Single phase transformerless photovoltaic inverter for grid connected systems - an overview

Renewable energy sources play a vital role in satisfying the growing electricity demand. Out of the numerous available sources, solar energy is projected as the most viable one. Solar photovoltaic is used for converting solar energy into unregulated DC electrical energy. The generated DC energy is converted to AC voltage of anticipated magnitude and frequency using solar inverters. Transformerless grid integrated inverter is the emerging topology used in the solar inverter. The objective of this paper is to provide a critical review of the grid integrated solar inverter. The review is done on the primary operation, research advancements in topologies and control, comparing performance parameters, and listing challenges. In addition, a review of industrial solutions with performance parameter is also provided. Furthermore, review of various maximum power point tracking (MPPT) techniques and its point of implementation is reviewed. The efficiency of transformerless grid integrated inverter lies between 93% to 97%. The total harmonic distortion (THD) reported is less than 5%. The review of fault detection method is also presented. A new topology is proposed, and its performance is evaluated and compared with the simulation results of conventional topologies. The common mode noise is reduced in the new proposed topology.