Publication:
Effects of aggregation on three-phase photovoltaic inverters with Sandia frequency shift islanding detection

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Authors
Saavedra Peña, Nelson Emil
Embargoed Until
Advisor
Aponte, Erick E.
College
College of Engineering
Department
Department of Electrical and Computer Engineering
Degree Level
M.S.
Publisher
Date
2022-11-08
Abstract
This thesis focuses on the development of an aggregated model of a three-phase photovoltaic (PV) inverter equipped with the Sandia frequency shift (SFS) islanding detection method. This SFS aggregated PV inverter model was developed using the dq0 reference frame theory as basis for its design and analysis. Mathematical theory for aggregation was used to scale the power rating of the aggregated PV inverter model and represent accurately a multi-inverter configuration using the reduced-order aggregated PV inverter model. The aggregated model was implemented and simulated using MATLAB/Simulink and compared to commercially available PV inverters hardware using a Power Hardware-in-the-Loop (PHIL) experimental setup. To validate the results obtained during simulation, the SFS aggregated PV inverter model was compared to a multi-inverter configuration. Over-frequency and under-frequency (OF/UF) islanding scenarios were used to characterize the behavior of hardware PV inverters as well as demonstrate the bi-directional capability of the SFS islanding detection method. Load quality factor tests were also performed to the aggregated PV inverter model to identify any possible influence of quality factor values on aggregated PV inverter islanding detection times. Finally, the scaling factor used to aggregate the PV inverter model was increased to identify the limits of increasing this parameter and yielding similar SFS islanding detection times for the aggregated PV inverter model as the multi-inverter configuration model. The aggregated SFS PV inverter model was able to represent the islanding detection dynamics of a multi-inverter configuration composed of 2 hardware inverters as well as simulated multi-inverter configuration of PV inverters.

Esta tesis se centra en el desarrollo de un modelo agregado de un inversor fotovoltaico (PV) trifásico equipado con el método de detección de isla de Sandia Frequency Shift (SFS). Este modelo de inversor fotovoltaico agregado SFS se desarrolló utilizando la teoría del marco de referencia dq0 como base para su diseño y análisis. Además, se utilizó la teoría matemática para la agregación y escalamiento de la potencia nominal del modelo de inversor fotovoltaico agregado. Esto para representar una configuración de múltiples inversores utilizando el modelo de inversor fotovoltaico agregado de orden reducido. El modelo agregado se implementó y simuló con MATLAB/Simulink. Para validar los resultados obtenidos durante la simulación, el modelo de inversor fotovoltaico agregado SFS se comparó con una configuración experimental utilizando Power Hardware-in-the-Loop (PHIL) compuesta por inversores que están comercialmente disponible. Se utilizaron escenarios de isla de sobre frecuencia y baja frecuencia (OF/UF) para caracterizar el comportamiento de los inversores fotovoltaicos de hardware, así como para demostrar la capacidad bidireccional del método de detección de isla SFS. También se realizaron pruebas del “quality factor” de la carga en el modelo de inversor fotovoltaico agregado para identificar cualquier influencia de los valores del “quality factor” en los tiempos de detección de isla del inversor fotovoltaico agregado. Finalmente, el factor de escala utilizado para agregar el modelo de inversor fotovoltaico se incrementó para identificar los límites y sensitividad del modelo agregado con relación a este parámetro. El modelo de inversor fotovoltaico SFS agregado pudo representar la dinámica de detección de isla de una configuración de varios inversores compuesta por 2 inversores de hardware, así como una configuración simulada de múltiples inversores fotovoltaicos.
Keywords
Inverter aggregation,
Sandia frequency shift,
PV inverter,
Photovoltaic (PV),
Islanding detection
Usage Rights
Except where otherwise noted, this item’s license is described as Attribution-NonCommercial-NoDerivatives 4.0 International
Cite
Saavedra Peña, N. E. (2022). Effects of aggregation on three-phase photovoltaic inverters with Sandia frequency shift islanding detection [Thesis]. Retrieved from https://hdl.handle.net/20.500.11801/3003