Numerical simulation method for the slip power recovery system

Abstract

A numerical simulation method for the slip power recovery system is presented. The dq induction-machine model, using flux linkages as state variables is used. This leads to a simple and efficient computer program. The diode bridge rectifier is modelled using three switching functions that are determined by the sign of the corresponding AC currents. The model obtained is very simple, and accurately represents the three-phase diode bridge rectifier including the current commutation process. To merge the models of the induction machine and the diode-bridge rectifier, no difficulties arise when a direct-voltage intermediate circuit is present. When a direct-current circuit is used in the intermediate circuit a model of the whole ‘induction machine and diode-bridge rectifier’ must be used. Park's variables can be used in this case, also. The operations performed to model the system are equivalent to assuming that the diode bridge rectifier and the DC circuits are transformed into a nonlinear circuit connected to the rotor terminals. MATLAB/simulink is used to integrate the equations. Experimental and simulated results are presented and compared showing good accuracy.