An approach to provide ride-through for ASD systems with supercapacitors

Voltage sags are one of the most common occurrences in industrial power distribution systems. Although typical sags may last for 5-20 cycles and their voltage magnitude is usually lower than 20% of its rated value, this disturbance can trip the protections of an adjustable speed drive (ASD). Such nuisance tripping of a continuous industrial process can be very costly. In this paper the use of super-capacitors to provide ride-through for voltage sags and short term voltage interruptions is explored, and a compensator topology is evaluated analytically and experimentally.