Frequency Dynamics-Constrained Renewable Energy Hosting Capacity Evaluation With Synthetic Inertia and Multi-Resource Frequency Support

With the growing adoption of renewable energy, conventional synchronous generators (CSGs) are gradually substituted by the renewable energy generation units, resulting in a significant decline in the inertia level and anti-disturbance capability of power systems. Consequently, the frequency security problem becomes increasingly prominent, which in turn hinders the effective accommodation of renewable energy. Hence, this paper proposes a novel frequency dynamics-constrained evaluation method of renewable energy hosting capacity (REHC) in power systems to provide insightful guidance for the healthy development of renewable energy. Firstly, we analyze the dynamic response mechanism in frequency regulation using various resources including CSG, energy storage and renewable energy. Subsequently, the frequency security algebraic constraints are derived based on the first-order swing equation considering the heterogeneity of multi-resource response characteristics and load-damping effect. Then, we formulate the REHC evaluation model with frequency security constraints considering both economic and technical aspects. To reduce the computation complexity and guarantee high-level accuracy, the piecewise McCormick envelop method is employed to relax frequency security constraints as linear equations, hence converting the original problem into a mixed- integer linear programming (MILP) problem. Eventually, the proposed REHC evaluation method is tested on the modified IEEE 39- bus system, and its effectiveness is verified by the numerical results.