Evaluation of Renewable Energy Hosting Capacity of Grid with Multi-Infeed HVDC

Abstract

Considering the impact of large-scale renewable energy access to a multi-infeed HVDC receiving-end system on its voltage stability and multi-infeed short circuit ratio, a renewable energy acceptance evaluation method based on an improved holomorphic embedding method is proposed. Firstly, to construct a model containing only an AC system, the DC inverter is simplified into an AC source model; secondly, the sigma index is used to judge the static voltage stability of the system bus and determine the access location of renewable energy, and sensitivity index is used to determine the scheme of replacing conventional units with renewable energy; then, with the voltage crossing the set range as the constraint condition, the analytical expression of each bus voltage obtained by the holomorphic embedding method is used to solve the maximum renewable energy capacity of the system; finally, under the maximum hosting scenario of renewable energy, verify the multi-infeed short circuit ratio at each DC drop point. The effectiveness of the proposed method is verified on an improved IEEE39-bus system.