  Non-ideal position estimation results in degraded performance of synchronous
motor drive systems due to reduction of the average capability of the drive as
well as torque harmonics of different orders. The signature and extent of the
performance degradation is further dependent, quite significantly, on the
current control architecture, i.e., feedforward or feedback control, employed.
This paper presents a comprehensive analysis of non-idealities or errors in
position estimation and their effects on the control performance of synchronous
motor drives. Analytical models capturing the error in various signals caused
by position sensing errors in the drive system for different control
architectures are presented and are validated with simulation and experimental
results on a prototype permanent magnet synchronous motor drive.
