基于广义多项式混沌法的电力系统时域仿真不确定性分析

发布时间：2018-06-03 09:12

本文选题：时域仿真 + 不确定性分析　；参考：《浙江大学》2017年硕士论文

【摘要】：时域仿真方法通常采用确定性的仿真模型,通过数值计算模拟系统的实际运行情况,目前已广泛应用于电力系统规划、设计与运行中。然而,电力系统中存在多种不确定性因素,若采用确定性仿真方法,其结果往往不符合实际情况,不利于对系统运行状态做出全面的判断。因此,有必要对时域仿真结果的不确定性进行分析和评估。针对电力系统模型参数和稳态条件的不确定性,本文提出一种基于广义多项式混沌法的时域仿真不确定性分析方法。广义多项式混沌方法近似认为变量在任一时刻与随机因素之间存在多项式关系,求解时首先获取最优的正交多项式基函数,对随机输入变量及待求变量实施多项式逼近,并基于Galerkin法,通过投影运算将描述系统暂态过程的随机方程转变为相应的确定性方程。通过求解该投影方程,即可得待求变量的多项式逼近系数,进而获得待求变量在任一时刻的统计特征及概率分布。为了适应广义多项式混沌法的求解,本文在现有暂态模型的基础上,通过数学变换,提出多项式形式的暂态仿真模型。文中,从理论上对该模型进行了推导,并基于IEEE9节点系统,验证了该模型的准确性。除此之外,文章通过将所提方法的计算量与蒙特卡洛法进行比较,从理论上分析了广义多项式混沌法的计算效率。并通过算例分析,验证了所提方法的有效性。
[Abstract]:The time domain simulation method usually uses deterministic simulation model. It is widely used in power system planning, design and operation by numerical calculation of the actual operation of the system. However, there are many uncertain factors in the power system. If the deterministic simulation method is used, the results are often not in line with the actual situation, which is not conducive to the overall judgment of the system operation state. Therefore, it is necessary to analyze and evaluate the uncertainty of time domain simulation results. In this paper, a time-domain simulation uncertainty analysis method based on generalized polynomial chaos method is proposed for the uncertainty of power system model parameters and steady-state conditions. The generalized polynomial chaotic method approximates that there exists a polynomial relationship between variables and random factors at any time. The optimal orthogonal polynomial basis function is first obtained when solving the problem, and polynomial approximation is carried out on the random input variables and the variables to be solved. Based on the Galerkin method, the stochastic equation describing the transient process of the system is transformed into the corresponding deterministic equation by projection operation. By solving the projection equation, the polynomial approximation coefficients of the variables to be solved can be obtained, and then the statistical characteristics and probability distribution of the variables to be solved at any time are obtained. In order to adapt to the solution of generalized polynomial chaos method, this paper presents a polynomial transient simulation model based on the existing transient models and mathematical transformation. In this paper, the model is deduced theoretically, and the veracity of the model is verified based on IEEE9 node system. In addition, the computational efficiency of the generalized polynomial chaotic method is theoretically analyzed by comparing the computational complexity of the proposed method with that of the Monte Carlo method. The effectiveness of the proposed method is verified by an example.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM743

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