FUZZY PERTURB AND OBSERVE BASED MPPT OF PV ARRAYS

Abstract

In this dissertation we have proposed very simple but efficient technique to track maximum power from photovoltaic module for a step change in temperature and radiation. Temperature is changed from 320.18 K to 600 K at 0.15 s and radiation is changed from 100 W/m2 to 1000 W/m2 at 0.05 s. We have compared the results for MPPT control using perturb and observe with fuzzy MPPT control and perturb and observe technique. In fuzzy MPPT techniques output from perturb and observe block is compared with PV module output voltage to get an error signal. This error signal is then feed to fuzzy controller. Fuzzy controller processes this error signal and generates a control signal which passes through PWM generator and produces pulse signal. The duty cycle of the pulse varies with control signal and is used to switch ON or OFF DC to DC converter. By using P & 0 based controller maximum power is obtained but significantly large oscillation is observed. The fuzzy MPPT controller achieves maximum power with less oscillation. In this case, the oscillation causes significantly lesser loss of energy at the load end. So we achieve efficient performance of PV arrays while using fuzzy P & 0 MPPT controller