NVH optimization in PMSM through harmonic current injection with optimum current trajectory

Inhalt:
Electrical machines generate unwanted noise. One method to counteract this is harmonic current injection (HCI). The paper shows that a harmonic current has an influence on both the torque and the radial forces. In this paper a method is presented which decouples the effect of the current on torque and radial forces. This enables the independent optimization of torque and radial forces. Trajectories are identified that improves both torque and radial forces simultaneously. Starting from simplified ideal assumptions, the new method is explained analytically and then applied to a real example. In addition, the paper explains for which machines and which operating points the proposed method is suited.