Reliability centered asset management tool : The development of RACalc

Abstract: Electrical distribution with high delivery quality is crucial for the society. The need for high quality power supply grows as people put more trust in electrical devices. However there are no perfect electrical distribution systems and interruptions occur randomly. To reduce the risk of outage, actions can be taken by the distribution system operator in the form of preventive maintenance. This report presents some of the methods for analysis that are available for the asset manager. The methods are all connected to the area of reliability centered asset management and have been implemented in RACalc, a software tool. RACalc is able to analyze the provided electrical distribution system and point out on which components maintenance should be placed to enhance the total system performance. Depending on what properties the distribution system operator wants to enhance, different components need to be maintained. RACalc provides the answer in relation to the system performance indices SAIFI, SAIDI, CAIDI, ASAI and AENS. The calculations have been validated by building small scale systems in RACalc and comparing results with hand made calculations.   As illustrated in this report a significant theoretical improvement of the overall reliability can be achieved. By using RACalc to categorize the importance of the components in the electrical distribution system a better placement of the assets can be achieved. In the report, the results of the component importance calculation have been restricted to the twenty most significant components of the analyzed distribution systems. Furthermore, an investigation of the theoretical improvement of the overall system availability is conducted. It is shown that by reducing the failure rate on the twenty most important components found by RACalc with ten percent, the total system performance is improved by almost eight percent in average.