Analysis of the Influence of UHV AC Access on Power Transmission and Receiving Capability of Provincial Power Grid

With the increasing scale of UHV DC infeed and the large-scale development of renewable energy in the province, the AC-DC hybrid characteristics of the power grid are more complex. After the ultra-high voltage DC bipolar blocking and transferred to the inter-regional connecting line, the power shortage is reduced, and the coupling characteristics between the 500kV regional interconnection line are weakened. The maximum inter-regional power flow and the receiving power of the ultra-high voltage DC are increased after the ultra-high voltage AC network is built. The existing problems of the actual provincial power grid are analyzed. Then, based on the UHV AC drop point, the power flow change of the main 500kV transmission line in the provincial power grid is analyzed under the access system scheme and different operation modes. Finally, from the aspect of improving the overall external power-receiving capability of the power grid, the improvement level of the power-receiving capability of the provincial power grid after UHV AC operation under different schemes is compared and analyzed.