微电网系统多目标优化运行研究

发布时间：2018-06-29 16:13

  本文选题：微电网 + 并网运行　； 参考：《兰州交通大学》2017年硕士论文

【摘要】：随着化石能源供比失调加剧、环境的持续恶化、用户的电力需求增加以及对电能质量要求提高,DG(Distributed Generation,分布式电源)能源利用率高、就地取材、供能灵活等优势逐步得到高度关注。纵然大规模利用DG带来了诸多好处,但其功率的间歇性、随机性、波动性等缺点造成大规模并网受限的问题。MG(Microgrid,微电网)可以集合多种种类的DG,保证DG优势得到发挥,能够供应电能、热能等不同能量形式,能够在并网状态和孤岛状态灵活切换,可用于解决DG大规模并网问题。MG的优化运行是在符合发电单元级限制及MG系统级约束的情况下,合理调整各单元功率输出,以实现降低发电成本、提高能源使用率及减少污染气体等目标。因此,研究包含多种微电源的MG优化运行是有现实价值的。本论文在查阅并归纳了大量的国内外文献的基础上,对现阶段MG及MG优化运行的研究背景和发展概况进行了总结。系统的对MG的基本概念及其运行特点进行了介绍,并结合典型MG结构对MG的联网方式、运行模式做了详细研究,为并网、孤岛不同情况下的MG优化运行做了理论铺垫。在SPP(Spot Power Price,实时电价)理论指导下,针对MG系统并网优化运行的问题,提出一种直观的启发式MG优化运行策略。通过分时电价机制将全天依据负荷情况划分为峰、平、谷三类,结合当前SB(Storage Battery,蓄电池)的SOC(Sate of Charge,荷电状态),建立了分时段运行策略。在比较可控型微电源与主网的SPP的基础上,设计了阶梯性的SB罚系数,并计入目标函数。采用POP NSGA-Ⅱ(Pareto Optimal Path Non-dominated Sorting Genetic Algorithm,寻优路径非支配排序遗传算法)优化可控型发电单元、SB及与主网交互的功率,实现对主网总体上的“削峰填谷”,提高系统的经济效益。通过一个典型的CCHP(Combined Cooling Heating and Power,冷热电联供型)MG日运行为算例,验证了所提策略和模型的有效性。针对MG系统在孤岛运行方式下的优化问题,在SB平滑负荷需求曲线的基础上,考虑经济和环境两方面的运行成本,本文提出了一种孤岛MG运行方法。运行方法共分两步:根据预测的电力负荷需求、不可控DG的发电预期、SB的容量信息及SOC等因素,运用考虑实际约束的功率差控制策略确定SB的运行方式。计及功率平衡约束,可控机组出力及爬坡约束等条件,建立经济成本和环境成本的目标函数,采用改进的GA(Genetic Algorithm,遗传算法)求解可控型发电单元出力分配。该方法在发挥SB削峰填谷作用的同时,还实现了孤岛MG系统的经济、环保优化运行。在典型孤岛MG系统的日优化运行算例中,针对SB在两种控制策略下进行了比较分析,并对比分析了单目标和多目标两类优化结果,为MG的孤岛运行提供了一种新思路。
[Abstract]:With the increasing imbalance of fossil energy supply ratio, the continuous deterioration of environment, the increase of power demand of users and the improvement of energy utilization ratio of distributed Generation (DG) to power quality, the advantages of local selection and flexibility of energy supply have been paid more and more attention. Although the large-scale utilization of DG brings many benefits, but its power such as intermittent, randomness, volatility and other shortcomings cause large-scale grid-connected problems. MG (Microgrid, microgrid) can gather a variety of DGs to ensure that the advantages of DG can be brought into full play. It can supply different forms of energy, such as electric energy and heat energy, and can switch flexibly in grid-connected state and isolated island state. It can be used to solve DG large-scale grid-connected problem. The optimal operation of MG is in accordance with the constraints of generating unit level and MG system level. The power output of each unit is adjusted reasonably to achieve the goals of reducing the cost of power generation, increasing the energy utilization rate and reducing the pollution gas. Therefore, it is of practical value to study the optimal operation of MG which includes a variety of micro power sources. On the basis of consulting and summarizing a large number of domestic and foreign literatures, this paper summarizes the research background and development of MG and MG optimization operation at present. The basic concept and operation characteristics of MG are introduced in this paper. Combined with typical MG structure, the network mode and operation mode of MG are studied in detail, which lays a theoretical foundation for the optimal operation of MG under different conditions of grid-connected and isolated islands. Under the guidance of SPP (spot Power Price) theory, an intuitive heuristic strategy for optimal operation of MG system is proposed. Based on the time-sharing pricing mechanism, the whole day load is divided into three types: peak, level and valley. Combined with the SOC (State of charge) of SB (Storage Battery), the strategy of time-divided operation is established. On the basis of comparing the SPP of the controllable micro-power source with the main network, the step SB penalty coefficient is designed and the objective function is taken into account. Pop NSGA- 鈪，

本文编号：2082659