Analysis of Five Level H-Bridge Inverter Using Bipolar Switching Schemes

Multilevel inverters are getting preference over conventional inverter in different applications due to inherent advantages offered by it, for example reduced harmonic distortion, higher number of voltage levels, lower switching losses, high power quality, etc. The two important conventional topologies for structure multilevel inverters are the clamped diode and the cascaded H-bridge inverter. There are two control techniques, unipolar and bipolar. In this paper bipolar control technique is opted to control the cascaded H-bridge five level inverter. The single-phase full bridge cascaded H-bridge inverter controlled by bipolar technique is presented. Cascading connections of two full bridge inverter helps to get five levels of the output voltage. A detailed analysis of the controlled technique and the performance of the inverter is represented in this paper. The controlled operation is performed at wide range of switching frequencies. The theoretical analysis is verified by simulation performed in Matlab/Simulink platform. The results are compared with unipolar control scheme of the inverter.