PROJECT TITLE :

Optimal DC-Segmentation for Multi-Infeed HVDC Systems Based on Stability Performance

ABSTRACT:

This paper analyzes the optimal issues of dc-segmentation for multi-infeed HVDC systems primarily based on stability performance and studies the selecting methodology for the optimal dc-segmentation scheme. Initial, three major stability issues of multi-infeed HVDC systems are discerned, which implies the necessity of the optimization for dc-segmentation. Second, 3 typical evaluation indices that correspond to the above 3 stability problems are introduced: multi-infeed interaction issue, multi-infeed effective short-circuit ratio, and frequency bias factor. To improve evaluation effects of the standard indices, the subindices are presented. Third, so as to solve this multi-objective call-creating drawback, a linear weighted add model is constructed, and a comprehensive weight technique is adopted to calculate the load coefficients. Based mostly on the stability issues, a selecting method is established to choose the optimal dc-segmentation scheme. Finally, a four-machine multi-infeed HVDC system and a practical multi-infeed HVDC system in China are taken as examples, respectively. Candidate dc-segmentation schemes of every system are evaluated by the proposed methodology, and therefore the optimal one is selected. Detailed stability studies of the candidate schemes are executed. The result indicates that the steadiness of the optimal theme is best than the stabilities of others, that verifies the validity of the proposed methodology.