SOLAR TRACKING USING FUZZY LOGIC Presented By

Megha Srikanth

An Overview

IntroductionPrinciple of MPPT ControlMPPT techniquesP & O controllerFuzzy logic of MPPT controlConclusion

INTRODUCTION

This scheme is capable of following the trajectory of the sun throughout the day on a year-round basis.

Various schemes have been proposed for optimizing the tilt angle and orientation of solar collectors

The actual energy conversion efficiency of PV module is rather low

PRINCIPLE OF MPPT

The photovoltaic module operation depends strongly on the load characteristics

The connection between the source and the load is considered

Furthermore the characteristics of a PV system vary with temperature and insulation

Current-voltage characteristic of a PV module

Photovoltaic system

MPPT TECHNIQUES

Voltage feedback based methods

Current feedback based methods

Power based methods

P & O CONTROLLER Principle is to provoke perturbation by acting

on the PWM duty cycle and observing the effect on the output PV power.

when dp / dv > 0 , the voltage is increased, D (k )= D (k – 1) + C

when dp / dv < 0 , the voltage is decreased, D(k ) = D(k − 1) − C .

Power-voltage characteristic of a PV module

Basic circuit of the boost chopper

Fuzzy logic of MPPT control

They have the advantage to be robust and relatively simple to design

They do require the complete knowledge of the operation of the PV system by the designer.

General diagram of a fuzzy controller

Membership functions of (a) error E - (b) change of error CE - (c) duty ratio D

CONCLUSIONFuzzy controller is faster than the P&O

controller in the transitional state

Presents also a much smoother signal with less fluctuations in steady state

It can provide an order more effective than the traditional controllers for the nonlinear systems

REFERENCESV. Salas, E. Olias, A. Barrado and A. Lazaro,

‘Review of the Maximum Power Point Tracking Algorithms for Stand-Alone Photovoltaic Systems’, Solar Energy Materials & Solar Cells

H. Knopf, ‘Analysis, Simulation and Evaluation of Maximum Power Point Tracking (MPPT)

F. Boehinger, ‘Self Adaptive DC Converter for Solar Spacecraft Power Supply’, IEEE