The electromagnetic efficiency and moment pulsations of a valve motor with discrete winding switching with non-sinusoidal EMF

This paper studies the energy parameters of valve motors (VM) based on a synchronous DC motor (SDCM) with discrete switching of the winding in the presence of higher harmonics in the EMF of rotation. The most common methods of discrete switching are given, a simplified mathematical model is compiled for calculating the currents and torque of the motor in the presence of higher harmonics in the EMF and the calculation of electromagnetic efficiency and moment pulsations is carried out. The six-stroke 180-degree switching is the most sensitive to the content of higher harmonics, from the point of view of energy indicators and moment pulsations in the drive. An increase in their content, most often, leads to a deterioration of these output parameters. The six-stroke 120-degree switching, from the point of view of electromagnetic efficiency, is insensitive to the content of the third harmonic in the phase EMF, and the second harmonic contributes to an increase in the electromagnetic efficiency of the motor. Twelve-stroke switching, in comparison with six-stroke, is less sensitive to the content of higher harmonics in the EMF. Although even here the presence of a second harmonic contributes to an increase in efficiency and an increase in moment pulsations.