基于三端口电力电子变压器的交直流混合微网分层多目标优化

Hierarchical multi-objective optimization of AC/DC hybrid micro-grid based on three-port power electronic transformer

三端口电力电子变压器(PET)具有交流、直流接口,便于主网、交流微网、直流微网协调优化。根据PET结构,将三端口PET并网的交直流混合微网分为微网层、混合层和并网点层,以并网点层功率波动最小、混合层新能源最大程度消纳、微网层新能源和负载功率变化率最小为目标建立分层多目标优化模型。基于PET端口容量、传输效率限制,改进了微网、PET并网点供蓄能力指标,减少了优化约束条件。在此基础上,实现了加权的多目标求解,提高了求解效率。算例验证了分层多目标优化和供蓄指标的有效性。

Three-port power electronic transformer (PET) with AC and DC port, can easily implement the coordinated optimization of main network, AC micro-grid and DC micro-grid. According to PET structure, the grid-connected AC/DC hybrid micro-grid is divided into micro-grid layer, hybrid layer and grid connection point layer. The hierarchical multi-objective optimization model is established with the goal of minimizing power fluctuation at grid-connected point, maximizing consumption of new energy at hybrid layer, and minimizing change rate of new energy and load power at micro-grid layer. Based on the capacity of PET port and transmission efficiency, the supply and storage index of micro-grid and grid connection point is improved, and the optimization constraints are reduced. On this basis, the weighted multi-objective solution is realized and the solution efficiency is improved. The example verifies the effectiveness of hierarchical multi-objective optimization and supply-storage index.