Design and control of energy storage system for enhanced frequency response grid service

Nowadays, new regulations are taking place that impose to integrate more renewable energy sources (RES) to the grid. The intermittent characteristics of these uncontrollable sources have a negative impact on the grid quality and stability. On the other hand, the ancillary services (ASs) have potential role in maintaining the grid stability and balancing the frequency and the voltage at the fundamental values. Thus, AS market exhibits a great expansion in the recent years and novel regulation frameworks are also developing. Very recently in UK, the distribution network operator, National Grid (NG) have developed a novel portfolio for providing a primary active power AS known as Enhanced Frequency Response (EFR) service. In this paper, a design guideline of electrical energy storage system (ESS) for this EFR provision is given. In addition, a power management system is described to ensure the control of a hybrid energy battery-supercapacitor storage system (HESS). Simulations are carried out for both battery only energy storage system (BESS) and HESS to analyze the regulation dynamics and to compare the performances for each system.