含风电电网的动态全局最优潮流及其两级协调控制算法

Dynamic Global Optimal Power Flow and its Two-Stage Control Algorithm of a Power Grid Integrated with Wind Power Farms

针对含风电电网中风电出力的波动性,开展动态全局最优潮流分析,提出2级协调控制算法,并建立相应的数学模型。该算法以风电出力全周期内全电网网损最小为目标函数,将传统控制手段(即控制变量为变压器档位和并联电容器组数)与快速响应的有功和无功补偿手段相结合进行分步优化,得到能充分发挥传统控制手段和快速响应补偿手段各自优势的优化调控方案,并减少了传统控制手段的动作次数。此外,为准确模拟风电并网特性并使该新算法快速收敛,以改进牛顿拉夫逊法为潮流计算手段,采用遗传算法实现寻优。其中,改进牛顿拉夫逊法考虑了双馈和异步2种风机并网方式,建立其P-Q(V)节点模型,修改雅克比矩阵对角线元素,可较好地适应含风电场电网的潮流计算,进一步提高2级寻优结果的准确性。最后,将所提算法应用于华中地区某风电场的并网分析,并与已有文献中的多时段最优潮流控制策略进行对比,表明所提算法合理有效,具有实用价值。

In order to solve the fluctuation problems of wind power in a grid, the dynamic global optimal power flow analysis is eoudueted and a lwo-slage control algorithm and its mathematical model are presented. The algorithm sets the minimum grid power loss as the objective function in a period of wind power output, arid opthnizes the traditiomal control method （with the taps of transformers and numbers of capacitors in parallel as variables） and the fast response control method （with active and reaetiw power compensation） separately, to redtwe the action limes of the traditional control method and get the optimal control strategy which lakes both methods＇ advantages. For accurate simulation of wimt power conneeted to the grid and fast convergence of the new algorithm, a modified Newton-l,aphson power tlow method wilh genetic algorithm for the dynamic global OPF is set up, in which the P-Q（V） equations are established and lhe Jaeobi Matrix is modified with consideration of the double-fed and aswwhronous wind generators eonnected to the grid. The method is suitable for power flow eah.uhllion of the grid integrated with wind farms, and can improve the accuracy of the two-stage control method. The reasomtbility and efficiency of the proposed algorithm are verified through its application in the analysis of the wind power integrated system in central China area. and comparison of the computed results with those of conventional multi-stage OPF method.