Risk Assessment of Substation Integrated Anti-Misoperation System Considering Human Reliability

Abstract

The integrated substation automation system (ISAS) based on IEC-61850 is the development direction of the intelligent substation. Currently, the reliability research of the ISAS rarely involves the quantitative influence of human factors. Therefore, a risk assessment technique of ISAS considering human reliability is proposed. The technique is based on Human Factors Analysis and Classification System framework, Fuzzy Fault Tree Analysis methodology, and Functional Decomposition method. Then, it's applied to the integrated anti-misoperation system in ISAS. The system's reliability considering human error is quantitatively evaluated through a series of studies. The results show that a quantitative method is valuable in assessing the reliability of ISAS. The main contributions of this paper are: 1) to give explicit formulas for risk assessment of ISAS, which objectively describes the system risk and provides risk prompts for dispatch operators; 2) to intuitively reflect how the reliability attributes of the system's equipment and network interfere with the reliability of the system; 3) to prove that human errors will seriously affect the risk level of the system. As the rate of human error increases, the risk level of the system rises until it collapses.