The technical trends and suggestions on the development of DC power grid

There was a dispute between alternating current transmission (AC transmission) and direct current transmission (DC transmission) at the beginning of electric power industry development. With much superiority, AC transmission is used more widely. With the development of power electronics, material science and other basic technologies, the main technical problems that limit the development of modern DC transmission are gradually solved. From the perspective of world-wide scope, DC power grid has not been developed for engineering practice but the related research and the research for part key equipments are developed gradually. In this thesis, the key technical trend and practice of DC power grid at the aspect of power transmission grid side, power distribution grid side and electricity side are studied; based on the tracking research for DC transmission technologies and the development of equipments and devices, the development trend of DC power grid is analyzed; finally, three suggestions for the development of DC power grid are promoted.