Study on the Influence of Receiving-end Power grid Cable Rate on Multi-Infeed Effective Short Circuit Ratio

In recent years, MIDC transmission has been greatly developed. And due to the urbanization progress in China, the cable transformation is gradually approaching to MIDC transmission system. Researches on the impact of the cable rate increase on MIDC should be carried out in advance. Firstly, in this paper, the definition of cable rate is clearly put forward, and the mathematical models of SIESCR and MIESCR, which take into account the influence of cable rate, are established. Secondly,sensitivity model for MIESCR on cable rate is established. Then, taking Linfeng and Fufeng two-infeed MIDC transmission system as an example, the influence of cable rate on MIESCR and sensitivity in three kinds of AC transmission lines is analyzed, which are respectively converter station directly connected; station-to-station connected and other converter station connected. Finally, suggestions on cable transformation are put forward.