Available at: https://digitalcommons.calpoly.edu/theses/3164
Date of Award
6-2025
Degree Name
MS in Electrical Engineering
Department/Program
Electrical Engineering
College
College of Engineering
Advisor
Taufik
Advisor Department
Electrical Engineering
Advisor College
College of Engineering
Abstract
This thesis studies the impacts of battery chemistry (specifically lithium-iron phosphate, sodium-ion, and solid-state), AC voltage, battery size, charging mode, state of charge (SOC), active power draw, and power factor on the power quality of a Battery Energy Storage System (BESS). For harmonic evaluation, the metrics provided by the IEEE Standard 519 are used as a guideline to quantify voltage and current harmonics. A comprehensive MATLAB Simulink using Simscape Electrical is used to develop and simulate the models for the battery, DC-DC converter, AC-DC converter, and the grid. A total of 57 simulation cases varying the BESS factors are performed, and the results show that battery chemistry, SOC, AC voltage level, charging mode, size, active power draw, and power factor have a noticeable effect on power quality. Key findings include sodium-ion chemistry, in particular, showing higher harmonics, especially at higher powers, due to its steep open-circuit voltage and large transient time constants. While charging, the constant voltage charging mode has higher harmonics due to lower fundamental current. Low AC voltages (e.g., 240 V) lead to higher distortion due to low modulation indices. Increasing battery size reduces internal impedance, thus reducing harmonics. Higher active power draw reduces relative harmonics for lithium iron phosphate and solid state. Lower power factors modestly reduce harmonics via reactive power contribution. Overall, the results identify key factors affecting power quality in the operation of BESS.