복합 고장 유형을 가지는 변압기에 대한 수명추정

Abstract

Purpose: Because transformers are the primary component for the delivery of electric power, failures but also small irregularities can lead to expensive damage. Wear-out failure, in particular, can be minimized using lifetime analysis. This study focuses on the lifetime estimation of transformers and considers multiple failure-modes. In this way, the reliability of aging equipment can be analyzed individually. Methods: We propose a change-point model for the Weibull distribution for multiple failure-modes. By defining the function for a generalized likelihood ratio, the change-point for wear-out failure as well as the parameters for multiple lifetime-distributions can be estimated. Results: The proposed approach is applied to real-life data of electric transformers. As a result of the lifetime analysis, the lifetime distribution, including multiple failure-modes and their cutoff points (in time) can be determined. Conclusion: Using the investigated change-point analysis, both the lifetime and maintenance schedule of transformers with respect to multiple failure-modes can be estimated, and the chance for expensive equipment failure is reduced significantly.