The application study of multi-level inverter in the PVMS

The research of Micro-grid technology has been a hot spot of distributed energy systems; moreover, micro-source (MS), the control and protection of micro-grid are key issues to the micro-grid technology research. Most of the MS are renewable energies such as wind power, Photovoltaic (PV) power generation, tidal power and so on, which must pass through the DC-AC/AC-DC-AC conversion equipment when supply power to the loads, the demand of the technology of power electronics is higher, and therefore power electronics technology has a decisive role in distributed generation (DG) and micro-grid technology based on renewable energy. The concepts and its basic structure of PV micro-grid power generation are presented in this paper, which lists the problems of traditional Photovoltaic micro-source (PVMS) power generation and analysis the reason why we cannot maximize efficiency when a number of PV modules in series connect with traditional two-level inverter, and finally propose a PV micro-grid control strategy based on multi-level diode-clamped inverter. The reliability and superiority of PVMS using in multi-level inverter are testified in simulation.