Research Article Evaluation of Fuzzy Logic Subsets Effects on Maximum Power Point Tracking for Photovoltaic System Shahrooz Hajighorbani, 1,2 M. A. M. Radzi, 1,2 M. Z. A. Ab Kadir, 1 S. Shafie, 1 Razieh Khanaki, 1,2 and M. R. Maghami 1,2 1 Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 2 Center of Advanced Power and Energy Research (CAPER), Malaysia Correspondence should be addressed to Shahrooz Hajighorbani; shahrooz.kntu@yahoo.com Received 23 January 2014; Accepted 8 August 2014; Published 2 September 2014 Academic Editor: Gopal N. Tiwari Copyright © 2014 Shahrooz Hajighorbani et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Photovoltaic system (PV) has nonlinear characteristics which are afected by changing the climate conditions and, in these characteristics, there is an operating point in which the maximum available power of PV is obtained. Fuzzy logic controller (FLC) is the artiicial intelligent based maximum power point tracking (MPPT) method for obtaining the maximum power point (MPP). In this method, deining the logical rule and speciic range of membership function has the signiicant efect on achieving the best and desirable results. his paper presents a detailed comparative survey of ive general and main fuzzy logic subsets used for FLC technique in DC-DC boost converter. hese rules and speciic range of membership functions are implemented in the same system and the best fuzzy subset is obtained from the simulation results carried out in MATLAB. he proposed subset is able to track the maximum power point in minimum time with small oscillations and the highest system eiciency (95.7%). his investigation provides valuable results for all users who want to implement the reliable fuzzy logic subset for their works. 1. Introduction Fossil fuel is a very common choice in many countries world- wide due to its large sources, but nowadays by increasing concerns about some issues such as fossil fuel storage, global warming, and skyrocketing oil costs, it is desirable to consider substitute possible energy source that has high productivity and low outpouring [1, 2]. All of the PV systems have some main problems afected by weather conditions such as dirt, changing irradiation, temperature, and other factors. he PV systems have two main characteristics, P-V and I-V, where P, V, and I are PV output power, voltage, and current, respectively. Changing the irradiation has the most efect on these characteristics. he PV system has an operating point that can be speciied by the crossing point between I-V curve of the PV panel and load line in I-V characteristic. he variation of some factors such as irradiation, temperature, and dust can change the operating point. here is single point in I-V and P-V curves of PV panel that power poses the maximum value and it is called maximum power point (MPP) [3]. In changing weather condition such as irradiation, the MPP controller should be capable of tracking MPP at minimum time in order to minimize the power loss. In order to ind the MPP, various methods have been proposed which can be classiied in two general methods: conventional and sot computing methods. Conventional methods include perturb and observe (P&O), constant volt- age (CV), and conductance increment (IC), and sot com- puting methods cover fuzzy logic controller, neural network predictor, genetic algorithm, and so on [4–12]. Every tracking control method has its advantages and disadvantages. One of the main factors for inding the best MPPT algorithm is that the MPP should be found by controller in the minimum time especially under changing condition. Another signif- icant factor is that the controller can operate at this point with minimum oscillation. he conventional methods have drawbacks such as low tracking speed and also oscillation Hindawi Publishing Corporation International Journal of Photoenergy Volume 2014, Article ID 719126, 13 pages http://dx.doi.org/10.1155/2014/719126