Torque Ripple Analysis of PSM Motors based on the Influence of ECU Control Deviations and Motor Harmonics

摘要

It is difficult to generate the ideal sinusoidal current for the inverter driven PSM motors in the reality. One factor that causes the current harmonics is the ECU hardware deviation such as current sensor failure, rotor position failure and transistor dead time. Another unavoidable origin for the current deformation comes from the motor magnetic circuit: the non-sinusoidal motor back EMF and the higher harmonics in dq-inductances. Since these two harmonics are not compensated in the standard 1st order controller, they will be translated into current ripple through the closed-loop system, e.g. Field Oriented Control (FOC). Consequently the parasitic higher harmonics will appear in the current and the corresponding torque ripple will be deteriorated. This work focuses on the current harmonic identification by considering the imperfection in both control unit and motor magnetic circuit, and the torque ripple robustness analysis.