【作者】 周觅路；

【导师】 韦化；

【作者基本信息】 广西大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 电力系统最优潮流(Optimal Power Flow,OPF)是一个复杂的非线性规划问题,是对系统稳定运行状态的优化分析。它要求在满足一定的电力系统运行及安全约束条件下,通过调整系统中的控制变量来实现预定目标函数的最优。随着电力系统的飞速发展,越来越多的控制设备被用于电网中以调节系统的运行。这些设备的投入使用在优化系统运行方式的同时,也使得本来就十分庞大的最优潮流问题更加复杂,增加了人们对其分析和计算的难度。变压器是电力系统中最重要的可控设备之一,广泛应用于电网中需要改变电压的各种场合。以往OPF模型多是基于传统的变压器Π型等值电路建立的,该等值电路不能直观地反映出变压器对电压的调节作用,且对应的OPF模型较为复杂,不利于计算。本文基于虚拟节点的变压器模型,建立了极坐标下以系统运行成本最小为目标函数的最优潮流模型。使用世界上广泛使用的极坐标表示方式,不但能够反映电力参数的物理意义,还可以使模型更加简洁,便于理解、分析和记忆;虚拟节点的引入,其电压幅值代替了变压器变比对功率的影响,使得表达式降低了两次。同时,等式约束的Jacobian和Hessian矩阵非零元素个数的减少量分别至少是有载调压变压器支路个数的2倍和6倍,从而减少了计算量。用Matlab编程,在极坐标系下应用基于扰动KKT条件的原始-对偶内点法对基于传统变压器Π型等值电路的OPF模型和基于虚拟节点变压器的OPF模型分别求解。在相同的环境下,对TEST 4、IEEE 14～300节点和S-1047节点等7个测试系统进行仿真实验,仿真结果证实两种变压器模型的等价性及基于虚拟节点变压器的OPF模型的优越性。更多还原

【Abstract】 Optimal power flow(OPF)is a complex non-linear programming problem.It is the optimization analysis of stable running.OPF must meet the requirements of the rules of the power system operation and security constraints.By adjusting control variables of the system, it can optimize the parameters of the intended target function.With the rapid development of the power system,more and more control equipment to be used for power grids in mediating system’s operation.These devices put into use in optimizing the running way of the system. But,at the same time,it makes the large optimal flow problems more complicated and an increase difficult of their analysis and calculation.Transformer is one of the most important control equipment in power system,widely used in every corner which current and voltage need to change.More than the previous model, OPF is based on the traditional transformer-type equivalent circuit∏established.This model can not be directly reflected in the surge voltage transformer’s regulatory role and is complex to the analysis and calculation.Based on the virtual node transformer model,in polar coordinates system,we established a new OPF model which the objective function is to minimize operating costs.The use of the widely used polar coordinates that not only to reflect the power of the physical parameters of significance but also to make the model more concise, easy to understand,analyse and memory.The import of virtual nodes,which put the transformer voltage amplitude replace variable ratio,reduced the number of variables of expressions.At the same time,for equality constraints of the Jacobian and Hessian matrix,the reduction in the number of non-zero elements were reduced at least in the number of transformers 2 times and 6 times,thus reducing the amount of computation.Using Matlab programming,in polar coordinates system,we applied the primal-dual interior point method to solve the OPF model based on the transformer model of traditional∏type equivalent circuit and based on virtual nodes transformer model respectively.In the same circumstances,we did such as TEST4,IEEE14～300 and S-1047 nodes seven test systems simulation.Simulation results confirm the equivalence of two transformal model and the superiority of this OPF based on a transformer model with a virtual nodes.更多还原