Probabilistic assessment of enhanced frequency response services using real frequency time series

This paper presents a probabilistic assessment of the novel enhanced frequency response (EFR) service in the Great Britain (GB) transmission system. Real frequency measurements with one-second resolution, released by National Grid (NG) corresponding to the years 2014 and 2015, are used for the performance assessment. Initially, the frequency quality is evaluated against Security and Quality of Supply Standards (SQSS) of NG. Afterwards, battery energy storage systems (BESSs) with different power to energy ratios have been modelled and fed with the GB frequency time-series while providing two variants of EFR service. Then, a state of charge (SOC) management algorithm is implemented for comparison purposes. Finally, cumulative probability distribution functions (CDF) are created to analyse the performance of the BESS. The high utilization rates obtained for one the EFR services suggests that for the provision of EFR to be profitable for the providers, the service should refocus towards the post-fault or frequency containment region.