虚拟同步发电机的无缝切换控制技术
第38卷第12期2017年12月自一动一化一仪一表PROCESS AUTOMATION INSTRUMENTATION Vol．38No．12Dec.2017
修改稿收到日期:2017-07-08
基金项目:山西省应用基础研究基金资助项目(201601D011058)二山西省重点实验室开放课题基金资助项目(MEI201603)
作者简介:白薇(1991 ),女,在读硕士研究生,主要从事现代电力电子与新能源发电技术的研究,E -mail:baiwakk@https://www.wendangku.net/doc/26160834.html,;
刘立群(通信作者),男,博士,教授,主要从事新能源发电系统控制二新能源混合供电系统结构化二智能电网等方向的研究,E -mail:llqd2004@https://www.wendangku.net/doc/26160834.html, 虚拟同步发电机的无缝切换控制技术
白一薇,刘立群,张聪明,马立群
(太原科技大学电子信息工程学院,山西太原030024)
摘一要:对微电网中并网逆变器的虚拟同步发电机(VSG)控制策略进行了研究三首先,搭建了VSG 控制的功频调节部分和励磁调节部分三VSG 通过模拟同步发电机的惯性和阻尼特性,实现了并网和离网的独立运行,但是在并离网切换时容易出现电流和电压冲击三为实现并离网的平滑切换,提出了一种离网模式下恒压/恒频控制二并网模式下VSG 控制的控制策略三在离网运行时,恒压/恒频控制模式为负载提供电压和频率的支撑;在并网运行时,由VSG 控制模式提供三同时,详细地分析了调差系数二阻尼系数和转动惯量对功频特性的影响三最后,利用Matlab /Simulink 搭建仿真模型,验证该控制策略的有效性三仿真结果表明:该控制策略解决了微电网在不同模式之间的无缝切换问题;与传统的切换过程相比,减小了切换过程中的电压和电流冲击,提高了微电网在运行过程中的稳定性,可以应用于多微源并联的微电网三
关键词:微电网;并网逆变器;无缝切换;虚拟同步发电机;调频调压;功频特性;预同步;励磁特性
中图分类号:TH -39;TP24一一一一文献标志码:A一一一一DOI:10.16086/https://www.wendangku.net/doc/26160834.html,ki.issn1000-0380.201712004一
Seamless Switching Control Technology of Virtual Synchronous Generator
BAI Wei,LIU Liqun,ZHANG Congming,MA Liqun
(School of Electronic Information Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)Abstract :The strategy of virtual synchronous generator (VSG)control for grid connected inverters in microgrid is studied.Firstly,the power frequency regulation section and the excitation regulation section of VSG control have been built.VSG simulates the inertia and damping characteristics of synchronous generator,which can realize the independent operation of grid connected and grid disconnected.But,during switching process of grid connected and disconnected,voltage and current shocks may occur.In order to realize smooth switching,a control strategy of constant voltage and constant frequency control in the off -network mode and VSG control in grid connected mode is proposed.In grid disconnected operation,constant frequency and constant voltage control provides the voltage and frequency support for the load.In grid connected operation,these are supplied by the VSG control mode.Then,the influences of the adjustment coefficient,the damping coefficient and the moment of inertia on the power frequency characteristics are analyzed.Finally,the effectiveness of the proposed control strategy is verified by a simulation model based on Matlab /Simulink.The simulation results show that the control strategy solves the seamless switching between different operation modes of microgrid;compared with the traditional switching process,the voltage and current shocks in switching process are reduced and the stability of the micro grid in the operation process is improved;it can be used in micro grid which consists of multiple micro sources in parallel.Keywords :Micro grid;Grid connected inverter;Seamless switching;Virtual synchronous generator;Frequency modulation and voltage regulation;Power frequency characteristic;Presynchronization;Excitation characteristic
0一引言
近年来,随着能源短缺二全球变暖和化石能源污染
等问题的日益严重,可再生能源的利用已成为全球研
究热点三分布式发电以其灵活性二清洁性和普遍性的特点,已成为颇具前景的微电源之一三但是当其大规模接入电网时,也带来了许多新的问题[1-2],如不易控制二随机性波动性较大等,进而会威胁电力系统的安全稳定运行三为了解决上述问题,众多学者对逆变器的控制策略进行了深入的研究,并提出了虚拟同步发电
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