考虑高海拔山区铁路沿线电网灵活性的分布鲁棒优化方法研究

A Distributionally Robust Optimization Method Considering the Flexibility of Power Grid Along High Altitude Mountain Railway

为避免因源–荷波动造成高海拔山区铁路沿线电网灵活性不足问题,该文提出了一种考虑灵活性的分布鲁棒优化方法。首先,针对在建的具有长大坡道的某高海拔山区铁路,通过拟规划的列车运行图和线路地势对高铁负荷进行模拟。其次,采用Wasserstein距离确立因源–荷波动引起的灵活性需求不确定集,并构建灵活性不足风险成本模型以耦合至目标函数,再结合灵活性机会约束,在模糊集内将灵活性越限概率限制在某一置信水平下,建立基于Wasserstein距离的分布鲁棒机会约束优化模型。然后,针对约束个数随着历史数据增加而增长造成的计算效率问题,提出一种基于共轭转换的分布鲁棒机会约束模型。对目标函数采用基于共轭函数的近似框架转换,对机会约束采用一种内逼近加松弛的方法近似处理。最后,对某高海拔山区铁路沿线电网进行仿真研究,验证了本模型的正确性与有效性。

To avoid the insufficient flexibility of power grids along the high-altitude mountain railways due to the source-load fluctuations,a distributionally robust optimization considering the flexibility is proposed in this paper.Firstly,for a high-altitude mountain railway with long ramps under construction,the high-speed railway load is simulated through the planned train operation map and the line topography.Secondly,the Wasserstein distance is used to establish the uncertainty set of the flexibility requirements caused by the source-load fluctuations.Furthermore,a risk cost model for the insufficient flexibility is constructed and coupled to the objective function.The probability of the flexibility is limited to a certain confidence level,and a distributionally robust chance constrained optimization model based on the Wasserstein distance is established.Then,for the computational efficiency problem caused by the increase of the number of the constraints with the increase of the historical data,a distributionally robust chance constraint model based on the conjugate transformation is proposed.An approximate frame transformation based on the conjugate function is used for the objective function,and a method of inner approximation and relaxation is used to approximate the chance constraints.Finally,a simulation study of the power grid and railways in a high-altitude mountainous area is carried out to verify the correctness and effectiveness of the model.