Bidirectional Isolated DC-DC Converter Research Articles

The Short-Time-Scale Transient Processes in High-Voltage and High-Power Isolated Bidirectional DC–DC Converters

This paper discusses the short-time-scale transient processes in an isolated bidirectional dc-dc converter with phase-shift control. The deadband effect on the steady-state and transient commutating process are analyzed. The current variations caused by phase-shift errors at the boundary conditions are simulated and validated through experiments. The concept of ldquoenergy deadbandrdquo is introduced to describe those specific transients where no energy flows from source to load or load to source. A set of strategies are proposed to increase the system robustness. Simulation and experiments on a 200-V/400-V, 6-kW DC-DC converter prototype validated these strategies.

Bi-Directional Isolated DC-DC Converter for Next-Generation Power Distribution-Comparison of Converters Using Si and SiC Devices

Bi-Directional Isolated DC-DC Converter for Next-Generation Power Distribution-Comparison of Converters Using Si and SiC Devices

A Bidirectional Isolated DC–DC Converter as a Core Circuit of the Next-Generation Medium-Voltage Power Conversion System

This paper describes a bidirectional isolated dc-dc converter considered as a core circuit of 3.3-kV/6.6-kV high-power-density power conversion systems in the next generation. The dc-dc converter is intended to use power switching devices based on silicon carbide (SiC) and/or gallium nitride, which will be available on the market in the near future. A 350-V, 10-kW and 20 kHz dc-dc converter is designed, constructed and tested. It consists of two single-phase full-bridge converters with the latest trench-gate insulated gate bipolar transistors and a 20-kHz transformer with a nano-crystalline soft-magnetic material core and litz wires. The transformer plays an essential role in achieving galvanic isolation between the two full-bridge converters. The overall efficiency from the dc-input to dc-output terminals is accurately measured to be as high as 97%, excluding gate drive and control circuit losses from the whole loss. Moreover, loss analysis is carried out to estimate effectiveness in using SiC-based power switching devices. Loss analysis clarifies that the use of SiC-based power devices may bring a significant reduction in conducting and switching losses to the dc-dc converter. As a result, the overall efficiency may reach 99% or higher