An AC/DC interaction analysis on the North China-Central China-East China UHV interconnected power grid

AC/DC interaction is a major concern in the North China-Central China-East China (simplified as `3C´) UHV interconnected power grid. The blocking of one or several DC lines is considered the most dangerous contingency because it can cause the power flows in AC lines exceed their stability limits. In this paper, a variant of stability constrained optimal power flow algorithm and an approximate calculation method are developed to study this problem, the algorithm/method is more efficient compared with the one reported in our previous work. An analysis on the interactions among AC/DC lines in the 2012 3C UHV interconnected power grid is performed, and the AC/DC interaction characteristics are partly revealed and the algorithms/methods are verified.