Power Electronics meets Information Theory: Towards A High-Performance Single-Phase Multi-Level PV Microinverter
Loading...
Authors
Awasthi, Abhishek
Date
2025-01-24
Type
thesis
Language
eng
Keyword
Multi-Level inverter , Active voltage balancing , Symbolic Dynamics
Alternative Title
Abstract
This thesis presents a novel methodology for controlling power electronic converters using an information-theoretic approach. Particularly, the focus is on the application of Symbolic Dynamics to power electronic converters. A grid-connected photovoltaic (PV) microinverter is used as an application to demonstrate the performance of the proposed schemes. In particular, a flying-capacitor-based multi-level inverter is examined in this work for the DC-AC stage. In the first part of the thesis, the design optimization of the flying capacitors and their voltage balancing are addressed. The design optimization is proposed by utilizing a systematic multi-objective optimization using the Pareto methodology. A new modulation scheme is proposed for precise voltage balancing of the flying capacitors. The proposed balancing technique is based on Boolean Logic bit manipulation. This scheme eliminates the need for computationally intensive real-time optimization to produce switching vectors. The second part of this thesis presents an advanced framework in power electronics, drawing on principles from information theory to enhance the control performance and reliability of the multi-level inverter. The framework utilizes symbolic dynamics for real-time state-variable dynamics analysis, enabling the evaluation of information-theoretic metrics. Specifically, Shannon block entropy is employed to optimize the long-term voltage swing characteristics of the flying capacitor voltage balancing technique. This entropy-based measure captures the statistical trends of flying capacitor
voltages and allows integration into the switching vector field selection process. As a result, the proposed framework ensures uniform long-term voltage swings across the flying capacitors and mitigates flying capacitance aging, resulting in enhanced voltage balancing performance and reliable control. Within the symbolic dynamics framework, the Lempel-Ziv Complexity (LZC) measure is utilized to characterize the trajectory dynamics of the flying capacitor
inverter current. The symbolic dynamics-based characterization enables the proposed complexity measure to specifically detect non-linear, irregular states, such as quasi-periodic and aperiodic, in real-time. A dynamic efficiency optimizer is implemented to identify periodic, quasi-periodic, and chaotic states, thereby eliminating the need for complex models. This optimizer guarantees regular periodic operation under parametric variations, consequently enhancing system reliability. Simulation studies and laboratory experiments are performed to validate the theoretical analysis of the ideas presented in this thesis.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.