Position Sensing Errors in Synchronous Motor Drives

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

Circulating Current Induced Electromagnetic Torque Generation in Electric Machines with Delta Windings

This paper explains the phenomenon of current circulation and the resulting electromagnetic torque generation in electric machines employing delta windings. The description entails a systematic assessment of the electrical and magnetic behavior of the machine to develop mathematical models, followed by intuitive explanations of the derived analytical forms. The modeling is thoroughly validated through simulation and experimental results on a prototype machine

Control Performance Analysis of Power Steering System Electromechanical Dynamics

Modern power steering systems employ an electric motor drive system to provide torque assistance to the driver. The closed-loop mechanical system dynamics that impact stability, performance and steering feel are significantly impacted by the electrical dynamics of the actuator depending on the structure and tuning of the motor torque controller. This paper presents an integrated approach to the analysis of this electromechanical dynamic control interaction through mathematical modeling which is confirmed with simulations