A Reliability Calculation Method for a Multistate System With Unidirectional Performance Sharing

In order to enhance reliability of engineering systems, multiple units within an engineering system are often strategically interconnected to achieve performance sharing. This performance sharing complicates the system interaction, making it challenging to calculate the reliability of such systems. This paper proposes a reliability calculation method for a multistate system with unidirectional performance sharing, where the surplus performance can only be transmitted unidirectionally among units, from one unit to its adjacent unit on one side. The reliability model for this type of system is first established. On this basis, a novel reliability calculation method of such systems is proposed to achieve accurate reliability calculation. This method leverages conditional probability theory alongside the universal generating function technique to overcome the challenges posed by the unidirectional correlation of units and the combinatorial explosion of unit states. Finally, the proposed reliability calculation method is validated for accuracy and computational effectiveness using the Monte-Carlo simulation method. Based on this, an interconnected power generation system is taken as an example to perform the reliability analysis. The analysis results can provide theoretical guidance on the reasonable setting of performance sharing and the unit arrangement in a performance sharing system.