Optimal solution in modified IEEE 69.

On the basis of predecessors’ coordination optimization of active and reactive power in distribution network, For the necessity of the optimal operation in the distribution network, part of power generated from photovoltaic (PV) cannot be sold to users, and cannot enjoy subsidies. Similarly, the network loss in the power transmission will also bring a certain economic loss. This paper comprehensively considers the economic loss caused by the network loss and PV abandon of the distribution system, and establishes a model to minimize the economic loss. To solve this problem efficiently, the method of DistFlow equation and mixed integer second order cone programming (MISOCP) is used to solve the problem, in this method, the original mixed integer nonlinear programming non-convex problem is transformed into a convex problem, which makes the optimization problem easy to solve. The modified IEEE 33 and IEEE 69 distribution networks are tested by the above method. The optimized results are able to meet the target and have very small relaxation gaps, and the voltage level is also optimized. This coordinated optimization approach helps to optimize the economic operation for active distribution networks with PVs.

在已有研究对配电网有功与无功协调优化的基础上，针对配电网优化运行的实际需求，部分光伏发电（Photovoltaic）机组所发电量无法并网售电且无法享受相应补贴。同理，配电网输电环节的电网损耗同样会造成一定的经济损失。本文综合考量配电网系统因电网损耗与弃光所造成的经济损失，建立了以最小化该经济损失为目标的优化模型。为高效求解该优化问题，本文采用DistFlow方程与混合整数二阶锥规划（MISOCP）方法：该方法将原混合整数非线性规划的非凸优化问题转化为凸优化问题，从而大幅降低了求解难度。采用上述方法对修正后的IEEE 33节点与IEEE 69节点配电网进行了仿真测试，优化结果能够满足预设目标，且松弛间隙极小，同时系统电压水平也得到了有效优化。该协调优化方法有助于实现含光伏发电系统的有源配电网的经济优化运行。