Improving the Performance of Interline Dynamic Voltage Restorer Based on Cascaded H-Bridge fed induction motor drive

Abstract

An Interline Dynamic Voltage Restorer (IDVR) is invariably employed in distribution systems to mitigate voltage sag/swell problems. An IDVR merely consists of several dynamic voltage restorers (DVRs) sharing a common dc link connecting independent feeders to secure electric power to critical loads. While one of the DVRs compensates for the local voltage sag in its feeder, the other DVRs replenish the common dc-link voltage. The proposed IDVR employs two cascaded H-bridge multilevel converters to inject AC voltage with lower THD and eliminates necessity to low-frequency isolation transformers in one side. The performance of designed MLI fed induction motor drives is investigated extensively for various operating conditions through MATLAB simulation.