Improvement of dynamic characteristic for V/f controlled induction motor drive system

This paper presents a method for improvement of the dynamic characteristic for V/f controlled induction machines. The basic control structure is the open-loop V/f control with voltage-drop compensation and slip compensation. Additionally, a new current damper control is utilized for suppressing the dynamic oscillation. The improvement of the current control is based on complete modal synthesis. In order to analyze the dynamic characteristic, the complex control system is built in a mathematical model and the eigenvalue loci theory is applied. The result of the analysis is proved by experiments.