Liu Xiaoou
China Power Engineering Consulting Group CO.,LTD., Ande Road 65, Xicheng District, Beijing, 100120, China.
Heliyon. 2024 Mar 5;10(5):e27615. doi: 10.1016/j.heliyon.2024.e27615. eCollection 2024 Mar 15.
In order to effectively address the uncertainty risks of port energy system caused by intermittence and fluctuation of renewable energy, this paper proposes a scheduling method for port energy system based on distributionally robust optimization (DRO) considering ammonia synthesis after hydrogen production by water electrolysis (P2H2A), and uses real data from Tianjin Port for example analysis. The calculation results show that 1 h selected for the scheduling interval of P2H2A is reasonable, it can ensure that the ammonia synthesis reaction transitions smoothly to the new steady state, and the temperature and pressure of the ammonia converter meet safety constraints. The two-stage scheduling of port energy system based on DRO can be divided into pre-scheduling in the day-ahead stage and rescheduling in the intraday stage, which can improve the capacity of anti-risk for stochastic optimization and overcome the conservatism of robust optimization, and consider economy and robustness. Moreover, the rescheduling decision can be transformed to a prediction error function, the result of two-stage scheduling based on DRO is the pre-scheduling result, which is between the cost of stochastic optimization and robust optimization. As the Wasserstein distance-based sphere radius increases, the pre-scheduling cost of DRO gradually deviates from risk neutral stochastic optimization and leans towards risk averse robust optimization. When the Wasserstein distance-based sphere radius remains constant, the variance gradually decreases as the number of scenarios increases, which can promote the Wasserstein distance-based fuzzy set to converge to the true distribution. When the number of scenarios is greater than 15, the pre-scheduling cost will no longer fluctuate significantly, and the calculation time is in the range of 1200 s-6600 s. It can meet the demands of day-ahead scheduling calculation time. Therefore, the scheduling model has outstanding advantages in the computing time to improve the flexibility and economy of Tianjin Port's energy system scheduling, considering ammonia synthesis after hydrogen production using renewable energy.
为有效应对可再生能源间歇性和波动性给港口能源系统带来的不确定性风险，本文提出一种基于分布鲁棒优化（DRO）的港口能源系统调度方法，该方法考虑了水电解制氢后合成氨（P2H2A）的过程，并以天津港实际数据为例进行分析。计算结果表明，P2H2A调度间隔选取1小时是合理的，能够保证合成氨反应平稳过渡到新的稳态，且氨合成塔的温度和压力满足安全约束。基于DRO的港口能源系统两阶段调度可分为日前阶段的预调度和日内阶段的重调度，能够提高随机优化的抗风险能力，克服鲁棒优化的保守性，兼顾经济性和鲁棒性。此外，重调度决策可转化为预测误差函数，基于DRO的两阶段调度结果为预调度结果，介于随机优化成本和鲁棒优化成本之间。随着基于瓦瑟斯坦距离的球半径增大，DRO的预调度成本逐渐偏离风险中性随机优化，向风险厌恶型鲁棒优化倾斜。当基于瓦瑟斯坦距离的球半径不变时，随着场景数增加方差逐渐减小，可促使基于瓦瑟斯坦距离的模糊集收敛到真实分布。当场景数大于15时，预调度成本不再显著波动，计算时间在1200秒至6600秒范围内，能够满足日前调度计算时间要求。因此，该调度模型在计算时间方面具有突出优势，能够提高天津港能源系统调度的灵活性和经济性，同时考虑了利用可再生能源制氢后合成氨的过程。
