Andrew Stillwell with adviser R. Pilawa-Podgurski Flying-capacitor multi-level (FCML) converters are attractive solutions for compact power conversion with a large step-down ratio. For many of these applications, there is a need for low-voltage auxiliary supplies to power control logic, gate drivers and/or subsystems. Traditionally, an additional converter with a low output voltage is implemented, but […]
High-Density, High-Frequency Multilevel Inverter for More-Electric Aircraft
Christopher Barth with adviser R. Pilawa-Podgurski The design of high power density motors frequently results in a significant reduction in motor reactance, which reduces the machine current filtering. A multilevel inverter strategy with high effective switching frequency is used to generate filtered, sinusoidal currents in low-reactance machine windings. This project is developing high-density, multilevel inverters […]
High Power Density Grid-Tied Single-Phase Converters
Shibin Qin with adviser 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). Conventionally, a very bulky electrolytic capacitor is required in single-phase systems for power decoupling. This results in very […]
Power Characterization of Wide Bandgap Power Electronic Devices Across a Range of Environments for Improved System Integration
Ross Liederbach with advisers P. Krein and R. Pilawa-Podgurski Wide bandgap device materials offer promising attributes for power conversion at high temperatures. Peak junction temperatures for power electronic devices are in the realm of ~250 °C. This project is looking to identify a complete converter system for high ambient temperature operating conditions. Gallium nitride (GaN) […]
Electric Machine Capability Characterization for Actuators of Disaster Response Robots
CEME Collaborator Professor Julia Zhang – Oregon State University The objective of this project, funded by the Grainger Center for Electric Machinery and Electromechanics, is to understand the torque-speed requirements of electric machines used as actuators for disaster response robots so these robots can accurately and safely accomplish search and rescue tasks. A humanoid robot […]
Interior Permanent Magnet Machine with Simplified Structure and Control for Harsh Environments
Professor Longya Xu – The Ohio State University This research funded by the Grainger Center for Electric Machinery and Electromechanics aims to design and evaluate a new version of an interior permanent magnet (IPM) machine with a simplified electromagnetic structure and control hardware to enhance machine reliability. The IPM drive system is brushless, slot-less and […]
Mechanical Design of High Power Density Machines
Reed Sanchez with adviser K. Haran Our group is facilitating the design of two high power density machines; one uses a super conductor and the other is a high-speed high-pole-count machine. For the super conducting machine, we built a super conducting coil to be bench-tested. Thermal performance and the forces acting upon it were quantified. […]
Diagnosis of Arcing in Retaining Rings of Turbogenerators
Sajal Kumar Harmukh with adviser K. Haran This research aims to diagnose arcing observed in the retaining rings of power plant turbogenerators. The main culprit behind arcing appears to be secondary currents induced on the rotor surface during unbalanced faults and operation. Two plausible hypotheses for the arcing in the shrink-fit region are being tested. […]
Development of High-Frequency “Airgap” Windings for High Power Density Electrical Machines
Jonathan Martin with adviser K. Haran This work is motivated by recent trends in electric machine design to obtain higher power densities in new generations of permanent magnet (PM) synchronous machines with a particular focus on the aerospace industry. The highest power density megawatt-class electrical machines to date have been developed on the order of […]
Hardware Validation for Superconducting Electric Machines
David Loder with adviser K. Haran High power density rotating machines are an important research thrust for applications such as offshore wind generation and turbo-electric aircraft propulsion. Although employing superconductors in electric machines can yield substantial increases in power and reductions in weight, many challenges remain, including the state of technology readiness, high risk, and […]