Effect of Voltage Unbalance on Adjustable Speed Drives and its Mitigation Using Supercapacitor

During the voltage unbalance, the resulting adverse effects on equipments such as induction motors and power electronic converters and drives on ASDs have been described. It has been observed that during unsymmetrical fault, the input rectifier slips into the single phase operation and draw heavy currents which may actuate the overload protection and trip the ASDs. The application of supercapacitors bank with boost converter to inject energy at DC-Link under voltage unbalance condition has been incorporated. The supercapacitor provides ride-through and reduces the current overshooting by injecting energy at DC-Link. Based on the designed topology, simulation model in MATLAB 7.5 (Sim Power Block set) has been developed for voltage unbalance conditions with supercapacitor as an energy storage device. The designed control technique is modeled, simulated and successfully implemented in the laboratory. The extensive simulation results supported by experimental results were provided to validate the proposed system International Journal of Electronics Communications and Electrical Engineering ISSN : 2277-7040 Volume 3 Issue 1 (January 2013) http://www.ijecee.com/ https://sites.google.com/site/ijeceejournal/ 37