Analyzing the Effects of Lightning Strike on Distribution Transformer Failure via Geographically and Temporally Weighted Regression

Due to the aging of the power systems, it is one of the important issues to identify the remaining useful life (RUL) of the power facilities including the environmental effects for the reliable power system operation. However, it is hard to identify the effects of spatially distributed environmental effects on each individual facility and manage the individual history of millions of distribution facilities. As a practical solution, we propose a spatiotemporal analysis to derive the comprehensive effects of the lightning strike that is one of the environmental effects on the RUL of the distribution transformers, and provides the guideline for the lightning protection through the decision of lightning-prone areas. We acquired the data related to the distribution transformer failures and the lightning strikes in South Korea, and a spatiotemporally weighted regression analysis is applied to the data for deriving the spatially cumulative effects of a lightning, which is hard to be identified through each field post-analysis. In addition, we propose a method for validating the regression model through the model evaluation using the categorized transformer failures by field post-analysis. All the proposed processes are performed through the real-world data analysis, and practical results are presented for the reinforcement of lightning protection within the Korean power system.