Topology Design of Constant Current Output for Electric Field Coupled Wireless Excitation System of Electrically Excited Motor without Receiver Compensation

The electric field coupled wireless excitation system addresses issues like poor reliability, short lifespan, and high cost caused by carbon brush slip rings in electrically excited synchronous motors. However, to meet the motor’s constant current excitation needs, most existing systems use bilateral resonant compensation topologies. The receiving-end compensation inductance adds weight and assembly difficulty to the system’s rotating side, limiting motor speed improvement. To solve this, this paper proposes a CLCLL (π)-N compensation topology without receiving-end compensation. It compensates the system’s reactive power solely through a resonant circuit at the transmitting end, resolving the poor mechanical reliability of traditional schemes. Additionally, via resonant cascade amplification, it achieves load-independent constant current output for the motor’s excitation winding and wide-range output current adjustment, further raising the motor’s speed limit.