Synchronous machine models for simulation of induction motor

The induction motor is the most common motor type used in industry. Analyzing its performance is either concerned with steady-state behavior, or the transient behavior during start-up and during system disturbances. Due to the advancement in power electronics, induction motors are now commonly used in adjustable-speed drives. The harmonic currents generated from these drives may result in voltage distortions and potential resonance problems. Computer simulations of induction motor performance are therefore more important than ever before. Although many simulation programs are available for induction motor studies, the Electromagnetic Transients Program (EMTP) is probably better than other simulation packages, because it contains detailed models of many other power system components, such as transformers, transmission lines and thyristors, which must be considered in certain types of motor simulations. This thesis presents a method of using the existing EMTP synchronous machine model to simulate induction motor transients. This approach allows simulations for both machine types using essentially the same program code. The data conversion algorithm, which converts standard motor specifications into equivalent circuit parameters, is explained. The steady-state initialization of an induction motor is discussed as well. The start-up of an induction motor is simulated using the proposed model. These simulation results are then compared with an independent program which uses a 4th-order Runge-Kutta solution method. It is observed that the results from the proposed model agree very well with the ones from the Runge-Kutta solution method.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat