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 10 (Sim Power Block set) has been developed for voltage unbalance conditions with supercapacitor as an energy storage device. The designed control technique is modelled, simulated successfully implemented in the laboratory. The extensive simulation results supported by experimental results were provided to validate the proposed system.

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Power Quality Adjustable speed drives direct torque controlled method dc link voltage.