Z - H CONVERTER WITH A NEW SIMPLE MPPT FOR PHOTOVOLTAIC POWER GENERATION SYSTEM

Abstract

Power electronic converters play the role of power conditioning unit in solar energy to electrical energy conversion for voltage conversion and acquiring the maximum power from the photovoltaic array. Z-source converters are the recently introduced power converters with buck and boost capability. They extend a greater range of output voltage, provide high reliability and reduce ripple and in-rush currents in the circuits. So, they can perform as power conditioning units and render better results compared to conventional power converters. A full bridge new Z-source converter named as Z-H converter has been newly added with additional features. It does not need the front end diode, but the operating principle of this converter is similar to that of Z-source converter and all the equations in boost mode are also valid. The operating principle with equivalent circuits and the steady state analysis are provided. A 37W solar panel with 36 series connected cells is taken in this work for simulation and implementation. A 300W photovoltaic array is developed from these panels and integrated with Z-H converter. A simple maximum power point tracking technique using perturb and observe algorithm is proposed to extract maximum power from the photovoltaic array at any operating conditions. The complete system is modeled and simulated using MATLAB. Also the proposed concepts are verified experimentally using a laboratory prototype.