Damping Rotor Angle Oscillations using Battery Energy Storage Systems

Replacement of traditional synchronous generators by renewable energy sources in modern power systems reduces the rotating inertia and causes stability and damping problems. Large scale battery energy storage systems (BESS) are now becoming an integral part of modern power systems to address the intermittency issues of renewables. This paper proposes a method of utilizing the BESS for damping rotor angle oscillations by modulating the machine output power through controlling the BESS current. First, an analytical expression for extra damping provided by the BESS is derived for a simple system. The effectiveness of the proposed method is then tested on a single-machine infinite bus (SMIB) system for both classical and higher order machine models using Matlab Simulink and DIgSILENT PowerFactory software. The control scheme is also tested in a multi-machine system. The additional damping provided by the BESS is compared with that obtained by using a static synchronous compensator (STATCOM). It is demonstrated that BESS is more effective than STATCOM in damping rotor angle oscillations.