Analysis and Simulation of New DC Power Grids for Large-scale Clean Energy Integration and Transmission

摘要

The impact of new energy fluctuation on the grid can be reduced and the reliability can be improved by the network structure of new DC transmission technology, compared with point-to-point structure of the traditional DC transmission technology. Focusing on this background, the main research efforts are listed as follows. Firstly, the planning schemes of new DC transmission system in industrialized and underdeveloped countries around the world are summarized, it is concluded that the HVDC technology with network structure will be the main choice of the future power grid instead of point-to-point structure. Secondly, the recent typical HVDC projects are illustrated and the manufacturer's improvements of converter technology are summarized, it is concluded that the DC voltage level will be raised and transmission capacity will be enlarged with the development of the technology. Thirdly, the principle, structure, advantages and challenges of VSC-HVDC technology are introduced, it is concluded that the future research will focus on the new modular topology of the converter and the coordination of protection strategy. Finally, the performance of point-to-point and network-to-network transmission structures is compared and simulated from the steady-state characteristics, transient characteristics and economical three aspects, the results show that more clean energy can be integrated and transmitted with network-to-network structure based on VSC-HVDC technology.