A Proposal of Sinusoidal Voltage Source Fed Optimal Current Control for IM with Active LC Filter by IRM-ILQ Control

Generally, inverters used for induction motors operate by PWM method, and the output voltage of PWM inverters contains many harmonic components due to switching. The harmonics of inverter output voltage causes the electromagnetic interference (EMI problem), torque ripple and noise. In this paper, a current control method for an induction motor with an LC filter is studied. The motor is driven with minimum distortion sinusoidal voltage. Since the LC filter has two dynamics and has a resonance phenomenon, multivariable control based on modern control theory is necessary. Therefore, an ILQ (Inverse Reference Model) design method that realizes robust multivariable control and a control system that uses IRM (Inverse Reference Model) with two degrees of freedom control are applied. The proposed method can avoid EMI problems (reduce electromagnetic noise), low torque ripple, low noise and by suppressing harmonics.