Review of Control Strategies for AC Microgrids under Distribution-micro Collaboration

Multi-microgrid access to the distribution network is an important way to realize the efficient interaction of source grid, load and storage, flexible energy mutual aid, and promote the consumption of new energy, which can significantly inhibit the negative impact of new energy fluctuations on the high reliability of power supply to the distribution network. However, the differences in the control strategies of distributed power sources within the microgrid, as well as the diversity of co-regulation techniques between the distribution grid and the microgrid under different fault scenarios, will have a significant impact on the power angle, frequency, and voltage stability of the microgrid accessing the distribution grid, thus posing a serious challenge to the safe and stable operation of the microgrid. Among them, AC microgrid is the main form of microgrid development at present, and the study of AC microgrid under distribution and microcoordination is of great significance. To this end, three system architectures and operation switching technologies for AC microgrid access to the distribution grid are introduced, and the advantages and disadvantages of the relevant architectures and switching technologies are summarized and compared. Subsequently, the steady state control strategy of distributed power supply is summarized from the inside of the AC microgrid. Secondly, taking into account the possible failures of the distribution grid, and then the transient control strategy adopted by distributed power supply of the AC microgrid in the event of a failure of the distribution network under the distribution-micro synergism are compared and analyzed. Finally, the development of AC microgrid control strategies under the distribution-micro synergy is outlooked to provide a reference for the subsequent research.