基于风险理论的含风电电力系统短期充裕性评估与决策

发布时间：2018-07-07 18:34

本文选题：风险理论 + 短期充裕性　；参考：《华北电力大学》2014年博士论文

【摘要】：电力系统充裕性问题是贯穿电力系统规划与运行全过程的重要问题。考虑不确定性因素的影响,对电力系统充裕性进行评估与决策是保障电力系统安全、可靠运行的前提和手段。近年来,大规模风力发电的接入给原本可调、可控的电源出力带来了较大的不确定性,加上用电侧大量电动汽车充、放电的不确定性,使得电力系统运行调控的难度和风险都大大增加。传统的电力系统充裕性评估指标与方法已经难以适应目前电力系统短期运行领域电源与负荷的新特点。在这样的背景下,本论文以含风电电力系统短期充裕性评估与决策研究为题,开展的主要工作和取得的成果如下。针对由风电不确定性引起的备用需求决策问题,在分析不同时间尺度下风电功率的波动特性、风电功率短期预测误差的分布特点的基础上,借鉴风险理论,以风电功率预测误差为风电不确定性的表征,提出了基于时间的和基于功率的风电不确定性度量指标；引入精算学中的Buhlmann信度模型,将2种指标综合起来,形成信度风险度量指标,并将其用于估计由风电不确定性引起的系统运行备用需求。算例分析及指标的有效性检验表明,信度指标继承了基于时间的和基于功率的2种指标的优点,能够恰当地从历史数据信息和未来预测信息中获得某置信度下风电功率预测误差的风险信息,能够在不降低对实际损失覆盖程度的前提下,合理地减少不必要的备用,对电力系统经济运行起到一定的促进作用。针对计及电源与负荷不确定性风险的发电充裕性评估问题,在总结电力系统充裕性的基本知识以及常用的发电系统充裕性评估方法和评估指标的基础上,从短期运行的角度,以系统可用发电容量缺额为充裕性表征函数,对运行失负荷概率(operational loss of load probability, OLOLP)、运行失负荷期望(operational expected load not served, OELNS)指标进行了重新描述,提出了一个新的充裕性度量指标：延迟失负荷概率(buffered loss of load probability, BLOLP);分别分析了充裕性评估指标与负荷需求、负荷预测误差、常规机组容量、常规机组停运率、风电机组停运率和风电功率预测误差等影响因素之间的关系。对指标的定性分析表明,所提出的充裕性评估指标以一种概率性方法将系统运行划分为充裕、警戒和不充裕3种状态,有利于提高系统运行的可靠性。仿真算例表明,所提出的概率评估指标隐含着充裕性函数概率分布的尾部信息,反映的充裕性更全面。针对不确定性对机组组合的影响,基于充裕性约束提出了一种含风电电力系统机组组合模型。在传统的基于机组投运风险(unit commitment risk, UCR)和基于失负荷概率(loss of load probability, LOLP)、基于失负荷期望(expected load not served, ELNS)的充裕性约束的基础上,建立了基于所提出的OLOLP和BLOLP的机组组合模型,研究了其充裕性约束的求解方法。与其它机组组合模型算例的对比表明,本文所提出的基于BLOLP的机组组合模型具有运算速度快、结果可靠性高的优势,还能够给出在不同充裕性水平要求下系统机组的启停方案,实现机组有功出力和提供备用的协调优化,给出运行方案相对应的系统充裕性量化值,为调度工作提供直观参考。以电动汽车作为用电侧主要不确定性的代表,研究了含电动汽车的配电系统短期充裕性动态决策问题。在明确电动汽车工作模式、充放电特性和参与调度的方式的基础上,考虑来自电源侧与负荷侧的双重不确定性因素,以系统运行备用容量为充裕性表征函数,定义了2个充裕性动态度量指标,建立了以最大充裕性为目标的多阶段决策模型。仿真算例结果表明,所提出的充裕性动态度量指标在保证研究期内系统整体充裕性的同时,还能根据负荷大小协调各时段的可调度负荷资源；所建立的多阶段决策模型同时优化购电方案与电动汽车充、放电方案,考虑了研究期内不同时段的优化变量之间的相互关联,体现了动态优化的本质；配电系统的运营部门可以通过适当的引导和管理,减少电动汽车充、放电对系统运行的负面影响,充分发挥其削峰填谷的正面作用。
[Abstract]:The problem of power system adequacy is an important problem throughout the whole process of power system planning and operation. Considering the influence of uncertain factors, the evaluation and decision of power system adequacy is the premise and means to ensure the safety and reliable operation of power system. In recent years, the access of large-scale wind power generation to the original and controllable power supply The difficulty and risk of power system operation and control are greatly increased by the uncertainty of the power supply and the uncertainty of discharge. The traditional power system adequacy evaluation index and method have been difficult to adapt to the new characteristics of power and load in the current power system in the short run field. Under the background of the sample, this paper focuses on the short-term adequacy assessment and decision making of wind power system. The main work and achievements are as follows.
In view of the decision problem of standby demand caused by wind power uncertainty, on the basis of analyzing the characteristics of wind power fluctuation under different time scales and the distribution characteristics of wind power short-term prediction error, using risk theory, the wind power prediction error is characterized by wind power uncertainty, and the wind based on time and power based wind is proposed. By introducing the Buhlmann reliability model in the actuarial science, the 2 indexes are combined to form the reliability risk measurement index, and it is used to estimate the standby demand caused by the wind power uncertainty. The calculation example analysis and the validity test table of the index show that the reliability index inherits the time based and based on the work. The advantages of the 2 indexes of the rate can be properly obtained from the historical data and future prediction information to obtain the risk information of the prediction error of the wind power of a certain confidence lower. It can reduce the unnecessary reserve reasonably without reducing the coverage of the actual loss, and it can play a certain role in the economic operation of the electric power system.
On the basis of summarizing the basic knowledge of power system adequacy and the commonly used evaluation method and evaluation index of power generation system adequacy, based on the summary of the basic knowledge of power system adequacy and the evaluation index of power generation system adequacy, the shortage of power generation capacity is used as an abundant characterization function, and the running load is lost. The probability (operational loss of load probability, OLOLP), the running load loss expectation (operational expected load not served, OELNS) is redescribed, and a new margin index is proposed. The relationship between the load demand, the load forecasting error, the conventional unit capacity, the conventional unit outage rate, the wind turbine outage rate and the prediction error of the wind power. The qualitative analysis of the indexes shows that the proposed adequacy evaluation index divides the system into abundant, alert and 3 states with a probability method. It is beneficial to improve the reliability of the system operation. The simulation example shows that the proposed probability evaluation index implies the tail information of the probability distribution of the abundant function, and the sufficiency of the reflection is more comprehensive.
In view of the influence of uncertainty on the unit combination, a combination model of wind power system is proposed based on the adequacy constraints. In the traditional unit commitment risk (UCR) and the load loss probability (loss of load probability, LOLP), the load loss expectation (expected load not) is filled. On the basis of margin constraints, the unit combination model based on the proposed OLOLP and BLOLP is set up, and the method of solving the adequacy constraints is studied. The comparison with other unit combination models shows that the proposed BLOLP based unit model has the advantages of fast operation speed and high reliability, and can also be given in this paper. The starting and stopping scheme of the system unit at different adequacy levels is required to realize the unit active power output and provide the coordination and optimization of the reserve, and give the quantitative value of the system adequacy in order to provide a visual reference for the scheduling work.
Taking the electric vehicle as the representative of the main uncertainty of the electric side, the dynamic decision problem of the short term adequacy of the power distribution system containing electric vehicles is studied. The dual uncertainty factors from the power side and the load side are considered on the basis of the working mode of the electric vehicle, the charging discharge characteristics and the mode of participating in the scheduling. The capacity is an abundant characterization function, and 2 abundant dynamic metrics are defined, and a multi-stage decision model with maximum adequacy is established. The simulation example shows that the proposed adequacy dynamic metric can also coordinate the adjustable periods according to the load size while guaranteeing the overall system adequacy in the study period. The multi stage decision model is set up to optimize the power purchase scheme and electric vehicle charging and discharging scheme at the same time, considering the interrelation between the optimized variables in the different period of the study period, reflecting the essence of dynamic optimization; the operation Department of the distribution system can reduce the charge and discharge of electric vehicles through proper guidance and management. The negative impact of electricity on the operation of the system will give full play to its positive role in cutting the peak and filling the valley.
【学位授予单位】：华北电力大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM614

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