Evaluation of inertia resource for securing nadir frequency in HVDC interconnected system with high penetration of RES

Abstract

For power systems to manage a variety of renewable energy sources while securing system stability and reliability, more resources are required. However, due to the interaction of the frequency response resources, determining the appropriate resources for frequency stability is challenging. In the Jeju system, where two HVDCs control the frequency primarily, this paper suggests a closed-form frequency response prediction model that represents the response characteristics of a high-voltage direct current link (HVDC). The Jeju system has reached its limit as a result of the increased penetration of renewable energy, which has led to increasingly frequent renewable energy curtailments. To ensure the frequency stability of the Jeju power system, it is thought to be necessary to construct a flywheel-connected synchronous condenser. The impact of the inertia constant and capacity of a flywheel-connected synchronous condenser is examined using the proposed closed-form frequency response prediction model. Case studies are presented to demonstrate the feasibility of the proposed method. PSSE simulations are performed with the HVDC user-defined model which manufactured by General Electric (GE) and the Jeju Island power system in Korea. The suggested approach can be successfully applied to choose appropriate resources and plan resources for frequency stability.