This paper presents an analysis of harmonics and stability in active damping control for a single-inverter dual parallel (SIDP) permanent magnet synchronous motors (PMSM) drive system. The proportional gain is analyzed concerning speed to evaluate its impact on control stability. The proportional gain is analyzed as a trade-off between total harmonic distortion (THD) and control stability. The validity of the stability and harmonic analysis is verified through simulations conducted using PSIM software.