电网不平衡下三电平逆变器无差拍控制  

Deadbeat Control for Three-level Inverter under Unbalanced Grid

作　　者：马蕾[1] 田世润 MA Lei;TIAN Shirun(Department of Electronic Engineering,Zhengzhou Railway Vocational and Technical College, Zhengzhou 450018,China;Mechatronics T&R Institute,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]郑州铁路职业技术学院电子工程系,郑州450018 [2]兰州交通大学机电技术研究所,兰州730070

出　　处：《实验室研究与探索》2018年第8期42-45,53,共5页Research and Exploration In Laboratory

摘　　要：针对电网不平衡条件下并网逆变器的并网问题,设计一种无差拍控制器,实现电网不平衡条件下的并网电流控制。首先在不平衡条件下,建立数学模型,提出无差拍控制器消除交流分量,实现电网不平衡条件下并网电流准确跟踪控制。实际系统中,电流采样和电网采样存在延迟误差,为了抑制延迟误差对并网电流跟踪的影响,提出一种拉格朗日预测方法,消除延迟造成的误差影响。针对三电平逆变器本身存在中点不平衡固有问题,提出一种新型矢量方法,消除中点电位电压偏移和振荡问题。结果表明,该方法能够在电网不平衡条件下准确跟踪并网电流。For grid interconnection of grid inverter under the condition of unbalanced problem,this paper designs a kind of no beat controller to realize the grid current control of unbalanced grid conditions.First under unbalanced conditions,a mathematical model is established,and no beat controller is put forward to eliminate AC component,and realize accurate tracking control of grid interconnection under the condition of unbalanced current.In the actual system,the current sampling and grid sampling delay error exist,in order to prevent the delay error influence on grid current tracking,a Lagrange-like prediction method is proposed to eliminate the influence caused by delay error.According to the three level inverter itself exists neutral unbalance inherent problems,we put forward a new kind of vector method to eliminate the neutral voltage deviation and oscillation problem.The simulation results show that the proposed method can accurately track the grid current under unbalanced grid conditions.

关 键 词：三电平逆变器 电网不平衡 无差拍控制器 中点平衡 

分 类 号：TM46[电气工程—电器]