Follow-Up Model to Evaluate Failure Factors of Single-Phase Distribution Transformers in High Environmental Pollution Zones

Abstract

Single-phase distribution transformers are commonly installed in outdoor distribution networks to supply electricity to final users. Utilities are used to receive abnormal operating reports related to typical failures that negatively affect the reliability and security indicators. Therefore, a follow-up model is proposed in this paper to evaluate the failure factors of distribution transformers installed in high environmental pollution zones. The results show that the main factors that cause failures are overload, overvoltage, overcurrent, moisture, hot spots, manufacturing process, and lack of technical knowledge. Furthermore, all those factors are presented in a typical case using time-lines diagrams to characterize the main failures. Finally, hot spots, overloads, and unauthorized connections are the most critical failure factors identified in the research. According to the statistical analysis, those failures could occur 16 days after installing the transformer. The follow-up model presented in this research can characterize the main failures presented in outdoor distribution transformers.