Multistate k-Out-of-n System Reliability for On-Grid PV System Using Universal Generating Function

In recent years, the number of studies for the reliability of intermittent energies have increased. As the applications grow, there is a need to research to maintain the reliability of the power systems. In the field of power systems engineering, reliability refers to the generating capacity to supply continuous service and be able to meet the demands of electrical loads. The traditional reliability assessment is based on two-state system, which is up and down. However, the binary model does not reflect intermittent fluctuations and randomness of renewable energy such as solar photovoltaic (PV) which are not always available and unpredictable. This article aims to present a multistate system reliability of photovoltaic system based on k-out-of-n system. A literature review shows that the multistate system is more represent the variability in the solar photovoltaic system. In addition, there is epistemic uncertainty in practical engineering results from incomplete information, lack of knowledge, subjectivity, and degradation of the system. The multistate system with a combinations of k units available resulting in different levels of performance for the entire system is called a k-out-of-n system. The component limitations of a PV system make it a model of k-out-of-n system. The multistate system reliability can be solved using Universal Generating Function (UGF). This article applies Universal Generating Function to a case study of PV system to find the multistate system reliability and the power is produced. The power generated by a multistate PV system depends on the choice of the number of modules in the PV array, which can affect the effective cost of the system.