考虑风能发电的概率动态电压稳定分析

The uncertainties of random loads and random wind power outputs have effects on power system voltage stability. To address this problem, this project considers these uncertainties and their coherence, and proposes a probabilistic dynamic method to analyze voltage stability. This project is divided into three parts: developing the probabilistic estimation index of voltage stability, presenting the probabilistic index to determine the weak bus under multi-operation conditions and optimizing the capability and controller parameters of reactive compensation devices. Firstly, probabilistic dynamic continuation power flow model is builded. Based on this model, the probabilistic eigenvalue technique is applied to determine the stability probability at different load levels, and the probabilistic distribution of stability margin can be estimated. Secondly, the probabilistic relationship between voltage stability weak bus and the multi-operation conditions is analyzed, so that the probabilistic stability index is developed for determination of the voltage stability weak bus under multi-operation conditions. Thirdly, based on the probabilistic stability index, the capability and controller parameters of reactive compensation devices at weak buses are optimized. Finally, the proposed probabilistic dynamic continue power flow model, probabilistic determination index of weak bus and the method to optimize the capability and controller parameters of reactive compensation devices at weak buses will be investigated on test system. The results will be compared and analyzed with those obtained by Monte Carlo method to validate the performance of improvements on the voltage stability of power systems.

针对电力系统中负荷的不确定性和大规模风电并网导致发电机出力不确定性影响系统电压稳定的问题，探究考虑这些不确定因素及其相关性的概率动态电压稳定分析方法。本项目的主要内容为建立电压稳定的概率评估指标，确定电压失稳弱节点的概率判断指标，提出考虑系统多运行方式的无功补偿设备容量优化及其控制器参数优化方法。在考虑不确定性因素的前提下，首先建立电压稳定分析的概率动态连续潮流模型，采用概率特征根技术，求取不同负荷水平下系统的稳定概率，从而确定系统电压稳定裕度的概率分布。接着分析系统电压稳定弱节点和多运行方式的概率对应关系，建立多运行方式下判断系统弱节点的概率指标，进而优化弱节点处无功补偿设备的容量，并且提出优化无功补偿设备控制器参数的方法。最后应用所提出的模型和方法对算例系统进行分析，并将结果与蒙特卡洛方法相比较，验证所建立模型和所提出方法的正确性和有效性。

由于人们越来越关注利用化石燃料导致的环境问题，而且不可再生的化石燃料的储量是有限的，发展替代的可再生清洁能源是必然的趋势。风能是一种可再生清洁能源，利用风能发电技术在世界范围内快速发展，越来越多的大规模风力发电场建成并网运行。然而，由于风能具有随机性和间歇性，风力发电机出力受风速的影响，不能像传统发电机那样调节，将对电力系统的稳定运行造成影响。. 结合无迹变换技术和最大熵原理，对包含风电场的电力系统电压稳定性进行了分析，确定了考虑负荷随机变化和风力发电机出力不确定性的电力系统电压稳定裕度的概率特征和概率分布。在算例系统上验证该方法的准确定和有效性。考虑到多种概率电压稳定分析方法先后被提出，并且均在保持了较高的计算精度下提高了计算效率。分析比较了各种概率电压稳定分析方法的特点，在算例系统上比较各种方法的计算准确度和计算时间。比较负荷标准差变化、风电场风速相关系数和负荷分布（服从正态分布或负荷运行曲线）对各种方法计算误差的影响，为后续的研究或者其他研究者选择合适的方法提供参考。考虑了部分动态因素的影响，在此基础上建立了风能发电并网下电压稳定分析的简单概率动态模型。