Proportion optimization of wind and solar power capacity for regional power network

Renewable energy curtailment has become a severe problem in some regional power networks of China. To alleviate the curtailment, optimizing the integrated wind and solar power capacities becomes an urgent need. This paper proposes an improved method to optimize the wind and solar power capacity based on the time sequence simulation technology. An optimization model is proposed to maximize the environmental benefit for a regional power network with considering the constraints of system power balance, thermal unit peak load regulation ability, system spinning reserve, power and heating coupling of the co-generation unit and tie-line transmission capacity. To handle the transmission capacity constraint, the regional power network is aggregated for simplicity. The annual wind and solar power time sequences are incorporated as inputs for optimization. By giving a series of scenarios with different proportion of wind and solar energy, the optimal capacities are obtained by comparing the environmental benefit and the curtailment. Case studies are conducted with a provincial power network of China and testing results verify the effectiveness of the proposed method.