A Strengthened SOCP-based Approach for Evaluating the Distributed Generation Hosting Capacity with Soft Open Points

With the increasing penetration of distributed generation (DG), the maximum hosting capacity of active distribution networks (ADNs) has become a major concern for the system operator. Soft open point (SOP), a flexible power electronic device installed to replace normally open point, can realize accurate active and reactive power flow control. This paper proposes an evaluation method to effectively assess the ability of ADNs to accommodate DGs, while considering the optimal operation of SOPs. Then, by applying the convex relaxation, the original nonlinear programming model is converted into a second-order cone programming (SOCP) model. And a strengthened SOCP-based approach is developed to guarantee the relaxation exactness and improve the computational efficiency. Finally, case studies are carried out on the modified IEEE 33-node system to verify the effectiveness of the proposed method.