Abstract
This paper presents a new approach of strictly analyzing the transient torque components as the corresponding steady state torque pulsation components by introducing the concept of vector transformation method. Based on this approach, a well-known and empirical phenomenon that, when the power source is closed to an induction motor under the condition of slip 0.5, the transient pulsating torque component becomes almost zero is analyzed and the mechanism is clarified. Although this phenomenon has been utilized for energy saving system of blowers, the physical explanation has not been made clear yet until now. The proposed analysis in general clarifies that there can certainly occur such a phenomenon as exposing a reduction effect of transient pulsating torque components to almost zero when the electrical angular frequency of rotor becomes equal to the arithmetic mean of both the frequencies of power source and of transient current component. These are also confirmed by computer simulation results.
