A Double Frequency Ripple Suppression Control in Quasi Z- Source Inverter

The quasi z-source inverter was implemented for boosting the voltage at the input side to the desired dc link voltage, thus the voltage gain and efficiency can be improved. The quasi z-source inverter draws the continuous input current and provides a common earthing between the pv and dc-link bus. The quasi z-source inverter configuration can be applied to a wide range of converting the power in electrical conversion system (ac-ac, ac-dc, dc-ac, dc-dc). One of the significant advantage of quasi z-source network is the reduced stress for the voltage on the inverter switches when compares to the traditional two stage inverter topology. Also quasi z-source inverter has lower total harmonic distortion (THD) values which in turn results in the reduced output filter size and cost. A new modulation technique for quasi z-source inverter configuration which can improve the voltage and current levels by using the additional converter stage was implemented. The converter has both buck and boost capabilities. Depends on the specific applications the converter can be replaced with buck, boost, buck-boost, cuk, sepic etc., Also a single photovoltaic (pv) module is sufficient to obtain the desired output and thus reducing the overall cost of the system. The quasi z-source inverter model can be used along with the flyback converter for laser, mobile phone charger, standby power supply in pc applications.