Transformer Less Photovoltaic: Optimizing Residential Grid Interface with Reduced Harmonics

The integration of Transformerless Photovoltaic (PV) systems into residential grid interfaces offers numerous advantages, such as reduced size, lower cost, and enhanced efficiency. This review paper focuses on optimizing residential grid connectivity with Transformerless PV systems, particularly through advanced inverter topologies. Traditional PV systems use transformers for galvanic isolation, which adds weight, cost, and inefficiency. Transformerless inverters, including topologies like HERIC and full-bridge designs, eliminate the transformer while maintaining power conversion efficiency and reducing Total Harmonic Distortion (THD). However, challenges remain regarding leakage currents and electromagnetic interference (EMI), primarily due to the fluctuating common-mode voltage (CMV). Various strategies have been explored to mitigate these issues, including unipolar and bipolar modulation schemes and specific inverter control techniques. The paper analyzes these approaches, comparing their performance, cost-efficiency, and suitability for residential applications. Through simulations and experimental data, the review presents a thorough understanding of how Transformerless inverters can optimize power generation, reduce harmonics, and enhance overall system performance. The findings offer valuable insights for improving PV grid integration, addressing the increasing demand for sustainable energy solutions in residential settings.