光伏不平衡接入的配电系统中电动汽车有序充电策略

摘 要：电动汽车和分布式光伏电源的广泛接入可能会加剧配电系统的负荷峰谷差和三相不平衡问题。在此背景下, 探讨以优化负荷轮廓和减小配电系统三相不平衡为目标的电动汽车有序充电策略。首先, 根据汽车出行特性和电池充电过程, 对充电负荷进行建模。之后, 在配电系统三相模型基础上，通过控制电动汽车充电接入相、充电功率和充电时间, 建立以优化负荷轮廓和减小三相不平衡为目标的电动汽车有序充电优化模型, 并采用自适应遗传算法求解。最后, 以修改的IEEE 33节点测试系统为例对所提方法进行仿真计算，结果表明：采用所提方法，电动汽车充电负荷可避开系统负荷高峰并起到“填谷”作用, 并有效缓解了分布式光伏发电引起的三相功率不平衡问题。

A Coordinated Charging Strategy for Electric Vehicles in a Distribution System with Unbalanced Three-phase Photovoltaic Power Inputs

Extensive integration of electric vehicles （EVs） and distributed photovoltaic （PV） units will probably deteriorate the three-phase imbalance problem in the distribution system. A coordinated charging strategy is presented for EVs in the distribution system with unbalanced three-phase PV power inputs. First, the charging load is modeled on the basis of the travel behavior and charging characteristic of EVs. Then, on the basis of the three-phase power flow model of distribution system, an EV coordinated charging strategy is proposed with the objectives to optimize the daily load profile and to minimize the three-phase imbalance degree in the distribution system. Relevant decision variables include the charging phase, charging power and charging time of EVs. The formulated optimization model is solved by using the adaptive genetic algorithm. Finally, a modified IEEE 33-bus distribution system is employed to demonstrate the proposed method.