delivery times, transportation methods, and other factors among different manufacturers can lead to differences in the life cycle cost of transformers.