: This paper proposes a rotor design for an open-ended winding interior permanent magnet synchronous motor (IPMSM) to reduce the zero-sequence current (ZSC) in a common DC-bus dual-inverter drive system. In such systems, the ZSC is induced by the third-harmonic component of the back-electromotive force (back-EMF). To reduce the third-harmonic back-EMF, a rotor structure with a non-uniform air gap is adopted to shape the air-gap flux density into a sinusoidal form. To verify the proposed design, finite element analysis (FEA) and circuit simulations were conducted under the condition that all electromagnetic specifications except the rotor  geometry were kept identical. The comparative analysis shows that the proposed model reduced the third-harmonic back-EMF by 96.7 % and the ZSC by 95.7 %. Additionally, while the torque ripple was reduced from 6.55 Nm to 2.76 Nm, the average torque decreased by 6.34 % (from 50.16 Nm to 46.98 Nm) due to the increased magnetic reluctance.