When offshore wind farm is connected to a distribution network lack of local generation

the voltage fluctuation caused by the wind power will become prominent. This paper studies the impacts of offshore wind farms on the voltage control of main network. For both constant power factor and constant voltage control modes

the relationships between the wind power capacity and the voltage fluctuation of the main grid are set up. Then the maximum capacity of offshore wind farms constrained by the permitted voltage variation range is calculated. In order to verify the theoretical analysis

a simulation system was built with EMTDC/PSCAD to study the maximum capacity of the wind farm under different short-circuit capacity of point of common coupling (PCC). Tests with a real life project

Guishan offshore wind farm

are presented in the end of the paper. This work is supported by National Basic Research Program of China (973 Program) (No. 2012CB215104).