Efficient availability assessment of reconfigurable multi-state systems with interdependencies

Abstract

Realistic engineering systems often possess attributes that complicate their availability assessment. Notable examples being complex topology, multi-state behaviour, component interdependencies, and interactions with external phenomena. For such systems, analytical techniques have limited applicability, and efficient simulation techniques are therefore required. In this paper, a novel load-flow simulation approach is proposed to simplify the availability assessment of realistic engineering systems. The approach is simple and generally applicable to systems, including those with limited maintenance teams, reconfiguration requirements, and multiple commodity flows. A novel metric for assessing maintenance inadequacy and a real-time component ranking procedure are also introduced. In real-time ranking, failed components are assigned maintenance priorities during simulation in accordance with how much their availability improves system performance and how many idle maintenance teams there are. This eliminates the need for component importance ranking algorithms prior to simulation, which for some systems are unnecessary. The applicability of the approach is demonstrated by analysing an offshore plant producing oil, gas, and water. The solution obtained is compared against another Monte Carlo simulation-based solution that requires the enumeration of the plant's cut-sets. The proposed approach is shown to be more intuitive, robust to human-induced errors, and require less human effort.

Extending the survival signature paradigm to complex systems with non-repairable dependent failures

“…It should be noted that this segregation is only required to enhance the intuitive representation of the inter-component dependencies and ensure a simplified simulation algorithm. The system, otherwise, could still be analysed, only the sampling algorithm and dependency matrix proposed in George-Williams and Patelli, 13,24 respectively, will be required, complicating an otherwise simple solution.…”

“…To validate the approach, we compare the solutions to the existing analytical survival signature-based approach, 16,23 as well as a simulation approach based on a modification of the load-flow approach. 13,24 The modified load-flow simulator is the same as Algorithm 4, save for the replacement of S τ ( x true¯ ′ ) with a structure function that is assigned the value 1 for non-zero flows across the system and 0, otherwise.…”

“…11 Various models have been developed to study the effects of cascading failures on complex systems (see Ouyang 12 for a detailed review). Again, like the existing CCF modelling techniques, these models, including the load-flow simulation proposed by George-Williams and Patelli, 13 consider the probabilistic and topological attributes of the system as a unit. They, therefore, are computationally expensive for certain system reliability problems.…”

Maintenance Strategy Optimization for Complex Power Systems Susceptible to Maintenance Delays and Operational Dynamics

“…Dynamic reliability models, on the other hand, possess sufficient flexibility to model the dynamic considerations and uncertainties that normally characterize the operation of realistic systems. Stochastic Petri Nets [20], Stochastic Hybrid Systems [21], and Monte Carlo Simulation [3], [22]- [24] are the most popular in this category. Stochastic Petri Nets, however, require the enumeration of the entire state space of the system, which makes them infeasible for complex multi-state systems, even of moderate size.…”

A New Identification Approach of Power System Vulnerable Lines Based on Weighed H-Index

“…But in fact, the maximum flow method only considers the structural vulnerability of the system, and the operating state system is not fully taken into account. In addition, a loadflow simulation approach was proposed to rank components in availability assessment of multi-state systems [24], [25], which is worth learning in the vulnerable assessment.…”