Power Quality Improvement Using PV Coupled Non-Isolated Quasi Z Source Inverter

Abstract

Z source inverter is a DC to AC converter, but it can be operated as buck boost converter without employing separate bridge converter. The proposed work presents the new Quasi- Z Source Inverter to improve the effectiveness by drop in conduction loss of the system. High boost capability with smaller capacitance and inductance makes the system output stable, which is also suitable for Photovoltaic and Fuel cell based renewable energy systems. The existing DC link in the converter system has been replaced by X shape connected capacitors and inductors in Z source network with common ground connection. the new Quasi- Z Source Inverter increases the output voltage range with improved power factor, reduced harmonics and has good ride through capability. Photovoltaic fed quasi-Z source inverter is employed nowadays for its high potential to integrate with power systems. The proposed converter reduces the damping of the grid connected grid connected system to reduce the transient interactions. Unipolar PWM technique is employed to reduce the THD of the system. MATLAB simulink has been employed to simulate the proposed method and the prototype has been developed to verify the simulink.