Reliability assessment of electric transmission lines and effects on employee safety

Due to the development of technology, it has become inevitable that all sectors provide products and services with higher quality and higher reliability. In particular, sectors such as electric power, gas and oil pipelines, transport, telecommunications and water are expected to continue without interruption. Reliability is the ability of a system or system components to function under specified conditions within a specified time. One of the most important criteria of electricity transmission systems is to be able to keep the energy on the system continuously within the limits and to go to the least possible interruption. Reliability offers important advantages such as determining the appropriate operating range of the system and making the necessary intervention. Reliability-centered maintenance has come to the fore in order to increase the continuity, cost and efficiency of maintenance processes in electrical transmission systems. Electrical transmission systems maintenance work often occurs as corrective maintenance and is in the form of intervention when a fault occurs. While this situation damages the system and equipment, it also has many negative effects such as cost planning, increased frequency and duration of power cut, environmental damage, and putting corrective maintenance teams at greater risk. Reliability-centered maintenance ensures high safety and cost-effectiveness by minimizing the failure of electrical transmission systems, has less impact on the environment and reduces employee exposure time, and aims to increase employee safety. In this study, reliability analysis was carried out by using the fault record data of the 380 kV transmission line belonging to the 11th Region of Kayseri, Turkey Electricity Transmission Company(TEIAS), between the years 2014 and 2020 with the aim of showing that the transmission line can be interrupted for the least amount of time within the determined limits when the maintenance and operation activities of the electrical transmission systems are carried out by keeping the reliability-centered maintenance in the foreground, and that the interventions have an effect on the working time under risk. In the study, fault data, load distribution information system and regional directorate data records were used. A goodness of fit test was applied and the similarity of the data to the distributions was determined and reliability evaluation was made in order to determine from which statistical distribution the failure data came. In order to reveal the effect of the reliability of the feeders on the reliability of the whole region, an evaluation was made by fault tree analysis. Maintenance for low-score feeders is higher than expected and negatively affects time, cost, and environment and employee safety. While the study is similar to other studies on reliability-centered maintenance activities, it does not show similarity in terms of its effects on the safety of employees involved in maintenance activities. If the recorded data is recorded considering reliability, high accuracy data will be obtained for future studies and it will be easier to switch to reliability-based maintenance activities due to these data.