2s -: __ k!!B ~bwgykbtaiak andSobrCc& ELSEVIER Solar Energy Materials and Solar Cells 37 (1995) 123-132 A new model for I-V characteristic of solar cell generators and its applications Mehmet Akbaba, Mohammed A.A. Alattawi Department of Electrical Engineering, The University of Bahrain, PO. Box 33547, Isa Town, Bahrain Received 3 February 1994; revised 20 July 1994 Abstract A new model is presented for accurate simulation of the external (Z-V) characteristic of solar cells generators and the model is applied to direct analytical evaluation of the maximum power points, without involving time consuming numerical techniques. The model is compared with the traditional (Z-V) characteristic, which is chosen from the published literature, and very satisfactory match is obtained between the two. The new model lends itself for easy analytical manipulations. To this end it is applied to resistive load and closed form solution is obtained for the performance which is not readily obtainable from the traditional (Z-V) characteristic. 1. Introduction Because of the drastic increases in oil prices and the decrease in oil reserves, many studies have been conducted for utilization of solar energy. Solar energy can be utilized in two ways, i.e., either to use it directly for heating or cooling of air and water without using an intermediate electric circuitry, or to convert it into electrical energy by using solar cells. Conversion of solar radiation to electrical energy is the most convenient way of utilizing solar radiation. Therefore, many studies have been devoted for analysis of cell generator driven DC motors and passive loads (R or R-L loads) [l-51. Also many other references are listed in Refs. [l] and [41. In the analysis of the performance of solar cell generator driven loads, one of the key element is the mathematical model of the 1-V characteristic of solar cells or solar cell generators. In all published literature [l-5] a single mathematical model is used for the Z-V characteristic of solar cells or solar cell generators, which is a traditional p-n junction I-V or V-1 characteristic model that has been used since long time in electronics using Eqs. (1) and (2) which are 0927-0248/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDI 0927-0248(94)00201-O