In order to accurately evaluate the performance of a traction machine/drive system, it is necessary to have an accurate excitation source which considers current harmonics. In this paper, four machine/drive systems with different excitation sources have been modeled, simulated, and studied to evaluate the effects on permanent magnet synchronous machines (PMSMs) from different perspectives. In Model I, the excitation is an ideal sinusoidal current source with no harmonics. Model II is excited by an ideal sinusoidal voltage source regardless of the pulse width modification’s (PWM’s) influence. Model III takes into account the influence of current harmonics under space vector pulse width modulation (SVPWM) control. Model IV is based on the equivalent circuit extraction (ECE) model (a look-up table motor model). We simulate these four models and study the characteristics of the excitation sources, based on the observations of current harmonics, torque, electromagnetic force, computation time, and efficiency. Experiments are also conducted to show that Model III allows the most precise study of the considered system. Model IV is a good substitution, providing similar results with a shorter running time.
Study of Excitation Characteristics of Traction Machine/Drive Systems