3.3.2. Capacity Allocation of Tie Lines

There is a contact exchange between this coastal area and other areas A and B in the province. The maximum exchange capacity of the contact line between this coastal area and area A or area B is 3000 MW. This means that the total capacity of the external contact line in this coastal area is 6000 MW. This is because the total annual load demand power ratio of region A and region B is 1:1.2. Without changing the coastal area foreign link under the premise of a total exchange capacity of 6000 MW, the capacity ratio of the two contact lines is adjusted, and the changes in the abandoned wind rate of the offshore wind power under different capacity ratios of the contact line are compared and analyzed after the operation simulation. The results are shown in Table 9.

**Table 9.** Utilization of offshore wind power under different capacity ratios of tie lines.


Therefore, the capacity ratio of the contact line can be optimized according to the load demand of the contact area. This is to reduce the maximum exchange capacity of the contact line between the coastal area and area A with low electrical demand, to limit and reduce the amount of electricity fed back to the coastal area, and promote the absorption and utilization of internal offshore wind power. Increasing the maximum exchange capacity of the link line between the coastal area and region B with a high electricity demand can effectively export the electrical power of the coastal area, and further export and utilize the offshore wind power that is difficult to be absorbed internally when needed.

On one hand, the abandonment of offshore wind power comes from transmission congestion in the transmission channel, and on the other hand, it comes from the lack of peak regulation capacity of the system. When the transmission protocol or tie line capacity ratio is optimized, the source-side energy storage can be further configured according to the method described in this paper, which can reduce the energy storage investment costs and operation and maintenance costs, and improve the economic performance.
