交直流混合微电网互联变换器功率流动的柔性控制策略  

Flexible power flow control strategy for interlinking converter in AC/DC hybrid microgrid

作　　者：施静容 李勇[1] 王姿雅[1] 贺悝 曹一家[1] SHI Jingrong, LI Yong, WANG Ziya, HE Li, CAO Yijia(College of Electrical and Information Engineering, Hunan University, Changsha 410082, China)

机构地区：[1]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《电力自动化设备》2018年第11期107-113,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51520105011);湖南省科技重大专项(2015GK1002)~~

摘　　要：针对交直流混合微电网系统间功率动态平衡以及分布式电源利用率不高的问题,提出一种适用于混合微电网互联变换器功率流动的柔性控制策略,所提策略无需通信且可灵活分配功率。首先,对交流子微电网与直流子微电网所连分布式电源采用的下垂控制方式进行详细的分析。然后,针对互联变换器需维持交流微电网侧频率与直流母线电压的稳定以及功率双向传输的特点,对混合微电网交直流接口的虚拟惯性进行分析,推导出交流频率与直流电压之间的线性耦合关系,以实现交直流两侧功率的相互支撑。最后,在DIgSILENT软件上建立典型的交直流混合微电网模型,验证了所提互联变换器功率控制方法的有效性。仿真结果表明,在离网情况下采用所提控制策略时,互联变换器可较好地维持交直流两侧功率平衡并提升电能质量,充分利用了分布式电源的功率调节能力。To address the issues of dynamic power balance in AC/DC hybrid microgrid and the low utilization of distributed generators,a novel flexible power flow control strategy for interlinking converter in hybrid microgrid is proposed,which can flexibly allocate power without the requirement of communication. Firstly,the droop control mode of distributed generators connected by AC and DC sub-microgrids is analyzed in detail. Secondly,based on the characteristics of interlinking converter,which is required to maintain the stability of AC microgrid frequency and DC bus voltage as well as the bidirectional power transmission,the virtual inertia of hybrid microgrid AC/DC interface is analyzed. At the same time,the linear coupling relationship between the AC frequency and DC voltage is deduced to accomplish the mutual support of AC/DC power at both sides. Finally,a typical AC/DC hybrid microgrid model is built on the DIgSILENT simulation platform,based on which the proposed power control strategy of interlinking converter is validated. Simulative results show that the proposed control strategy can effectively maintain the power balance at both sides and improve the power quality under the islanded mode,which fully exploits the power adjustment capability of distributed generators.

关 键 词：交直流混合微电网 互联变换器 功率控制 下垂控制 虚拟惯性 

分 类 号：TM727[电气工程—电力系统及自动化] TM761