一种光储交直流微网并/离网无缝切换策略  

A Seamless Transfer Strategy Between Grid-connected and Islanding Operation for Photovoltaic/battery AC/DC Microgrid

作　　者：薄鑫 吴倩 赵菲菲 杨杰 郑建勇[3] 缪惠宇 顾盼盼[3] BO Xin;WU Qian;ZHAO Feifei;YANG Jie;ZHENG Jianyong;MIAO Huiyu;GU Panpan(State Grid Jiangsu Economic Research Institute, Nanjing 210008, China;Nanjing Electric Engineering Design Co. , Ltd. , Nanjing 210009, China;Electrical Engineering Department, Southeast University, Nanjing 210096, China)

机构地区：[1]国网江苏省电力公司经济技术研究院,江苏南京210008 [2]南京电力工程设计有限公司,江苏南京210009 [3]东南大学电气工程学院,江苏南京210096

出　　处：《现代电力》2018年第3期70-76,共7页Modern Electric Power

基　　金：江苏省科技成果转化专项项目(BA2015086)

摘　　要：微网存在并网与离网独立运行两种不同的工作模式,为解决其在两种模式之间的无缝切换问题,本文首先设计微网预同步软件算法,保证交流母线电压相位平稳连续,为并/离网的无缝切换奠定基础。其次,研究微网系统的基本结构和工作模式,结合微网系统并/离网工作模式切换时的外环输出特征,提出一种改进的外环将其应用于储能控制外环以及逆变器控制外环。该改进外环实现并/离网模式切换瞬间输出需求的重置功能,以补偿传统PI调节器切换时因线路潮流变化而引起的超调量,较好地解决了切换过程中交直流母线电压波动问题。最后,利用matlab/simulink建立光储微网系统模型对并/离网模式切换进行仿真验证,运行结果验证了所提改进策略的有效性。There are two different operation modes for microgrid,which are grid-connected and islanding operation.In order to solve the problem of seamless transfer between these two operation modes,apresynchronization software algorithm for microgrid is firstly designed to make the phase angle of AC bus maintain smoothly,which lay foundation in seamless transfering between grid-connected and islanding operation.Then the basic structure and operation mode of the microgrid are analyzed.According to the dynamic output behavior of voltage loop exhibited in the mode transfer process,an improved controller for voltage-loop in the DCDC converter and inverter is proposed.The improved controller can achieve reset function of transient output demand between grid-connected and islanding operations to compensate the overshoot caused by power flow mutation in the system for traditional PI controller.Thus,the vibration of DC bus and AC bus can be well reduced during transfer process.In the end,simulation of microgrid with photovoltaic/battery system is built by using matlab/simulink,the result verifies the effectiveness of proposed strategies.

关 键 词：光储 交直流微网 并网运行 离网运行 无缝切换 

分 类 号：TM722[电气工程—电力系统及自动化]