Effect of Pre-Determined Maintenance Repair Rates on the Health Index State Distribution and Performance Condition Curve Based on the Markov Prediction Model for Sustainable Transformers Asset Management Strategies

Muhammad Yahaya,Norhafiz Azis,Young Yang Ghazali,Mohd Ab Kadir,Mohd Talib,Jasronita Jasni,Amran Mohd Selva,Mohd Hairi

doi:10.3390/su10103399

Abstract

This paper presents an investigation of the condition state distribution and performance condition curve of the transformer population under different pre-determined maintenance repair rates based on the Markov Prediction Model (MPM). In total, 3195 oil samples from 373 transformers with an age between one and 25 years were tested. The previously computed Health Index (HI) prediction model of the transformer population based on MPM utilizing the nonlinear minimization technique was employed in this study. The transition probabilities for each of the states were updated based on 10%, 20% and 30% pre-determined maintenance repair rates for the sensitivity study. Next, the HI state distribution and performance condition curve were analyzed based on the Markov chain algorithm. Based on the case study, it is found that the pre-determined maintenance repair rates can affect the HI state distribution and improve the performance condition curve. The 30% pre-determined maintenance repair rate gives the highest impact, especially for the transformer population at state 4 (poor). Overall, the average percentage of change for all HI state distributions is 16.48%. A clear improvement of HI state distribution is found at state 4 (poor) where the highest percentage can be up to 63.25%.

Highlights

Asset management and maintenance strategies have become important aspects of the electrical utility for a sustainable operation
The effects of maintenance, repair, and replacement on the Health Index (HI) states based on Markov Prediction Model (MPM) have been investigated in this study
A study between updated and non-updated transition matrices reveals distribution depend on the percentage of the pre-determined maintenance repair rate, and depend on the transition of HI state improvement in the MPM

Summary

Introduction

Asset management and maintenance strategies have become important aspects of the electrical utility for a sustainable operation. One of the key components in CBM is the future assessment of transformers which could assist utilities for asset management activities such as maintenance, repair, and replacement [1,2]. Updated MPM with dedicated management strategies that can be represented by the intentional pre-determined maintenance repair rate could assist utilities to plan and forecast the effectiveness of the intervention actions [31]. The aim of this paper is to investigate the effect of pre-determined maintenance repair rates by MPM on the HI state distribution and performance condition curve of the transformer population. The current study is a continuation of a previous study in [20], whereby the state distribution and performance condition curve of the transformer population with and without pre-determined maintenance repair rates are compared and analyzed

Objectives

Findings

Conclusion