导　　师： 刘明波

学科专业： 080802

授予学位： 博士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 随着电网规模的不断膨胀和结构日趋复杂，国内外大面积停电事故呈多发趋势，且造成无法估量的经济损失和严重的社会影响。当电网出现事故时如何尽量减小停电范围和停电负荷，当电网出现大面积停电时如何尽快恢复供电减少停电时间，是现代大电网必须面对和解决的问题。目前，大停电后电力系统的恢复控制尚处于离线编制方案、调度员凭经验调度恢复的阶段，如何实现电力系统恢复控制的自动化和实用化，并利用先进理论和技术加速故障后的恢复进程，是一个值得深入研究的课题，具有重要的工程背景和理论价值。 黑启动是电网恢复的首要阶段，大量的非黑启动机组需要在这一阶段尽快恢复，该阶段最重要的参数是恢复时间。传统的黑启动电源多为小水电及小型燃机，地处偏远、容量小、接入电压等级低，难以满足大面积停电后电网快速恢复的需要。快速切负荷（FastCut Back，FCB）技术能使火电机组在与电网解列后不停机不停炉，带厂用电孤岛运行，在电网故障消失后迅速并网升负荷，是一种理想的黑启动电源。本文讨论大型火电机组实现FCB功能的关键技术，建立FCB静态与动态模型，为深入研究FCB机组在系统恢复控制过程中的关键性作用奠定了模型基础。通过台山电厂1000MW机组的FCB试验和空充500kV线路试验，验证了FCB机组维持孤岛运行及启动高压输电网架的能力，进而验证了FCB机组在电网恢复控制中的关键作用。 电力系统的恢复控制策略与系统的特性有很大的关系，很难制定一个通用的故障恢复策略。然而，不同电力系统恢复过程中的阶段性目标是相同的，实现阶段性目标的策略也存在很大的相似性，因此从目标解耦的角度出发，存在建立具有兼容性、通用性的电力系统恢复控制方法的可能性。基于该思路，本文在分析电网恢复控制的共性问题和特殊需求的基础上，根据解耦的思想，深入研究系统恢复涉及的物理过程和主要关注的问题，将其解耦成若干相对独立的子问题，建立了基于目标驱动的电网恢复控制方法框架。在该框架下，本文考虑了FCB机组对电力系统恢复控制的关键性作用，建立了含FCB机组的电力系统恢复控制策略优化模型，该模型能够计及多种运行约束，找出最优的机组启动顺序和系统恢复总时间，但该非线性模型目标函数含有积分项，现有优化方法无法直接求解该模型，本文从物理本质出发，提出一种实用计算方法避免了繁冗的积分运算，快速求得优化的机组启动顺序。 本文进一步研究了FCB机组容量及安装位置的不同对系统恢复时间的影响。确定FCB机组的最优布点方案，需要解决两个问题：一是计划改造几台FCB机组，二是对哪几台火力发电机进行FCB技术改造。利用枚举法求解FCB机组布点方案计算量非常大，工程上无法接受。本文将序优化理论引入FCB机组布点问题中，以系统恢复时间最短为优化目标，并考虑约束条件，建立相应的优化模型并给出求解方法。 最后，本文基于风险与效率的综合考虑，针对给定的布点方案，通过遍历寻优得到所有较优的黑启动方案，并将这些黑启动方案的评估指标进行综合，得到用于表征该黑启动机组布点方案所具有的风险、效率水平的量化评估结果。该评估方法能够很好评估FCB机组布点方案所对应的黑启动过程所具有的效率及风险应对能力，对于FCB机组布点的选取具有一定的指导意义。 本文工作得到广东电网公司重大科技项目（K-GD2011-553）的资助，部分研究成果已经成功应用于广东电网公司，有效的解决了该电网中水电机组不足而电网运行可靠性要求高的技术难题，取得了良好的社会和经济效益。 With the power grid continues to expand and its structure becomes more and morecomplex, there is an upward trend of the occurrence of the large-scale blackouts, which causehuge economic loses and serious social impact. Basically, what the current power grid musttackle with are how to minimize the blackout scale and blackout load when there is a gridfailure, and how to expedite the power system restoration process as quick as possible after alarge-scale blackout. Currently, the control of power grid restoration after a blackout stillremains in a stage of offline-plan makeup and next, power system restoration according todispatcher’s experience. Researches about the automation of the power system restoration andthe application of advanced theory and technology to accelerate the restoration process have asignificant engineering and theoretical value. Black start is the first and most important stage in a power system restoration, and a largenumber of non-black start units need to be restored as soon as possible in this stage. The mostimportant parameter of the stage is restoration time. Traditional black start units are lowcapacity hydroelectric units and gas turbines, which cannot meet the requirements of a fastrestoration after a large-scale blackout due to the remote location, low capacity, and lowvoltage level. Fast Cut Back /(FCB/) technology can keeps thermal units continuing islandoperation to generate auxiliary power even after the units are split from the power grid, whichfinally makes thermal units an ideal black start power because thermal power can reconnectinto grid after the elimination of the grid failure. In this paper, the critical technologies forthermal units to acquire FCB function are discussed, and both the static and dynamic modelsof FCB units are established, which lays a modeling foundation to investigate the keyfunctions of FCB units in a power restoration process. The abilities of the FCB units tomaintain island operation and to start high voltage power grid are verified through the FCBtest of1000MW thermal unit in Taishan power plant and the test of charging unloaded500kVline. These also proceed to verify the significant role performed by the FCB units in therestoration control. Generally, it is hard to figure out a universal failure restoration strategy because the restoration control method has a strong relationship with the system’s characteristics.However, considering that the stage targets of different systems are the same, and the methodsto fulfill these targets are similar, it is possible to establish a compatible universal controlmethod for the power system restoration based on the decoupling of stage targets. Followingthis idea, issues of common concern and special requirements for power system restorationcontrol are analyzed. According to the idea of decoupling, the physical processes and the maincommon issues are investigated, and the restoration process is decoupled into severalindependent problems, and finally the target-based control method frame is established forpower system restoration. Considering that FCB units play a key role in power systemrestoration, an optimal control model is developed for power system with FCB units based onthe control frame method mentioned above. The model takes several operating constrains intoaccount and finds out the optimal unit starting sequence and the corresponding systemrestoration time. However, there are some integration terms in the objective function of thisnonlinear model, which cannot be solved directly using the current optimal method. Apractical computational method is proposed in this paper to avoid the onerous integrationcalculation, therefore it can be applied in finding out the optimal starting sequence of units ina much quicker way. The paper proceeds to investigate the influences of different FCB unit capacities andlocations on system restoration time. Basically, two main problems should be settled to findout the optimal layout of FCB units. The first one is how many units need to be transformedinto FCB units, the second one is to determine which thermal generators should betransformed. Computing the layout of FCB units by enumeration method exists a combinationexplosion problem, and the computation requirement is too heavy for the engineeringapplication. This paper introduces the Ordinal Optimization Theory to find out the optimallayout. The minimum system restoration time is regarded as the optimization goal, theconstraint conditions are considered, and the corresponding optimal model are developed. Thesolution to the model is also presented. Finally, based on the comprehensive consideration of both risk and efficiency, for a specific given layout, all of the optimal black start schemes are obtained through traverse. Theassessment indexes of these schemes are synthesized, and a quantized assessment resultreflecting the risk and efficiency level of the black start schemes is obtained. The assessmentmethod has some guiding significance on the layout of the FCB units since it can evaluate theefficiency and response capacity for risk of the corresponding black start process. This work was supported by Special Fund of Key Science and Technology Projects ofGruangdong Power Grid Corporation, China,/(K-GD2011-553/). Some of the research resultsare successfully applied in Gruangdong Power Grid Corporation, which has yielded somesatisfactory results through effectively solving the technical problem of a lack of hydroelectricunits in the power grid with a demand of high reliability of the grid operation.

关 键 词： 恢复控制 快速切负荷 静态模型 动态模型 现场试验 布点规划

分 类 号： [TM621]

领　　域： [电气工程]