The Analysis of the Components of the Power of a Direct Current Motor Armature Circuit at Periodic Change of Voltage

Based on the differential equations of voltage balance for the electric circuit of the DC motor armature and the balance of torques acting on its armature, the equation of power balance was obtained. Using the trigonometric representation of the Fourier series, the equations of balance for each power harmonic at the periodic change of the armature voltage and the constant excitation flux were formed. The power components for the armature equivalent circuit inductance were analytically determined. The power components for all the elements of the armature circuit and the mechanical power were determined digitally. It is determined that in some cases the values of the power components formed by different-order harmonics essentially exceed the values of the power components formed by the same-order harmonics. It is found out by the results of the experiments that, under the condition of the action of the periodically changing armature voltage, the constant component of the angular velocity significantly influences the amplitude of the armature power oscillation. Because this constant component determines the amount of energy accumulated by the rotating masses of the armature.