With the rapid increase of large-scale wind, solar and other new energy sources generation, large power grid with new energy has put forward new requirements towards flexible alternating current transmission technology. Firstly, the background of the new energy power generation and energy storage, MMC, WAMS and other emerging technologies are summarized. Then on the basis of new energy power generation characteristics, the power control technologies about UPFC access to power system are analyzed, and put forward the concept of new energy power grid system. Finally, points out that the UPFC combined with energy storage technology is the important way of future to solve the problem of large power grid with new energy system transporting power, and prospects the research direction of power control about UPFC access to new energy system of large power grid in the future.