V/F 제어 유도전동기의 토크 특성 분석

Constant V/F control of induction motor is widely used in various industrial applications. In this speed control, it is well known that maximum torque remains constant as the frequency of supply voltage is varied. However, maximum torque does not remain constant as the frequency of supply voltage is varied because constant V/F control is derived from simplified equivalent circuit of induction motor which has errors. In this paper, it is presented that maximum torque does not remain constant by conventional constant V/F control. And then, the method for maximum torque to remain constant is proposed. In the proposed method, supply voltage for maximum torque to remain constant is calculated by not simplified equivalent circuit but equivalent circuit. The effectiveness of the proposed method is verified by analysis results.