A TRANSFORMER LESS PV CELL BASED COUPLED INDUCTOR SINGLE STAGE BOOST THREE PHASE INVERTER

Abstract

PV cells without transformer in grid connected power system have been attracting many researchers for its smaller volume, lower cost and very higher efficiency as compared to the normal transformer. But while implementing this kind of system one of the biggest technical challenge is issue of leakage current mainly caused by common mode voltages, this leakage current are mainly caused by parasitic capacitors between the solar panel and the ground. In this research article a coupled inductor single stage boost inverter (CL-SSBI) is been implemented. In which introduced an impedance network, this includes the coupled inductor in the front end of the inverter bridge. In this technique uses shoot through zero vectors to store and limit transfer energy within impedance network which will be unique in nature, and it will be utilize for stepping up the bus voltage. Turns ratio of the coupled inductor within the impedance network has designed to improve the boosting voltage. This gives the facility to boost the voltage and also can be regulated over a wide range and step up at higher value is possible. If we adopt higher boost gain scheme then higher power loss and lower efficiency would be unavoidable. However, the transformer less PV system connected to grid based on CLSSBI shows significant reduction in leakage current. A addition of the diode in front of the topology blocks the leakage current.