【作者】 查浩；

【导师】 韩学山；

【作者基本信息】 山东大学 ， 电力系统及其自动化， 2009， 博士

【摘要】 随着电力系统规模的扩大,以及发输电资源格局的变迁,系统运行中所面临的不确定性问题日渐增多,运行工况也日益复杂。尤其是市场竞争机制的引入,增加了系统的运行紧张程度,使得电力系统运行水平趋于安全的边界,再加上发电机组停运和输电元件断开等随机扰动因素,进一步增大了电力系统的运行风险水平。传统的电力系统运行调度理论框架一直是基于确定性的模型和分析方法,往往不考虑运行中随机事件的发生概率,也未对事件发生可能性与后果严重性之间做出协调,因而难免得出保守或冒进的决策方案。针对目前电力系统发展中所呈现出的运行工况愈加复杂,以及市场参与各方经济利益交互影响的特点,使得传统基于确定性方式的调度理论已难以适应当前的形势要求,面临着完善提升的迫切需要。因此,关联考虑电力系统运行中随机事件的发生概率与其对应后果代价,揭示调度方案所蕴含的风险理念与经济规律,给出资源优化配置的引导方向,即构建在经济规律引导下、概率规律为主导线索,将风险和调度有机统一,就成为电力系统运行优化调度理论亟待解决的问题。本文工作正是在这一背景下,以电力系统运行中的概率规律为线索,以经济规律为引导,以优化数学为手段,将风险与调度融合、衔接及协调为研究内容,进行概率优化调度理论研究和探索,其主要工作和有新意成果体现如下:(1)提出了电力系统概率优化调度的基本概念,构建了该问题的一般数学模型及理论框架体系。通过电力系统优化调度理论演变过程分析,表明概率优化调度理论是对电力系统优化调度、可靠性评估和运行风险评估等理论的融合、提升和发展。概率优化调度理论研究目的在于通过关联电力系统运行中随机事件的发生概率与其对应后果,从而给出协调考虑运行安全、经济和可靠的优化调度决策。以此概念为基础,本文以直流潮流为基础,重点针对机组故障和输电元件停运所对应的随机概率事件,建立系列概率优化调度模型和算法,在电力系统运行调度理论研究领域有所进展。(2)建立计及发电机组故障的概率优化调度模型和算法。该模型以期望的发电运行成本最小为目标,以机组故障发生概率为协调手段,以事故后发电机组的调整速率为牵制条件,统筹考虑了机组的运行成本、事故状态下的出力再调整成本以及需求侧的负荷中断赔付。这样,该模型以概率方式协调了机组事故前后状态之间的经济性牵制,实现了经济规律引导下对机组旋转备用的优化配置、调用以及责任的度量。由该模型提出的算法,通过对三种调度方式的对比研究与分析,表明这一最基本的概率优化调度模型是有效的。(3)建立计及输电元件停运的概率优化调度模型和算法。该模型通过引入电网安全价值系数,构成电力系统运行调度经济性和安全性折中统一的期望优化目标,在满足电网正常状态和一定的输电元件预想事故集合对应约束下,获取概率的最优调度解。其中,所谓运行调度的经济性,是考虑了系统的期望运行总成本,并考虑了输电元件停运事件状态下的发电机组再调整和负荷中断所对应的安全校正耗费;所谓运行调度的安全性,则是考虑了输电网络在事故前后状态所对应的期望负载严重程度。这样,该模型以概率方式实现了运行调度中经济性与安全性的均衡协调,量化了电力系统运行调度方式所对应的安全经济运行风险水平。由该模型提出对应的算法,通过对五种调度方式的对比研究与分析,表明这一扩展的概率优化调度模型是有效的。(4)建立协调系统运行综合效益的概率优化调度模型和算法。该模型以电力系统的期望运行效益最大为目标,综合考虑发电机组的正常运行成本和再调度调整成本、以及需求侧负荷的正常收益与中断补偿,采用马尔可夫链对未来调度时段由输电元件所引起的随机事件状态概率进行预测,在满足所有输电元件停运事故发生前后状态所对应约束集下获取调度解。其中,在输电元件停运事件发生后的紧急容许时间内,针对可能出现的电力系统安全破坏情形,在约束集合中考虑了发电机组所允许的输出功率再调整、需求侧负荷中断、以及输电元件的短时紧急允许过载量,并考虑相应安全校正措施的费用代价。这样,由该模型提出对应的算法,该模型实现了电网运行状态概率预测与有功优化调度决策的紧密结合,得到了电网期望最大运行效益的时序变化曲线,以及各个时段下风险与效益相均衡的调度方式和事故状态下的优化校正措施。通过对该模型所含不同调度方式的对比研究与分析,表明这一丰富电力系统概率优化调度模型是有效的。(5)对概率优化调度模型复杂性分析的基础上,提出对适应大规模电网快速求解的手段。针对概率优化调度模型规模庞大,整体求解计算效率不高的实际现状,通过吸取传统安全约束优化调度的分解处理思路,对概率优化调度模型特点进行了分析。这样,通过从输电元件对应的随机事件集合中循环遴选关键有效事件,实现了对问题规模的降阶处理,提高了计算效率,显现了该处理方式对解算大系统有一定适用前景。更多还原

【Abstract】 With the expansion and deregulation of the power system, which is confronting more operating uncertainties, thus the operation condition is becoming more and more complicated. Especially the introduction of market competition mechanism, which leads the operation of power system to the margin of security, coupling with the contingency of generator outage and transmission component failure, thus the power system operating risk is increasing much more. Traditional power system dispatching framework is based on the deterministic model and method, which can not reflect the real system operating risk, so the dispatching results may be either conservative or radical as it does not take into account of the possibility of the contingency. Because of the complicated operating condition and the economic interaction of market participants, the traditional deterministic pattern is not suitable for current situation and needs to be upgraded urgently. Therefore, the coordination of severity and probability of the contingency in power system operating condition, unfolding the risk essence and economic meaning, and presenting the optimal allocating direction of the resources, i.e.constructing the direction by the economics and probability theory, combining the consideration between operating risk and dispatching strategy, so the power system probabilistic optimal dispatching in the real-time operating condition has become a urgent research problem.This thesis has investigated the optimal dispatching by considering probabilistic disciplinarian and economic law under the real-time operating background. Based on the mathematical optimization theory, the research of probabilistic optimal dispatching has been carried out. The main research work and innovation of this thesis are shown as follows:(1) The concept and frame of power system probabilistic optimal dispatching have been established in this thesis. By analyzing the evolution of power system optimal dispatching model, it can be demonstrated that the probabilistic dispatching theory develops and integrates the traditional optimal dispatching, reliability evaluation and operating risk research. The intention of power system probabilistic optimal dispatching is to associate probability and outcome of the contingency, and giving the optimal decision-making of coordinating the security, economy and reliability. Based on the DC power flow model, the probabilistic optimal dispatching model and solution method have been investigated by considering the generator outage and transmission component failure. Therefore, the power system operating dispatching researching level has been promoted.(2) The power system probabilistic optimal dispatching model and it’s solution arithmetic of considering generator outage has been established. This model has the objective function of the expected operating cost minimum, by considering the generator probabilistic outage characteristic and ramping rate, so the operating cost, corrective cost and the load interruption compensation have been taken into account altogether. Therefore, the economic relation has been coordinated in this mode for pre-contingency and post-contingency states, and the optimal allocation of spinning reserve, also the responsibility among the generators can be quantified for each other. With the comparison and analysis of three different dispatching modes, the basic probabilistic optimal dispatching model has been demonstrated effectively by the solution arithmetic.(3) The power system probabilistic optimal dispatching model and solution arithmetic of considering the transmission component failure has been established. With the power network security value factor, the power system operating economy and security have been compromisingly combined into one uniform expected objective function, thus the probabilistic optimal results can be obtained with the constraint-set of power network normal state and definite contingency states. Thereinto, the so-called dispatching economy has considered the power system expected operating cost, which has also included the security-corrective costs of generator ramping and load interruption at the contingency state. The so-called dispatching security has been represented by the power network expected loading severity of both the pre-contingency and post-contingency states. Therefore, the dispatching economy and security have been coordinated, and the operating risk of dispatching mode has been quantified. With the comparison and analysis of five different dispatching modes, the further evolutive probabilistic optimal dispatching model has been demonstrated effectively by the corresponding solution arithmetic.(4) The power system probabilistic optimal dispatching model and solution arithmetic of considering the compositive operating benefit has been established. This model has the objective function of power system expected operating benefit maximum, which has considered the generator operating cost and the redispatching costs, also the load normal benefit and interruption compensation in demand-side has been considered. With the forecasting probabilities of transmission conponent contingency states in future period by markov chain, the optimal dispatching results can be obtained with the constraint of both pre-contingency and post-contingency state. And for the possible security breaking case during the post-contingency state, the generator unit ramping, emergent load interruption and transmission component short-term overloading within the allowable time have been included in the constraint-set, also the cost of the corrective measures have been taken into account. Therefore, the forecasting probability of the power network operational tendency and active power optimal dispatching decision-making have been combined in this model, which can attain the curve of expected operating maximal benefit in different dispatching period, also the coordinated dispatching mode under the probabilistic framework of harmonizing risk with benefit corresponding to that period and the corrective strategies for emergent states. By contrasting the different dispatching modes, this progressive power system probabilistic optimal dispatching model has been demonstrated to be effectively.(5) Based on the complexity analysis of the probabilistic optimal dispatching model, an efficient solution pattern has been brought forward. For the huge dimension of probabilistic optimal dispatching, it is inefficient to solve it as a whole problem. Enlightened by the decomposing thought of the traditional optimal dispatching method, the probabilistic optimal dispatching model characteristic has been analysed. Thus, the decrescent model has been obtained by the critical contingency selecting in cyclical pattern. Therefore, the dimensions of the original model has been decreased ,and the calculation efficiency has been improved by this solution pattern, thus it may be feasible for the large power system.更多还原