Emergency Control Strategy for Sending-End Power Grid Under UHVDC Blocking Fault

When a blocking fault occurs on a large capacity ultra-high voltage dc (UHVDC), a large amount of power surplus will be generated in the sending-end system. At this time, reasonable control measures need to be taken in the whole sending-end network. Firstly, the electrical dissection theory is introduced and optimized in this paper, in order to make the calculation of electrical dissection faster in large-scale systems. Then, this paper proposes an emergency control strategy based on the optimized electrical dissection algorithm. Finally, the proposed strategy is applied to the Northeast China Power Grid, and its control effect is compared with that of the so-called proximity control strategy. Case study shows the proposed method is effective. It can significantly reduce the impact of the UHVDC blocking fault, and avoid cascading failures due to transmission line overload.