Improving Reliability of Electric Power Systems Based on Application of Risk Assessment Model

The paper presents the approach to the process of assessment of risks as a complex reliability indicator during the operation of complicated technical systems, particularly of the electric power systems (EPS). The methodology of risk assessment during the EPS operation on the basis of a hierarchical model, reflecting the interconnection of threats, the causes of their occurrence, protective measures, components of EPS with the supporting organization process is proposed. As a particular case, the “bow tie” model of the dangerous event “failure of the power transformer” is shown in the paper. The calculation example of risks assessment for failure of a power transformer due to various reasons is demonstrated. The methodology for risks assessment during operation of EPS based on the hierarchical model is applicable to any components of the complex, and can also be adapted to technical systems and industrial automated systems of other types. The example of the practical application field of the developed methodology for industrial technical systems is the solution of the problem of transition from repair strategies of the emergency and preventive type to a more flexible and optimal maintenance and repair systems. The quantitative risk assessments for complex technical system, obtained by the methodology, allow one to identify system vulnerabilities, to apply the obtained data about the equipment units condition in automated diagnostic and monitoring subsystems, decision support systems for selecting the repair strategy, to take measures to minimize the probability of dangerous events and thus increase the reliability of the entire system.