With the increasing demands of modern industrial society on the capacity and reliability of the power supply system, distributed power supply system control technology has emerged. In the context of a large number of mature power electronics technologies, power systems are gradually evolving into power electronics, and more and more power electronic devices are emerging in power systems. In today's power technology transformation field, multi-inverter parallel operation control technology has become a research trend. It can not only expand the power supply capacity but also makes the system more stable and reliable. Firstly, this paper introduces the main problem of parallel operation of multi-inverter, namely the circulation between inverters. According to the analysis of the circulation problem, the control method of the parallel operation of a multi-inverter is introduced. The non-interconnected control technology of drooping control has obvious advantages and development potential. Finally, according to the principle of drooping control, some new improved control methods are introduced, and it is pointed out that drooping control technology will become the mainstream of the development of parallel control technology of inverter in the future, and the development trend of this kind of control technology is forecasted.
