Optimal Decision-Making Model for Renewable Energy Cost Analysis in Cross-Regional DC Transmission Channels under Medium-to-Long Term and Spot Trading Modes

Currently, DC power transmission trading modes are primarily divided into two types: medium-to-long-term transmission trading and cross-regional spot trading of surplus renewable energy. To investigate the impacts of these different transmission modes on renewable energy accommodation, this study establishes a renewable energy accommodation model that incorporates both medium-to-long term transmission trading and cross-regional spot trading of renewable energy. Using this model, we analyze the effects of different trading modes on key indicators such as renewable energy curtailment rate, the proportion of renewable energy generation in total electricity output, and DC transmission utilization hours. Based on actual data from a northwestern province in China, the DC transmission scheduling is optimized for this province, effectively reducing the renewable energy curtailment rate while ensuring the required DC transmission utilization hours.