基于双层规划的微网经济调度

发布时间：2018-01-20 12:54

本文关键词： 经济调度微网双层优化可控负荷储能系统　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：在电力行业,大电网与分布式电源相结合是解决电力需求增长与环境污染、能源供给之间矛盾的方法。微网作为一种局部网络技术,能充分利用分布式电源为用户和大电网所带来的技术经济效益,并有效解决电网与分布式电源间的矛盾。优化调度在微网中有着非常重要的地位,它有效解决能源优化分配问题,使微网运行更加经济环保。从上世纪90年代引入电力市场化开始,分层协调决策成为系统优化决策的重要方式。此时,基于传统的单目标或多目标优化方法无法求解具有阶层性的经济调度问题,双层优化模型开始受到人们的广泛关注。本文利用双层优化方法研究微网经济调度中分层优化的问题,主要工作如下:首先,研究了包含储能系统的发电商最优供给问题。为了提高供电的可靠性和安全性,系统常需要考虑一定的旋转备用,传统的方法一般是在供电侧考虑燃气轮机和柴油机组,但随着整合的分布式能源越多,需要的旋转备用越多,这种方式既不经济,也增添了污染。储能系统具有快速吸收或释放电能的优点,可有效地弥补可再生电源波动性的缺点,从而为大规模可再生能源集中并网提供了一些新的解决思路。本部分基于已有研究,建立了发电商和能源服务提供商之间的双层优化模型,其中上层考虑的是柴油机组供应商的利润最大,下层考虑的是能源服务提供商的总利润最大,并考虑以储能系统作为旋转备用。数值实验分析了参数变化对模型的影响,并验证了所提模型比无储能系统时具有明显的经济性。其次,针对大规模风电并网给电力系统带来的影响,本文应用需求侧响应的能量管理策略,建立了用户与微网管理方的双层优化调度模型。上层根据用户侧可控负荷的特性和运行特征,将所有的可控负荷分成四类,目标函数为用户四类可控负荷总的用电成本最小,并用数学表达式对其特性进行了刻画;下层优化目标函数是在满足供电可靠性的条件下使微网总的供电费用最小,并采用高估与低估的方法来处理风电出力的不确定性。数值实验证明了所提模型具有明显的经济性,且增强了对风电的消纳能力。最后,针对本文所建的优化模型的目标函数都含有分段函数,运用了光滑化的处理方法。通过KKT条件(Karush-Kuhn-Tucker)将双层优化转化成一个单层优化问题进行求解。随着电力市场化改革的深入,分层协调决策成为电力系统的特征将会越来越明显,此时,利用双层规划求解优化调度问题也会越来越广泛。本文利用双层规划建立了两个优化模型,并通过数值实验验证了所提模型和算法的经济性和有效性。本文的研究为双层规划在电力系统的广泛应用提供了一定的理论基础。
[Abstract]:In power industry, the combination of large power grid and distributed generation is a method to solve the contradiction between power demand growth and environmental pollution, energy supply. Microgrid as a local network technology. It can make full use of the technical and economic benefits brought by distributed generation to users and large power grids, and effectively solve the contradiction between power grid and distributed generation. Optimal dispatching plays a very important role in microgrid. It effectively solves the problem of optimal distribution of energy and makes the operation of microgrid more economical and environmentally friendly. Since the introduction of electricity marketization in -10s, hierarchical coordinated decision-making has become an important way of system optimization decision. Based on the traditional single-objective or multi-objective optimization method, the hierarchical economic scheduling problem can not be solved. Bilevel optimization model has been paid more and more attention. In this paper, the hierarchical optimization problem in microgrid economic scheduling is studied by using bilevel optimization method. The main work is as follows: first of all. In order to improve the reliability and safety of power supply, the system often needs to consider a certain rotation reserve. The conventional approach is to consider gas turbines and diesel units on the power side, but with more integrated distributed energy, more rotating reserves are needed, which is neither economical. Energy storage system has the advantages of fast absorption or release of electric energy, which can effectively compensate for the shortcomings of the fluctuation of renewable power supply. This provides some new solutions for the large-scale renewable energy centralized grid connection. Based on the existing research, the two-layer optimization model between power generation and energy service providers is established in this part. Among them, the upper layer considers the biggest profit of the diesel unit supplier, and the lower level considers the biggest total profit of the energy service provider. Considering the energy storage system as the rotation reserve, the effect of the parameter change on the model is analyzed by numerical experiments, and it is proved that the proposed model is more economical than that without the energy storage system. Secondly. Aiming at the impact of large-scale wind power grid connection on power system, the energy management strategy of demand-side response is applied in this paper. A two-layer optimal scheduling model for users and microgrid managers is established. According to the characteristics and operation characteristics of controllable load on the user side, all controllable loads are classified into four categories. The objective function is that the total power cost of four kinds of controllable loads is the least, and its characteristics are characterized by mathematical expressions. The objective function of the lower layer optimization is to minimize the total power supply cost of the microgrid under the condition of satisfying the reliability of the power supply. The method of overestimation and underestimation is adopted to deal with the uncertainty of wind power output. The numerical experiments show that the proposed model has obvious economy and enhances the ability to absorb wind power. Finally. The objective functions of the optimization model in this paper contain piecewise functions. The smoothing method is used. The Karush-Kuhn-Tucker condition is obtained by using the KKT condition. The bilevel optimization is transformed into a single-layer optimization problem to be solved. Hierarchical coordination decision will become the characteristic of power system more and more obvious. In this case, bilevel programming can be used to solve the optimal scheduling problem more and more widely. In this paper, two optimization models are established by using bilevel programming. The economy and effectiveness of the proposed model and algorithm are verified by numerical experiments. The research in this paper provides a theoretical basis for the wide application of bilevel programming in power systems.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM73

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