TRANIENT ANALYSIS OF INDUCTION MOTORS THEIR INFLUENCE ON THE ELECTRICAL DISTRIBUTION NETWORKS

In this paper influence of large Induction motors starting on the electrical distribution network is studied Starting a single induction motor or several large induction motors are investigated when In the latter case the are started simultantuosly or with a suitable dine Intervals. Mutual effects of the motors and distribution system for different busbar impedances are studies. Influence of an unbalanced three phase supply on the performance of the motors during the starring mode, and later the resulted effects are reported, The results show that simultantuos staffing of the large induction motors leadds to a large dip of the basbar voltaga If the motors are started with a suitable time interval the voltage dip will be smaller and its duration will be longer. When motor connected to an unbalanced supply, its input current contains harmonies and Is Injected to the network This unbalanced supply leads to the delay in starting of the motor.