Load frequency control using battery energy storage system in interconnected power system

Abstract

The main objective of Load Frequency Control (LFC) is to regulate the power output of the generator within an area in response to changes in system frequency and tie-line loading. LFC helps in maintaining the scheduled system frequency and tie-line power interchange with the other areas within the prescribed limits. The conventional controllers are slow and do not allow the controller designer to take into account possible changes in operating condition and non-linearities in the generator unit. When there is a variation in the load demand on a generating unit, there is a momenterial occurrence of unbalance between real power input and output. To compensate this power imbalance, an external Battery Energy Storage (BES) system is incorporated. Frequency oscillations due to large load disturbance can be effectively damped by fast acting energy storage devices such as Battery Energy Storage systems. The energy storage devices share the sudden changes in power requirement in the load. This paper presents the qualitative and quantitative comparison of conventional controllers and BES system in Load Frequency Control (LFC) of a typical two area interconnected power system. The superiority of the performance of BES over conventional controllers is highlighted and discussed in this paper.