An Interline Dynamic Voltage Restorer Using Neutral-Point-Clamped (NPC) Multilevel Converter

Abstract

Because of increased number of sensitive loads and automated processes in industry, need for high quality power is nowadays inevitable. Deteriorated power quality my result in huge financial losses and also decreases the productivity. The power electronic based solutions for improving power quality have become more common in the recent years. One of these solutions is to use the Dynamic Voltage Restorer (DVR), which is a series-connected voltage compensator. Interline DVR (IDVR) is a special structure, in which two DVRs share a DC-link. These two DVRs are installed in two independent distribution feeders which may have two different voltage levels. In this paper, a new structure for IDVR is proposed. The proposed DVR is based on the multilevel converters. Therefore, we call it as Multilevel Converter based IDVR (MLC-IDVR). Because of using multilevel converter, the quality of voltage waveform in the proposed structure is improved in comparison with the conventional IDVR. Also, it is more suitable for higher voltage applications. The performance of the proposed MLC-IDVR is verified by simulation results carried out by PSCAD/EMTDC software.

Keywords

• dynamic voltage restorer
• multilevel converter
• voltage sag.