| Title |
Parallel Operation Control Method of Grid-connected Inverters with Seamless Transfer for Energy Storage System in Microgrid |
| Authors |
Sung-Youl Park ; Joo-Ha Kim ; Ah-Jin Jung ; Se-Wan Choi |
| DOI |
10.6113/TKPE/2016.21.3.200 |
| Keywords |
Microgrid; ESS(Energy Storage System); Master-slave; Seamless mode transfer; Indirect current control; Critical load |
| Abstract |
In the microgrid, inverters for energy storage system are generally constructed in a parallel structure because of capacity expandability, convenience of system maintenance, and reliability improvement. Parallel inverters are required to provide stable voltage to the critical load in PCC and to accurately share the current between each inverter. Furthermore, when islanding occurs, the inverters should change its operating mode from grid-connected mode to stand-alone mode. However, during clearing time and control mode change, the conventional control method has a negative impact on the critical load, that is, severe fluctuating voltage. In this study, a parallel operation control method is proposed. This method provides seamless mode transfer for the entire transition period, including clearing time and control mode change, and has accurate current sharing between each inverter. The proposed control method is validated through simulation and experiment. |