Impact of energy storage systems on the stability of low inertia power systems

This paper discusses the effect of energy storage systems (ESS) on power system stability. The paper first demonstrates the improvement in frequency nadir with ESS. Following this, the effect of the energy storage system (ESS) on small signal stability is investigated. The analysis is further extended to explore the contribution of ESS to improve transient stability by using the same ESS controls and parameter setting. The results demonstrate as expected that ESS can provide an enhanced primary frequency response to reduce the drop in frequency nadir. Small signal stability analysis shows that frequency control coupled with active power control does not affect the damping of interarea modes while voltage control can reduce the damping of these modes. The results also indicate that ESS installed to provide primary frequency support can also contribute to the improvement of transient stability of the system. The studies are performed in the modified version of IEEE 16 machine, 68 bus network.