直流配电网下垂参数小干扰稳定优化调控方法

以基于下垂控制的直流配电网为研究对象,推导建立了下垂控制模式下典型环状直流配电网的小信号状态空间模型,对传统下垂参数经济优化模型中存在的系统调控不稳定问题进行了分析,进而提出了考虑小干扰稳定约束的直流配电网下垂参数优化调控方法,以确定性预测场景和极端场景下直流配电网小信号状态方程的特征值谱横坐标作为系统小干扰稳定约束,来优化系统网损。此外,为求解该模型,针对传统算法中存在的易陷入局部最优解、特征值迭代误差积累和计算效率较低等问题,在序列非线性规划算法和遗传算法的基础上提出了改进策略。数值实验结果表明,该优化模型在保证系统小干扰稳定的前提下能较大程度地提升系统运行经济性,同时提高系统适应不确定源荷功率随机波动的鲁棒性;所提出的算法改进策略可以在保证优化结果可靠有效的前提下,提高算法的寻优能力和计算效率。

Optimized Dispatching and Control Method of Droop Parameters with Assurance of Small-signal Stability in DC Distribution Network

The DC distribution network adopting droop control is chosen as the research object, of which the small signal state space expression is established. The possibility of instability in the traditional economic optimization model of droop parameters is analyzed. Consequently, the economic optimization model of droop parameters with the assurance of small-signal stability is put forward, which optimizes the network loss with constraints on the eigenvalues of small-signal state space equations under the prediction scenarios and extreme scenarios. To solve the optimization model, the improved strategies based on nonlinear programming algorithm and genetic algorithm are put forward to directly against the defects in the traditional algorithm of slow, easily getting trapped in local optimum and having an accurate solution because of the error. Numerical results show that this optimization model can improve the performance of the economic operation of the system on the premise of ensuring the small-signal stability and improve the robustness of the system when facing uncertain power fluctuation. The strategies can improve the optimization ability and computational efficiency while the results are ensured to be reliable and effective.