Abstract: With the increasing scale of wind farms，large scale wind farm is gradually shifting from onshore

wind farm to offshore wind farm，squirrel cage induction generator（SCIG），which is the main type of offshore wind farm，has become the main research object of offshore wind farm dynamic characteristics. In order to study the dynamic characteristics of offshore wind farm，based on the aggregation principle of keeping wind farm external characteristics unchanged，a new aggregation algorithm of offshore SCIG wind farm considering the aggregation of cable capacitance of collection system was proposed，including the aggregation algorithm of wind turbine parameters and the collection system internal parameters. Finally，taking an actual offshore wind farm in Jiangsu province as a case study，a detailed wind farm model with 34 SCIGs and the corresponding aggregation model were established on PSCAD simulation software. The dynamic characteristics of the two models at the PCC points under grid fault conditions were compared. The results show that the proposed dynamic aggregation algorithm can reflect the dynamic characteristics of the wind farm with high accuracy.

     Key words: wind power generation；offshore wind farm；parameter aggregation；dynamic characteristics