Modelling of Distribution Compensator for Inrush Current of Medium Voltage Induction Motor in an Air Separation Plant Power Systems

This paper presents modelling of a Compensator for an Inrush Current in Power system that caused by a Starting of a Medium Voltage Induction motor. Compared to government regulation to limit the Voltage sag caused by a motor starting maximal on 5 percent, in the real plant condition, starting of a 4500 HP motor at 6.6 kV weak grid can causing 47 % voltage sag for 0.6 second duration. In a worst condition, a black out in this area is possible to happen. This condition is making the power quality in this area is not good. The Inrush Current Compensator modelling is using a space vector transformation and conventional PI controller to drive the inverter bridges in Matlab software. The simulation result is showing an improvement to the power quality in the area compared to the original condition that causing voltage sag or power outage. In this modelling, we will see that the Inrush Current is improved by reduction the magnitude of voltage sag about 14 % and also improved by reduction the duration of voltage sag about 0.3 second.