Date of Award


Document Type


Degree Name


Organizational Unit

Daniel Felix Ritchie School of Engineering and Computer Science, Electrical and Computer Engineering

First Advisor

Amin Khodaei

Second Advisor

Kimon P. Valvanis

Third Advisor

Mohammad Abdul Matin

Fourth Advisor

Shimelis Assefa


Critical bus, Microgrid, Objective function, Operation cost, Reactive power, Solar


Reactive power plays an essential role in voltage control and stability in electric power systems. Various Volt/VAR techniques are utilized in electric power systems to maintain the voltage profile within defined acceptable limits and accordingly provide reliability and stability. Reactive power has been commonly generated through large-scale synchronous generators or distributed capacitor banks to provide proper transmission and distribution level system management, however, reactive power can be further used as an effective means to reduce total system operation cost. In this dissertation, an optimal reactive power model is proposed to determine the optimal nodal reactive powers that result in the lowest total system operation cost. Microgrid is introduced as a source of real and reactive power where its capability curve as a single generator unit is further determined and utilized. An optimization-based method is proposed to determine this capability curve. The results of numerical analyses of this proposal show how the reactive power behaves under gradual changing of real power generation in a microgrid and how these two outputs are correlated. This model is further integrated into an optimal power flow problem to show the potential economic benefits of microgrid-generated reactive power of the larger system. The numerical analyses on standard test systems show the performance of the proposed model and provide insights on the role of microgrid as a source of reactive power in the system.

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Rights Holder

Sarhan Hasan


Received from ProQuest

File Format




File Size

66 p.


Electrical engineering, Energy, Engineering