Emergency DC power support can effectively improve the frequency stability of multi-infeed DC power grids after the disturbance of high-power shortage fault. This paper analyzes the principle of emergency DC power support. Considering the DC overload capacity

DC operation conditions and AC transmission capacity

a method is proposed to estimate the real-time boosting power of single DC line. Based on the safety and stability constraints of DC power transmission network

this paper proposes a calculation method of calculation the maximum supportability of the regional power grid and the coordination and optimization algorithm of the actual support amount of DC lines with the same sending-ends and same receiving-ends. On this basis

the frequency coordinated control scheme of multi-DC power emergency support is proposed and simulated in the East China multi-infeed power grid.