Grid Connected Transformer Less HERIC based Photovoltaic Inverter

Abstract

Transformer is used to design PV System for safety purpose and galvanic isolation. But at the conversion stage overall frequency is decreased, due to use of heavy, expensive and bulky transformer.  In further conversion process, increase the power losses, due to this, efficiency of the system is reduced. Therefore, the tendency is to eliminate the transformer in order to increase the efficiency. To overwhelmed these problems, transformer less Photo Voltaic System is introduced. It will be highly effective, smaller in size, lighter in weight and low cost. But, due to the stray capacitance it will be dangerous because of leakage current will flow between PV array and the grid. In this paper, design a two stage single phase grid connected PV Inverter without galvanic isolation is been carried out. In this paper DC/DC boost converter is used to rise the output of PV panel, after that MPPT control method is being utilized to control the input of step up converter. So as to change from DC to AC with greater efficiency the step upped output is fed to the HERIC inverter.