基于开关电容单元的多电平逆变器研究  

Research on Multilevel Inverter Based on Switched-capacitor Cell

作　　者：岳舟 李波 刘涛 鲁重文 YUE Zhou;LI Bo;LIU Tao;LU Chongwen(College of Energy,Mechanical and Electrical Engineering,Hunan University of Humanities,Science and Technology,Loudi 417000)

机构地区：[1]湖南人文科技学院能源与机电工程学院,娄底417000

出　　处：《电气工程学报》2024年第4期194-203,共10页Journal of Electrical Engineering

基　　金：国家自然科学基金(61702182);湖南省自然科学基金(2023JJ50489);湖南省创新训练(S202310553062)资助项目。

摘　　要：为在光伏应用中获得高幅值电压,将若干光伏组件串联形成光伏串,然后通过H桥逆变器将光伏串的电压转换为交流电压。基于H桥逆变器的光伏系统会产生有害谐波和泄漏电流,并增加元件的电压应力。鉴于上述问题,提出一种新的基于开关电容单元的多电平逆变器。所提多电平逆变器使用串联直流电源作为输入直流源,能够产生高质量的阶梯交流电压,并减小泄漏电流。而且所提拓扑结构可以方便地拓展为三相逆变器,在三相拓扑中,其三相仅连接到一个串联光伏组件或直流电源。对所提多电平逆变器的工作原理、电平移位SPWM调制策略、泄漏电流以及电路参数等方面进行了详细分析,同时还对所提多电平逆变器与现有多电平逆变器进行对比分析。最后采用Matlab建立仿真模型,并搭建试验样机,仿真和试验结果验证了所提电路的有效性和可行性。In order to approach a voltage of high magnitude in photovoltaic(PV)application,several PV modules are connected in series to form a PV string,the voltage of PV string is converted to an AC voltage through an H-bridge inverter.This system causes harmful harmonics,brings about leakage current,and increases the voltage stress of the components.In view of the above problems,a new multilevel inverter topology is proposed based on switched-capacitor cell that uses series-connected DC sources as the input DC source and generates a staircase AC voltage of high quality and mitigates the leakage current.Moreover,the proposed topology can be easily extended to a three-phase inverter,where the three phases only connect to a single series photovoltaic module or DC power source in the three-phase topology.The operation principle,the level-shifted sinusoidal pulse width modulation(SPWM)strategy,leakage current and circuit parameters of proposed multilevel inverter are analyzed in detail.A comparative analysis is also conducted between the proposed multilevel inverter and existing multilevel inverters.Finally,the simulation model is established by Matlab,and the experimental prototype is made.The effectiveness and feasibility of the proposed circuit are verified by simulation and test results.

关 键 词：开关电容单元 泄漏电流 多电平逆变器 

分 类 号：TM464[电气工程—电器]