Model of Induction Motor Changes to Power System Disturbances

A composite load consists of static and dynamic loads. The main component of dynamic load is the induction motor. Therefore, it is important to model dynamic nature of an induction motors with shaft loads accurately. The main objective of this paper is to develop an induction motor model with different types of shaft loads in order to reflect the real (∆P) and reactive (∆Q) power changes due to the random changes of power system Voltage (∆V), frequency (∆f). The research documented in this paper considers cases where the system affects the load as well as vice versa. A new model to describe this relationship is presented in this paper. It is really important to verify the model developed by analysis of both simulated and measured data. In this paper measured data from a Queensland substation is used to confirm the model which is found to be an adequate predictor of load changes in response to variations in frequency and voltage. 1