Layout optimization of China's power transmission lines for renewable power integration considering flexible resources and grid stability

To eliminate power transmission bottleneck and improve cross-regional consumption of renewable power in China, a multi-objective optimization model for transmission line layout is established by considering grid stability and the flexible resource. The optimal line route, technology selection among eleven types of direct current (DC) and alternating current (AC) transmission technologies, transmission capacity, and completion time of inter-regional transmission lines among the six major regions are determined. The results show that power transmission capacity of Northwest-to-East and North-to-Central will increase by 265% and 160%, respectively, in 2039, compared with that in 2018. DC of 800 kV (10 GW) will become the main transmission technology from 2033. The peak period of the line-construction completion will be 2036-2039. The central and eastern regions have registered the fastest growth in the proportion of wind and solar power-installed capacity in China. The proportion of wind and solar power-installed capacity in these areas in 2039 will be 4-6 times that in 2018. Increasing energy storage and improving demand-side response can increase the on-grid renewable power by 1.7% and 2.6%, respectively; however, it will lead to a reduction of 2-6 and 7-9 newly-built lines, respectively.

Automated summary

The research suggests that power transmission capacity in China will increase significantly, with the focus on the Northwest-to-East and North-to-Central regions. The main transmission technology will be 800 kV DC, and the peak period for line construction completion will be in 2036-2039. Central and eastern regions are experiencing the fastest growth in the proportion of wind and solar power installed capacity.