Optimal Scheduling of Coupled Systems Considering Rapid Load Adjustment and Flexibility Supply-Demand Matching

The coupled system formed by renewable energy and thermal power units with rapid load adjustment retrofit at the same grid connection point is an effective means to enhance flexibility in regions such as deserts, gobi, and wilderness, where proportions of renewable energy are high but flexible power generation resources are lacking. To explore the economics and flexibility of the retrofitted thermal power units in the coupled system, this paper proposes a multi-objective optimal scheduling method for wind-solar-thermal coupled systems. First, based on the actual calculated operational coal consumption data of the thermal power units after flexibility retrofitting, a coal consumption calculation formula for the unit ramping process is fitted, and the impact of the improved rapid load adjustment capability on the economy and flexibility of the coupled system is analyzed. On this basis, taking the daily comprehensive operation revenue and the flexibility supply-demand matching degree as objective functions, considering system operation constraints including the ladder-type ramp rate, a multi-objective optimal scheduling model is constructed. By using grouped and linked polynomial mutation operators in the optimization algorithm, the ability to solve multiobjective optimal scheduling problems in power systems with high dimensions and complex constraints is improved. Finally, an optimal scheduling simulation is conducted by using a coupled system in a certain region as an example. Results show that the proposed method can obtain an optimal scheduling scheme for the coupled system with relatively better comprehensive economy and flexibility. © 2025 Automation of Electric Power Systems Press. All rights reserved.