【作者】 潘炜；

【导师】 杨以涵； 刘文颖；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2008， 博士

【摘要】 针对我国电力市场建设和电网运行中出现的节能调度、电网输送能力不足、动态稳定问题突出等问题,对概率最优潮流、PSS为电网提供的稳定服务评估、机组同调识别和大区电网稳定分析四个问题进行研究和探索,提出新的思路和方法,主要成果有:提出一种基于三点估计的概率最优潮流算法。这种算法采用随机变量的高阶矩构造估计点,通过随机变量与目标函数之间的确定性关系对目标函数进行点估计,得到目标函数的统计特征值。所提出的算法能方便地将概率问题转化为确定性问题处理,因此可以有效利用电力系统中已有的计算资源,提高计算效率,得到的结果中包含丰富的概率信息,能更全面地揭示市场运营情况。提出用经济学的观点来看待PSS增强系统阻尼、改善系统动态品质和提高电网输送能力的作用,指出电力系统稳定器(PSS)所提供的稳定服务是一种辅助服务。提出可以用合作博弈中的Shapley值和核仁方法,评估PSS对系统动态稳定性的贡献,量化分析PSS对大型互联电网输送能力的影响。这为全面衡量励磁控制在电力市场中的价值,推动发电方改进励磁控制技术,深化电力市场改革,提供了新的思路。提出一种采用独立分量分析技术对故障后的发电机受扰轨迹进行特征提取,来识别机组同调特性的方法。与现有方法相比,这种方法不需要获得系统元件模型和参数,而是直接采用WAMS系统测量得到的发电机转速信号,利用独立分量分析进行模式识别得到分群结果。由于这种方法不需要知道机组参数,因此在市场化环境中这种方法有较好的应用前景。提出在市场化的时代背景下,西北750kV电网运行初期面临的安全稳定问题及对策。在西北电网仿真计算中引入实测励磁系统模型和参数,对结果进行分析发现西北电网动态品质和稳定水平显著上升,西北电网输送能力可以大幅度提高。研究了750/330kV电磁环网运行方式对系统安全稳定性的影响,提出在未形成坚强的750kV网架结构前,合环运行比解环方式更有利于提高西北电网输送能力和稳定水平。还提出了西北电网安全稳控系统建设目标,指出需基于广域信息,开展振荡解列装置、电网在线稳定控制系统和低频/低压减载装置的在线控制策略研究,增强西北电网安全稳定控制装置的自适应性和协调控制能力,进而实现广域控制,提高处于动态变化中的西北电网安全稳定运行水平。更多还原

【Abstract】 In this thesis the following issues related with electric power system and electricity market are researched. They are probabilistic optimal power flow, transfer capability and ancillary services, coherency identification, and large-scale power grid stability analysis. The main achievements are as follows:A three-point estimate method to solve the probabilistic optimal power flow for electricity market with uncertain factors was proposed in this paper. The high-order moments of stochastic variables to construct the estimate points and the certain relations between stochastic variables and objective function were utilized to determine the estimate value of objective function. By this method the probabilistic problems can be handled with same routines as those corresponding to deterministic problems while alleviating the computational burden. Probabilistic information obtained by this method is helpful to reveal the actual status in electricity market.From the point of economic theory view, the issue of pricing the services provided by Power System Stabilizers (PSS) to damp out low-frequency oscillations in large interconnected electrical power grids was proposed. Methods based on Shapley value and nucleolus in the cooperative game theory were utilized to determine the PSS impact on power system transfer capability and its contribution to power system dynamic stability. All of these give new concepts in evaluating the value of excitation control in electricity market , and provide Genco incentives to improve excitation control technology.An independent component analysis (ICA) based feature extraction method for analyzing perturbed trajectories of generators was proposed. Comparing with existing methods, generators’speed signal measured by WAMS can be utilized directly in new solution while detailed model and parameter of power system components were not needed. By this means high-order data of multi-machine perturbed trajectories were reduced to lower dimensions, and coherent generator groups were identified by pattern recognition consequently. This method is useful in electricity market environments because of it no need for generators’parameters.The problems of 750kV Northwest China power grid encountered in initial operating stage and corresponding solutions were proposed. The actually measured excitation system models and their parameters were led into annual power network stability calculation. Simulation results show that by use of such models and parameters the dynamic performance and stability level of Northwest China power grid is evidently improved. The transmission capability of Northwest China power grid can be raised considerably. Influence of operation modes of electro-magnetically coupled 750/330 kV power grid on system security and stability when Northwest China 750 kV main network preliminarily completed is also researched. The results of static security and stability analysis show that before a strong 750 kV network is built up, the operation mode of electro-magnetically coupled power grid, i.e., the close-loop operation mode, is available to enhance the transmission capacity and stability level of Northwest China power grid than open loop operation mode. The target of constructing Northwest China power grid was also proposed. It is pointed out that based on the wide area measurement system, on-line control schemes of controlled system splitting, stability control and low-frequency/low-voltage load-shedding should be studied immediately. Adaptive and coordinated control on Northwest China power grid can be achieved by establishing wide area control system. By these means, Northwest China power grid can keep secure and stable operation and healthy development.更多还原