Abstract: For great number of wind turbines and large wind power of centralized wind farms, 10 kV or 35 kV meshed grids were proposed to build power collection grids of wind farms, in order to improve the reliability of power collection grids. The topology of meshed power collection grid and its outage rate evaluation model were established, and the outage rate evaluation index of both meshed and radial power collection grids were calculated. The outage simulation models of the two power collection grids were built on MATLAB / Simulink software platform, and the current level and voltage level of collecting bus before and after the fault being cut off in the two grids were analyzed, and the power collection capacity of meshed power collection grid for wind farm was studied, and the cable investment and power income of the two grids were compared. The results show that the equivalent expected energy not supplied（EENS） of radial power collection grid is 4.6 times as much as that of meshed power collection grid, and the total income of meshed power collection grid is 0.612 million RMB more than that of radial power collection grid, and meshed power collection grid is better at collecting wind farm power and smoothly sending out wind farm power than radial power collection grid, and meshed power collection grid has good investment prospects.

Key words: wind farm, meshed grid, power collection grid, power collection capacity