Overview of power system operational reliability

The traditional reliability evaluation assesses the long-term performance of power system but its constant failure rate cannot reflect the time-varying performances in an operational time frame. This paper studies the operational reliability of power system in the real-time operating conditions based on online operation information obtained from the Energy Management System (EMS). A framework of operational reliability evaluation is proposed systematically. The effects of components´ inherence conditions, environment conditions and operating electrical conditions on failure rates are considered in their operational reliability models. To meet the restrictive requirement of real-time evaluation, a special algorithm is presented. The indices for operational reliability are defined as well. The software, Operational Reliability Evaluation Tools (ORET), is developed to implement the above described functions. The work reported in this paper can be used to assess the system risk in an operational timeframe and give warnings when the system reliability is low.