A two-layer optimal dispatch model for thermal unit deep peaking shaving and dynamic line rating

Abstract

To address the challenges of limited system regulation and renewable energy accommodation capacity in new power system, this paper proposes a two-layer optimal dispatch model incorporating thermal unit deep peak shaving and dynamic line rating. The upper-layer model aims to minimize net load fluctuation and enhance energy storage utilization by optimizing the peak regulation schedule of thermal units through deep regulation capability, while analyzing load flow distribution. The lower-layer model calculates real-time dynamic capacity limits for overloaded transmission lines using conductor thermal balance equations and meteorological parameters, enhancing line transmission capacity to improve renewable energy utilization. The model aims to minimize system operating costs and reduce wind and PV curtailment. Taking IEEE39 as an example to verify the effectiveness of the proposed model, combined with the actual power system, it is calculated that the line capacity can be increased by up to 21.27% and 64.83% during the peak load period in different seasons, while wind and PV curtailment rates can be decreased by 4.44% and 9.43%, respectively. This model effectively reduces the consumption pressure of the system on renewable energy, promotes system stability, and lowers operating costs.