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Maximum Power Point Tracking Using Fuzzy Logic Control

Prof. Dr. Mohamed M. Algazar Electrical Power & Machines Dept. Faculty of Engineer Al-Azhar University

Assist. Prof. Dr. Hamdy AL-monier Electronics & communication Dept. Faculty of Engineer Mansoura University

Dr. Hamdy Abd EL-halim Electrical Power & Machines Dept. Faculty of Engineer Al Azhar University

Eng. Mohamed Ezzat El Kotb Salem B.Sc. Electrical Power & Machines engineer

Al Azhar University, 2004 ABSTRACT: This paper proposes an intelligent control method for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and insolation conditions. This method uses a fuzzy logic controller applied to a DC-DC converter device. The different steps of the design of this controller are presented together with its simulation. The PV system that I chose to simulate to apply my techniques on it is stand-alone PV water pumping system. Results of this simulation are compared to those obtained by the system without MPPT. They show that the system with MPPT using fuzzy logic controller increase the efficiency of energy production from PV. Keywords: Photovoltaic (PV), Maximum power point tracking (MPPT), Fuzzy Logic Control (FLC), MATLAB/SIMULINK.

I. INTRODUCTION In our Arabian nation peopled areas is very small comparing to total area because fresh water resources concentrate in these areas. Now, the existing fresh water almost enough for our needs, but in the near future with increasing in people numbers it will be huge problem. On the other hand we have shining sun all the year, so we can use stand alone PV-powered water pumping system to get water in non peopled areas. Unfortunately the actual energy conversion efficiency of PV module is rather low. So to overcome this problem and to get the maximum possible efficiency, the design of all the elements of the PV system has to be optimized. In order to increase this efficiency, MPPT controllers are used. Such controllers are becoming an essential element in PV systems. A significant number of MPPT control have been elaborated since the seventies, starting with simple techniques such as voltage and current feedback based MPPT to more improved power

feedback based MPPT such as the perturbation and observation (P&O) technique or the incremental conductance technique [1-2]. Recently intelligent based controls MPPT have been introduced. In this paper, an intelligent control technique using fuzzy logic control is associated to an MPPT controller in order to improve energy conversion efficiency.

II. MAXIMUM POWER POINT TRACKING ALGORITHMS

When a PV module is directly coupled to a load, the PV module’s operating point will be at the intersection of its I–V curve and the load line which is the I-V relationship of load. For example in Figure 1, a resistive load has a straight line with a slope of 1/Rload as shown in Figure 2. In other words, the impedance of load dictates the operating condition of the PV module. In general, this operating point is seldom at the PV module’s MPP, the optimal adaptation occurs only at one

 

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As shown in Figures 15, the flow rate of Kyocera SD 12-30 water pump is proportional to the power delivered. When the total dynamic head is 30m, the flow rate per watt is approximately 86.7cm3/W.min. The minimum power requirement of pump motor is 35W [13]; therefore as long as the output power is higher than 35W, it pumps water with the flow rate above. Figure 15 show also that the direct-coupled PV water pumping system has a severe disadvantage because in the morning the pump will delay starting while the same system with MPPT is already pumping water. Similarly, in the afternoon it goes idle nearly earlier than the system with MPPT. The flow rate of water is also lower throughout the operating period. The figures show that MPPT offers significant performance improvement.

V. CONCLUSION

The main purpose of this paper was to propose a new technique for MPPT of stand alone PV system using Fuzzy Logic Control. This purpose leads us to achieve many goals, which can be summaries as follow: • Design and simulate a PV array in MATLAB/SIMULINK using data sheet for commercial PV array, which give us the performance of the PV array (I-V curve and P-V curve) under any atmospheric conditions ( irradiance and Temperature) and can be used in any research related with photovoltaic. The result shows that the PV model using the equivalent circuit provides good matching with the real PV module. • Design and simulate DC-DC Cúk converter and Pulse Width Modulator in MATLAB/SIMULINK (SimPowerSystems) which can be use in any power electronics research. • Design and simulate a MPPT controller using FLC in MATLAB/ FUZZY TOOL BOX/ SIMULINK.

Finally, this paper presents a simple but efficient photovoltaic water pumping system. It models each component and simulates the system using MATLAB/SIULINK. Simulations use SimPowerSystems in SIMULINK to model a DC pump motor. It performs simulations of the whole system and verifies functionality and benefits of MPPT. Simulations also make another comparison with the system without MPPT in terms of energy produced and flow rate of water pumped using atmospheric conditions for one day. The results validate that MPPT can significantly increase the efficiency of energy production from PV and the performance of the PV water pumping system compared to the system without MPPT. This increasing could bring large savings if the system is large.

REFERENCES

[1] Hohm, D. P. & M. E. Ropp “Comparative Study of Maximum Power Point Tracking Algorithms” Progress in Photovoltaics: Research and Applications November 2003, page 47 62. [2] Hussein, K. H., I. Muta, T. Hoshino, & M. Osakada “Maximum Photovoltaic Power Tracking: an Algorithm for Rapidly Changing Atmospheric Conditions” IEE Proceedings – Generation, Transmission and Distribution – v. 142 January 1995, page 59-64. [3] M.S. Aït Cheikh*, C. Larbes†, G.F. Tchoketch Kebir and A. Zerguerras “Maximum power point tracking using a fuzzy logic control scheme” Revue des Energies Renouvelables Vol. 10 N°3 (2007) 387 – 395. [4] H. Knopf, ‘Analysis, Simulation and Evaluation of Maximum Power Point Tracking (MPPT) Methods for a Solar Powered Vehicle’, Master Thesis, Portland State University, 1999.

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[5] Oi, Akihiro “Design and Simulation of Photovoltaic Water Pumping System” Master's Thesis, California Polytechnic State University, San Luis Obispo, 2005. [6] Antonio Luque, Steven Hegedus “Handbook of Photovoltaic Science and Engineering” John Wiley & Sons Ltd, 2003. [7] Messenger, Roger & Jerry Ventre “Photovoltaic Systems Engineering 2nd Edition” CRC Press, 2003. [8] M. Veerachary, T. Senjyu, and K. Uezato, ‘Voltage-Based Maximum Power Point Tracking Control of PV Systems’, IEEE Trans. Aerosp. Electron. Syst., Vol. 38, pp. 262 - 270, Jan. 2002. [9] K.M. Passino and S. Yurkovich, ‘Fuzzy Control’, Addison, Wesley, 1998. [10] M. A. S. Masoum and M. Sarvi, “A new fuzzy-based maximum power point tracker for photovoltaic applications” Iranian Journal of Electrical & Electronic Engineering, Vol. 1, January 2005. [11] Nopporn Patcharaprakitia,1 , Suttichai Premrudeepreechacharnb,* , Yosanai Sriuthaisiriwongb,2 “Maximum power point tracking using adaptive fuzzy logic control for grid-connected photovoltaic system” a Department of Electrical Engineering, Rajamagala Institute of Technology, Chiang Rai 57120, Thailand. b Department of Electrical Engineering, Chiang Mai University, Chiang Mai 50200, Thailand. [12] National Renewable Energy Laboratory (NREL) Daily Plots and Raw Data Files May 8, 2010 and July 4, 2010 (downloaded from http://www.nrel.gov/solar_radiation/data.html). [13] Kyocera Solar Inc. “Solar Water Pump Applications Guide 2001” (downloaded from www.kyocerasolar.com). [14] BP Solar BP SX150 - 150W Multi-crystalline Photovoltaic Module Datasheet, 2001.

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