Research on Wireless Excitation of Synchronous Motors Using Zero-Phase Angle Controlled Magnetically Coupled Resonators

The permanent magnet synchronous motor (PMSM) is widely used in electric drives, especially in electric vehicles, due to its high torque and power density. However, challenges such as control complexity, system reliability, and cost arise from the use of permanent magnets. This paper proposes a novel solution using electromagnetic coupling resonance to transfer excitation power to the rotor windings of a brushless electric excitation motor. A phase-shifting regulation zero-phase-angle control strategy based on a self-excited oscillation circuit is introduced. This method stabilizes the system at the zero-phase-angle frequency, mitigating frequency splitting and self-inductance variations. The proposed control strategy achieves constant output current and voltage, independent of the coupling coefficient and load, without requiring bidirectional communication. It offers a simple structure, high cost-effectiveness, and strong reliability, validating the feasibility of the magnetic coupling resonant brushless excitation method. This solution is highly suitable for applications like electric vehicles that require stable output current and voltage.