Analysis of the effect of the parameter variation on the flux weakening controller for improving torque capability

This paper analyzes the effect of the parameter variation on the flux weakening controller which utilizes the difference between the outputs of the current regulator and the PWM block. To perform this analysis, the parameter variation is modeled as a disturbance, and a Bode plot and a time domain response is presented. From the result, it can be known that the flux weakening algorithm itself is robust, but the current controller is subject to the parameter variation. A method to overcome this problem is presented, and the results are verified by computer simulation and experimental results.