A Bipolar Multilevel Structure for DC/AC Conversion with Reduced Device Count

The present demand of multilevel inverter (MLI) has been increased rapidly from previous few decades, due to its reduced low harmonic components and decrease in stress across power semiconductor switches. Various topology of inverter has been proposed. This paper presents a bipolar single phase symmetrical MLI that has been incorporated to reduce device count and capable of generating five level output voltage waveform. To control the newly introduced multilevel structure a sinusoidal pulse width modulation (SPWM) scheme is used. In order to produce five level output, sources are connected in additive manner. The presented structure results in reduction of losses, number of component count, size and cost of inverter. A comparison study of the presented structure with basic conventional and some recently developed structures shows that the presented structure requires fewer numbers of device count and isolated driver circuits. The proposed design can be evaluated under different loading conditions (R-Load and RL-Load) using MATLAB/Simulink platform. The theoretical analysis and results of simulation study confirm the proper operation of the proposed inverter with experimental validation.