基于光储控制的微电网改进预同步控制及离并网切换策略研究  

Research on improved pre synchronization control and off-grid/on-grid switching strategy of microgrid based on optical storage control

作　　者：张文煜 李明 任巍曦 刘宏勇 赵靖英[2] Zhang Wenyu;Li Ming;Ren Weixi;Liu Hongyong;hao Jingying(State Grid Jibei Zhangjiakou Wind and Solar Energy Storage and Transportation New Energy Co.,Ltd.,Zhangjiakou 075000,China;Collegeof Electrical Engineering,Hebei Universityof Technology,Tianjin 30013l,China)

机构地区：[1]国网冀北张家口风光储输新能源有限公司,张家口075000 [2]河北工业大学电气工程学院,天津300131

出　　处：《电子测量技术》2022年第16期8-14,共7页Electronic Measurement Technology

基　　金：国家自然科学基金重点项目(5137704);河北省自然科学基金(E2019202481);河北省自然科学基金(E2017202284);河北省重点研发计划项目(20312102D);公司成本类项目(2021120011000683)资助。

摘　　要：光储配合的微电网预同步控制和离并网切换策略是保证电网平滑运行的重要支撑。针对微电网和大电网之间存在的电压幅值、相位和频率偏差等问题,基于储能逆变器的V/f控制,引入大电网电压作为控制器参考量,简化预同步控制环节结构,提出一种改进的预同步方法。基于离网到并网负序电流变化,提出孤岛检测方法,确定离网信号的发出。考虑光储电源输出随机性和离并网切换特点,提出两储能单元分时转换V/f控制模式和P/Q控制模式的离-并网切换策略,分时控制降低系统切换冲击。设计离-并网切换试验、并-离网切换试验、三组光储出力并网策略对比实验,仿真运行结果表明,改进预同步方法在保证离-并网电压幅值、频率、相角偏差分别小于1%、±0.1 Hz、5°的同时,结构简单;基于两储能单元切换策略的并-离网切换时间缩短、冲击降低,验证了改进预同步方法和基于两储能单元切换策略的有效性。The off-grid switching strategy of solar-storage microgrid is an important support to ensure the smooth operation of the grid.Aiming at the problems such as deviation of voltage amplitude,phase and frequency between the microgrid and the large power grid,based on the V/f control of the energy storage inverter,the large power grid voltage is used as the reference value of the controller to simply the structure of the pre-synchronization control link.An improved pre-synchronization method is proposed.Based on the negative sequence current change from off-grid to grid-connected,the islanding detection method is explored to determine the off-grid signal.Considering the output characteristics of photovoltaic power supply and off-grid switching operation,a control mode of two energy storage units is proposed.The switching sequence of V/F and P/Q control modes of different energy storage units is determined.According to the time-sharing conversion,the impact of system switching is reduced.Off-grid switching test,parallel-off-grid switching test,three groups of optical storage and output power grid-connected strategy simulation comparison tests are designed.The results show that off-grid voltage deviations of amplitude,frequency and phase angle are less than 1%,±0.1 Hz and 5°respectively with improved pre-synchronization control,and the structure is more simple.Based on the switching strategy of the two energy storage units,the switching time of the off/grid mode is shortened and the impact is reduced.The result verifies the effectiveness of the proposed improved pre-synchronization method and the switching strategy based on the two energy storage units.

关 键 词：光储微网 离并网切换策略 改进预同步控制 V/F控制 P/Q控制 

分 类 号：TM727[电气工程—电力系统及自动化]