Decoupled control strategy for the operation of capacitor‐excited induction generator for DC power applications

Abstract

In this study, voltage oriented decoupled current mode control technique has been proposed for the operation of the capacitor-excited induction generator with pulse-width modulation (PWM) rectifier systems for supplying isolated DC loads. The proposed controller maintains constant voltage at the DC load terminals and also maintains unity power factor with very less harmonics at the PWM rectifier input terminals. The configuration and implementation of the control scheme employing dSPACE 1103 real-time controller have been fully described. A method for predetermining the steady-state performance of the proposed system has been developed and described with relevant analytical expressions. The effective load at the generator terminals becomes only resistance, since unity power factor is maintained at the PWM rectifier input terminals by the closed-loop controller. To verify the successful working of the proposed control strategy during transient conditions, the proposed system has been modelled in the MATLAB/Simulink toolbox and results are presented. A prototype system consisting of CEIG, PWM rectifier and the associated control circuits has been built in the laboratory for experimental verification. A close agreement between the experimental results and predicted values confirms the validity of the analysis and successful working of the proposed control strategy.