Steady-State Operating-Point Calculation of Variable Frequency Induction-Motor Drive

Three-phase squirrel-cage induction motors are greatly used in many industrial applications. Their speed control is necessary for many applications, such as fluid control processes and electric vehicles. The modern widely-used method is volt per hertz (V/f) control, generally known as variable frequency drive (VFD). Hence, in this paper, an analytical approach for computing the steady-state characteristics of the VFD is presented. The analytical solution of VFD's operating point with different profiles of the motor's mechanical loads is also presented, allowing a precise operating condition to be found for most steady-state analysis.