Reliability Optimization Using Fault Tree Analysis in the Grid Connected Mode of Microgrid

Abstract

In a microgrid, PTC Wind Solutions is used toimplement the optimization of reliability with the help of FaultTree Analysis (FTA). The reliability of each energy source alongwith the non-critical load is calculated. To interpret the faulttree results, the quantitative and qualitative analysis arecalculated. Then the importance measures like RiskAchievement Worth, Risk Reduction Worth, CriticalityImportance and Fussel -- Vesely Importance are used tocalculate the sensitivity and uncertainty of fault tree results. Thecomponents which are sensitive and at high risk are calculatedfrom the results. Using the logic gates in the PTC WindchillSolutions, the entire fault tree for a non-critical load outage isbuilt and studied. From the results, the unreliability andunavailability of the fault tree are used to calculate thereliability and availability of non-critical load outage. From theFault Tree Analysis, the unavailability and unreliability of noncriticalload outage are calculated which illustrates the values ofavailability and reliability. From the fault tree analysis, theunavailability and unreliability of non-critical load outage arecalculated as 0.01228, which illustrates that the availability andreliability as 98.77%. Minimal cut sets of circuit breaker acrossthe non-critical load, Point of Common Coupling at the maingrid, and a transformer are calculated from the QualitativeAnalysis. The top event probability evaluation of a non -- criticalload is performed using the Quantitative analysis whichindicates the system failure probability. The calculation ofImportance measures -- Risk Achievement Worth, RiskReduction Worth, Criticality Importance, Fussel -- VeselyImportance is performed. Thus, the reliability and availabilityof non-critical load is obtained using the PTC WindchillSolutions. The top event occurrence is caused by the basic andintermediate events of a fault trees. The components at high riskare calculated using the importance measures. Therefore, fromthe Qualitative and Quantitative analysis the components whichare at high risk and sensitive are obtained and maintained wellto optimize the reliability.