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 efficiency 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. The new HMPPT technique is compared with simple HMPPT techniques based on the scan of the power versus voltage inverter input characteristic. The 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 continuously 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, different orientation of parts of the PV field, dust, aging, and so forth. In case of mismatch, the characteristic of the PV field 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 efficiency [1–4]. Moreover, the global maximum power of the mismatched PV field 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 converters (microinverters) [5, 6] or module-dedicated DC/DC converters (microconverters) and central inverters [7–25]. The 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 (often called microconverters or power optimizers) includes SolarMagic power optimizers by
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