The power generated by renewable sources such as solar photo-voltaic (PV) arrays and wind turbines is time varying and unpredictable. In order to minimize the wastage of power obtained from such sources, there is a great need of efficient power converters which are compact and can effectively manage power in Smart Grid applications. The design of such power converters would require the use of new semiconductor materials, novel device structures, improved switching and control circuits, and advanced packaging technologies. Wide bandgap materials are promising for RF/microwave and power switching electronics. Among these materials, III-V Nitrides - especially Gallium Nitride (GaN), and Silicon Carbide (SiC) are heavily investigated by industry because of their superior electrical and thermal properties, and improved radiation hardness compared to the standard semiconductor material -silicon.
A smart DC microgrid suitable for high-penetration in commercial applications and that efficiently utilizes energy available from distributed, renewable generators is described. GaN HEMTs based converters should be incorporated in the DC microgrid. It iv is shown that the proposed DC power distribution system can produce savings in excess of 10-15% over the current approach that uses inverters.
Performance evaluation between silicon MOSFET and GaN HEMT is presented for chip-scale and maximum peak power tracking DC-DC power converter applications. The current circuit model available for GaN HEMTs does not converge for converter topology. Thus circuit calculations are based on improved circuit model for the FET with accurate description of capacitances and thermal on-resistance. It is shown that GaN power HEMTs used in a synchronous buck converter topology (for a 19/1.2VDC, 7.2W) can potentially lead to nearly 77% power conversion efficiency at 25°C when switched at 5 MHz. However, results show that the current formulation for loss calculation in the topology described is erroneous and so there is a need of new loss formulation and device selection criteria based on circuit dynamics and device parameters.
Similarly simulations were carried out for a DC-DC boost converter topology (200/380VDC, 10kW) and it has been shown to have 93% power conversion efficiency at 25°C when switched at 1 MHz. But using new semiconductors materials like GaN HEMT and SiC in this case causes high dv/dt stress on switch and diode during switching which may cause failure of device.
|Commitee:||Jha, Rashmi, King, Roger, Shenai, Krishna|
|School:||The University of Toledo|
|School Location:||United States -- Ohio|
|Source:||MAI 57/06M(E), Masters Abstracts International|
|Keywords:||Circuit, Converters, Dc-dc, Gan, Hemt, Performance, Power|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be