Title |
Development of 3kW Hybrid ESS with Function of Emergency Power Supply |
Authors |
Seok-Hyun Yang ; Min-Jae Kim ; Se-Wan Choi ; Jun-Seok Cho |
DOI |
10.6113/TKPE/2015.20.1.11 |
Keywords |
ESS(Energy Storage System); UPS(Uninterruptible Power Supply); Seamless transfer; Resonant converter; ZVS; ZCS |
Abstract |
This paper proposes a high-efficiency 3-kW hybrid ESS with emergency power supply. The proposed system enables efficient use of power from photovoltaic (PV) cells and energy storage system (ESS). The proposed system can operate as an uninterruptible power supply (UPS) when grid fault occurs, providing seamless transfer from grid-connected mode to stand-alone mode. The LLC converter for PV achieves ZVS turn-on of switches and ZCS turn-off of diodes, and the isolated bidirectional DC-DC converter for ESS achieves ZCS turn-off regardless of load condition, resulting in high efficiency. The efficiency and performance of the proposed hybrid ESS has been verified by a 3-kW prototype. |