快速计算概率不安全指标及基于DSR的运行成本的优化

发布时间：2019-06-19 04:56

【摘要】：随着全球经济迅猛发展,联合电力系统的出现满足了用户的需求,与此同时,拓扑结构的复杂性和多变性也为大电网运行埋下了安全隐患。传统的安全性分析可以通过“逐点法”对系统运行状态进行定性的判断,但考虑到在进行定性计算时,会出现难以忍受的计算量和耗时,因此所得到的结果也不令人满意。动态安全域的思想,可以将问题转化为发生扰动时,系统运行点是否还在一个域内。同时,动态安全域也对系统运行状态进行定量的判断,即安全裕度以及概率不安全指标。本文提出了基于角度旋转法快速计算概率不安全指标的方法。首先对系统输电线路不同故障点的动态安全域及边界进行大量仿真,发现不同故障点的动态安全域边界有近似平行的关系,且有一个空间夹角。同时,从首端沿着线路延伸发生故障,各个超平面与参考超平面之间的夹角呈线性变化。因此,可以通过该规律,先用拟合法计算出故障首末两端的DSR边界超平面,再根据各超平面之间系数的线性关系进行分析计算,快速求得各地故障时系统的概率不安全指标。以WSCC4机11节点系统为例,可以得出:概率不安全指标的数值基本一致,最大综合误差仅为2.84%,计算时间仅为拟合法所用时间的15.39%。同时,系统越复杂,注入维数越多,角度均匀旋转法的优势越明显。通过快速计算概率不安全指标,可以快速判定系统的暂态运行状态。如果故障发生需要进行紧急控制,就必然要考虑到系统需付出的正常运行成本以及紧急控制措施的成本。因此,本文提出了以整个系统总期望成本为目标函数的最优化潮流模型,模型中计入了预想事故的发生概率。一部分成本为正常运行时的成本;另一部分为最优紧急控制措施的成本,将这两部分成本按照其发生概率计入目标函数。10机39节点算例表明,本文模型所得结果较传统的考虑多个暂态稳定约束的最优化潮流模型总成本减少12%。
[Abstract]:With the rapid development of global economy, the emergence of joint power system meets the needs of users. At the same time, the complexity and variability of topology also lay a hidden danger for the operation of large power grid. The traditional security analysis can qualitatively judge the running state of the system by "point-by-point method", but considering that there will be unbearable computation and time consuming in the qualitative calculation, the results obtained are not satisfactory. The idea of dynamic security domain can transform the problem into whether the running point of the system is still in a domain when disturbance occurs. At the same time, the dynamic security domain also quantitatively judges the running state of the system, that is, the safety margin and probability insecurity index. In this paper, a fast calculation method of probability insecurity index based on angle rotation method is proposed. Firstly, a large number of simulations are carried out on the dynamic security domain and boundary of different fault points of the system transmission line, and it is found that the dynamic security domain boundary of different fault points is approximately parallel, and there is a spatial angle. At the same time, the fault occurs along the line extension from the first end, and the angle between each hyperplane and the reference hyperplane changes linearly. Therefore, through this law, the DSR boundary hyperplane at the beginning and end of the fault can be calculated by fitting method, and then the probability insecurity index of the system can be obtained quickly according to the linear relationship between the coefficients between the hyperplanes. Taking the 11-bus system of WSCC4 machine as an example, it can be concluded that the value of probability insecurity index is basically the same, the maximum synthesis error is only 2.84%, and the calculation time is only 15.39% of the time used by fitting method. At the same time, the more complex the system is and the more the injection dimension is, the more obvious the advantage of the angle uniform rotation method is. By calculating the probability insecurity index quickly, the transient operation state of the system can be determined quickly. If the fault needs emergency control, it is necessary to take into account the normal operation cost of the system and the cost of emergency control measures. Therefore, this paper proposes an optimal power flow model with the total expected cost of the whole system as the objective function, which takes into account the probability of the expected accident. One of the costs is the cost of normal operation, the other is the cost of the optimal emergency control measures, which is included in the objective function according to the probability of occurrence. The 39-node example of 10 machines shows that the total cost of the optimal power flow model with multiple transient stability constraints is reduced by 12% compared with the traditional optimal power flow model with multiple transient stability constraints.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM732

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