Research on Control and Structure of the Cascaded Multilevel Inverters

The cascade multilevel inverter can reduce the voltage stress of the power switches and output filter inductance, also it is easy to modularize and some phase voltages are redundant, so it is very suitable for high voltage applications. In this paper a multi-level cascaded DC/AC converter with on single DC power source are presented and a practical modulation are give. The stepping modulation method makes harmonic distortion of output voltage being less than conventional cascaded converters. This cascaded converter can save a number of switching devices and separated powers source.