单相级联七电平逆变器拓扑结构及其控制方法  

Topology and Control Method of Single-Phase Cascaded Seven-Level Inverter

作　　者：张琦[1,2] 李江江 孙向东[1,2] 安少亮[1] Zhang Qi;Li Jiangjiang;Sun Xiangdong;An Shaoliang(School of Automation and Information Engineering Xi’an University of Technology,Xi’an 710048 China;Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi’an University of Technology,Xi'an 710048 China)

机构地区：[1]西安理工大学自动化与信息工程学院,西安710048 [2]西安理工大学陕西复杂系统控制与智能信息处理重点实验室,西安710048

出　　处：《电工技术学报》2019年第18期3843-3853,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51607142);陕西省自然科学基金(2017JQ5102);新疆维吾尔自治区重大科技专项基金(2016A02004-5);陕西省教育厅重点实验室基金(17JS087)资助项目

摘　　要：针对传统多电平逆变器结构复杂等问题,提出一种单相级联七电平逆变器拓扑及其控制方式。该逆变器由三电平Boost电路和六开关逆变电路构成,利用三电平Boost电路调节中点电位,使得中间母线电容电压占比为1∶2,为实现七电平输出提供电位条件。相对于传统多电平拓扑,该拓扑使用较少的开关器件,简化了电路结构。由于中间母线电容电压控制效果是系统可靠运行的关键,所以在讨论电路拓扑的运行机理的基础上,建立直流侧电压控制系统数学模型,并据此提出一种电压控制方法,从而实现逆变器控制系统的有效运行。最后,借助系统仿真与实验验证了所提电路拓扑的可行性以及理论分析的正确性。Traditional multilevel inverters are restrained due to complicated topologies. In this paper, a single-phase cascaded seven-level inverter topology and its control method are presented. The inverter consists of a three-level Boost circuit and a six-switch inverter circuit. The midpoint voltage is adjusted by the controlling of Boost converter, and the intermediate bus capacitor voltage ratio is controlled to 1∶2, and seven-level voltage output is achieved. Compared to a traditional multilevel topology, the topology requires fewer switching devices at the same output level, which simplifies the circuit structure. The DC bus capacitor voltage control is the key to the system stability. The mathematical model of the voltage control system is established, and the voltage control method is studied to achieve the effective operation of the inverter. Finally, simulation and experimental results verify the feasibility of the proposed circuit topology and the theoretical analysis.

关 键 词：七电平逆变器 三电平 BOOST 电压偏差 电流前馈 

分 类 号：TM464[电气工程—电器]