1. 大连理工大学水电与水信息研究所, 辽宁省大连市 116024; 2. 云南电力调度控制中心, 云南省昆明市 650011
考虑水电调度复杂非线性关系,提出水电站日负荷优化分配的混合整数非线性规划(MINLP)模型。采用多项式拟合技术处理MINLP模型中的水位、库容、流量、出力等多变量耦合函数关系,分析确定了适合的多项式阶数和描述方式,构建了水位与库容、尾水位与出库流量的一元四次多项式,提出表征机组出力的水头和发电流量二元二次拟合方法,得到了水头—流量—出力关系三维拟合曲面,可以满足变化水头下机组出力的精细化计算要求。最后,采用成熟的MINLP求解器实现高效计算。提出的模型通过溪洛渡18台机组日负荷分配问题得到验证,从模型应用复杂度和结果精度两方面与经典混合整数线性规划(MILP)模型进行比较,表明MINLP模型应用便捷且精度较高,与实际耗水量的误差较MILP模型减少91%,更能反映水电站实际情况。
国家自然科学基金资助项目(51579029);中央高校基本科研业务费专项资金资助项目(DUT16QY30)
1. Institute of Hydropower and Hydroinformatics, Dalian University of Technology, Dalian 116024, China; 2. Yunnan Electric Power Dispatching and Control Center, Kunming 650011, China
Considering complex nonlinear relationships of hydropower dispatch, this paper proposes a mixed-integer nonlinear programming(MINLP)model for optimizing load distribution of hydropower plant. A polynomial fitting technology is used to deal with nonlinear functions involving at least two variables of water level, storage, discharge, and generation in the MINLP. The order and formulation of each function are analyzed and determined. Two fourth-order polynomial formulations are developed to express the fore-bay and tailrace water levels in terms of storage volume and total outflow of the reservoir, respectively. Considering the effect of water head on power generation, a quadratic function of water head and turbine discharge is proposed to accurately describe the power generation of the unit. Thus, a three-dimensional surface which can represent the relationship among water head, discharge, and generation is obtained, which can satisfy the requirement of calculating power generation under different net heads. Finally, the MINLP model is worked out by a mathematical solver and verified by solving the actual load distribution problem of Xiluodu hydropower plant with 18 generating units. A comparison between MINLP model and mixed-integer linear programming(MILP)model is presented in terms of application complexity and result accuracy. The results show that the MINLP model is easy to use and capable of producing higher-accuracy optimization results. Furthermore, the error of total turbine water consumption through the actual curve reverse interpolation is 91% less than that from MILP, better representing the actual unit operation.
[1] | 申建建,张秀飞,王健,等.求解水电站日负荷优化分配的混合整数非线性规划模型[J].电力系统自动化,2018,42(19):34-40. DOI:10.7500/AEPS20171127003. SHEN Jianjian, ZHANG Xiufei, WANG Jian, et al. Mixed-integer Nonlinear Programming Model for Daily Load Optimization of Hydropower Plant[J]. Automation of Electric Power Systems, 2018, 42(19):34-40. DOI:10.7500/AEPS20171127003. |