SiC H-Bridge

Project Overview & My Contribution

This project has encompassed a variety of different components, all directed towards developing a high-power switching H-Bridge power supply. This was the first grant that I was heavily involved in that successfully transitioned from Phase I to Phase II. The commercialization goal was to produce two different types of supplies: (1) a high peak-power version designed for 200kW operation on pulsed (100s of ms) timescales, and (2) an H-bridge-based pulse generator capable of producing square wave pulses of arbitrary length at CW powers of up to 5kW.

I was involved in the design and engineering of the basic H-Bridge switching topology for four different iterations of the PCB throughout the Phase I/II period. The Phase I was completed with the design at right, a highly-parallelized H-brige designed as a hybrid board that could be populated for either CW or pulsed operation. In pulsed mode, it produced clean bipolar output waveforms at load currents up to 6kA at output voltages of about 1kV, operating at frequencies up to 1MHz. The transition to Phase II is largely accredited to the success of this board as well in conjunction with our detailed research into the heating characteristics if SiC-based MOSFETs. Successive iterations in Phase II have been optimizations of the Phase I board, with a focus on designing circuitry to allow for easier interface with external trigger signals, higher output voltages, and rectification of the bipolar output waveform.

The testing during the Phase II also involved a great deal of component thermal testing. While most semiconductor-based switch datasheets discuss switching and conduction losses (sometimes combined into a single value), this number often varies radically from real-world operation. Along with my coworker, Akel Hashim, we designed a test setup to measure the energy dissipated by switches operating in different switching modes (switching loss-dominated or conduction loss-dominated).

Skills Demonstrated / Gained

  • Circuit/PCB design from basic concept to operational prototype
    • Design of both control logic and high power/voltage switching circuitry
  • Theory and construction of resonant/tank networks
  • Device characterization
  • Circuit analysis and 'debugging'
  • Project management/goal setting
  • Commercialization of a research-level power supply


Poster Presented at 2015 APS DPP in Savannah, GA Silicon-carbide (SiC) MOSFET-Based Full-Bridge for Fusion Science Applications

American Physical Society Division of Plasma Physics (APS DPP) Abstract

Poster Presented at 2015 IEEE PPC & SOFE in Austin, TX Silicon-carbide (SiC) MOSFET-Based Full-Bridge for Pulsed-Power Applications

Poster Presented at 2014 APS DPP in New Orleans, LA Silicon-Carbide (SiC) MOSFET-Based Full-Bridge for Fusion Science Applications

2014 APS DPP Abstract Listing

Poster Presented at APC GEC ICRP 2015 in Honolulu, HI




Rectified - "Arbitrary Pulse Generator Mode"

Bipolar - "Bipolar Mode"

EHT's Arbitrary Pulse Generator (APG), based on the SiC-MOSFET H-Bridge research and development

Phase I H-Bridge testing setup