DAB级联单相逆变器系统的阻抗特性及稳定性分析  

Impedance characteristics and stability analysis of DAB cascade single-phase inverter system

作　　者：刘欣[1] 袁静 高鑫波 LIU Xin;YUAN Jing;GAO Xinbo(School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学电气与电子工程学院,河北保定071003

出　　处：《电机与控制学报》2023年第12期1-11,共11页Electric Machines and Control

摘　　要：针对双有源桥(DAB)直流变换器级联单相并网逆变器系统因阻抗失配而造成系统发生振荡失稳的问题,通过建立DAB和单相逆变器的输出和输入阻抗模型,基于阻抗分析法对级联系统的交互稳定性进行了分析。首先,推导采用双环控制策略的前级DAB输出阻抗模型和考虑锁相环影响的后级逆变器直流侧输入阻抗模型,并通过扫频法验证其准确性。在此基础上,建立二者阻抗交互模型,详细分析了DAB反馈控制器的PI参数对其输出阻抗频率特性和级联系统稳定性的影响,并据此提出一种DAB控制参数的优化设计方法,在兼顾动态性能的同时提升了级联系统的稳定性。最后,通过仿真算例验证了阻抗模型的准确性,分析了结论的正确性以及稳定性改善方法的有效性。Aiming at the problem of oscillation instability of the dual active bridge(DAB)DC-DC con-verter cascaded single-phase grid-connected inverter systems due to its impedance mismatching,the out-put and input impedance models of DAB and single-phase inverter were established,and the interaction stability of the cascade system was analyzed based on impedance analysis method.Firstly,the output im-pedance model of the front-stage DAB using the double-loop control strategy and the DC-side input im-pedance model of the back-stage inverter considering the influence of the phase-locked loop were derived,and the accuracy of the models were verified by frequency sweep method.Based on this,the impedance interaction model between the two was established.Additionally,the effects of PI parameters of DAB feedback controller on its output impedance frequency characteristics and cascade system stability were analyzed in detail,and the optimal design method of DAB control parameters was proposed accordingly,which improves the stability of the cascade system while taking into account the dynamic performance.Fi-nally,the simulation examples verify accuracy of the impedance model,correctness of the analytical con-clusions and effectiveness of the stability improvement method.

关 键 词：级联系统 稳定性 阻抗重塑 双有源桥 单相并网逆变器 阻抗模型 

分 类 号：TM46[电气工程—电器]