考虑死区非线性的L滤波单相并网逆变器的精确离散迭代模型及其分岔行为  

An exact discrete-time model and the bifurcation performance of single phase grid-connected inverter with L-filter considering dead-time nonlinearity

作　　者：谢瑞良[1] 郝翔[1] 王跃[1] 杨旭[1] 黄浪[1] 王超[1] 杨月红[1] 

机构地区：[1]西安交通大学电气工程学院,电力设备电气绝缘国家重点实验室,西安710049

出　　处：《物理学报》2014年第12期97-105,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51177129);国家高技术研究发展计划(批准号:2011AA05A305)资助的课题~~

摘　　要：并网逆变器系统作为一个时变非线性系统,具有复杂的动力学行为,而死区非线性的引入使系统的非线性行为更为复杂和难以预测.本文以考虑死区非线性的L滤波单相并网逆变器为研究对象,首先观察不同死区时间下系统的输出电流波形,发现在控制器参数固定的情况下,随着死区时间的增加,系统会出现分岔现象;其次,根据死区非线性特性及其引起的电流过零钳位现象,分多种情况全面地建立了精确完整的离散迭代模型,并在此基础上对系统的分岔行为进行理论分析.此外,系统的稳定性判定具有重要的工程指导意义,由于死区非线性的引入,常规解析方法使用困难,而图解法的精度又难以令人满意,因此提出了一种基于等效占空比的稳定性判断方法,可以精确地判定系统的稳定边界,为控制器参数设计和死区时间设计提供了可靠依据.Grid-connected inverter system is recognized as a time-varying nonlinear system, and it has complex nonlinear behaviors in practice. However, the introduction of dead-time nonlinearity can make the nonlinear behaviors of the system more complex and harder to predict. In this paper, the proportional control single-phase grid-connected inverter with L-filter considering dead-time nonlinearity is investigated. The observation of current waveforms under fixed controller parameter and different dead-time parameters shows that the bifurcation phenomenon occurs with the increase of dead-time. According to the features of dead-time nonlinearity and the zero current clamping phenomenon caused by dead-time, an exact and complete discrete-time model is established by comprehensively considering the system from various aspects. And the theoretical analysis of bifurcation behaviors of system is carried out based on the proposed model. Moreover, the stability judgment has engineering significance. However, with the consideration of dead-time nonlinearity, analytical methods are difficult to use and the graphic methods do not have satisfactory accuracy. Therefore, a stability criterion based on equivalent duty ratio is proposed in this paper, which can accurately judge the stability boundary and provide reliable references for the parameter design of controller and dead-time.

关 键 词：并网逆变器 死区非线性 离散迭代模型 分岔行为 

分 类 号：TM464[电气工程—电器]