Analysis of maintenance scheduling transformer oil using Markov method

This paper presents the maintenance scheduling of transformer oil in Banaran Substation, Indonesia. Based on the function of the transformer is important to distribute electricity. If there was a fault, it can decrease the reliability of the transformer. Therefore, it is necessary to schedule the periodic maintenance of transformer oil to improve the power transformer reliability. So in this research using Markov method to analyze the reliability and availability of transformer oil. It happened because of Markov method can increase estimates effectively. This research adds the used parameters, namely the results of the DGA test with TDCG and the results breakdown voltage test. These parameters will be processed by using Markov method to find the value of reliability and availability with calculated using the deterioration rate (λ) and the repair rate (μ). The calculation results are simulated using Matlab R2014a, and the results show us that the reliability and availability of transformer oil decrease every month. The biggest decrease occurred on day 180 in a period of 365 days, with the value of TDCG is 9.844% and 3.395% while the value of breakdown voltage is 32.19% and 24.83%. Therefore, maintenance is carried out at least twice a year to improve the quality of transformer oil which functions as an isolation transformer and prevents transformer failure.