Studies on Input DC and output AC Current of 1-Phase Inverter for Unipolar and Bipolar Switching

Single Phase Inverter along with a 12V, 220Ah battery has been used by millions of households, thus switching topologies and its effects on the battery performance needs to be analyzed and studied. In this paper, performance of the single phase inverter with 180 degree switching (i.e. square wave output), sinusoidal pulse width modulation (SPWM) with bipolar and unipolar switching techniques has been analyzed. The input DC current and the output AC current for the various switching techniques has been compared on the basis of percentage of harmonics. Matlab R2022a software has been used to obtain the harmonic spectrums. The fundamental components and total harmonic distortion (THD) of input current waveform, output current and voltage waveform using various techniques has been presented as well as tabulated. SPWM with unipolar switching results in low THD output voltage and high efficiency, but at the cost of polluting the DC supply current with higher percentage of harmonics compared to bipolar and 180 degree switching.