风电场入网的可靠性分析及运行风险评估

发布时间：2018-08-17 16:23

【摘要】：风能具有分布范围广、清洁、零排放和可再生性等优点,随着风电技术日益成熟,风力发电逐渐被认为是最具发展规模和市场竞争力的可再生能源发电形式。然而,由于风能的随机性、间歇性和波动性,风电并网将对电力系统的安全可靠运行带来不可忽视的影响,尤其在风电场并网规模逐年增大的背景下,如何准确衡量风电场的容量价值,合理评估风电场入网后对系统可靠性及运行风险的影响是一个十分重要的问题。本文在已有相关理论研究和实践经验的基础上,开展了以下研究工作。第一,建立自回归滑动平均风速预测模型,并给出了表征风电场群间风速相关性大小的表达式,采用两状态马尔可夫过程描述风电机组的随机停运,考虑风电场的尾流效应,基于风电机组的功率输出特性曲线,建立风电场的可靠性模型。第二,从发电系统可靠性层面,基于序贯蒙特卡罗仿真,采用超线性收敛的抛物线法,计算风电场的容量可信度指标。同时,探讨了采用不同的指标衡量系统的可靠性水平时,容量可信度计算结果的差异,并研究了影响容量可信度大小的主要因素。第三,从长期规划角度,根据大电网中发电机、线路、变压器等元件的停运模型,结合风电场的可靠性模型,提出了一套含风电场的大电网可靠性评估模型和指标评估体系。基于IEEE-RTS79测试算例,分别研究了风电场装机容量大小、风电场替代常规电源以及风电场群之间风速的相关性对大电网可靠性的影响。第四,从短期运行的角度,分析含风电场的大电网在运行中的风险因素,依据风险因素产生的原因不同,将其分为偶然失效模式、老化失效模式以及预测的不确定性这三类,并分别建立时变风险评估模型。同时,建立了表征系统短期运行风险的指标体系,包括状态类指标、越限类指标和期望切负荷量指标。在此基础上,基于IEEE-RTS79算例,研究风电场并网对大电网运行风险的影响。
[Abstract]:Wind energy has the advantages of wide distribution, clean, zero emission and renewable. With the development of wind power technology, wind power generation is gradually considered as the most developed scale and market competitiveness of renewable energy generation. However, due to the randomness, intermittency and volatility of wind energy, wind power grid connection will have an important impact on the safe and reliable operation of power system, especially in the background of wind power grid increasing year by year. How to accurately measure the value of wind farm capacity and how to evaluate the impact of wind farm on system reliability and operation risk after entering the network is a very important issue. Based on the relevant theoretical research and practical experience, the following research work has been carried out in this paper. First, an autoregressive sliding average wind speed prediction model is established, and the expression of wind speed correlation between wind farm groups is given. The two-state Markov process is used to describe the random outage of wind turbine units, and the wake effect of wind farm is considered. Based on the power output characteristic curve of wind turbine, the reliability model of wind farm is established. Secondly, based on sequential Monte Carlo simulation and superlinearly convergent parabola method, the capacity reliability index of wind farm is calculated from the reliability level of power generation system. At the same time, the difference of the calculation results of capacity reliability is discussed when different indexes are used to measure the reliability level of the system, and the main factors influencing the reliability of capacity are studied. Thirdly, from the long-term planning point of view, according to the outage model of generator, line, transformer and other components in large power network, combined with the reliability model of wind farm, a set of reliability evaluation model and index evaluation system of large power network with wind farm are put forward. Based on IEEE-RTS79 test examples, the effects of wind farm installed capacity, wind farm replacing conventional power supply and wind speed correlation among wind farm groups on the reliability of large power grid are studied respectively. Fourthly, from the perspective of short-term operation, the risk factors of large power grid with wind farm in operation are analyzed. According to the different causes of risk factors, the risk factors are classified into three categories: accidental failure mode, aging failure mode and uncertainty of prediction. Time-varying risk assessment models are established respectively. At the same time, an index system is established to represent the short-term operating risk of the system, including the state index, the over-limit index and the expected load shedding index. On this basis, based on the IEEE-RTS79 example, the influence of wind farm grid connection on the operation risk of large power grid is studied.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM732

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