SOLAR TRACKING USING FUZZY LOGIC Presented By Megha Srikanth

An Overview Introduction Principle of MPPT Control MPPT techniques P & O controller Fuzzy logic of MPPT control Conclusion

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

CONCLUSION Fuzzy 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

REFERENCES V. 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