Comparative Analysis of Differential-Mode Impedance in Single-Phase Induction Motors

This paper presents an experimental study of the high-frequency impedance behavior of four types of single-phase induction motors: Split-Phase Induction Motor (SPIM), Permanent Split Capacitor Induction Motor (PCIM), Capacitor Start Induction Motor (CSIM) and Single Phase Repulsion Motor (RIM). A differential-mode impedance and phase angle over a range of frequencies, including resonance and anti-resonance points, are the focus of the present study. The obtained results show that every type of motor has distinctive impedance characteristics; the RIM always shows higher impedance than other motors, whereas the CSIM exhibits lower impedance in low frequencies. Those differences unveil the influence of the motor design on Electromagnetic Compatibility (EMC) performance, since high-impedance motors, such as the RIM, present lower Electromagnetic Interference (EMI) emissions and lower susceptibility to external electromagnetic interference, therefore better general EMC performance. Also, the frequencies of resonance and anti-resonance vary between the motors, which is also reflected in their different electrical and structural designs. The study provides helpful insights into the optimization of motor designs to achieve better EMC compliance and operational stability in various applications.