Date of Award
Master of Science (MS)
Dr. Elham Makram, Committee Chair
Dr. Keith Corzine
Dr. John Gowdy
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.
Liu, Zhanhe, "Power Quality Study of a Microgrid with Nonlinear Composite Load and PV Integration" (2015). All Theses. 2459.