The present paper presents the calculation of the speed controller parameters of the scalar control systems with permanent magnet synchronous motors with sinusoidal current control used in low power applications. The shaft position sensor used to determine the rotor position, respectively its rotation speed is made of two Hall sensors. In the considered numeric example, we presented the Bode diagrams of the speed loop with and without considering the viscous friction coefficient, in the case the low-pass filter does or does not interfere in the negative reaction.

Keywords: Permanent magnet synchronous motor, Scalar control, Speed controller, Calculation of parameters