Power system operational reliability evaluation based on real-time operating state

Traditional reliability evaluation theory, which reflects long-term average reliability level of power systems in the typical operating mode, ignores the impact of real-time operating conditions on system´s reliability, so that the system´s reliability level in fault states or special operating modes can not be expressed. In order to evaluate power system´s reliability in realtime operating states, the concept and algorithm of operational reliability are proposed for the first time. Analyzing the impact of such operating conditions as transfer capacity of lines, bus voltage and system frequency on failure probability of components, component´s reliability models based on real-time operating conditions are established in the algorithm of operational reliability. Fault consequences are analyzed with the influence of operating conditions, such as power generation dispatch, load level and network configuration. The evaluation results of a simple system show that real-time operating conditions have a strong impact on system´s operational reliability which can be reflected by the presented algorithm