Invention Reference Number
This invention enables a brushless excitation system for wound-field synchronous machines (WFSMs) using controlled magnetic field harmonics. The approach eliminates the need for traditional brushes or rotary transformers—offering a more reliable, cost-effective, and simplified alternative for delivering rotor excitation, with potential to reduce reliance on critical materials like rare-earth magnets.
Description
The invention introduces a method for non-contact rotor excitation in wound-field synchronous machines by leveraging magnetic field harmonics generated from the stator. The stator windings are engineered to support multiple harmonics, each associated with distinct pole numbers. These harmonics induce voltage in an auxiliary rotor winding, which is then rectified and used to energize the rotor’s field coils. This eliminates the need for brushes or additional excitation systems like rotary transformers. Importantly, the same stator windings and power electronics serve both torque production and wireless power transfer functions, reducing system complexity and improving reliability.
Benefits
- Eliminates mechanical brushes, improving system reliability
- Simplifies machine architecture by avoiding extra windings or converters
- Reduces dependence on critical materials such as rare-earth magnets
Applications and Industries
- Electric vehicle traction motors for automobiles, buses, and aircraft
- Electric generators for aircrafts and conventional energy systems
Contact
To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.
