A Fast Battery Cycle Counting Method for Grid-Tied Battery Energy Storage System Subjected to Microcycles

In this paper, a fast battery cycle counting method for grid-connected Battery Energy Storage System (BESS) operating in frequency regulation is presented. The methodology provides an approximation for the number of battery full charge-discharge cycles based on historical microcycling state-of-charge (SOC) data typical of BESS frequency regulation operation. An enhanced frequency response (EFR) algorithm, a new and fast frequency response service in the UK, that provides a charge/ discharge response with respect to the deviations in the grid frequency, is used for analysis. The obtained historical SOC data from the EFR analysis is then considered as an input for evaluating the proposed battery cycle counting estimation method.