CAREER: Exact Actuation of Magnetic Field Forces Across All DOF in Electric Motors

Title: CAREER: Exact Actuation of Magnetic Field Forces Across All Degrees of Freedom in Electric Motors Abstract:

Non-technical description: Electric motors are responsible for transporting the world's supply of fresh water, heating and cooling homes and offices, driving critical medical and surgical equipment, and, increasingly, operating transportation systems. The efficiency of this technology is vital in enabling energy sustainability and reducing humanity's carbon footprint.

Conventional electric motors rely on bearings to support their shafts. Unfortunately, these bearings have critical lifetime, reliability, and efficiency shortcomings that limit the electrification of transportation systems, the utilization of renewable generation technologies, and the efficiency of fluid handling infrastructure. This project will investigate a new type of motor that does not use bearings.

The new bearingless motors will utilize electric current to create controllable magnetic forces that function as set of bearings. The new motors will look and behave in fundamentally different ways that will enable new, extremely efficient, and ultra-reliable systems. This project targets a 9% reduction in US electric energy consumption by enabling new concepts in compressor systems, electrified transportation, renewable energy generation, and energy storage.

To translate these research outcomes into the real world, the project incorporates engagement of both the technical community and general public. Beyond the research outcomes, the team's outreach activities will facilitate development of the diverse STEM workforce needed to maintain US leadership in electromechanical power conversion. The team will develop interactive public exhibits of motor and levitation technology and host STEM-enriched experiences aimed at increasing interest and participation in STEM opportunities for middle and high school females and youth from rural, economically disadvantaged regions.

Technical Description: The objective of this research is to overcome fundamental challenges of both conventional motor bearings and magnetic bearings. While today's electric motors utilize and control only one degree of freedom (rotation) this project will develop a new generation of electric motors that are precisely actuated in all six degrees of freedom.

These new motors will utilize magnetic field forces that are already present within the motor to create a completely bearingless motor that levitates its own shaft. Modelling, control, and design techniques will be developed to unify the science of electric motors and magnetic levitation. The project will use analytic and numeric modeling approaches to create a framework that models the normal and tangential magnetic stresses on the rotor's surface.

This framework will be used to determine the required stator currents needed to produce exact force and torque vectors on the motor's shaft. The project will research optimal design of these new motors and test prototypes to validate this new science. The team will develop the science of bearingless motors for both high speed motor systems (industrial compressors and power grid flywheel energy storage) and low speed motor systems (large diameter, rim-driven motors for flight electrification).

The outcomes of the research will be disseminated through the standard channels of academic research (presentations and papers) as well as through the construction of a portable bearingless motor prototype that will be exhibited in public demonstrations, conferences, and visits to research institutes. The team will also develop open source, interactive laboratory electronics kits to demonstrate the principles of magnetic levitation and electromechanical power conversion that will be promoted to allow youth to develop county fair exhibits, lifelong learners to explore electromechanical principles, and teachers to adapt the material for their curriculum.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.