A Method for HVDC Location Evaluation Based on Multi-Objective Fuzzy Decision-Making

In the planning stage of multi-HVDC system, in order to improve the DC transmission capacity, the impact of imperfectness of the grid during transition period needs to be considered. The paper analyzes the mechanism by which the DC transmission capacity is affected by the DC short-circuit ratio, thermal stability, and voltage stability after AC/DC faults. Accordingly, four indicators, namely DC power pooling channel adequacy, evacuation capability of power flow channels under DC fault, DC short-circuit ratio, and voltage security after DC fault, are designed respectively to reflect the security and stability of the system after fault. On this basis, a DC planning location selection method based on fuzzy decision-making is proposed. The correctness and effectiveness of the proposed method are verified by the evaluation of three alternative locations for Jin-Shang HVDC in southwest power grid of China.