计及AGC与AVC控制作用的静态电压稳定研究

发布时间：2018-02-10 08:01

本文关键词： AGC AVC 无功电压分区扩展潮流静态电压稳定裕度　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：为了合理利用能源，提高经济环保效益，国内外电力系统快速向大机组、互联电网、超高压远距离输电方向发展，导致电压稳定问题日益突出，成为威胁现代电网安全稳定的主要因素[1]。AGC (Automatic Generation Control，自动发电控制)及AVC (Automatic Voltage Control，自动电压控制)系统的有功、无功控制行为对电网的电压稳定性有着深刻的影响[5]。本文对此进行了深入研究，主要工作如下：提出考虑区域发电机有效无功备用的AVC控制分区方法。AVC应用于实际系统时，无功电压分区是否合理对其控制效果至关重要，也间接影响系统的电压稳定程度。现有分区方法仅依据节点间电气耦合程度对电网进行划分，本文在其基础上，进一步考虑分区内部的无功储备要求，建立了优化分区模型，目标函数包括各分区无功电源的供电半径平方和最小和发电机无功储备最少的分区其有效无功备用值最大化两个目标，约束方面要求各分区满足静态无功平衡及连通性约束。针对所建模型的离散性特点，采用多目标进化规划算法进行求解，并在算法中引入随机分区变量的自适应变异策略及可行性调整策略以提高搜索效率。最后将分区方法应用到IEEE39节点系统中并于现有的研究进行对比，证明了本文所提的AVC控制分区方法的有效性及优越性。提出计及机组频率调节特性与二级电压控制的联合扩展潮流计算方法。目前大多数静态电压稳定分析方法都基于潮流方程，其结果是否合理依赖于潮流模型对实际电网的反映能力。常规潮流虽过程简单、计算效率高，但求解已知条件相对固定且人为确定成分较多，难以有效用于实时电压安全稳定分析中。基于此，本文结合现有的考虑工频特性潮流[64]及节点类型扩展潮流[63]模型的特点，，对常规潮流模型进行了改进。首先，系统中发电机根据各自频率调节系数共同承担不平衡功率，相比常规潮流仅靠平衡节点来承担网损的处理方式更符合系统实际。其次，通过对中枢节点和受控发电机节点的建模及引入区域无功协调方程，考虑了二级电压控制对潮流分布的影响。并综合考虑受控发电机的无功裕度及其与中枢节点间的电气距离来协调区域内无功电源的出力，使得无功分布更加合理。最后，通过算例仿真证明了本文模型的合理性及优越性。在上述研究基础上，提出计及AGC与AVC控制作用的静态电压稳定分析方法。针对现有的基于连续潮流的静态电压稳定研究在负荷增长方向、发电机有功分配方式及系统无功控制等的模拟中存在较多偏离系统实际运行情况的假设，从而导致计算出的负荷裕度无法真实反映系统实际的电压稳定程度，本文做了如下研究：首先，为了使连续潮流的负荷增长方式更符合实际情况，利用实时调度中的超短期负荷预测曲线，通过线性拟合确定各节点的负荷增长系数；其次，在发电机有功出力分配方面，考虑了机组的一次调频与AGC的共同作用，因而更贴近实际系统的有功调度方式。再次，模型计及了随着负荷增长AVC控制系统对节点电压的调整作用，并在模拟AVC控制策略时考虑了连续控制变量与离散设备的无功协调问题。最后，以IEEE39节点系统为例进行了仿真计算，分析了上述因素对静态电压稳定裕度的影响，并通过与现有研究的结果对比分析，证明了所提方法的有效性和优越性。
[Abstract]:In order to make rational use of energy, improve the economic benefit of environmental protection, power system at home and abroad to large units, interconnected power grid, UHV long distance transmission direction, leading to voltage stability problems have become increasingly prominent, has become the main factors of [1].AGC security and stability of modern power grid (Automatic Generation threat Control, automatic generation control (Automatic) and AVC Voltage Control, automatic voltage the control system of active power and reactive power) control the voltage stability of power grid has the profound influence of [5]. conducted a thorough study, the main work is as follows:
Put forward the effective reactive power reserve generator considering regional AVC control.AVC partitioning method is applied to the actual system, voltage and reactive power partition is reasonable is very important to its control effect, but also indirectly affect the voltage stability of system. The existing partition method is only based on the degree of coupling between nodes on the grid Electrical Division, this paper on the basis of further consideration reactive power reserve requirements within the established optimization partition, partition model, the objective function including the partition of reactive power supply radius and minimum square and generator reactive power reserve minimum partition the effective reactive power reserve value maximization two objectives, constraints requires each partition satisfy the static reactive power balance and connectivity constraints for. The model of the discrete characteristics, using multi-objective evolutionary programming algorithm to solve the problem, and the introduction of random variables in the partition algorithm in the adaptive mutation strategy And the feasibility adjustment strategy to improve the search efficiency. Finally, the partition method is applied to the IEEE39 node system. Compared with the existing research, it proves the effectiveness and superiority of the AVC control partition method proposed in this paper.
The regulation characteristics combined with extended power flow calculation method of two level voltage control unit and frequency meter. At present most of the static voltage stability analysis method based on power flow equations, the results are reasonable or not depends on the current model of a real power system. Although the ability to reflect the trend of conventional process is simple, high computational efficiency, but the solution of known conditions are relatively fixed and human to determine the composition of the more difficult to effectively for the analysis of real time voltage security and stability. Based on this, this paper consider the characteristics of power frequency characteristics and node type [64] trend to expand the trend of the [63] model, the conventional power flow model is improved. Firstly, the system generator according to their frequency regulation factor share the unbalanced power, compared to the conventional power flow alone to undertake the processing way to balance the node network loss is more consistent with the actual system. Secondly, based on the central node and controlled generator The node modeling and introducing regional reactive power coordination equation, two level voltage control on power flow distribution is considered. And considering the electrical distance controlled generator reactive power margin and central node to coordinate the output reactive power supply area, the reactive power distribution is more reasonable. Finally, through the simulation example to prove the rationality and superiority of the proposed model.
On the basis of the above study, static voltage stability and control effect of AGC and AVC analysis method is proposed. According to the continuous trend of the static voltage stability of load in the growth direction based on the existing, there are more deviation from the actual operation of the system simulation hypothesis generator active and reactive power control and distribution system, which leads to calculate the load margin can not reflect the actual degree of voltage stability, this paper has done the following research: first, in order to load growth mode of continuous power flow more in line with the actual situation, the use of ultra short term load forecasting curve in real-time scheduling, each node of the load growth coefficient determined by linear fitting; secondly, the distribution of active power output, a function of a FM and AGC unit is taken into account, thus closer to the active power dispatching mode of actual system. Thirdly, the model of The effect of load increase with the adjustment of AVC control system on the node voltage, and the reactive power coordination problem of the continuous control variables and discrete devices in the simulation of AVC control strategy. Finally, an example of IEEE39 bus system was simulated and analyzed the influence of above factors on static voltage stability margin, and through comparison with the existing research results, validity and superiority of the proposed method.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM712

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