11/8/2018 Christopher Barth 4 min read
Written by Christopher Barth
“The student demo competition provides a great opportunity to interact individually with a large number of conference attendees”, Barth explained, “this exchange can lead to many valuable contacts with both researchers and industry”. This was especially true for this demonstration. During the demo, Barth was explaining the converter operation and happened to glance down at the name tag of one of the individuals listening attentively. He immediately realized that he was speaking to the original inventor of the FCML topology Professor Thierry Meynard. “Neither myself, nor Professor Pilawa had met Professor Meynard before, so it was a bit of a surprise.”
A significant portion of the work that has gone into optimizing this motor drive has focused on characterizing the performance of newly developed GaN FETs and ceramic capacitors. Proper converter design requires understanding how changes in the design will affect the amount of energy lost in the converter. “GaN FETs have low parasitic capacitance which gives them good performance, but they also have some second-order losses that are important for designers to understand,” explained Thomas Foulkes, “Characterizing these losses, which arise from a parameter called dynamic on-state resistance, requires careful measurements.” Sam Coday has performed similarly detailed measurements of the second-order losses in ceramic capacitors.
Nathan Pallo has assumed the lead role in incorporating the data measured by Tom and Sam into the third and final revision of the inverter hardware. Nathan’s work experience with starts-ups WiTricity, Loci Controls, and Joby Aviation gave him a broad background in both electrical and mechanical design before returning to graduate school. The group is currently in the process of assembling the individual inverter modules into a larger multi-phase motor drive. Pourya Assem has designed the custom control hardware Barth is using to develop a hierarchical motor drive system.
The final demonstration of a 200 kW motor drive will be conducted at Research Park in the newly dedicated 200 kW power test facility built by the POETS Engineering Research Center. (https://poets-erc.org/). The center for Power Optimization of Electro-Thermal Systems (POETS) is an NSF sponsored interdisciplinary engineering research center based at UIUC, which provides a context for researchers from Illinois, Howard University, University of Arkansas, and Stanford University to solve problems related to the cooling of power electronics.
“We are seeking to demonstrate one of the lightest and most efficient inverters built to date” says Barth, “it is exciting to see what a smart team of dedicated researchers can accomplish.”