Abstract:Flexible DC transmission technology is a new type of high-voltage transmission technology developed based on voltage source converter technology, which plays a significant role in improving the interaction between AC and DC and improving the stability of power grid. The technical characteristics of flexible DC transmission are firstly analyzed in response to the uneven distribution of offline loads, the risk of power loss in Jinshan substation, and the small margin of short-circuit current on 220 kV side in Chongqing Jiangbei power grid. Then, a detailed discussion is carried out on flexible DC transmission technology and its engineering application in urban distribution networks. Finally, based on the research on operation problems of Chongqing Jiangbei power grid, two solutions of AC and DC are proposed to solve the overload problem caused by 500 kV power loss in Jinshan substation in 220 kV power grid. The application of flexible DC transmission technology is also-proposed tosolve the problem of unbalanced load in 220 kV substations in 110 kV power grid, which provides a guidance for the engineering application of flexible DC transmission technology.