Sam Coday and Robert Pilawa-Podgurski

EECS Department, University of California, Berkeley

Technical Report No. UCB/EECS-2023-79

May 9, 2023

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-79.pdf

Innovations within power electronics are necessary to enable future electric aircraft and space exploration. In these aerospace applications, power converters must be light-weight, efficient and reliable. Conventional, inductor-based, power electronics tend to be heavy, and have high switch stress making them difficult to implement in these applications. In this thesis, hybrid switched-capacitor converters are explored as they utilize energy-dense capacitors as the primary energy storage element, and also decrease the voltage stress of the switches. The basics of hybrid switched-capacitor converters are covered, with a focus on why these topologies are suitable for aerospace applications. Next, the losses of the capacitors, the main building block of these converters, are characterized and a model is proposed which allows for simple loss estimation. Then, the design and flight qualification of a hybrid switched-capacitor converter is discussed, showcasing a converter with high efficiency, power density and reliable control. Moreover, the safe control of hybrid switched-capacitor converters during shutdown is described, with a model proposed which allows designers to understand the shutdown of the converter and trade-offs in different shutdown techniques. Hybrid switched-capacitor converters are motivated for their use in harsh space environments, where radiation effects make designing high performance converters challenging. Two different converters designed for space applications are then described, utilizing techniques such as partial power processing to minimize passive component mass. Overall, this thesis showcases the design of several high performance hybrid switched-capacitor converters, but also introduces models and comparison frameworks to allow future designers to better understand the design and operation of hybrid switched-capacitor converters in aerospace applications.

Advisors: Robert Pilawa-Podgurski

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BibTeX citation:

@phdthesis{Coday:EECS-2023-79,
    Author= {Coday, Sam and Pilawa-Podgurski, Robert},
    Title= {High Performance Hybrid Switched-Capacitor Converters for Aerospace Applications},
    School= {EECS Department, University of California, Berkeley},
    Year= {2023},
    Month= {May},
    Url= {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-79.html},
    Number= {UCB/EECS-2023-79},
    Abstract= {Innovations within power electronics are necessary to enable future electric aircraft and space exploration. In these aerospace applications, power converters must be light-weight, efficient and reliable. Conventional, inductor-based, power electronics tend to be heavy, and have high switch stress making them difficult to implement in these applications. In this thesis, hybrid switched-capacitor converters are explored as they utilize energy-dense capacitors as the primary energy storage element, and also decrease the voltage stress of the switches. The basics of hybrid switched-capacitor converters are covered, with a focus on why these topologies are suitable for aerospace applications. Next, the losses of the capacitors, the main building block of these converters, are characterized and a model is proposed which allows for simple loss estimation. Then, the design and flight qualification of a hybrid switched-capacitor converter is discussed, showcasing a converter with high efficiency, power density and reliable control. Moreover, the safe control of hybrid switched-capacitor converters during shutdown is described, with a model proposed which allows designers to understand the shutdown of the converter and trade-offs in different shutdown techniques. Hybrid switched-capacitor converters are motivated for their use in harsh space environments, where radiation effects make designing high performance converters challenging. Two different converters designed for space applications are then described, utilizing techniques such as partial power processing to minimize passive component mass. Overall, this thesis showcases the design of several high performance hybrid switched-capacitor converters, but also introduces models and comparison frameworks to allow future designers to better understand the design and operation of hybrid switched-capacitor converters in aerospace applications.},
}

EndNote citation:

%0 Thesis
%A Coday, Sam 
%A Pilawa-Podgurski, Robert 
%T High Performance Hybrid Switched-Capacitor Converters for Aerospace Applications
%I EECS Department, University of California, Berkeley
%D 2023
%8 May 9
%@ UCB/EECS-2023-79
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-79.html
%F Coday:EECS-2023-79