Simplified model of an inverter-fed induction motor for the analysis of a dc power system

The development of a simplified model of an inverter-fed induction motor that can be used in the analysis of a dc power system containing motor drive loads is presented. The model is based on the steady-state T-type equivalent circuit of the induction motor and the input-output relationships of the six-step voltage source inverter. In the simplified model, a V-I load characteristic curve is established that allows the inverter, motor, and load to be replaced by a current-controlled voltage source. The model is verified using PSPICE and Matlab. The simplified model also has the potential to be utilized in the analysis of a multiple bus dc power system by incorporating the V-I load curves of each motor-drive load into a Newton-Raphson iterative procedure.