【作者】 王永强；

【导师】 张勇传； 周建中；

【作者基本信息】 华中科技大学 ， 水利水电工程， 2012， 博士

【摘要】 厂网协调模式下的流域梯级电站群短期联合优化调度受水文径流过程、电网负荷需求、机组状态、下游用水需求等多种影响因素制约,是一类非线性、高维度、多约束的复杂水-机-电耦合优化问题,也是水电能源科学与复杂性科学交叉发展的重要研究领域之一。随着我国大型梯级电站群的相继建成与投运,流域梯级水电能源系统的规模与拓扑结构日趋复杂,流域电站群短期联合优化调度涌现出一系列新问题。水电能源综合利用要求大幅提高,而互联大电网下流域水能资源联合优化调度还缺乏统一有效的管理和协调机制；电力供需矛盾日益突出,易出现负荷峰谷差过大和调峰容量不足的情况；在负荷低谷时段,水电站往往被迫运行于低效率区,导致整个电网经济效益显著降低,因此,亟需协调电网吸纳与电站出力关系,研究并发展新的厂网协调模式下的流域梯级电站群短期联合优化调度理论与方法。本文围绕全国互联大电网背景下流域梯级电站群联合优化运行存在的关键科学问题和技术难题,以水电能源学、系统科学、群智能优化等基础理论为支撑,以三峡梯级电站群为主要研究对象,对厂网协调模式下梯级电站群短期联合优化调度建模和求解方法开展研究,取得了一些有理论意义和工程实用价值的成果。主要研究内容和创新包括：(1)针对水电站机组检修计划、健康状况、运行状态等对机组稳定运行的影响程度,提出水电机组综合运行状态评价指标与评价模型。结合本文所提出的综合运行状态评价指标,对水电机组在当前面临时段发电优化调度中的综合运行状态进行评价,由此确定可参与运行机组的开机或停机优先次序,为优化调度过程时段间负荷变化引起的增加或减少机组台数提供选择依据；通过对机组母线出力限制、机组气蚀振动区限制与机组出力上下限求取交集,精确描述机组稳定出力区域的边界值,为水电站安全、稳定运行提供可靠的数据支撑。(2)在水电站机组综合运行评价的基础上,提出基于多种群蚁群优化算法的梯级电站实时自动发电控制方法。针对不同时间尺度,以梯级电站耗水量最小为目标,分别建立单时段梯级电站实时发电控制与当前时段至余留期梯级电站自动发电控制的数学优化模型,提出适用解决电站机组组合问题的多种群蚁群优化算法,在收敛过程中以前期最优解集不断替代进化种群,加速模型求解速度,合理分配梯级各电站所需承担的系统负荷,并根据时段负荷需求在各级电站内制定最优开机机组组合与机组间最优负荷分配方案,有效满足电网实时性要求。(3)综合分析电网中梯级电站日发电计划编制与厂内经济运行在发电过程中的共性与差异性,提出梯级电站日发电计划编制与厂内经济运行循环嵌套模式。针对二者优化目标不同而产生的电站下泄流量可行域冲突问题,将日发电计划编制优化结果作为厂内经济运行优化计算的输入,对发电计划编制方案进行目标反向演算,二者循环嵌套计算直至满足各项约束条件,同时获得梯级电站最优发电计划与厂内经济运行方案,实现二者的一体化运作,为梯级电站调度中心水调部门与电调部门以及电网调度中心的有机协调运行提供保障,且有效降低发电计划与电网实际发电需求的偏差。(4)结合流域梯级电站群归口管理层级、隶属电网关系、区域分布特征以及电站间的水力、电力补偿关系,提出厂网协调模式流域梯级电站群分层分区分级短期精细化调度方法。对流域梯级电站群短期发电优化调度进行分层分区分级划分,以流域梯级电站群短期发电量最大或效益最优为目标,以中长期优化调度水位消落过程为指导,建立流域梯级电站群短期发电优化调度模型,给出最优发电流量和有功负荷分配方案,制定流域梯级电站群短期联合最优发电计划,提高流域梯级电站群的短期发电效益。(5)以流域水文过程、电网负荷要求以及不同部门间用水需求的非线性耦合特性作为水火电力系统优化的建模基础,针对水火电能源丰枯、峰谷补偿特性,研究水火电力系统可描述化网络拓扑及其补偿调节机制,建立水火电力系统短期联合优化调度模型,提出基于实数差分量子进化算法的水火电力系统优化方法与启发式约束处理策略,有效处理系统运行约束,实现水火电力系统运行域边界的精确描述,制定水火电力系统短期优化调度方案,为区域电网的安全、稳定、经济运行提供数量基础和理论依据。更多还原

【Abstract】 The short-term optimal operation of cascade hydropower stations is a nonlinear, high-dimensional, multi-constraint, complex water-machine-electrical coupling optimization problem, which is constrained by hydrological runoff process, electric load demand, the units state and water demand of downstream. The short-term optimal operation of hydropower under the coordination on power plants and power grid is one of the most important research field mixed by hydropower and complexity science. With large-scale hydropower system are completed and put into operation in China, the requirements of comprehensive utilization for hydropower have been improved. The scale and topology structure of basin hydroelectric cascade energy system has become more and more complicated. The short-term optimal operation of cascaded hydropower stations emerge a series of new problems. The optimal scheduling of basin water resources is lack of effective management of unity and coordination mechanism under the background of interconnected power grid. The contradiction between power supply and demand has become increasingly prominent. The big gap between load peak and valley appears frequently and peak-load regulating capacity is not enough. In low load period, hydropower stations are often forced to reduce output and abandon water, which will cause great loss of power grid economic benefit. Therefore, it is necessary to develop new optimization theories and methods to solve these problems. This dissertation focuses on the key scientific and technical problems of optimal operation for cascade hydropower stations under the background of joint grid all over the country. Supported by the theories of hydropower science, systems science, and swarm intelligent optimization, Three Gorges cascade hydropower stations are set as the main research object. Finally, we study the modeling and the solving method of short-term optimization operation under the coordination on power plants and power grid and get valuable achievements on theories and engineering practice. The main research contents and innovations include:(1) Aiming at the influence type and extent caused by maintenance plan, health condition and running state of the hydropower unit, the evaluation index and model of hydropower unit are proposed for comprehensive operation state. Based on the suggested operation state evaluation indexes, the comprehensive operation state of hydropower units is evaluated in the current scheduling period. And then the running and stop priorities is selected for increasing or reducing the number of units. Considering the power limits of transformer, the requirements of unit cavitation vibration area and dynamic characteristics of the units, the upper and lower limits of unit stable output are determined, which gives reliable support for security and stability of hydropower station.(2) After the comprehensive evaluation of hydropower station is presented, real-time automatic generation control strategy of cascade hydropower stations is proposed by the population-based ant colony optimization. Considering minimizing water consumption as the goal in different time scales, the model of real-time generation control of cascade hydropower stations is established in single schedule period and so is the mathematical optimization model in remaining periods. Meanwhile, a multi-population ant colony optimization is proposed in this literature. According to replace the population by optimal solutions obtained in early evolution, the convergence will be accelerated. Finally, distribute the load demand to each plant and develop the schedule scheme of optimal unit combination as well as the load distribution among each unit.(3) With analyzing the commonalities and the differences between the daily generation scheduling and internal economic operation(DAI) of the cascade hydropower stations in power grid, the seamless nested mode of the the daily generation scheduling and internal economic operation(DAI) is proposed for cascade hydropower stations. Considering the feasible region conflict problem of discharge volume engendered by the different optimization goals of DAI, the optimal results of daily generation scheduling is provided as the input of internal economic operation calculation to conduct objective reverse calculus for the daily generation scheduling. The optimal scheme of DAI is got until circulation nested calculation end with meeting the constraint conditions, and the integration operation of DAI is realized which can ensure organically coordination dispatching for the water and electricity department in the center of cascade hydropower stations as well as effective reduction of the deviation between the generation plan and actual power demand of the power grid.(4) Combined with regional distribution characteristics, relationship between district power grids, the hydraulics and electric power compensation of cascade hydropower stations, a division grade refinement scheduling method of cascade hydropower stations is proposed for the coordination model of the power plant and grid. With dividing the subregion and classification for short-term generation optimization scheduling of cascade hydropower stations, the short-term generation optimization scheduling models of cascade hydropower stations for energy maximization and benefits maximization are established according the water level fluctuating process of the long-term optimized scheduling. The optimal the optimal generation flow, active load distribution solutions and short-term optimal generation scheme are obtained by the established model to improve the short-term generation benefit of cascade hydropower stations.(5) The nonlinear coupling characteristics of the hydrologic processes, power load demand and water demands of different departments is the optimization modeling foundation for the hydrothermal power system. According to plentiful-low and peak-valley compensation characteristic of the hydrothermal electricity energy, the short-term combined optimization scheduling model of the hydrothermal power system is established. And the heuristic constraint processing strategy and optimization method of the hydrothermal power system based on the real difference quantum evolutionary algorithm, are put forward to deal with the operation constraints of the system effectively. To provide theoretical basis and number basis for the regional network safety, stability and economic operation, the operation domain boundary of the hydrothermal power system is been described accurately and short-term optimal generation scheme is formulated for the hydrothermal power system.更多还原