含风电场电力系统概率潮流计算的研究

发布时间：2018-08-04 10:36

【摘要】：近些年来，伴随着新能源发电技术的大力发展，尤其是风力发电技术得到了大规模应用，而风力发电因其自身的随机特性对电网的安全稳定运行带来了新的问题，特别是大规模的风力发电场并网运行以后，对电网的安全稳定运行造成的影响更加明显，再加上电力系统自身具有的不确定性因素的影响，如发电机输出功率的波动、负荷功率的变化、线路故障等，对电力系统潮流计算带来新的挑战，普通的确定性潮流分析的思想和方法已经不能满足新的需求，考虑随机因素影响的概率潮流计算分析方法得到了发展和应用。概率潮流计算把概率理论的思想和方法与电力系统的潮流计算相结合，应用概率理论的方法来分析电力系统的潮流。普通的潮流计算得到的是电力系统电压和功率的确定值，而概率潮流计算方法可以给出电力系统节点电压和支路功率分布的概率统计特征，以概率统计特性的角度来分析节点电压和支路功率在一定变化范围内的概率值以及期望值、方差等概率特征，这对于电力系统的规划设计、稳定性评估等具有重要意义。通常在概率潮流计算时一般都假设系统的网络拓扑结构不变，支路之间相互独立，这样处理虽然简化了运算，但是计算结果产生了一定的误差。实际电力系统中由于各种不同因素的影响，，系统中的支路由于外部或自身的原因产生随机开断，造成网络拓扑结构的改变；而且支路故障后对其他支路的潮流分布产生影响，表明支路相互之间存在一定的相关性，并不是相互独立的。因此，在概率潮流计算时为了更加全面、准确的反映实际电力系统的运行状况，应该考虑系统网络拓扑结构的变化与支路之间存在的相关性因素。本文针对目前大量风力发电场并网运行的实际情况，建立了风力发电机的概率模型，在概率潮流算法的基础上建立了综合考虑系统网络拓扑结构变化和支路之间相关性因素的概率潮流计算模型，应用Matlab仿真软件编写程序，分析了网络拓扑结构及支路之间相关性因素对电力系统节点电压与支路功率的影响。
[Abstract]:In recent years, with the development of new energy generation technology, especially the large-scale application of wind power technology, wind power has brought new problems to the safe and stable operation of power grid because of its random characteristics. Especially after the large-scale wind farm is connected to the grid, the influence on the safe and stable operation of the power network is more obvious, plus the influence of the uncertain factors in the power system itself, such as the fluctuation of the output power of the generator. The change of load power, line fault and so on, bring new challenge to power flow calculation of power system. The common idea and method of deterministic power flow analysis can no longer meet the new demand. The probabilistic power flow analysis method considering the influence of random factors has been developed and applied. Probabilistic power flow calculation combines the idea and method of probabilistic theory with power flow calculation of power system, and applies the method of probabilistic theory to analyze power flow of power system. The common power flow calculation results are the definite values of the power system voltage and power, and the probabilistic power flow calculation method can give the probability and statistical characteristics of the power system node voltage and branch power distribution. In this paper, the probabilistic characteristics of node voltage and branch power in a certain range are analyzed from the point of view of probabilistic statistical characteristics, which is of great significance for the planning and design of power system and the evaluation of power system stability. It is generally assumed that the network topology of the system is invariant and the branches are independent of each other in the calculation of probabilistic power flow, which simplifies the operation, but results in certain errors. In the actual power system, due to the influence of various factors, the branch of the system is broken randomly because of the external or its own reasons, which results in the change of the network topology, and the power flow distribution of the other branches is affected after the branch failure. The results show that there is a certain correlation between branches and is not independent of each other. Therefore, in order to reflect the actual power system operation more comprehensively and accurately in the calculation of probabilistic power flow, the correlation between the network topology and the branch should be considered. In this paper, the probability model of wind power generator is established according to the actual situation that a large number of wind farms are connected to the grid. Based on the probabilistic power flow algorithm, the probabilistic power flow calculation model considering the network topology changes and the correlation between branches is established, and the program is compiled by Matlab simulation software. The influence of the network topology and the correlation between branches on the node voltage and branch power of power system is analyzed.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM744

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