Flyback DCM High Efficiency Utility Interactive Inverter using MPPT for Solar Energy Applications

Abstract: This paper proposes a topology of inverter without center tapping which improves the wave shape of the load voltage. By avoiding Centre tapping of the Fly back transformer, a more symmetrical waveform without any dc component in the output is obtained. This further improves Transformer Utilization Factor (TUF) and the voltage stress across various components is also reduced. The presence of fly back Transformer further avoids the problems of TCO corrosion in solar panel and the leakage current by providing double grounding on the PV panel side and ac neutral. Due to unfolding type inverter, switching losses are also reduced since only one switch is operated at high frequency during the entire operation and the losses are reduced since it works under MPPT technique. DCM operation is preferred due distortion of current waveform in CCM mode which in turn requires an additional inner current shaping loop and also voltage spikes in the transformer winding. Its operation design and analysis is discussed in this paper.

Keywords: fly back Inverter; CCM and DCM Operation modes; Maximum power point tracking ( MPPT)