PhD student Zichao Ye with advisor R. Pilawa-Podgurski Flying capacitor multi-level converters (FCMC) have received increased attention for medium- to low-power designs. Compared to conventional two-level converters, FCMCs have the advantages of lower device stress ratings, greatly reduced inductor values, increased effective ripple frequency and reduced dv/dt transients. There are many demonstrated examples showing a […]
High Power Density Flexible Power Electronics
MS student Derek Chou with advisor R. Pilawa-Podgurski Wide-bandgap semiconductor devices such as gallium nitride and silicon carbide have found use in power electronics as high-performance switches, allowing for higher frequency switching with minimal losses; this in turn reduces the required physical size of many of the passive components required in such designs, mainly the […]
Active Power Decoupling in High Power Density Single-Phase DC-AC and AC-DC Converters
MS student Nathan Brooks with advisor R. Pilawa-Podgurski Single-phase ac-dc and dc-ac converters have fundamental power-processing limitations at twice the ac line frequency. The conventional solution for twice-line cycle energy storage utilizes a large dc link capacitor across the dc bus to buffer the instantaneous energy difference between the ac and dc side. This research […]
High Power Density Grid-Tied Single-Phase Converters
PhD student Shibin Qin with advisor R. Pilawa-Podgurski Single-phase grid-tied converters (single-phase ac-to-dc, or dc-to-single-phase-ac) have wide applications in both energy harvesting (such as solar micro-inverters) and consumption (such as chargers for electric vehicles). High-efficiency and high-power-density converters are the most critical features for many of these applications. In this research, a power factor correction […]
Electric Field Jumping Droplet Condensation for Active Hot-Spot Cooling of High-Power-Density Electronics
PhD Thomas Foulkes with advisor R. Pilawa-Podgurski Enhanced cooling methods to remove heat generated by hot spots inside of power electronic devices, while not sacrificing weight and volume, are required to decrease overall size and weight of power electronic converters as shown in Figure 12. Leveraging recent advances in both wide-bandgap power transistors as well […]
Analysis of Volts per Hertz Scalar Control as Governor of High Pole Count, High Frequency Permanent Magnet Synchronous Machine
MS student Katherine O’Kane with advisor K. Haran This research is motivated in part by the National Aeronautics and Space Administration (NASA) under Grant NNX14AL79A purposed for Space Science and Applications – Basic Research studies currently supporting the first iteration development of a permanent magnet synchronous machine (PMSM) intended for eventual use as a propulsor […]
Mechanical Development of a High-Power-Density Rotor
MS student Reed Sanchez with advisor K. Haran High-power-density electric machines are crucial to enabling electric aircraft. This work is developing a topology for these machines that addresses associated mechanical and thermal challenges, including expansion due to high speed, thin radial builds that affect rotor dynamics, and high electromagnetic loading which necessitates powerful cooling. These […]
High-Speed, High Frequency Air-Core Machine and Drive
MS student Irin Jose with advisor K. Haran This research developed a conventional hex bridge inverter to test the control algorithm developed for the 1 MW high-speed, high-frequency air-core machine drive for the NASA Fixed-Wing project. The 3-phase 220 V AC 750 W inverter which was designed and developed is shown in Figure 6. The […]
AC Loss in Fully Superconducting Electric Machines
MS student Matthew Feddersen with advisor K. Haran Superconducting electric machines have shown potential for dramatic increases in power density for applications such as offshore wind generation, turbo-electric distributed propulsion in aircraft, and ship propulsion. Superconductors exhibit zero loss when in dc conditions, though ac current produces considerable loss due to hysteresis, eddy currents, and […]
Mitigating Power Systems Variability in More Electric Aircraft Utilizing Power Electronics Implemented Dynamic Thermal Storage
PhD student Yue Cao with adviser P. Krein Increased power levels in more electric aircraft (MEA) bring opportunities to optimize energy flow in multi-physics domains to benefit the power system’s stability and aircraft fuel economy. This project introduces thermal energy inherent in the cabin air and aircraft fuel as a dynamic management solution to offset […]