Active torque ripple reduction based on an analytical model of torque

Abstract

The vibration caused by torque ripple may degrade the performance of drivetrain, thus the reduction of torque ripple are necessary for hybrid electrical vehicle/electrical vehicle application, while an analytical description of torque will be the basis. In this study, two-dimensional Fourier series supplemented by polynomial fitting is introduced to reconstruct the numerical solution of magnetic coenergy (MCE) from finite element analysis. An analytical torque model, which can describe torque ripple precisely at all working points, is derived from the reconstructed MCE. On the basis of the torque model, the expressions of harmonic currents used to reduce torque ripple are obtained. The proposed expression also satisfies the principle of maximum torque per ampere. Then, a feedforward torque controller based on the expression of harmonic currents is introduced. Meanwhile, a feedback torque controller based on a torque observer is developed as a comparison. The results of simulation and experiments show that both two controllers can reduce the torque ripple in steady state, but the feedforward torque controller has obviously better effects when motor speed increases. Furthermore, the feedforward torque controller is also beneficial to decline torque ripple during transient process of torque response.

Untersuchung der Reduktion der harmonischen elektrischen Größen beim Betrieb einer Synchron-Reluktanzmaschine

“…Eine Variante ist die iterative Bestimmung der aufzuschalteten Größe, was allerdings einen Verzicht auf Determinismus nach sich zieht [10]. Eine weitere Variante ist das Anlegen eines Referenzsignals, welches empirisch oder mittels exakter motorspezifischer Modellierung offline ermittelt und in einer Tabelle abgespeichert wird [14,16]. Nachteilig hierbei ist die Verringerung der Robustheit der Regelung bezüglich Parameterschwankungen bzw.…”

Cancellation of harmonic torque disturbance in permanent magnet synchronous motor drives by using an adaptive feedforward controller

“…γ˙m = − gω er sin(mθ + φ) (11) parameters g, φ are, respectively, the AFC gain and regressor. The steady-state values of the adaptation parameters can be obtained by setting θ = ωt in (9) and comparing with the righthand side of (7)…”

Torque Ripple Reduction of DTC Based on an Analytical Model of PMSM

“…For active control of current harmonics, the methods applied include PI control in multiple synchronous frames [14], proportional resonant (PR) [15], and repetitive control [16]. However, these methods are mainly focusing on eliminating the current harmonics, for the injection of current harmonics, the feedforward controller is a commonly used method [17,18]. The feedforward controller can effectively make up for the shortcomings of the insufficient bandwidth of the feedback closed-loop controller, but it requires an accurate motor model as a prerequisite [19].…”

“…A harmonic voltage model in a multi-synchronous coordinate system was derived and a feedforward harmonic voltage controller is designed in [17]. Zhong et al proposed an accurate motor model that is based on magnetic common energy reconstruction, on this basis; a feedforward controller is designed to suppress the torque ripple [18]. These researches have achieved significant results in suppressing the torque ripple that is caused by the harmonic and magnetic saturation characteristics of the motor.…”