INVESTIGATING FREQUENCY SERVICES TO STABILISE LOW INERTIA POWER SYSTEMS

Abstract

The frequency stability of the future power system will be increasingly difficult to manage as Renewable Energy Resources (RES) rapidly displace synchronous generators. To overcome this problem in the GB system, National Grid Electricity System Operator (NGESO) has started procuring fast frequency support services, named Dynamic Containment (DC). This paper stud-ies the effectiveness of primary frequency response services and DC services provided by Battery Energy Storage System (BESS) with respect to containing frequency within statutory limits (above 49.5 Hz.). Reduced order power plant and BESS models appropriate for the GB system have been developed to study frequency containment service provision. The simulation results obtained showed that DC significantly improves the frequency nadir of the GB system under low inertia conditions but has a very small effect on the Rate of Change of Frequency (ROCOF). The results obtained support the selection of DC capacity target of approximately 1 GW by the GB electricity system operator NGESO.