两级式单相逆变器的二次功率解耦控制  

Decoupling control of second-harmonic power for two-stage single-phase inverter

作　　者：孙瑞东 曾国宏[1] 王静 吴学智[1] 张子超 刘琦远 SUN Ruidong;ZENG Guohong;WANG Jing;WU Xuezhi;ZHANG Zichao;LIU Qiyuan(National Active Distribution Network Technology Research Center,Beijing Jiaotong University,Beijing 100044,China;Shenzhen Power Supply Bureau Co.,Ltd.,Shenzhen 518000,China)

机构地区：[1]北京交通大学国家能源主动配电网技术研发中心,北京100044 [2]深圳供电局有限公司,广东深圳518000

出　　处：《电力自动化设备》2023年第4期30-38,共9页Electric Power Automation Equipment

基　　金：中国南方电网有限责任公司科技项目(090000KK52210134)。

摘　　要：两级式单相逆变器由前级DC/DC和后级DC/AC组成,通常利用负载电流前馈提高DC/DC的动态响应能力,但DC/AC输出瞬时功率的二次脉动,会由前馈通道使DC/DC的输入源产生二倍频电流。为了消除负载瞬时功率脉动对前级DC/DC的影响,提出在电压环引入串联虚拟阻抗以及增加电流环有功指令的前馈解耦控制方法,并推导出2条前馈通路的最优组合方式。在此基础上给出串联虚拟阻抗和有功电流前馈的优化选取方法以及控制器参数设计思路。该方法不仅能有效抑制输入侧的低频纹波电流,保证了系统的稳态性能,而且能够完整快速提取前馈分量,提高了DC/DC负载突变时的响应速度,实现了前后级之间的二次功率解耦。理论分析表明,所提控制既能满足二倍频电流抑制要求,又增大了电压环带宽,系统的动态特性更强。仿真和实验结果验证了所提控制策略的有效性。Two-stage single-phase inverter consists of front-stage DC/DC and back-stage DC/AC.Usually,load current feedforward is used to improve the dynamic response capability of DC/DC.However the feedforward control will cause the input source of DC/DC to generate second-harmonic current(SHC),because of the DC/AC output instantaneous power fluctuates at twice the output voltage frequency.In order to eliminate the influence of load instantaneous power pulsation on the front-stage DC/DC,a feedforward de⁃coupling control method of introducing series virtual impedance in voltage loop and increasing active power command in current loop is proposed,and the optimal combination of two feedforward paths is deduced.On this basis,the optimal selection method of series virtual impedance and active current feedforward and the design idea of controller parameters are given.This method can not only effectively suppress the lowfrequency ripple current at the input side,and ensure the steady-state performance of the system,but also extract the feedforward component completely and quickly,improve the response speed when DC/DC load suddenly changes,and realize the second-harmonic power decoupling between the front-stage and back-stage.Theoretical analysis shows that the proposed control method can not only meet the requirements of SHC suppression,but also increase the bandwidth of the voltage loop,making the dynamic response of the system stronger.Simulative and experimental results verify the effectiveness of the proposed control strategy.

关 键 词：两级式单相逆变器 低频纹波电流 二倍频电流 二次功率解耦 负载扰动抑制 虚拟阻抗 

分 类 号：TM464[电气工程—电器]