Skip to Main Content
 

Global Search Box

 
 
 
 

ETD Abstract Container

Abstract Header

Circuit Modeling and Performance Evaluation of GaN Power HEMT in DC-DC Converters

Shah, Krushal S.

Abstract Details

2011, Master of Science, University of Toledo, College of Engineering.
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.
Krishna Shenai, PhD (Committee Chair)
Rashmi Jha, PhD (Committee Member)
Roger King, PhD (Committee Member)

Recommended Citations

Citations

  • Shah, K. S. (2011). Circuit Modeling and Performance Evaluation of GaN Power HEMT in DC-DC Converters [Master's thesis, University of Toledo]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1321475503

    APA Style (7th edition)

  • Shah, Krushal. Circuit Modeling and Performance Evaluation of GaN Power HEMT in DC-DC Converters. 2011. University of Toledo, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=toledo1321475503.

    MLA Style (8th edition)

  • Shah, Krushal. "Circuit Modeling and Performance Evaluation of GaN Power HEMT in DC-DC Converters." Master's thesis, University of Toledo, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1321475503

    Chicago Manual of Style (17th edition)