SCALAR CONTROL SYSTEMS WITH PERMANENT MAGNET SYNCHRONOUS MOTORS WITH SINUSOIDAL CURRENT CONTROL. CALCULATION OF SPEED CONTROLLER PARAMETERS

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. Permanent magnet synchronous motors (PMSM) are used in the regulated systems with variable speed, by their association with frequency converters. Generally, in the case of PMSM, in order to determine the rotor position, a shaft position sensor is used, while to determine the rotor speed, a speed sensor is used, or it can be calculated using the position data, thus the speed sensor can be removed. The frequency converter used with such control system is the traditional one, except for the control module of the phase power devices which must be correlated with the rotor position. The present paper will approach the permanent magnet synchronous motors with sinusoidal current control (BLAC). These machines have, from a constructive point of view, the stator windings sinusoidal distributed or concentrated, being characterized by a fractional number of slots per pole and phase. The permanent magnets can be placed on the surface of the rotor (it results BLAC with full pole, to which Ld = Lq) or in its interior (BLAC with prominent poles are obtained, Ld ≠ Lq). The control systems with BLAC can be