Frequency aspects of power system operational reliability

In an autonomous micro grid or a power system with high renewable power penetration, the intermittency of renewable energy resources becomes major concern of system operation. Dynamic process of frequency response and control due to unit failures and resource variation may have significant impacts on system operational reliability because the outputs of committed conventional generators have to be frequently adjusted for frequency recovery. This paper proposes a technique to investigate system operational reliability from the aspect of frequency variation and control. The time durations of primary and secondary frequency controls are considered in the proposed technique. Frequency related reliability indices are defined. The IEEE-RTS is used to illustrate the applications of the proposed method.