Impact of utilising sequential and nonsequential simulation techniques in bulk-electric-system reliability assessment

The paper illustrates the impact of using two fundamentally different Monte Carlo simulation techniques to predict interruption-frequency indexes of bulk electric power systems. The two Monte Carlo simulation techniques designated as the sequential (state-duration sampling) and nonsequential (state sampling) methods are utilised. Two test systems designated as the Roy Billinton test system (RBTS) and the IEEE-reliabifity test system (IEEE-RTS) are used, and the results with respect to annualised and annual reliability indexes obtained using both techniques are demonstrated. The impacts of failure state transitions and chronology on frequency-index calculations are investigated and discussed. The results show that the approximate frequency index obtained using the nonsequential technique could provide either a high estimate or a low estimate of the more accurate frequency indexes obtained using the sequential technique, depending on the factors included in the calculation.