| Title |
Development of 80kW Bi-directional Hybrid-SiC Boost-Buck Converter using Droop Control in DC Nano-grid |
| Authors |
Yeon-Woo Kim ; Min-Ho Kwon ; Sung-Youl Park ; Min-Kook Kim ; Dae-Ki Yang ; Se-Wan Choi ; Seong-Jin Oh |
| DOI |
https://doi.org/10.6113/TKPE/2017.22.4.360 |
| Keywords |
DC nano-grid ; Droop control ; ESS(Energy Storage System) ; Bi-directional boost-buck converter ; Hybrid SiC-IPM(Hybird Silicon Carbide Intelligent Power Module) ; High efficiency |
| Abstract |
This paper proposes the 80-kW high-efficiency bidirectional hybrid SiC boost/buck converter using droop control for DC nano-grid. The proposed converter consists of four 20-kW modules to achieve fault tolerance, ease of thermal management, and reduced component stress. Each module is constructed as a cascaded structure of the two basic bi-directional converters, namely, interleaved boost and buck converters. A six-pack hybrid SiC intelligent power module (IPM) suitable for the proposed cascaded structure is adopted for high-efficiency and compactness. The proposed converter with hybrid switching method reduces the switching loss by minimizing switching of insulated gate bipolar transistor (IGBT). Each module control achieves smooth transfer from buck to boost operation and vice versa, since current controller switchover is not necessary. Furthermore, the proposed parallel control using DC droop with secondary control, enhances the current sharing accuracy while well regulating the DC bus voltage. A 20-kW prototype of the proposed converter has been developed and verified with experiments and indicates a 99.3% maximum efficiency and 98.8% rated efficiency. |