Unified Approach for Synthesis and Analysis of Non-Isolated DC-DC Converters

• Published in: IEEE access Vol. 9; pp. 120088 - 120109
• Main Authors: Gitau, Michael Njoroge, Adam, Grain P., Masike, Lebogang, Mbukani, Mwana Wa Kalaga
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Basic building blocks; Basic converters; converter cells; current waveforms; DC-DC power converters; First principles; Inductors; non-isolated DC-DC converters; Semiconductor diodes; Steady-state; steady-state gains; Stress; Switches; Switching; Synthesis; Systematics; unified analysis of DC-DC converters; unified synthesis of DC-DC converters; Voltage converters (DC to DC); Waveforms
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2021.3108191

Transformational techniques unifying synthesis of two-state DC-DC converters and analytical synthesis techniques allowing generation of all possible converters meeting a certain criteria already exist. The analysis of a family of converters derived from a single converter cell has also been unified. Current waveforms generated by the family of converters were shown to be related. However, a concept or basic building blocks that facilitate unified synthesis, analysis, prediction of current waveforms and assignment of switch states over a very wide range of DC-DC converters is still lacking. This study will propose three 3-terminal basic building blocks and one 3-terminal filter block. It will be shown that between them, they are sufficient for realizing all non-isolated DC-DC converters excluding those with coupled inductors. The various DC-DC converters fall into those realized through cascade, stacked, stacked plus cascade, interleaved/paralleled or differential connection of the basic building blocks. A systematic approach for evaluating input-output current gains will be presented. Moreover, a basic building block will be shown to have fixed switching states for proper operation. This gives rise to the generation of a unique set of current waveforms at the three terminals irrespective of where a basic building block is embedded. It has been shown that the effort and time needed to design DC-DC converters can be reduced as switching device stresses can be estimated without the need for tedious first principle derivations.