Congratulations Francisco Paz!
It takes many years of hard work and dedication to conclude a PhD with such exceptional results: congratulations Francisco Paz!
Some of Francisco's PhD Highlights:
- Over 15 IEEE Publications
- Industrial Collaboration with Alpha Technologies in PV, Wind, Multilevel Converters, and Telecom DC Systems
- Vice-Chair of the IEEE Power Electronics Society Chapter in Vancouver (Outstanding Small Technical Chapter 2016, 2018)
- Instructor for courses on renewable energy and digital electronics in the UBC Vancouver Summer Program
Awards and Fellowships
- Killam Graduate Teaching Assistant Award
- Best Paper Award at PEDG
- Four Year Fellowships
- Faculty of Applied Science Graduate Award
- ICICS Graduate Scholarship
With these accomplishments and much more under his belt, Francisco Paz defended his PhD thesis at @The University of British Columbia, concluding a key milestone in his career. We're both proud and honoured to have been part of Francisco's success and are delighted to have him continue working with us at #MartinOrdonezLab.
We would like to thank the Chair, Dr. Anthony Lau; Supervisor Committee, Dr. Martin Ordonez, Dr. John Madden, and Dr. William Dunford; and University Examiners, Dr. Andre Ivanov and Dr. Elod Gyenge, for their participation.
Abstract for Francisco Paz’s PhD Thesis
Title:
“Advanced Monitoring and Control of Distributed DC Systems: An Embedded Impedance Detection Approach”
Abstract:
Direct Current (DC) systems, made possible by power electronics technology, are becoming more prevalent due to their advantages when integrating renewable energy sources, energy storage, and DC loads. Microgrids and local area energy systems are instrumental to DC systems, and much progress has been made around them. However, DC microgrids face numerous challenges due to their decentralized nature, such as resource optimization, control, and protection.
This thesis focuses on developing a core technology, an embedded impedance detection (EZD) method for DC systems, and its application to five critical challenges in DC systems. The proposed method uses a reference signal of minimal amplitude and high frequency, injected in the control loop of the power electronics converter, and a digital Lock-In Amplifier to extract the incremental behavior of the voltage and current around the DC operating point. These can be used to calculate the incremental impedance in the resistive and reactive term, which are representative of the reactive part of the system as well as the nonlinear characteristics of the system.
The proposed EZD method is applied to address five critical problems in today's DC systems:
- Adaptive control in the presence of active loads - to expand stability and improve transient response.
- Islanding detection - to detect the connection and disconnection of the utility grid and change controllers for autonomous operation.
- Fault location - to detect the distance to a fault and simplify the system restoration.
- High-impedance fault detection - to accurately distinguish a fault condition from a load increase.
- Maximum power point tracking of photovoltaic panels - to ensure efficient energy harvesting.
For all these applications, the proposed EZD-based solution offers critical benefits and advantages, such as high sensitivity and accuracy at a low system disturbance and fast detection. The work presents a detailed analysis of the proposed EZD technique as well as considerations for its implementation in commercial microcontrollers, followed by simulations to illustrate its capabilities. The thesis also presents a detailed analysis of each DC system application and its particular considerations. The outlined benefits are supported by simulations and validated through experimental results using a real power electronics platform.