Durham School of Architectural Engineering and Construction


First Advisor

Dr. Mahmoud Alahmad

Date of this Version

Fall 12-9-2020

Document Type



A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Architectural Engineering, Under the Supervision of Professor Mahmoud Alahmad. Lincoln, Nebraska: December 2020

Copyright 2020 Mhd Anas Alkrch


The representation of load components deemed to be an essential factor for power system studies as the load characteristics influence the system performance. Thus, choosing an appropriate load model for load behavior studies is very significant for system analysis purposes. Load models can be categorized into three types: static, dynamic, and composite models. Static ZIP load model is a well-known model in the power industry, it represents the relationship between the active and reactive power as a function of the applied voltage. In this paper, a detailed review of the existing static ZIP model coefficients for load components achieved by the work researches over time is provided. Then, the documented ZIP coefficients were grouped into end-use types to plot and visualize the load components in terms of the voltage-power relationship, and the ZIP coefficients for each end-use type are determined for three cases: minimum, maximum, and typical case. In addition, to update the load model for modern lighting and have a better load representation, ZIP load model is developed for LED lights, and the model coefficients is experimentally determined for each light fixture. Next, conservation voltage reduction (CVR) impact on LED lights is investigated, and power reduction estimation based on ZIP coefficients is validated against the actual measurement data of load variations under CVR technique.

Advisor: Mahmoud Alahmad