IMPROVED PERFORMANCE OF AN ADJUSTABLE SPEED DRIVES DURING VOLTAGE SAG CONDITION

摘要

Voltage sags normally do not cause equipment damage but can easily disrupt the operation of sensitive loads such as electronic Adjustable Speed Drives (ASDs). Voltage sags cause a momentary decrease in DC-link voltage triggering an under voltage trip leading to nuisance tripping of adjustable speed drives (ASDs) employed in continuous-process industries which contributes to loss in revenue. A practical ride-through scheme for an adjustable speed drives based on supercapacitor during voltage sag has been presented in this paper. The supercapacitor maintains the ASD dc bus voltage under voltage sag condition. Energy storage module is connected to support the DC-link voltage during power system faults. The performance of ASDs under normal and power system faults is first simulated in MATLab Simulink and then experimentally verified. The Data AcQuisition boards (DAQ) of National Instruments along with LabVIEW software have been used to record the observed waveforms.