Dynamic Analysis Of Induction Machine Connected To Infinite Bus-Bar

ABSTRACT

The dynamic simulation is one of the key steps in the validation of the design process of the motor drive systems and it is needed for eliminating inadvertent design mistakes and the resulting error in the prototype construction and testing. A quality mathematical model of induction machine based on the dynamic equations and D-Q transformation technique is presented in rotor reference frame and a computer simulation of a 7.5kW three phase induction motor was carried out based on this mathematical modeling. The model is used to investigate the effects of variations in temperature, load torque, moment of inertia and blocked rotor condition. Different operating conditions were simulated using MATLAB codes. Also the behavior of the induction machine when connected to an infinite bus-bar was compared with the conventional model. The results show that the starting current in the conventional machine model is higher than that of the machine when connected to infinite bus with an average difference of 36% at max and 35% at min. Similarly, moment of inertia greatly affects the inrush current drawn by the induction machine. Low values of moment of inertia results into a low settling time whereas it increases with increase in moment of inertia.