中文摘要：

从经济性和功率集成角度提出一种单电源级联型多电平逆变器。该拓扑在保留了传统级联型多电平逆变器中单管耐压低、所需器件少、易于模块化的优点上，其直流侧仅有一个独立电源，其它电源可用电容代替。通过引入充电开关管组，电源可为电容频繁地充电，使电容电压在一定程度上保持恒定。独立电源和电容有效组合使得多电平逆变器稳定运行。详细地介绍单电源级联型七电平逆变器的工作原理及采用的载波移相调制策略；通过数学推导得到电容电压稳定性的影响因素，结果用于电容参数设计；充电损耗也进行了计算；控制系统通过TMs320LF2407A DSP和XC3S400FPGA数字化实现。搭建一台1kW逆变器样机，验证了提出拓扑的可行性。

英文摘要：

From the view of economy and power integration, a novel single-supply cascaded multilevel inverter is proposed in this paper. Retaining the traditional cascaded multilevel inverter＇s merits of low voltage stress on each switch, few quantities of switches and easy modularization, it contains only one independent DC source in DC-link and DC source in other bridges are replaced by some capacitors. The independent DC source can charge the capacitors frequently by the introduction of the charging-switches pairs and keeps the voltage of the capacitors to be regarded as constant to some extent. The effective combination of the independent DC source and capacitors ensures that the cascaded multilevel inverter operates stably. The operation principle and carrier phase-shifted sinusoidal pulse width modulation （SPWM） strategy of the single-supply cascaded seven-level inverter are first presented in detail. The influencing factors of the capacitors voltage stability are deduced by mathematical analysis, and the result serves as theoretical basis of the parameter optimization. In addition, the charging-loss is calculated. Control system is digitally implemented with TMS320F2407A DSP and XC3S400 FPGA. A 1 kW inverter prototype has been built to verify the feasibility of the proposed topology.