Author ORCID Identifier:
Date of Graduation
7-2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Engineering (PhD)
Degree Level
Graduate
Department
Electrical Engineering
Advisor/Mentor
Mantooth, Alan
Committee Member
Huitink, David
Second Committee Member
McCann, Roy
Third Committee Member
Zhao, Yue
Keywords
Coupled-Inductors; DC-DC Converters; High-Frequency Power Conversion; Modular Converters; Power Electronics; Three-port Converters
Abstract
Modular DC–DC converters have emerged as promising power‐conversion topologies for renewable‐energy systems, particularly in photovoltaic (PV) array–battery energy storage systems (BESSs). Conventional two-port modular architectures often suffer from active-power imbalance among submodules and underutilization of converter capacity when interfacing batteries of heterogeneous chemistry, state of health, or state of charge. This work presents a novel modular three-port DC-DC converter topology designed to overcome these limitations by enabling seamless integration of multiple discrete battery sources and a shared PV energy input. At the input, PV panels are paralleled to form a single low-voltage source feeding each submodule; at the storage side, each submodule is equipped with its own low-voltage battery port; and at the output, series-connected galvanically isolated high-voltage DC ports form the common DC bus. Each submodule employs a planar-transformer-based three-port converter (TPC) operating at 1 MHz, featuring partial isolation between the non-isolated PV/battery ports and the isolated load port. Zero‐voltage switching (ZVS) is achieved across all primary switches over the entire operating range, yielding high efficiency, reduced switching losses, and zero input-current ripple. Independent duty-cycle control on the primary side enables bidirectional buck–boost conversion between PV and battery ports, while phase-shift modulation on the secondary side regulates power transfer to the high-voltage bus. A digital control algorithm provides autonomous maximum-power-point tracking, load regulation, and coordinated battery management without centralized supervision. An 800 W laboratory prototype—with a 120 V PV input, a 48 V battery port, and a 340 V DC bus—demonstrates a peak efficiency of 97.7 %, thermal stability below 45 °C, and fault-tolerant operation under submodule disconnection. Furthermore, the modular architecture enables effortless scalability to higher power levels by simply adding or removing submodules. The proposed modular converter architecture achieves compact size, high power density, simplified control, and full utilization of heterogeneous storage assets, making it an attractive solution for next‐generation PV–BESS applications.
Citation
Chavoshipour Heris, P. (2026). Modular High-Frequency Three-Port DC-DC Converters. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6330
