含不对称负荷的微电网黑启动控制策略研究

Islanded microgrids need for proper black start to ensure their operation after a black out or shoot down of the system. Nevertheless, since major part of microgrids operate in three-phase supporting three-phase and single-phase loads, current unbalances may appear, which may produce voltage unbalances. This fact may difficult the black start process, specially connecting inverters to voltage unbalanced microgrids. Consequently, it worth to study microgrid black start strategy including unbalanced loads. This paper will study the use of droop controlled inverters supplying unbalanced loads, by using a synchronization method with the aim of achieving their parallel operation after a general failure. Further, the black-start sequence is an essential part of this study, which imposes the order of recovery in order to achieve microgrid to be successfully restored. The microgrid model is established by using Matlab/Simulink in order to verify the correctness of the black-start strategy under unbalanced load conditions. Finally, the comparison among the re-connection order of the different inverters in the microgrid is presented.