互联直流微电网多模式协调控制策略

Multi-mode Coordinated Control Strategy of Interconnected DC Microgrid

由于各种可再生能源接入渗透率不断提高,互联直流微电网作为一种新型多微电网集群架构,受到了广泛关注。针对互联直流微电网对系统电压稳定以及自主功率分配的要求,考虑到储能虚拟容量和变流器容量限制,提出一种基于电压分区的互联直流微电网多模式协调控制策略。该策略首先在分析互联直流微电网结构的基础上,考虑分布式电源和负荷的波动,将系统调压模式分为并网调压和自治调压。其次在并网和离网状态下,通过实时监测直流电压信息,保障系统各单元在不同电压分区之间的平滑切换,并通过自适应下垂控制实现自主功率均衡分配,满足系统对各单元即插即用的要求。最后利用PSCAD/EMTDC验证了不同运行状态下系统协调控制策略的有效性。

As the continuous improvement of renewable energy sources connecting to power systems,as a new type of multi-microgrid cluster architecture,interconnected DC microgrid has attracted extensive attention.In the light of the requirements of interconnected DC microgrid for system voltage stability and autonomous power distribution,as well as the limitation of energy storage virtual capacity and converter capacity,an interconnected DC microgrid coordinated control strategy is put forward.Firstly,on the basis of analyzing the structure of interconnected DC microgrid,considering the fluctuation of distributed power and load,system voltage regulation modes are divided into on-grid voltage regulation and autonomous voltage regulation.Secondly,under the on-grid and off-grid conditions,smooth switchof system unit among different voltage partitions can be guaranteed by means of real-time monitoring of DC voltage information.Meanwhile,autonomous power balanced allocation can be realized through self-adaptive droop control,so as to meet the plug-and-play requirements for all units.The effectiveness of the proposed control strategy under different operation conditions is verified by PSCAD/EMTDC simulation.