Research of three harmonic excitation synchronous motor speed control system

This paper presents a speed control system based on the third harmonic excitation synchronous motor. Compared with harmonic excitation by adding harmonic windings in the electric excitation motor, the structure is simpler, with lower hardware costs and higher versatility. The working principle of the system and the design idea of the harmonic extraction circuit are described. Harmonic injection technology is used to ensure the stability of excitation current. Stator current, harmonic current, flux density, and other motor performance parameters are calculated by the finite element method and co-simulation, and the advantages compared with the traditional excitation method are analyzed. Experimental results of a 300-W prototype machine agree well with theoretical analysis and co-simulation results, confirming its feasibility and accuracy.