含电力电子变压器的交直流混合配电系统网架结构规划

Network Planning of AC/DC Hybrid Distribution System with Power Electronic Transformers

电力电子变压器(power electronics transformer,PET)技术作为一种新型的电力电子变电设备,能够实现交直流系统灵活组网、功率路由和电能质量管理等功能,为增强配用电系统的调控能力、提高可再生能源的渗透率提供了一种可行的发展方案。因此,基于含PET交直流混合配电系统的结构形态特性,提出了一种网架结构规划方法。首先以待规划设备的接入类型、电压等级、地理位置以及功率特性为匹配特征对规划区域内的源荷储设备进行最优交直流分区;再以系统投资、运行经济性最优为目标,考虑PET的端口约束、分区转供路径等约束建立网架结构优化模型,并将模型简化为主次网架双层模型迭代求解。对实际的工程案例分析结果表明,所提方法既解决了末端源荷储设备的最优集成,也解决了PET的选址定容和供电子区的多端互联问题;同时,与传统交流配用电系统相比,采用所提方法得到的含PET分层系统结构网架复杂度低,既可实现局部环节中源荷储的互补协调,也顾及了电能在系统范围内的平衡和互济,进而从规划配置的角度证明了PET的实用价值。

As a new type of power electronic transformer, power electronic transformer(PET) can realize the functions of AC/DC system flexible networking, power routing, and power quality management. The PET technology provides a feasible development scheme for enhancing the regulation ability of distribution system and for increasing the penetration rate of renewable energy. Therefore, based on the configuration characteristics of AC/DC hybrid distribution system with pet, a grid structure planning method is proposed. Firstly, the access type, voltage level, geographical location, and power characteristics of the device to be planned are adopted as the matching characteristics, and the optimal AC/DC partition of the source load storage equipment in the planning area is carried out. Secondly, the optimal system investment and operation economy are taken as the objectives, a network structure optimization model is established considering the port constraints and partition transfer path constraints of pet, and the model is simplified as a double-layer network structure. Finally, the model is solved iteratively. The analysis results of practical engineering cases show that the proposed method can be adopted not only to solve the optimal integration of terminal source charging and storage equipment, but also to solve the problems of location and capacity of pet and multi terminal interconnection of electronic supply area. At the same time, compared with the traditional AC power distribution system, the grid structure of hierarchical system with pet obtained by the proposed method has low complexity and can realize the complementary coordination of source charging and storage in local links. Furhermore,the balance and mutual benefit of electric energy in the system are taken into consideration to prove the practical value of pet from the perspective of planning and configuration.