This paper applies a dynamical electrical array reconfiguration (EAR) strategy on the photovoltaic (PV) generator of a grid-connected PV system based on a plant-oriented configuration, in order to improve its energy production when the operating conditions of the solar panels are different. The EAR strategy is carried out by inserting a controllable switching matrix between the PV generator and the central inverter, which allows the electrical reconnection of the available PV modules. As a result, the PV system exhibits a self-capacity for real-time adaptation to the PV generator external operating conditions and improves the energy extraction of the system. Experimental results are provided to validate the proposed approach.

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Electrical PV Array Reconfiguration Strategy for Energy Extraction Improvement in Grid-Connected PV Systems

Cell modelling and model parameters estimation techniques for photovoltaic simulator application: A review

Partial shading in photovoltaic (PV) arrays renders conventional maximum power point tracking (MPPT) techniques ineffective. The reduced efficiency of shaded PV arrays is a significant obstacle in the rapid growth of the solar power systems. Thus, addressing the output power mismatch and partial shading effects is of paramount value. Extracting the maximum power of partially shaded PV arrays has been widely investigated in the literature. The proposed solutions can be categorized into four main groups. The first group includes modified MPPT techniques that properly detect the global MPP. They include power curve slope, load-line MPPT, dividing rectangles techniques, the power increment technique, instantaneous operating power optimization, Fibonacci search, neural networks, and particle swarm optimization. The second category includes different array configurations for interconnecting PV modules, namely series-parallel, total-cross-tie, and bridge-link configurations. The third category includes different PV system architectures, namely centralized architecture, series-connected microconverters, parallel-connected microconverters, and microinverters. The fourth category includes different converter topologies, namely multilevel converters, voltage injection circuits, generation control circuits, module-integrated converters, and multiple-input converters. This paper surveys the proposed approaches in each category and provides a brief discussion of their characteristics.

Control and Circuit Techniques to Mitigate Partial Shading Effects in Photovoltaic Arrays

The power-voltage characteristic of photovoltaic (PV) arrays operating under partial-shading conditions exhibits multiple local maximum power points (MPPs). In this paper, a new method to track the global MPP is presented, which is based on controlling a dc/dc converter connected at the PV array output, such that it behaves as a constant input-power load. The proposed method has the advantage that it can be applied in either stand-alone or grid-connected PV systems comprising PV arrays with unknown electrical characteristics and does not require knowledge about the PV modules configuration within the PV array. The experimental results verify that the proposed global MPP method guarantees convergence to the global MPP under any partial-shading conditions. Compared with past-proposed methods, the global MPP tracking process is accomplished after far fewer PV array power perturbation steps.

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A New Technique for Tracking the Global Maximum Power Point of PV Arrays Operating Under Partial-Shading Conditions

A novel fault diagnosis technique for photovoltaic systems based on artificial neural networks

A new estimation method of irradiance on a partially shaded PV generator in grid-connected photovoltaic systems

Univer Project. A grid connected photovoltaic system of 200kWp at Jaén University. Overview and performance analysis

Estimation of the energy of a PV generator using artificial neural network

A comprehensive method for estimating energy losses due to shading of GC-BIPV systems using monitoring data

This paper includes a definition of a new and original concept in the photovoltaic field, RMS current of a photovoltaic generator for grid-connected systems. The RMS current is very useful for calculating energy losses in cables used in a PV generator. As well, a current factor has been defined in order to simplify RMS current calculation. This factor provides an immediate (quick and easy) calculation method for the RMS current that does not depend on the case particular conditions (orientation, location, etc.). RMS current and current factor values have been calculated for different locations and modules.

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P.J. Pérez

Papers

A new estimation method of irradiance on a partially shaded PV generator in grid-connected photovoltaic systems

Univer Project. A grid connected photovoltaic system of 200kWp at Jaén University. Overview and performance analysis

Estimation of the energy of a PV generator using artificial neural network

A comprehensive method for estimating energy losses due to shading of GC-BIPV systems using monitoring data

RMS Current of a Photovoltaic Generator in Grid-Connected PV Systems: Definition and Application