基于虚拟同步发电机的多逆变器并联改进控制策略  

Improved control strategy of multi-inverter parallel based on virtual synchronous generator

作　　者：万晓凤[1] 詹子录 丁小华[1] 郗瑞霞 王胜利 WAN Xiao-feng;ZHAN Zi-lu;DING Xiao-hua;XI Rui-xia;WANG Sheng-li(School of Information Engineering,Nanchang University,Nanchang 330031,China;State Grid Jiangxi Electric Power Co.,Ltd.,Nanchang 330077,China)

机构地区：[1]南昌大学信息工程学院,南昌330031 [2]国网江西省电力有限公司,南昌330077

出　　处：《电机与控制学报》2020年第2期118-127,共10页Electric Machines and Control

基　　金：国家自然科学基金(61563034);国家国际科技合作专项(2014DFG72240);江西科技落地计划(KJD14006)。

摘　　要：针对低压微网中由于逆变器间的等效输出阻抗和输电线路阻抗的差异,使得采用传统虚拟同步发电机(VSG)控制的多逆变器并联功率均分及环流抑制效果较差问题,提出一种基于虚拟同步发电机的多逆变器并联改进控制策略。该策略首先在无功功率环中引入负载电压负反馈和积分环节,减小负载电压波动和实现无功功率与传输阻抗的解耦,提高无功功率分配精度。然后引入动态虚拟复阻抗,降低VSG输出电压跌落,改善电能质量。最后进行了预同步单元的设计,减小并联瞬间电流冲击,加快动态响应。改进后的虚拟同步发电机并联控制策略使输出电压能够稳定在正常范围内,实现了功率均分且具有环流抑制能力。仿真和实验结果验证了所提出控制策略的有效性。Aiming at the difference of equivalent output impedance and transmission line impedance between inverters in low-voltage microgrid,and the problem that power sharing and circulation suppression is less effective when multi-inverters parallel controlled by the traditional virtual synchronous generator(VSG),an improved control strategy of multi-inverter parallel based on virtual synchronous generator was proposed.Load voltage negative feedback and integral links in reactive power loop were introduced,load voltage fluctuation and decoupling reactive power distribution and transmission impedance were reduced,which improves reactive power distribution accuracy.Secondly,the dynamic virtual complex impedance was introduced to reduce the VSG output voltage drop and improve the power quality.Finally,the design of the presynchronization unit was carried out to reduce the instantaneous current impact and accelerate the dynamic response.The improved parallel control strategy of virtual synchronous generator can stabilize the output voltage in the normal range,and achieve the equal power sharing and have the circulating current restraning ability.The simulation and experimental results verify effectiveness of the proposed control strategy.

关 键 词：虚拟同步发电机并联 动态虚拟复阻抗 电压跌落 功率均分 环流抑制 

分 类 号：TM31[电气工程—电机]