Date of Award

Summer 8-18-2023

Level of Access Assigned by Author

Open-Access Thesis



Degree Name

Master of Science (MS)


Electrical and Computer Engineering


Mohamad Musavi

Second Committee Member

Yifeng Zhu

Third Committee Member

Paul Villeneuve

Additional Committee Members

Shengen Chen

Jon Gay


There has been an increasing interest in renewable energies due to public awareness of the negative effects of fossil fuel-fired electricity generation on the environment, and policies have been enacted requiring progressive reduction of such generation. Due to some favorable characteristics of solar over other renewables, solar power has grown considerably. Integration of solar generation into the existing power grids poses significant challenges. Solar generators' limited reactive power capability can cause several problems, such as significant voltage drops or rises in the system. Therefore, voltage stability is a major concern. This thesis presents an investigation of the voltage characteristics of an electric microgrid connected to solar generators and subject to increasing penetration of solar generation. The New England region possesses abundant potential for developing microgrid power generation. However, microgrids are installed mostly in remote locations in Northern New England, far from major load centers. Therefore, long transmission lines are required to connect the microgrids to the rest of the power grid. This study includes an analysis of the level of renewable energy penetration into the grid while keeping the system stable. The voltage magnitude, angle, and losses seen by the system have been used as a measure of stability. The test case system used in this thesis has not been used in the literature review for analyzing the stability, and it is proved by this work to be a useful tool for assessing the best option when connecting a solar farm to a power grid. The IEEE standard 9-bus system, a simplified representation of an electric grid, has been used to illustrate the developed methodology. The present study has set the basis for extending the analysis to the real New England power system.