Common Mode Voltage Analysis Of Transformerless Photovoltaic Grid Connected Converters

Renewable energy sources(RES)such as solar and wind energies are getting more and more widespread.Solar energy and photovoltaic(PV)technologies have become much popular due to that they are environmentally friendly and the Sun is available almost everywhere.The distributed generation energy is also one of the solutions for the unabated population and economy growth of today.The motivation and harnessing of renewable energy come also from power electronics development that has fueled a zeal for everyday new research.Most of the PV systems require to be integrated on electrical grid.The removal of isolation transformer between the PV system and the grid leads to the efficiency improvement,size and cost reduction.However,this also leads to appearance of common mode current(CMC)through a parasitic capacitance between the PV panels and the ground.So,this CMC must be carefully tackled since it damages solar panels and poses safety problems.The Pulse Width Modulation(PWM)techniques and inverter topologies can play a vital role to tackle the CMC problem.The fluctuating Common Mode Voltage(CMV)gives rise to CMC.So,in order to mitigate the CMC to comply it with the standard requirements and make the PV system safe for human interaction CMV is also dealt with.The primary task of this research was the investigation and analysis of Common Mode Voltage of Transformerless Inverters for PV Grid Connected System.This Thesis mainly consists of five Chapters:Chapter 1 introduces the research.Background,benefits and contribution,objectives and problem statement are also the part of this chapter.Chapter 2 investigates the CM voltage and leakage current for Single Phase Converters.It details the HB inverter Common Mode equivalent circuits.Mathematical Equations are also provided while.The role of DC and AC decoupling method is talked about in this chapter.Chapter 3 analyses the CM voltage and leakage current for Three Phase ConvertersChapter 4 deals with results and findings of the thesis.Power Decoupling with Common Mode Current reduction inverters are also provided.Finally,Chapter 5 provides final conclusion based on theoretical and final results.The contributions and guidelines for future work are also provided.