【作者】 贾晓峰；

【导师】 颜伟；

【作者基本信息】 重庆大学 ， 电气工程， 2010， 硕士

【摘要】 发电计划是节能优化调度的重要组成部分,在当前建立节约型社会的大背景下,对发电计划进行优化,降低运行成本,具有重要的社会和经济意义。在实际系统中为了兼顾经济性和安全性,发电计划一般分为发电计划编制和电网安全校核两个阶段。基于此,本文对日发电计划编制的模型和算法进行了研究;同时还对电网安全校核的重要组成部分-潮流计算进行了研究,以提高安全校核的计算速度。具体研究内容如下:首先,建立了考虑机组出力调节频繁程度目标的日发电计划编制新模型,并提出了基于启发式规则的多种群遗传算法进行该问题的求解。针对优化模型中总发电费用最低和降低发电设备调节次数的双重目的,采用系统负荷曲线优化分段、机组出力曲线近似合并等措施来分别降低系统负荷的有效时段数和机组的出力调节次数。其中,为保证算法更好的全局寻优性,对系统负荷曲线进行了多次段数不等的划分,从而形成多条有效时段数不等的等值曲线,之后采用遗传算法的多种群方式来协同寻优。对于上述曲线等值过程中产生的不平衡量由指定的细调机组来承担。另外,针对优化模型中的多种约束条件,尤其是机组合同电量和功率平衡这两个交叉约束,提出了完善的个体初始化和可行性调整策略,保证相关约束的满足,使寻优在可行域中进行。以上措施,保证了优化模型的有效求解,使机组出力更加平稳高效。其次,在对电网安全校核的重要组成部分-潮流计算的研究中,基于高压电网中环网和辐射分支并存的特性,提出了复杂电网的逆流分层拓扑搜索法及对应的分层解耦潮流算法。通过拓扑搜索将原电网分解成拥有共同边界节点的主环网和辐射子网2部分,并自动形成辐射子网的支路层次结构。分解后将辐射子网等效为主环网对应边界节点的负荷,而将主环网中边界节点的电压等效为辐射子网的电源电压,然后采用P-Q分解法和前推回代法交替求解主环网与辐射子网,并通过等效负荷和等效电压的交互修正来实现分解协调,从而达到一体化计算的目的。其中,辐射子网的前推回代计算按其支路层次结构分层进行。经过IEEE标准系统和实际系统的仿真计算,验证了本文模型和算法的正确性和有效性。更多还原

【Abstract】 Generation scheduling is an important part of energy-saving optimal scheduling. According to the national call for the establishment of conservation-oriented society, it is of great social and economic significance to reduce operation cost by generation scheduling optimization. Consideration to economy and safety, generation scheduling is generally divided into two stages: making generation schedule and security checking in practical system. Based on this point, the model and algorithm of daily generation scheduling have been studied in this paper; and power flow algorithm, the important part of security checking, has also been studied to enhance the security checking speed. The contents presented in the paper are as follows:Firstly, an optimization model for daily generation scheduling is established considering the unit regulating times as one of the targets, and an improved multi-population genetic algorithm (GA) based on heuristic rules is proposed to solve the problem. Consideration to minimizing total generation cost and reducing generator unit regulating times, system load curve optimizing division and unit output curve approximate merging are adopted to reduce effective time periods of system load and unit regulating times respectively. To enable better global optimization ability of the algorithm, the system curve is divided several times to form several equivalent curves with different effective time periods, and then multi-population strategy of GA is adopted to collaborative optimization. Finally, the appointed fine adjustment unit is used to undertake the power imbalance appeared within the curve equivalent progress. Moreover, according to the constrains in the optimization model, especially the unit energy contract and power balance as two cross constrains, suitable individual initialization and feasibility adjustment strategy are proposed to ensure the optimization searching in the feasible region. The above measures enable effective solving of the optimization model, and the unit output should be more stable and efficient.Secondly, during the study of power flow algorithm, the important part of security checking, an countercurrent-layered topological search method and layer-decoupled power flow algorithm for complex networks are proposed based on the characteristic of meshed network and radial branches coexisting in the high voltage grid. Through topological search, the original grid is disintegrated into two parts with common boundary nodes, a main meshed network and some radial subnets, and the branch hierarchy of the radial subnets is formed automatically. Then, the radial subnets are assumed to be equivalent to the nodal load of the main meshed network, and the boundary nodes voltage of the main meshed network equivalent to the supply voltage of the radial subnets. The fast decoupled method and the back/forward sweep method are employed to calculate the main meshed network and the radial subnets alternately, and the integrated calculation is realized by the alternate modification of the equivalent load and equivalent voltage. The back/forward sweep calculation for radial subnets is made layer-by-layer according to the branch hierarchy.The model and algorithms presented in this thesis have been verified by IEEE standard systems and practical power systems, the simulation results proved that they are correct and effective.更多还原