This paper analyzes the stability of single inverter dual parallel PMSM drives according to the d-axis current in the field-weakening region. The variation
in rotor position difference between the two motors according to the injected d- axis current is mathematically analyzed in field-weakening control. The
allowable range of rotor position difference for stable operation of the SIDP PMSM system is determined using the load angles of both motors. The stable
operating range of d- axis current in the field-weakening region is derived from this analysis. The validityof the analysis is verified through simulation results.