JournalTOCs

IEEE Open Journal of Power Electronics
Number of Followers: 11

This is an Open Access Journal

Open Access journal
ISSN (Online) 2644-1314
Published by IEEE

[228 journals]

IEEE Open Journal of Power Electronics Information for Authors
- Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.
  PubDate: 2023
  Issue No: Vol. 4 (2023)
Online-Harmonic-Detection-Based System Stabilization Function for
Grid-Forming Inverters Under Various Grid Conditions
- Authors: Le Kong;Yaosuo Xue;Liang Qiao;Fei Gae Wang;
  Pages: 2 - 13
  Abstract: In power systems with grid-forming inverters (GFMs), small-signal instability issues could occur due to harmonic excitation, impedance interactions, and poor inverter control design. There mainly exist two types of stability issues based on the frequency range. One is the low-frequency resonance (0 – 2f0 Hz) and the other is the high-frequency harmonics (above 2f0 Hz), where f0 is the system fundamental frequency. By assuming that the low-frequency related controls are well designed, this paper addresses the high-frequency harmonic issues. The goal is to develop a system stabilization function (SSF) to eliminate any high-frequency stability issues under various grid conditions without affecting predefined low-frequency behaviors. The idea is to conduct the inverter passivation test at the system harmonic resonant frequency so that the corresponding harmonic instability can be removed. To achieve this, the resonant frequency of the harmonic instability is detected first, and then if the magnitude of the resonant component exceeds the threshold value, the proposed SSF will be enabled, thus the system would be stabilized. Both simulation and experimental tests are conducted to validate the effectiveness of the proposed approach.
  PubDate: 2023
  Issue No: Vol. 4 (2023)
Efficiency-Oriented Parameter Design and Comparison of Medium Voltage
Isolated Bidirectional DC/DC Converters
- Authors: Runtian Chen;Rui Lu;Xianzhe Bao;Chushan Li;Wuhua Li;Xiangning He;
  Pages: 14 - 23
  Abstract: In a medium voltage (MV) solid state transformer(SST), the isolated bidirectional DC/DC converter (IBDC) is the core circuit for controlling power flow and galvanic isolation. Current research works on MV single-cell IBDC mainly focus on two directions: resonant and non-resonant topologies. However, for different scenarios with various voltage regulation ranges and power ranges, which topology should be adopted to achieve better efficiency performance is unclear. To effectively illustrate the two IBDCs’ respective benefits, a comparison between the two IBDCs is conducted in this study along with the optimization design method. For resonant IBDC, a complex objective optimization-based parameter design strategy is developed to realize rapid automatic design under various operating conditions. For non-resonant IBDC, a multi-phase modulation scheme aimed at minimizing the current stress under different voltage and power ranges is introduced. The optimal operating range of the two IBDCs has been derived. A 4 kV/1 kV 200 kW non-resonant IBDC experimental prototype has been built and its efficiency is tested under various operating conditions. The test data were compared with the established power loss model to derive the converter's full range efficiency, and the efficiency of the converter over a wider power range could then be projected.
  PubDate: 2023
  Issue No: Vol. 4 (2023)
Characterization and Modeling of Ceramic Capacitor Losses Under Large
Signal Operating Conditions
- Authors: Samantha Coday;Robert C. N. Pilawa-Podgurski;
  Pages: 24 - 33
  Abstract: Recent work on hybrid switched-capacitor converters has demonstrated exceptionally high efficiencies and power densities through the use of multilayer ceramic capacitors (MLCCs). However, when used in such converters as the main energy transfer components, the capacitors experience high voltage and current ripple often under large dc voltage bias. Yet, capacitor characterization is typically done only with small signal excitation, and under low or no dc bias, yielding highly inaccurate loss models. This work presents a technique for obtaining detailed loss characterizations of MLCCs under more realistic operating conditions through a carefully designed calorimetric setup. Experimental results from several types of MLCCs are presented over a wide range of operating conditions. Finally, a linear model is presented to accurately estimate MLCC losses.
  PubDate: 2023
  Issue No: Vol. 4 (2023)
Multilevel Switched Capacitor LLC-DCX Converter With Embedded Filter
- Authors: Shota Okutani;Ryo Nishiyama;Pin-Yu Huang;Yuichi Kado;
  Pages: 34 - 51
  Abstract: A multilevel switched capacitor LLC-DC transformer (LLC-DCX) converter with an embedded filter is presented for a power module of solid-state transformers. The proposed converter is a hybrid converter composed of resonant switched capacitor converters (RSCCs) and a previously reported ripple-cancel converter. In contrast to the conventional SCC, which faces the issue of an inrush hard-charging current during switching transition, the proposed converter can be implemented using a soft-charging operation without additional inductors. Further, it inherits the advantages of the two converters, including load-independent soft switching, automatic voltage sharing, automatic current sharing, reduction of the current ripple, an embedded filter function, constant voltage gain, and flexible extensibility. This paper comprehensively analyzes these characteristics and the conditions for soft-charging operation. The design theory based on the analysis is also presented. We fabricated a prototype of the proposed converter with input and output voltages of 900 V and 150 V, respectively and the rated output power of 2 kW to demonstrate the validity of the analysis and design.
  PubDate: 2023
  Issue No: Vol. 4 (2023)