Permanent magnet synchronous motor torque ripple analysis under ECU caused non-sinusoidal current

Abstract

The 3-phase current form of a permanent magnet synchronous motor under Field Oriented Control (FOC) will be influenced by both motor harmonics and the Electronic Control Unit (ECU) deviations. In this work, the current shape deformation due to the influence from the specific ECU failures, including transistor dead time and current measurement error will be introduced and simulated. As the torque ripple under the non-sinusoidal current will increase compared to the one under sinusoidal current, the torque ripple robustness against current harmonics can be considered as an important design concept when optimizing the electromagnetic circuit of PMSMs. This paper builds up a connection between the torque ripple and the static inductance by introducing coenergy for torque approximation purpose. This method will be approved by the Finite Element Analysis.