No-sag industrial power with DVRs

Voltage sag is a relatively long-duration drop in line voltage. It is defined as a decrease between 0.1 and 0.9 per unit (pu) in alternating-current line voltage for durations of 0.5 cycles to 1 minute, where "per unit" is a fraction of the base voltage. The author compared the performance of a DVR and the more conventional shunt capacitors in mitigating voltage sag by simulation using PSCAD software. The paper also illustrates the effects of motor parameters on the sag during startup.