Abstract: Nowadays bulk power system is consisted of multiple interconnected controllable areas. In Interconnected power system, small disturbance occurs in load at any areas that causes the fluctuation of frequency at each and every area. Also fluctuate the power flow between the different areas. So, the main objectives of LFC are to maintain the frequency to its nominal value and scheduled the power exchange between the areas. LFC scheme contain the appropriate control system for an interconnect power system, which have the capability to bring the frequency of each area and tie line power back to its specified nominal value. For this consider three hydro thermal area.

Keywords: load frequency control (LFC) scheme, Automatic generation control (AGC), battery energy storage (BES), AC/DC link .Generation rate constraint.