含三端口电力电子变压器的交直流混合微网分层优化

三端口电力电子变压器(PET)具有交流、直流接口,便于主网和交直流混合微网的协同优化。针对PET容量小、过载能力差的现状,提出一种分层优化模型:PET层以对公共耦合点负荷曲线削峰填谷为目标,从而优化主网、交流微网和直流微网的功率调度曲线;交流微网和直流微网以降低各自运行成本为目标、上层调度曲线为约束协调各微源出力,并在下层优化中计及了储能放电深度、荷电状态对运行成本的影响,将镜像转换和自适应惯性权重引入粒子群优化算法中对其进行求解。参照浙江某地交直流微网示范工程构建算例,验证了所提优化模型和求解方法的有效性。

Layered optimization of AC/DC hybrid microgrid with three-port power electronic transformer

The three-port PET(Power Electronic Transformer) has AC and DC ports, and it is convenient for the coordinate optimization of main grid and AC/DC hybrid microgrid. In view of the small capacity and poor overload capability of PETs, a layered optimization model is proposed. At PET layer, the target is the peak load shifting of PCC(Point of Common Coupling) load curves, so as to optimize the power scheduling curves of main grid, AC microgrid and DC microgrid. At microgrid layer, the target is to minimize operating cost of AC and DC microgrid, and PET-layer scheduling curves are used as constrains to coordinate the output of each micro source. At the same time, the influences of discharge depth of energy storage and state of charge on operating cost are considered in microgrid-layer optimization model. The mirror conversion and adaptive inertia weight are induced to particle swarm optimization algorithm to solve the model. Taking the demonstration project of AC/DC microgrid in Zhejiang province as a case, and the case results verify the effectiveness of the proposed optimization model and solution method.