A MAXIMUM POWER POINT TRACKING TECHNIQUE FOR SINGLE-PHASE PHOTOVOLTAIC SYSTEMS WITH REDUCED DC-LINK CAPACITOR

Authors

P. Nagasekhara Reddy
Department of Electrical and Electronics Engineering Mahatma Gandhi Institute of Technology, Hyderabad, Telangana, India.

Abstract

Electrolytic capacitors used in photovoltaic (PV) power conditioning units (PCU) for power decoupling purposes are less reliable in nature. Film capacitors can be adopted instead of electrolytic capacitors if the energy storage requirement of the PCU is reduced, since they offer better reliability and have a longer lifetime. The energy storage capacitor size reduction is facilitated by allowing DC-link voltage to have a specified amount of ripple. However, a high DC-link voltage ripple imposes a double-line frequency ripple in the PV panel voltage and current. This leads to oscillations in the extracted panel power and thereby results in power loss. In view of this, this thesis develops a locus line based maximum power point tracking (MPPT) control algorithm to mitigate this power loss. The proposed digital control algorithm was simulated in MATLAB Simulink.