Kinetic energy and frequency response comparison for renewable generation systems

Power systems are usually operated within strict frequency ranges. When there is a change in the power system load the power system frequency will change at a rate initially determined by the inertia of the power system. Power system inertia is therefore an important component of a power system as it determines the sensitivity of the system frequency to supply demand imbalances. As renewable energy generation systems are added to power systems, it is important to assess their impact on overall system inertia. This is especially important for small island systems with little interconnection. There are two important considerations in this regard namely the stored kinetic energy of the generation system and the ability of the generation system to provide or absorb the energy imbalance that will occur when a change in load occurs. The factors that affect this are both the physical make up of the generation system and the type of electrical generator employed. This paper examines these factors both for wind turbines and tidal energy devices