Research Article Fast Hybrid MPPT Technique for Photovoltaic Applications: Numerical and Experimental Validation Gianluca Aurilio, 1 Marco Balato, 1 Giorgio Graditi, 2 Carmine Landi, 1 Mario Luiso, 1 and Massimo Vitelli 1 1 Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa, Italy 2 ENEA Portici Research Centre, P. E. Fermi 1, Naples, 80055 Portici, Italy Correspondence should be addressed to Mario Luiso; mario.luiso@unina2.it Received 14 January 2014; Revised 31 March 2014; Accepted 22 April 2014; Published 3 June 2014 Academic Editor: Pavol Bauer Copyright © 2014 Gianluca Aurilio 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. In PV applications, under mismatching conditions, it is necessary to adopt a maximum power point tracking (MPPT) technique which is able to regulate not only the voltages of the PV modules of the array but also the DC input voltage of the inverter. Such a technique can be considered a hybrid MPPT (HMPPT) technique since it is neither only distributed on the PV modules of the PV array or only centralized at the input of the inverter. In this paper a new HMPPT technique is presented and discussed. Its main advantages are the high MPPT eiciency and the high speed of tracking which are obtained by means of a fast estimate of the optimal values of PV modules voltages and of the input inverter voltage. he new HMPPT technique is compared with simple HMPPT techniques based on the scan of the power versus voltage inverter input characteristic. he theoretical analysis and the results of numerical simulations are widely discussed. Moreover, a laboratory test system, equipped with PV emulators, has been realized and used in order to experimentally validate the proposed technique. 1. Introduction In PV applications, the maximum power point (MPP) of the power versus voltage (-) PV characteristic must be contin- uously tracked in order to extract the maximum energy. Many MPP tracking (MPPT) techniques have been presented in the literature [1–4]. Mismatch operating conditions of the PV modules are due to clouds, shadows of neighboring objects, dirtiness, manufacturing tolerances, diferent orientation of parts of the PV ield, dust, aging, and so forth. In case of mismatch, the - characteristic of the PV ield may exhibit more peaks, due to the presence of bypass diodes. In such conditions, MPPT algorithms can fail causing a marked reduction of the overall system eiciency [1–4]. Moreover, the global maximum power of the mismatched PV ield is lower than the sum of the available maximum powers that the mismatched modules would be able to provide if each of them could operate in its own MPP. In order to allow each PV module of the array to provide its own maximum power, it is possible to use module-dedicated DC/AC con- verters (microinverters) [5, 6] or module-dedicated DC/DC converters (microconverters) and central inverters [7–25]. he module-dedicated converters carry out the MPPT on each PV module. In this paper, the attention is focused on PV applications adopting module-dedicated DC/DC converters and central inverters. A not exhaustive list of commercial MPPT DC/DC converters (oten called microconverters or power optimizers) includes SolarMagic power optimizers by National Semiconductors (four-switch buck-boost topology) [26], SolarEdge power box (buck-boost topology) [27], Tigo Energy Module Maximizers (MM-ES50, MM-ES75, MM- ES110, MM-ES170, buck topology) [28], Xandex SunMizers (buck topology) [29], SPV1020 produced by STMicroelec- tronics (boost topology) [30], eIQ Energy Vboost (boost topology) [28], and Tigo Energy power optimizers (MM- EP35, MM-EP45, MM-EP60 (boost topology)) [28]. here- fore, commercial power optimizers based on the buck, or on the boost or on the buck-boost topology, are available. In [20], Hindawi Publishing Corporation Advances in Power Electronics Volume 2014, Article ID 125918, 15 pages http://dx.doi.org/10.1155/2014/125918