摘要
独立与并网工作模式无缝切换是直流微电网的重要研究问题。为了解决这一问题,提出了一种基于大电网电压检测和储能双向DC/DC变换器多控制环调度的切换策略,该策略根据同步参考坐标系-锁相环SRF-PLL(synchronous reference frame-phase locked loop)检测的交流电压对DC/DC控制环路进行调度,在不同的运行状态下启动不同的控制环路,调整储能双向DC/DC变换器的功率流向与控制对象,实现微电网运行模式的无缝切换。在建立SRF-PLL和双向DC/DC变换器的s域小信号模型并设计不同控制环路补偿器的基础上,搭建了直流微电网的仿真平台,实现了所提出的无缝切换控制策略。在搭建的仿真平台上,对储能双向变换器不同能量流向条件下的模式切换进行了研究。仿真结果表明,所提控制策略具有良好的稳态和暂态性能,可以满足直流微电网独立与并网模式无缝切换的控制要求。
The seamless switching between the stand-alone and grid-connected modes of DC microgrid is an important research issue.To solve this problem,a switching strategy based on large grid voltage sensing and the dispatching of multiple control loops of an energy-storage bidirectional DC/DC converter was proposed in this paper.According to the AC voltage sensed by the synchronous reference frame-phase locked loop(SRF-PLL),this strategy dispatches the DC/DC control loop,starts different control loops in different operation states,and adjusts the direction of power flow in the converter and the control object,thus realizing seamless switching between different operation modes of microgrid.On the basis of building an s-domain small-signal model of the SRF-PLL and the bidirectional DC/DC converter and designing different control loop compensators,a simulation platform for DC microgrid is established,thereby realizing the proposed seamless switching control strategy.On this platform,the switching between different modes of the converter under different energy flow directions is studied,and simulation results show that the proposed control strategy has good performance in both the steady and transient states,which can satisfy the control requirements of seamless switching between stand-alone and grid-connected modes of DC microgrid.
作者
薛慧杰
朱天璋
田启川
XUE Huijie;ZHU Tianzhang;TIAN Qichuan(School of Electrical and Information Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China)
出处
《电源学报》
CSCD
北大核心
2020年第6期77-85,共9页
Journal of Power Supply
基金
北京市自然科学基金资助项目(3152008)。
关键词
微电网
变换器
无缝切换
控制策略
microgrid
converter
seamless switching
control strategy
