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a b s t r a c tThis paper focuses on a PV system linked to the electric grid by power electronic converters, identification of the five parameters modeling for photovoltaic systems and the assessment of the shading effect. Normally, the technical information for photovoltaic panels is too restricted to identify the five parameters. An undemanding heuristic method is used to find the five parameters for photovoltaic systems, requiring only the open circuit, maximum power, and short circuit data. The I-V and the P-V curves for a monocrystalline, polycrystalline and amorphous photovoltaic systems are computed from the parameters identification and validated by comparison with experimental ones. Also, the I-V and the P-V curves under the effect of partial shading are obtained from those parameters. The modeling for the converters emulates the association of a DC-DC boost with a two-level power inverter in order to follow the performance of a testing commercial inverter employed on an experimental system.

This paper presents a systemic modeling for a PV system integrated into an electric grid. The modeling includes models for a DC-DC boost converter and a DC-AC two-level inverter. Classical or fuzzy PI controllers with pulse width modulation by space vector modulation associated with sliding mode control is used for controlling the PV system and power factor control is introduced at the output of the system. Comprehensive performance simulation studies are carried out with the modeling of the DC-DC boost converter followed by a two-level power inverter in order to compare the performance with the experimental results obtained during in situ operation with three commercial inverters. Also, studies are carried out to assess the quality of the energy injected into the electric grid in terms of harmonic distortion. Finally, conclusions regarding the integration of the PV system into the electric grid are presented.

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In the residential sector, energy micro-generation and its intelligent management have been creating novel energy market models, considering new concepts of energy use and distribution, in which the prosumer has an active role in the energy generation and its selfconsumption. The configuration of the solar photovoltaic system with a battery energy storage in Portugal is unclear in the technical, energetic and mostly in the economical point of view. The energy generation and consumption management, jointly with the battery operation, have a great influence in the configuration's profitability value. The present work evaluates different photovoltaic configurations with and without energy storage for the normal low voltage C consumer profile, for a contracted power of 3.45 kVA, to evaluate the systems' cost-effectiveness, framed in the regulation in force in Portugal -the decree-law 153/2014 -, which promotes the micro-generation and self-consumption. The analysis consists of three different geographical locations in the country, considering distinct electric tariffs. These are relevant parameters in the choice of the configuration, concluding that although the solar photovoltaic system by itself is already economical presently, its integration with battery energy storage isn't in most of the configurations, however it is already possible to find profitable PV+battery configurations, considering all the most relevant criteria, and supported by good energy management.