Photovoltaic Sources Modeling

Giovanni Petrone, Carlos Andres Ramos-Paja, Giovanni Spagnuolo

• Publisher: Wiley-IEEE Press
• Year: 2017
• Print ISBN: 9781118679036
• eBook ISBN: 9781118756492
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

A practical reference to support choosing, customising and handling the best PV simulation solution

This comprehensive guide surveys all available models for simulating a photovoltaic (PV) generator at different levels of granularity, from cell to system level, in uniform as well as in mismatched conditions. Providing a thorough comparison among the models, engineers have all the elements needed to choose the right PV array model for specific applications or environmental conditions matched with the model of the electronic circuit used to maximize the PV power production.

Key features:

• Multiple mathematical models are given for different application requirements.
• The shading effect is taken into account to improve the model accuracy.
• Procedures for parameter identification of the PV model are analysed and compared.
• Mathematical manipulations are introduced to some models to reduce their calculation time.
• The electronic interface effect on the power chain is analysed.
• Analytical expressions are used to design and control the power converter driving the PV field.

The book is an essential reference for R&D in the PV industry; designers of power converters for PV; PV systems designers; and practicing engineers.

1
PV Models

1.1 Introduction

As for any physical system, PV cell modeling can be done with different levels of accuracy, depending on the user’s purposes. In this book the PV generator is always modeled through an equivalent circuit and by using concentrated parameters and variables. Indeed, the aim is to give the reader tools for implementing the PV array model in simulation environments, allowing them to analyze and design the whole PV generator, including the power‐processing system feeding a load or the grid. For users interested in this kind of study, access to data concerning the physical properties of the semiconductor material involved or parameter values that depend on the cells’ manufacture, such as dopant concentrations or material response to the radiation spectrum, is either not easy or the figures are not readily translated into circuit parameters. Instead, the use of laboratory measurements at the PV terminals, in terms of current and voltage values, or use of experimental data from the product datasheet, are more viable ways of proceeding.

This chapter introduces the two main circuit PV models used in the literature: the single‐diode and the double‐diode models. The first is the more widely used because of the reduced number of circuit parameters to be identified. The double‐diode model (DDM) has better accuracy, especially at low irradiance levels, but it requires a more involved identification of the parameter values. Thus while some space is dedicated in this chapter to the DDM, in the following chapters the single‐diode model (SDM) will be considered the reference one.

1.2 Modeling: Granularity and Accuracy

In the last five years a huge literature has been devoted to modeling PV sources, for two main purposes. The first is the reproduction of the I–V curve at the generator terminals through a suitable electrical model, regardless of the size of the PV source: from one PV cell, or even sub‐portions of it, up to large PV fields made of series‐connected modules forming strings that are in turn connected in parallel. The second purpose is performing energetic analyses concerning plant productivity, using models based on empirical or semi‐empirical equations.

The first set of models aims to describe the functional current–voltage relationship at the PV terminals on the basis of the equivalent electrical circuit of the PV source. Such models are usually scalable and the parameter values can be varied according to the operational weather conditions at the PV source. They are also useful for modeling unusual operating conditions, such as mismatches due to partial‐shading phenomena. The implementation in circuit‐oriented simulators such as PSPICE and PSIM, or in general‐purpose simulation environments such as MATLAB^® and SCILAB, is almost straightforward. This allows study of the PV source together with dedicated controls, power‐processing systems, switching converters, and so on. The PV‐source non‐linearity is ...

Table of contents

• Cover
• Title Page
• Table of Contents
• Acknowledgements
• Introduction
• Tables of Symbols and Acronyms
• 1 PV Models
• 2 Single-diode Model Parameter Identification
• 3 PV Simulation under Homogeneous Conditions
• 4 PV Arrays in Non-homogeneous Conditions
• 5 Models of PV Arrays under Non-homogeneous Conditions
• 6 PV Array Modeling at Cell Level under Non-homogeneous Conditions
• 7 Modeling the PV Power Conversion Chain
• 8 Control of the Power Conversion Chain
• Index
• End User License Agreement