Optimized Four-leg Inverter for Advanced SiC Motor Drive Applications with CM Voltage Elimination, Zero Damaging EDM Bearing Currents and Full Torque Capabilities
Abstract
The objective of this project is to advance SiC four-leg inverters for higher power motor drive applicationswith novel common mode (CM) voltage elimination to also prevent damaging electrical dischargemachining (EDM) bearing currents, increase dc-bus utilization and investigate the effects of active frontend rectifiers. When the motor shaft voltage, caused by CM voltages, exceeds the dielectric insulatingcapability of the bearing lubricant, a damaging EDM current pulses through the bearing, leading to eventualbearing failure, exacerbated by WBG switching devices such as SiC. By implementing CM voltageelimination approaches, the four-leg inverter will be able to meet the conducted emission limits in MILSTD-461G without a large CM choke and without damaging EDM bearing currents to enable the extensionof bearing life in SiC inverter driven motors.Leveraging the successful results of a previous collaboration with the Naval Postgraduate School (NPS)(funded FY21-23) on novel CM elimination,sigma-delta modulation techniques based on pulse densitymodulation (PDM) will be optimized to also increase the dc-bus utilization. A Typhoon HIL will be usedas the system-level controllerwhich allows for rapid control prototyping of systems. The benefits of usinga PDM control algorithm are 1) synchronized switching for the phases that are changing state, which iscritical for the four-leg inverter to achieve CM voltage elimination and 2) reduced need of CM filters tomeet the conducted emission limits. Filtering, modulation and control strategies will be investigated, inaddition to the effect of active rectifier topologies with the goal of meeting the conducted EMI limits inMIL-STD-461G. Hardware validationusing SiC devices will be conducted to demonstrate the CM EMImitigation and dc-bus utilization strategies including an investigation of the effects of deadtime and asystem comparison between SiC and GaN four-leg inverters in motor drive applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412582
Entities
People
- Annette von Jouanne
Organizations
- Baylor University
- Office of Naval Research
- United States Navy