Analysis and control of impedance network based inverters for photovoltaic applications

Abstract

Nowadays the penetration of renewable energy sources into the newlinepower generation system is increasing due to the depletion of fossil fuels and newlinecontinuous increase in load demand. Among the available renewable energy newlinesources, solar energy is the widely used resource because of its availability newlineand eco friendly nature. Power electronic converters play a vital role in the newlinegeneration and distribution of solar energy. There must be a power newlineconditioning stage i.e DC-DC converter in between Photovoltaic (PV) source newlineand load inorder to buck or boost the available PV voltage as required by load. newlineIn grid connected mode, there are two power conditioning stage (DC-DC and newlineDC-AC) needed in between PV source and grid. This may increase the cost newlineand volume of the system. Impedance source inverter is a single power newlineconditioning topology widely used in PV applications. There are many newlineimpedance topologies are available. Every topology has its own advantages newlineand limitations interms of boost factor, efficiency and leakage current. Hence newlinein this work, a novel switched capacitor inductor quasi admittance source newlineH6(SCL-QYS H6) inverter is proposed. newlineThe controller design is a crucial part of the grid connected system. newlineIn grid connected system, there may be the possibility of uncertainties like newlineimpedance variation, frequency variation and voltage amplitude variation. newlineThese uncertainties are not able to compensate by conventional controllers. newlineHence in this work, robust Hand#8734; controller is designed and implemented in newlinequasi admittance source inverter. The proposed controller is compared with newlineproportional integral and proportional resonant controller. The Hand#8734; controller newlineis verified both in simulation and experiment. newline