Date of Award

12-2015

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Electrical Engineering

Committee Member

Dr. Elham Makram, Committee Chair

Committee Member

Dr. Keith Corzine

Committee Member

Dr. John Gowdy

Abstract

Harmonics distortion is a crucial problem in microgrid. Harmonic sources can be categorized as two main factors: renewable energy integration and nonlinear loads. Both factors are investigated in this thesis. For renewbale energy, photovoltaic (PV) power is one of the most effective solutions for energy crisis and it is showing great potential for serving customers in microgrid. A three phase PV source model is established from both mathematical equations and power electronic control schemes. A composite load model by Crossed Frequency Admittance Matrix theory is illustrated and built as well. Due to the fact that microgrid should be able to run under two different operating modes: grid-connected and stand-alone, energy storage devices are considered as neccesity. Therefore the energy storage with droop control is included in this thesis. A practicdal microgrid loacated at GA, USA is used as a study system. Instead of making the ideal assumption, the unbalanced feeder structure and historical meteorological data are considered in the study. The microgrid, PV model, nonlinear load model and energy storage are simulated in MATLAB/Simulink environment. Multiple PV sources are integrated at different locations in order to observe the impact of harmonics on the microgrid and power quality (PQ). The results show the impact of installing PV sources in both grid-connected mode and stand-alone mode considering linear and composite nonlinear loads. In addition, three PQ indices are discussed to demonstrate the numerical impacts with various perspectives. Furthermore, the mitgation of harmonics is developed by adding a active power filter on energy storage devices in the stand-alone mode.

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