Summary: The RTEEBM is an innovative electric machine that combines the simplicity of a brushless DC motor with the controllability of wound-field excitation — without slip rings or permanent magnets. Using a rotating transformer to deliver excitation to the rotor, this design enables full electromagnetic control of torque and field response with high efficiency and robustness. It is ideal for aerospace, electric vehicles, and high-reliability industrial systems.

🔌 Motivation

Conventional brushless motors either rely on rare-earth permanent magnets (high cost, limited tunability) or use slip rings (wear, EMI). RTEEBM eliminates both by inductively coupling excitation energy into the rotor via a coaxial rotating transformer. This allows independent control of rotor excitation in a compact, brushless topology.

🔹 Architecture Overview

  • Stator: Traditional 3-phase winding (AC induction or BLDC-type)

  • Rotor: Salient or cylindrical structure with wound-field coils

  • Rotating Transformer: Coaxial core transmits AC excitation into rotor

  • Rectifier (on rotor): Converts AC to DC for the rotor field winding

  • Control System: Separately regulates stator drive and excitation amplitude

🔢 Key Features

  • Electrically excited rotor without slip rings

  • No permanent magnets (avoids rare-earth sourcing)

  • Continuous control of magnetic field strength

  • High reliability and long life (no brushes or contacts)

  • Scalable for high-power, high-speed systems

  • Can be integrated with wide-bandgap inverters (SiC, GaN)

🌐 Applications

  • Electric aircraft propulsion

  • Satellite and spacecraft reaction wheels

  • High-efficiency EV traction motors

  • Variable-speed industrial drives

  • Submersible and sealed motors (e.g., pumps, compressors)

📄 Included Files

  • RTEEBM: Full architecture whitepaper

  • Innovation Analysis PDF: Comparative evaluation vs. legacy brushless and PM motors

  • Architecture PDF: Modular breakdown of RTEEBM architecture

This project is open for contributions from motor designers, power electronics engineers, and researchers exploring sustainable high-performance electric machines.