Miniature Inverter for Feeding into the Grid at Low Power with Minimum Number of Components

Inhalt:
In the renewable energy field, the photovoltaic (PV) inverters are used for the conversion from DC to AC power. Connections between the PV inverter and the PV systems can be done considering the island operation or grid connected systems. These connection methods offer a solution to counteract the high use of fossil resources that, due to their depletion, increases their prices and at the same time, produce a negative impact on the environment. Most of the times the grid connection is employed, and when this happens, some requirements need to be taken into consideration. The standard EN 50160 contains the maximum harmonic content for the voltage, whereas the standard IEC 61000-3-2 contains the current that it can be fed into the grid. Those standards cannot be violated. Taking this into consideration, a new low-power PV inverter in the range of several 100 W is proposed. This PV inverter concerns a minimalist solution for achieving the grid connection without infringing the existing standards. The topology was simulated and its feasibility was validated through a 57.5 W first prototype.