基于连续潮流的配电网供电能力评估

随着非全相运行的分布式电源大量接入配电网,配电网固有的三相不平衡特征更加突出,传统配电网供电能力评估因忽略配电网三相不平衡特征导致结果不准确。为了准确分析三相不平衡特征对配电网最大供电能力评估的影响,建立了以配电网供电负荷参数最大为目标函数,考虑了支路热约束和节点电压等状态变量和分布式电源的有功和无功功率等控制变量的含分布式电源三相不平衡配电网供电能力评估模型。选择电压跌落情况最严重的相作为连续参数,确保预测-校正过程的的连续潮流法求解的结果更加精确。最后,采用拓展的IEEE33节点配电系统进行仿真验证,表明文中所提的模型和求解方法是有效的。

Power supply capability evaluation of distribution network based on continuation power flow

The extensive penetration of open-phase running distributed generators such as photovoltaic generators to distribution systems may lead to a serious three-phase unbalanced condition, which is an intrinsic characteristic of distribution systems. The effect of the traditional evaluation of the power supply capability for distribution network is poor without considering the unbalanced problem. In order to accurately analyze the influence of unbalanced three-phase characteristics on the power supply capability for distribution network, the evaluation model of power supply capability for unbalanced three-phase distribution network with distributed generators is proposed, which takes the maximum load parameter of the distribution network as the objective function, considers the state variables such as branch thermal constraints and nodal voltage, and the control variables such as active and reactive power of the distribution power supply. The phase with the most serious voltage sag is selected as the continuous parameter to ensure the continuation power flow algorithm of prediction and correction is accurate. Finally, the simulation result of the modified IEEE 33-bus three-phase test system shows that the proposed model and method are effective.