投切电容式单相九电平逆变器研究  

Research of Switch Capacitor Single-phase Nine-level Inverter

作　　者：谭国俊[1] 张旭[1] 薛映霞[1] 严广[1] 

机构地区：[1]中国矿业大学电气与动力工程学院,江苏省徐州市221008

出　　处：《中国电机工程学报》2017年第8期2351-2360,共10页Proceedings of the CSEE

摘　　要：在交流模块结构并网逆变器领域,传统拓扑结构往往采用先升压再逆变的结构,效率进一步提升受到限制且输出电压电平数较少。针对以上问题,提出投切电容式逆变器。以投切电容式九电平(SC-9L)逆变器为例,研究投切电容式逆变器工作原理,给出了投切电容数量为n时投切电容式逆变器的输出特性,研究了该拓扑结构中投切电容电压平衡问题。通过数学推导得到电容电压稳定的影响因素,通过低次谐波最小原则阶梯波调制与EPWM混合控制的方式提升电容电压平衡效果,同时实现了PWM的方式调压。控制系统通过TMS320C28346型DSP和XC95288XL型CPLD数字化实现,搭建了小功率实验平台,通过实验结果验证了所提拓扑的可行性及所提算法的有效性。Modular structures are always used in traditional topologies to boost firstly and then to invert voltages in the field of grid-connected inverters, which have disadvantages of lower efficiency and less output voltage levels. Faced with these problems, this paper proposed a switch capacitor inverter. The principle of illustrated by the example was researched based on a nine-level inverter, and the output characteristics of it were given under n capacitors. Meanwhile, the voltage balance of switching capacitances in this topology was studied as well. Factors of capacitor voltage stability were got by mathematical derivation. The hybrid control method by combining the step waveform modulation algorithm with EPWM method was applied to balance capacitor voltages and to regulate voltages. A low power test bench was built, and a hardware control system was digitally realized by DSP （TMS320C28346） and CPLD （XC95288XL）. The validity and superiority of the proposed topology and algorithm were verified by experimental results.

关 键 词：逆变器 投切电容 九电平 升压 单相 

分 类 号：TM46[电气工程—电器]