High-efficiency non-isolated dynamic voltage restorer using soft-switching dc-dc converter for parallel-voltage compensation

This paper proposes a high-efficiency non-isolated dynamic voltage restorer (DVR) for the parallel-voltage compensation. Compared with the conventional isolated DVR, the non-isolated DVR using the dc-dc converter can reduce cost, weight, size and losses related with the injection transformer. However, the dc-dc converter of the non-isolated DVR operates under hard-switching operation, increasing switching power losses. The proposed non-isolated DVR using the soft-switching dc-dc converter has zero-voltage switching (ZVS) of all power switches, improving power efficiency. The performance of the proposed DVR has been verified by simulation and experimental results for a 1.0 kW output power prototype system.