Award Date

5-1-2012

Degree Type

Thesis

Degree Name

Master of Science in Electrical Engineering (MSEE)

Department

Electrical and Computer Engineering

First Committee Member

Baghzouz Yahia

Second Committee Member

Selvaraj Henry

Third Committee Member

Jiang Yingtao

Fourth Committee Member

Taghva Kazem

Number of Pages

66

Abstract

Grid-connected photovoltaic (PV) power systems have been sustaining an exponential growth rate during the past decade. This steep growth is driven by a growing concern about climate change, the adoption of an aggressive regional renewable portfolio standard, rebates and tax incentives, and reduction in PV system cost. One of the main technical barriers that can ultimately limit further PV penetration is the fast variations in the PV system's output power induced by cloud transients. Such events are known to cause voltage fluctuations which may lead to excessive operations of voltage regulation equipment and light flickering.

Solar irradiance variability, which can be easily recorded using a pyranometer and a data logger, is used in numerous studies to assess the AC power injected into the electrical network by PV systems. But in reality, the two variables are not perfectly proportional with one another, nor synchronized in time due to delays within the inverter circuit elements and controls.

As a consequence, computer models that accurately simulate the dynamic behavior of PV systems under moving clouds would thus be of high value. In this thesis, a dynamic MATLAB/Simulink model of a single phase single stage grid-connected PV system that can be used to predict the deviations in AC power output under variable solar irradiance is presented. The commonly used perturb-and-observe technique for Maximum Power Point Tracking (MPPT) is used in the model. It is found that the deviation between solar radiation and output power variability that may be caused by the MPPT and buffer capacitor is minimal and can often be neglected. As a consequence, variations in solar irradiance can be considered as a good indication of power fluctuations.

Keywords

Clouds; Computer simulations; Dynamic modeling; MATLAB/Simulink; Maximum power point tracking (MPPT); Photovoltaic; Photovoltaic power generation; Photovoltaic power systems; PV systems; Solar

Disciplines

Electrical and Computer Engineering | Oil, Gas, and Energy | Power and Energy

Language

English


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